Melanopsin mediates UVA-dependent modulation of proliferation,pigmentation, apoptosis,and molecular clock in normal and malignant melanocytes

Cutaneous melanocytes and melanoma cells express several opsins, of which melanopsin (OPN4) detects temperature and UVA radiation. To evaluate the interaction between OPN4 and UVA radiation, normal and malignant Opn4^WT and Opn4^KO melanocytes were exposed to three daily low doses (total 13.2 kJ/m²) of UVA radiation. UVA radiation led to a reduction of proliferation in both Opn4^WT cell lines; however, only in melanoma cells this effect was associated with increased cell death by apoptosis. Daily UVA stimuli induced persistent pigment darkening (PPD) in both Opn4^WT cell lines. Upon Opn4 knockout, all UVA-induced effects were lost in three independent clones of Opn4^KO melanocytes and melanoma cells. Per1 bioluminescence was reduced after 1st and 2^nd UVA radiations in Opn4^WT cells. In Opn4^KO melanocytes and melanoma cells, an acute increase of Per1 expression was seen immediately after each stimulus. We also found that OPN4 expression is downregulated in human melanoma compared to normal skin, and it decreases with disease progression. Interestingly, metastatic melanomas with low expression of OPN4 present increased expression of BMAL1 and longer overall survival. Collectively, our findings reinforce the functionality of the photosensitive system of melanocytes that may subsidize advancements in the understanding of skin related diseases, including cancer.     

NK cells and monocytes modulate primary HTLV-1 infection

We investigated the impact of monocytes, NK cells, and CD8⁺ T-cells in primary HTLV-1 infection by depleting cell subsets and exposing macaques to either HTLV-1 wild type (HTLV-1_WT) or to the HTLV-1_p12KO mutant unable to infect replete animals due to a single point mutation in orf-I that inhibits its expression. The orf-I encoded p8/p12 proteins counteract cytotoxic NK and CD8⁺ T-cells and favor viral DNA persistence in monocytes. Double NK and CD8⁺ T-cells or CD8 depletion alone accelerated seroconversion in all animals exposed to HTLV-1_WT. In contrast, HTLV-1_p12KO infectivity was fully restored only when NK cells were also depleted, demonstrating a critical role of NK cells in primary infection. Monocyte/macrophage depletion resulted in accelerated seroconversion in all animals exposed to HTLV-1_WT, but antibody titers to the virus were low and not sustained. Seroconversion did not occur in most animals exposed to HTLV-1_p12KO. In vitro experiments in human primary monocytes or THP-1 cells comparing HTLV-1_WT and HTLV-1_p12KO demonstrated that orf-I expression is associated with inhibition of inflammasome activation in primary cells, with increased CD47 “don’t-eat-me” signal surface expression in virus infected cells and decreased monocyte engulfment of infected cells. Collectively, our data demonstrate a critical role for innate NK cells in primary infection and suggest a dual role of monocytes in primary infection. On one hand, orf-I expression increases the chances of viral transmission by sparing infected cells from efferocytosis, and on the other may protect the engulfed infected cells by modulating inflammasome activation. These data also suggest that, once infection is established, the stoichiometry of orf-I expression may contribute to the chronic inflammation observed in HTLV-1 infection by modulating monocyte efferocytosis.     

Retinaldehyde dehydrogenase enzymes regulate colon enteric nervous system structure and function

The enteric nervous system (ENS) forms from the neural crest-derived precursors that colonize the bowel before differentiating into a network of neurons and glia that control intestinal function. Retinoids are essential for normal ENS development, but the role of retinoic acid (RA) metabolism in development remains incompletely understood. Because RA is produced locally in the tissues where it acts by stimulating RAR and RXR receptors, RA signaling during development is absolutely dependent on the rate of RA synthesis and degradation. RA is produced by three different enzymes called retinaldehyde dehydrogenases (RALDH1, RALDH2 and RALDH3) that are all expressed in the developing bowel. To determine the relative importance of these enzymes for ENS development, we analyzed whole mount preparations of adult (8–12-week old) myenteric and submucosal plexus stained with NADPH diaphorase (neurons and neurites), anti-TuJ1 (neurons and neurites), anti-HuC/HuD (neurons), and anti-S100β (glia) in an allelic series of mice with mutations in Raldh1, Raldh2, and Raldh3. We found that Raldh1^−/−, Raldh2^+/−, Raldh3^+/− (R1^KOR2^HetR3^Het) mutant mice had a reduced colon myenteric neuron density, reduced colon myenteric neuron to glia ratio, reduced colon submucosal neuron density, and increased colon myenteric fibers per neuron when compared to the wild type (WT; Raldh1^WT, Raldh2^WT, Raldh3^WT) mice. These defects are unlikely to be due to defective ENS precursor migration since R1^KOR2^HetR3^KO mice had increased enteric neuron progenitor migration into the distal colon compared to WT during development. RALDH mutant mice also have reduced contractility in the colon compared to WT mice. These data suggest that RALDH1, RALDH2 and RALDH3 each contribute to ENS development and function.     

The roles of p53 and p21 in normal development and hyperthermia‐induced malformations

BACKGROUND : Hyperthermia (HS) is a well‐studied teratogen that induces serious malformations, including neural tube defects. Our previous studies have shown that HS induces apoptosis by activating the mitochondrial apoptotic pathway. Prior to activation of the mitochondrial apoptotic pathway, HS also activates p53 and its target genes. In the present study, we determine whether p53 and/or p21 play a role as teratogen suppressors or inducers of HS‐induced malformations. METHODS : Pregnant mice carrying all three p53 or p21 genotype embryos were exposed to HS on day 8.5. Subsequently, fetuses were collected on day 15.5, and genotyped. In addition to genotype, we also determined the number of resorptions and dead fetuses as well as the number and types of external malformations. RESULTS : In the absence of HS exposure, fetuses exhibiting exencephaly and spina bifida were observed in approximately 11% of p53 ?/? fetuses, whereas no malformations were observed among p21 ?/? fetuses. Exposure to HS resulted in an increase in exencephaly and polydactyly in fetuses of all three p53 genotypes. However, the incidence of these malformations was statistically significantly higher in p53 ?/? compared to p53 +/? and p53 +/+ fetuses. Exencephaly was the only malformation observed in p21 fetuses exposed to HS, with an approximately 2‐fold increase among p21 +/? and a 3‐fold increase among p21 ?/? compared to p21 +/+ fetuses. CONCLUSIONS : Our study confirms that p53 plays a role in normal development and has shown, for the first time that p53 and p21 function to suppress HS‐induced malformations. Birth Defects Res (Part B) 86:40‐47, 2009. © 2009 Wiley‐Liss, Inc.     

A 66‐bp deletion in growth hormone releasing hormone gene 5′‐flanking region with largemouth bass recessive embryonic lethal

Growth hormone releasing hormone (GHRH) regulates the secretion of growth hormone (GH) in the pituitary gland. A 66‐bp deletion (c.‐923_‐858del) was detected in the 5′‐flanking sequence of the largemouth bass (Micropterus salmoides) GHRH gene. In two cultured random populations of adult individuals (A: n = 170 and B: n = 150), the genotype ratios of +/+:+/? were 2.5:1 and 2.8:1 respectively. Only one ?/? fish was detected. A Largemouth bass family was constructed with two heterozygous individuals (+/?) as parents. The genotype ratio of +/+:+/?:?/? in the filial generation embryos was 1:1.6:0.1 at the neurula and 1:2:0 at hatched larvae stages. This indicated that the 66‐bp deletion was a recessive lethal site and that homozygous individuals (?/?) died off in embryonic development. The growth traits (body weight, body length and body depth) were measured, and the GHRH mRNA expression levels in brain tissue were detected using real‐time PCR. The effects of genotype (+/?) on growth traits and GHRH mRNA expression were not significant. Although the cause of death was not clear, the results hint that the 66‐bp deletion site in GHRH 5′‐flanking sequence significantly affects the livability in largemouth bass embryonic development.     

Maternal hypertensive disorder of pregnancy and offspring early-onset cardiovascular disease in childhood,adolescence, and young adulthood: A national population-based cohort study

BackgroundThe prevalence of cardiovascular disease (CVD) has been increasing in children, adolescents, and young adults in recent decades. Exposure to adverse intrauterine environment in fetal life may contribute to the elevated risk of early-onset CVD. Many studies have shown that maternal hypertensive disorders of pregnancy (HDP) are associated with increased risks of congenital heart disease, high blood pressure, increased BMI, and systemic vascular dysfunction in offspring. However, empirical evidence on the association between prenatal exposure to maternal HDP and early-onset CVD in childhood and adolescence remains limited.Methods and findingsWe conducted a population-based cohort study using Danish national health registers, including 2,491,340 individuals born in Denmark from 1977 to 2018. Follow-up started at birth and ended at the first diagnosis of CVD, emigration, death, or 31 December 2018, whichever came first. Exposure of maternal HDP was categorized as preeclampsia or eclampsia (n = 68,387), gestational hypertension (n = 18,603), and pregestational hypertension (n = 15,062). Outcome was the diagnosis of early-onset CVD from birth to young adulthood (up to 40 years old). We performed Cox proportional hazards regression to evaluate the associations and whether the association differed by maternal history of CVD or diabetes before childbirth. We further assessed the association by timing of onset and severity of preeclampsia. The median follow-up time was 18.37 years, and 51.3% of the participants were males. A total of 4,532 offspring in the exposed group (2.47 per 1,000 person-years) and 94,457 in the unexposed group (2.03 per 1,000 person-years) were diagnosed with CVD. We found that exposure to maternal HDP was associated with an increased risk of early-onset CVD (hazard ratio [HR]: 1.23; 95% CI = 1.19 to 1.26; P < 0.001). The HRs for preeclampsia or eclampsia, gestational hypertension, and pregestational hypertension were 1.22 (95% CI, 1.18 to 1.26; P < 0.001), 1.25 (95% CI, 1.17 to 1.34; P < 0.001), and 1.28 (95% CI, 1.15 to 1.42; P < 0.001), respectively. We also observed increased risks for type-specific CVDs, in particular for hypertensive disease (HR, 2.11; 95% CI, 1.96 to 2.27; P < 0.001) and myocardial infarction (HR, 1.49; 95% CI, 1.12 to 1.98; P = 0.007). Strong associations were found among offspring of mothers with CVD history (HR, 1.67; 95% CI, 1.41 to 1.98; P < 0.001) or comorbid diabetes (HR, 1.56; 95% CI, 1.34 to 1.83; P < 0.001). When considering timing of onset and severity of preeclampsia on offspring CVD, the strongest association was observed for early-onset and severe preeclampsia (HR, 1.48, 95% CI, 1.30 to 1.67; P < 0.001). Study limitations include the lack of information on certain potential confounders (including smoking, physical activity, and alcohol consumption) and limited generalizability in other countries with varying disparities in healthcare.ConclusionsOffspring born to mothers with HDP, especially mothers with CVD or diabetes history, were at increased risks of overall and certain type-specific early-onset CVDs in their first decades of life. Further research is warranted to better understand the mechanisms underlying the relationship between maternal HDP and early-onset CVD in offspring.

Chen Huang and co-workers study associations between maternal hypertensive disorders and cardiovascular disease in offspring.     

Real-Time 3-Dimensional Echocardiographic Assessment of Ventricular Volume,Mass, and Function in Human Fetuses

Objectives

We sought to determine the feasibility and reproducibility of real-time 3-dimensional echocardiography (RT3DE) for evaluation of cardiac volume, mass, and function and to characterize maturational changes of these measurements in human fetuses.

Methods

Eighty pregnant women in the 2^nd and 3^rd trimesters (59 with normal fetuses and 21 with fetuses with congenital heart disease [CHD]) were enrolled. We acquired RT3DE images using a matrix-array transducer. RT3DE measurements of volume, mass, stroke volume (SV), combined cardiac output (CCO), and ejection fraction (EF) were obtained. Images were scored and analyzed by two blinded independent observers. Inter- and intraobserver variabilities and correlations between fetal cardiac indices and gestational age were determined.

Results

Fifty-two of 59 normal data sets (88%) and 9 of 21 CHD data sets (43%) were feasible for analysis. In normal fetuses, the right ventricle (RV) is larger than the left ventricle (LV) (P<0.05), but no difference exists between the LV and RV in mass, SV, CO, and CO/CCO. The EFs for the LV and RV were diminished; the RVSV/LVSV was reduced in CHD fetuses compared with normal fetuses (P<0.05). Fetal ventricular volumes, mass, SV, and CCO fit best into exponential curves with gestational age, but LVEF, RVEF, and RVSV/LVSV remain relatively constant.

Conclusions

RT3DE is feasible and reproducible for assessment of LV and RV volume, mass, and function, especially in normal fetuses. Gestational growth of these measures, except for EF, is exponential in normal and CHD fetuses. CHD fetuses exhibit diminished LV and RV EFs.     

Association of Second and Third Trimester Weight Gain in Pregnancy with Maternal and Fetal Outcomes

Objective

To investigate the association between weekly weight gain, during the second and third trimesters, classified according to the 2009 Institute of Medicine (IOM/NRC) recommendations, and maternal and fetal outcomes.

Methods

Gestational weight gain was evaluated in 2,244 pregnant women of the Brazilian Study of Gestational Diabetes (Estudo Brasileiro do Diabetes Gestacional – EBDG). Outcomes were cesarean delivery, preterm birth and small or large for gestational age birth (SGA, LGA). Associations between inadequate weight gain and outcomes were estimated using robust Poisson regression adjusting for pre-pregnancy body mass index, trimester-specific weight gain, age, height, skin color, parity, education, smoking, alcohol consumption, gestational diabetes and hypertensive disorders in pregnancy.

Results

In fully adjusted models, in the second trimester, insufficient weight gain was associated with SGA (relative risk [RR] 1.72, 95% confidence interval [CI] 1.26–2.33), and excessive weight gain with LGA (RR 1.64, 95% CI 1.16–2.31); in third trimester, excessive weight gain with preterm birth (RR 1.70, 95% CI 1.08–2.70) and cesarean delivery (RR 1.21, 95% CI 1.03–1.44). Women with less than recommended gestational weight gain in the 2^nd trimester had a lesser risk of cesarean deliveries (RR 0.82, 95% CI 0.71–0.96) than women with adequate gestational weight gain in this trimester.

Conclusion

Though insufficient weight gain in the 3^rd trimester was not associated with adverse outcomes, other deviations from recommended weight gain during second and third trimester were associated with adverse pregnancy outcomes. These findings support, in part, the 2009 IOM/NRC recommendations for nutritional monitoring during pregnancy.     

Legumain promotes tubular ferroptosis by facilitating chaperone-mediated autophagy of GPX4 in AKI

Legumain is required for maintenance of normal kidney homeostasis. However, its role in acute kidney injury (AKI) is still unclear. Here, we induced AKI by bilateral ischemia-reperfusion injury (IRI) of renal arteries or folic acid in lgmn^WT and lgmn^KO mice. We assessed serum creatinine, blood urea nitrogen, histological indexes of tubular injury, and expression of KIM-1 and NGAL. Inflammatory infiltration was evaluated by immunohistological staining of CD3 and F4/80, and expression of TNF-α, CCL-2, IL-33, and IL-1α. Ferroptosis was evaluated by Acsl4, Cox-2, reactive oxygen species (ROS) indexes H₂DCFDA and DHE, MDA and glutathione peroxidase 4 (GPX4). We induced ferroptosis by hypoxia or erastin in primary mouse renal tubular epithelial cells (mRTECs). Cellular survival, Acsl4, Cox-2, LDH release, ROS, and MDA levels were measured. We analyzed the degradation of GPX4 through inhibition of proteasomes or autophagy. Lysosomal GPX4 was assessed to determine GPX4 degradation pathway. Immunoprecipitation (IP) was used to determine the interactions between legumain, GPX4, HSC70, and HSP90. For tentative treatment, RR-11a was administrated intraperitoneally to a mouse model of IRI-induced AKI. Our results showed that legumain deficiency attenuated acute tubular injury, inflammation, and ferroptosis in either IRI or folic acid-induced AKI model. Ferroptosis induced by hypoxia or erastin was dampened in lgmn^KO mRTECs compared with lgmn^WT control. Deficiency of legumain prevented chaperone-mediated autophagy of GPX4. Results of IP suggested interactions between legumain, HSC70, HSP90, and GPX4. Administration of RR-11a ameliorated ferroptosis and renal injury in the AKI model. Together, our data indicate that legumain promotes chaperone-mediated autophagy of GPX4 therefore facilitates tubular ferroptosis in AKI.Subject terms: Necroptosis, Glomerulus, Acute kidney injury     

The effects of beta-arrestin1 deletion on acute cannabinoid activity,brain cannabinoid receptors and tolerance to cannabinoids in mice

Abstract

Context: Previous studies have indicated a role for beta-arrestin2 in the regulation of brain cannabinoid effects and cannabinoid CB₁ receptors, but whether beta-arrestin1 has a role has not been investigated. Objective: To determine the role of beta-arrestin1 in cannabinoid activity. Materials and methods: Beta-arrestin1 ?/? mice and their wild-type (+/+) counterparts were assayed for antinociceptive and temperature-decreasing effects of two ligands, Δ⁹-tetrahydrocannabinol (THC) and CP55940, after both single and repeated administration. In vitro assays examined the effects of deletion on CB₁ receptor density, agonist-binding and G-protein activation. Results: Deletion of beta-arrestin1 diminished the effects of CP55940 in both antinociception (latency to tail withdrawal) and temperature-depression assays in mice. However, deleting beta-arrestin1 had no effect on the actions of THC in either assay. Antagonist radioligand ([³H]SR141716A) saturation binding indicated no difference between beta-arrestin1 +/+ and ?/? mice in the density or affinity for cannabinoid CB₁ receptors in brain membranes. CP55940 agonist binding in brain membranes from beta-arrestin1 +/+ mice exhibited high- and intermediate-affinity sites, but beta-arrestin1 ?/? membranes exhibited an additional site with low affinity. CP55940 produced greater stimulation of [³⁵S]GTPγS binding to membranes from whole brain of beta-arrestin1 ?/? than +/+ mice. The rates of the development of tolerance to chronic THC or CP55940 administration did not appear to be affected by genotype. Discussion: Beta-arrestin1 appeared to mediate the actions of CP55940, but did not affect the activity of THC. Conclusion: Beta-arrestin1 regulates cannabinoid CB₁ receptor sensitivity in an agonist-selective manner, but may not be the primary mediator of tolerance to cannabinoid agonists.     

Estrogen effects on MMP-13 and MMP-14 regulation of left ventricular mass in Dahl salt-induced hypertension

Background:Female Dahl salt-sensitive (DS) rats fed a low-salt diet develop hypertension at 6 months of age. Ovariectomy at 2 months of age accelerates the development of hypertension, and estrogen replacement delays it. Although acute pressure overload induces structural changes in the left ventricle (LV) further effects of gradual hypertension on LV remodeling have not been examined in the DS rat model.Objective: The purpose of this study was to test the hypothesis that aging and estrogen loss in hypertensive DS rats are accompanied by changes in LV remodeling.Methods: Four groups of DS rats were examined: young intact, middle-aged (MA) intact, MA ovariectomized (MA-OVX), and MA-OVX with 17β-eestradiol (E₂) supplementation (MA-OVX+E²). Myocardial matrix metalloproteinases (MMPs),tissue inhibitors of metalloproteinases (TIMPs),and extracellular matrix (ECM) proteins were assessed by immunoblotting.Results: Each of the 4 groups comprised 6 animals. Mean (SEM) LV mass was significantly greater in the MA-intact and the MA-OVX groups (1257 [31] mg and 1199 [25] mg, respectively; both, P < 0.05) compared with the young-intact group (697 [6] mg). LV mass in the MA-OVX+E₂ group was significantly lower compared with the MA-intact and MA-OVX groups (both, P < 0.05), suggesting that estrogen may attenuate LV remodeling.Fibronectin and collagen III and IV concentrations increased significantly in the MA-intact and MA-OOVX groups (all, P < 0.05),indicating increased fibrosis. Multiple MMPs also increased in the MA-intact an nd MA-OVX rats, including MMP-3, -7, -99, -113, and -114, and all TIMPs. In contrast, estrogen attenuated fibrosis by increasing MMP-8 concentrations and increasing collagen III fragments. From good-fit regression modeling, MMP-13 and MMP-14 concentrations correlated positively with LV mass for the MA-intact and MA-OVX groups, respectively.Conclusions: Gradual hypertension stimulated ECM turnover by increasing both MMP/TIMP production and ECM degradation.Estrogen loss or gain resulted in a shift in MMP profiles, suggesting that MMP-13 and MMP-14 may be differentially regulated in postmenopausal hypertension.     

Synaptotagmin VII restricts fusion pore expansion during lysosomal exocytosis

Synaptotagmin is considered a calcium-dependent trigger for regulated exocytosis. We examined the role of synaptotagmin VII (Syt VII) in the calcium-dependent exocytosis of individual lysosomes in wild-type (WT) and Syt VII knockout (KO) mouse embryonic fibroblasts (MEFs) using total internal reflection fluorescence microscopy. In WT MEFs, most lysosomes only partially released their contents, their membrane proteins did not diffuse into the plasma membrane, and inner diameters of their fusion pores were smaller than 30 nm. In Syt VII KO MEFs, not only was lysosomal exocytosis triggered by calcium, but all of these restrictions on fusion were also removed. These observations indicate that Syt VII does not function as the calcium-dependent trigger for lysosomal exocytosis. Instead, it restricts the kinetics and extent of calcium-dependent lysosomal fusion.     

The influence of beta-arrestin2 on cannabinoid CB1 receptor coupling to G-proteins and subcellular localization and relative levels of beta-arrestin1 and 2 in mouse brain

Abstract

Context: Beta-arrestins are known to couple to some G-protein-coupled receptors (GPCRs) to regulate receptor internalization, G-protein coupling and signal transduction, but have not been investigated for most receptors, and for very few receptors in vivo. Previous studies have shown that beta-arrestin2 deletion enhances the efficacy of specific cannabinoid agonists. Objective: The present study hypothesized that brain cannabinoid CB₁ receptors are regulated by beta-arrestin2. Methods: Beta-arrestin2+/+ and ?/? mice were used. Western blotting was used to determine the relative levels of each beta-arrestin subtype in mouse brain. Receptor binding was measured to determine whether deletion of beta-arrestin2 influences agonist binding to brain CB₁ receptors, or the subcellular localization of CB₁ in brain membranes subjected to differential centrifugation. A variety of cannabinoid agonists from different chemical classes were investigated for their ability to activate G-proteins in the presence and absence of beta-arrestin2 in cerebellum, hippocampus and cortex. Results: No differences were found in the density of beta-arrestin1 or cannabinoid CB₁ receptors in several brains of beta-arrestin2+/+ versus ?/? mice. Differences between genotypes were found in the proportion of high- and low-affinity agonist binding sites in brain areas that naturally express higher levels of beta-arrestin2. Cortex from beta-arrestin2?/? mice contained less CB₁ in the P1 fraction and more CB₁ in the P2 fraction compared to beta-arrestin2+/+. Of the agonists assayed for activity, only Δ⁹-tetrahydrocannabinol (THC) exhibited a difference between genotypes, in that it was less efficacious in beta-arrestin2?/? than +/+ mouse membranes. Conclusion: Beta-arrestin2 regulates cannabinoid CB₁ receptors in brain.     

Divergent effects of peripheral and global neuropeptide Y deletion

Objectives:Neuropeptide Y (NPY) is involved in the coordination of bone mass and adiposity. However, multiple NPY sources exist and their individual contribution to the skeleton and adiposity not known. The objectives of our study were to evaluate the effects of peripheral mesenchymal derived NPY to the skeleton and adiposity and to compare them to the global NPY^KO model.Methods:To study the role of mesenchymal-derived NPY, we crossed conditional NPY (NPY^fl/fl) mice with Prx1cre to generate PrxNPY^KO mice. The bone phenotype was assessed using micro-CT. The skeletal phenotype of PrxNPY^KO mice was subsequently compared to global NPY^KO model. We evaluated body weight, adiposity and functionally assessed the feeding response of NPY neurons to determine whether central NPY signaling was altered by Prx1cre.Results:We identified the increase in cortical parameters in PrxNPY^KO mice with no changes to cancellous bone. This was the opposite phenotype to global NPY^KO mice generated from the same conditional allele. Male NPY^KO mice have increased adiposity, while PrxNPY^KO mice showed no difference, demonstrating that local mesenchymal-derived NPY does not influence adiposity.Conclusion:NPY mediates both positive and negative effects on bone mass via separate regulatory pathways. Deletion of mesenchymal-derived NPY had a positive effect on bone mass.     

Association between hypertensive disorders during pregnancy and end-stage renal disease: a population-based study

Background:

Studies into the association between hypertensive disorders during pregnancy and end-stage renal disease are limited. We investigated the risk of end-stage renal disease after delivery among women with hypertensive disorders during pregnancy.

Methods:

We used insurance claims data from 1998 to 2009 to identify 26 651 women aged 19–40 years old who experienced hypertensive disorders during pregnancy; these women had no history of hypertension, diabetes, kidney disease or lupus. We also randomly selected 213 397 women without hypertensive disorders during pregnancy as a comparison cohort; the frequency was matched by age and index year of pregnancy. We compared the incidence of end-stage renal disease in the 2 cohorts. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) after controlling for demographic and clinical factors.

Results:

Women with hypertensive disorders during pregnancy had a greater risk of chronic kidney disease and end-stage renal disease, with adjusted HRs of 9.38 (95% CI 7.09–12.4) and 12.4 (95% CI 8.54–18.0), respectively, after controlling for urban status, coronary artery disease, congestive heart failure, hyperlipidemia and abruption. The HR for end-stage renal disease was 2.72 (95% CI 1.76–4.22) after we also controlled for hypertension and diabetes. Women with preeclampsia or eclampsia had a higher risk of end-stage renal disease (adjusted HR 14.0, 95% CI 9.43–20.7) than women who had gestational hypertension only (adjusted HR 9.03, 95% CI 5.20–15.7).

Interpretation:

Women with hypertensive disorders during pregnancy were at a high risk of end-stage renal disease. The risk was much greater for women who had preeclampsia or eclampsia than those who had gestational hypertension only.Hypertensive disorders during pregnancy are major causes of maternal and fetal morbidity and mortality, affecting 5%–10% of pregnancies.^1,2 Hypertensive disorders during pregnancy include gestational hypertension and preeclampsia.³ Gestational hypertension is referred to as new-onset hypertension (blood pressure > 140/90 mm Hg) without proteinuria after 20-weeks’ gestation.³ Preeclampsia is characterized by new-onset hypertension (blood pressure > 140/90 mm Hg) with proteinuria of at least 300 mg in a 24-hour urine sample after 20-weeks’ gestation.³ Gestational hypertension progresses to preeclampsia in 10%–20% of pregnant women.⁴ The risk factors associated with preeclampsia include family history of preeclampsia, first pregnancy, multiple gestation, advanced maternal age, obesity, pre-existing hypertension, renal disease and diabetes mellitus.⁵ Women with a history of hypertensive disorders during pregnancy are at higher risk of hypertension, diabetes mellitus and cardiovascular disease in later life. Hypertensive disorders during pregnancy and cardiovascular disease share several common risk factors, such as obesity, pre-existing hypertension, renal disease and insulin resistance.^6–14 Hypertensive disorders during pregnancy also increase the risk of cardiovascular disease because of long-term metabolic and vascular changes.¹⁵Hypertensive disorders during pregnancy affect the function and morphology of the kidney.¹⁶ Previous studies have reported an increased prevalence of microalbuminuria after pregnancy in women who had a hypertensive disorder during pregnancy.^17,18 In a case–control study, there was an association between biopsy-proven renal disease and a history of preeclampsia.¹⁹ However, studies about whether hypertensive disorders during pregnancy are associated with end-stage renal disease in later life are limited.²⁰ Only 1 study, performed using birth and renal registries from Norway, has reported that women with preeclampsia during their first pregnancy had a 3.2-fold higher risk of end-stage renal disease.²⁰ In the present study, we investigated the risk of end-stage renal disease among Taiwanese women who had a hypertensive disorder during pregnancy.     

Effects of forskolin on inotropic performance and phospholamban phosphorylation in exercise-trained hypertensive myocardium.

Beta-adrenergic receptor (beta-AR) responsiveness is downregulated in left ventricular (LV) hypertrophy induced by chronic hypertension. While exercise training in hypertension enhances beta-AR responsiveness, the role of adenylyl cyclase remains unclear. The purpose of the present study was to test whether treadmill running in the spontaneously hypertensive rat (SHR) model improves LV responsiveness to forskolin (FOR) or the combination of FOR + isoproterenol (FOR+ISO). Female SHR (16-wk) were randomly placed into sedentary (SHR-SED; n = 7) or treadmill-trained (SHR-TRD; n = 8) groups. Wistar-Kyoto (WKY; n = 7) animals acted as normotensive controls. Langendorff, isovolumic LV performance was established at baseline and during incremental FOR infusion (1 and 5 micromol/l) and FOR+ISO (5 micromol/l + 1x10(-8) mol/l). Heart rate, systolic blood pressure, and heart-to-body weight ratio were lower in WKY relative to both SHR groups (P < 0.05). LV performance and heart rate significantly increased in all groups to a similar extent with incremental FOR infusion. However, in the presence of 5 micromol/l FOR, ISO increased LV developed pressure, positive change in LV pressure, and negative change in LV pressure to a greater extent in SHR-TRD relative to SHR-SED (P < 0.05). Phospholamban phosphorylation at the Thr17 was greater in SHR-TRD relative to SHR-SED and WKY (P < 0.05). Absolute LV developed pressure was moderately correlated with phospholamban phosphorylation at both the Ser16 (r = 0.64; P < 0.05) and Thr17 (r = 0.52; P < 0.05). Our data suggest that the adenylyl cyclase step in the beta-AR cascade is not downregulated in the early course of hypertension and that the enhanced beta-AR responsiveness with training is likely mediated at levels other than adenylyl cyclase. Our data also suggest that beta-AR inotropic responsiveness in the presence of direct adenylyl cyclase agonism is improved in trained compared with sedentary SHR hearts.     

Plantago asiatica L. seeds extract protects against cardiomyocyte injury in isoproterenol- induced cardiac hypertrophy by inhibiting excessive autophagy and apoptosis in mice

BackgroundCardiac hypertrophy is the early stage of many heart diseases, such as coronary heart disease, hypertension, valvular dysfunction and cardiomyopathy. Cardiomyocyte autophagy and apoptosis play an important role in the process of cardiac hypertrophic response. Plantago asiatica L. seeds extract (PASE) is prepared from a traditional herbal medicine in Asia with tremendous pharmacological activities. However, whether PASE could relieve cardiac hypertrophy has not been elucidated. The present study is aimed to investigate the effect of PASE on cardiac hypertrophy and explore its potential underlying mechanism.MethodsCardiac hypertrophy was induced in C57BL/6 mice by subcutaneous injection of isoproterenol (ISO) for two weeks. Meanwhile, the mice were intraperitoneally injected with PASE at dosages of 20, 40 and 80 mg/kg/day. Cardiac hypertrophy was evaluated by echocardiographic examination, haematoxylin and eosin staining and quantitative real-time polymerase chain reaction. Expressions of proteins involved in autophagy and apoptosis such as Beclin1, p62, LC3II, Bax, Bcl-2 and Cleaved-caspase-3 were detected by western blot analysis. Western blot, transient transfection, acridine orange staining, TUNEL staining and autophagy inducer were used to observe the effect and explore the mechanism of PASE on cardiomyocyte and H9c2 cells with excessive autophagy and apoptosis induced by ISO.ResultsISO induction for two weeks disturbed the myocardial contractility and cardiac function of left ventricles of mice. PASE treated mice showed significantly improved cardiac function indexes, including EF, FS, SV and CO, compared with the ISO group. Treatment with PASE also decreased the heart weight/body weight ratio and cardiomyocyte size, and downregulated the mRNA and protein expressions of hypertrophic markers ANP, BNP, and β-MHC. Furthermore, the changes of autophagy and apoptosis markers, such as LC3II, Beclin1, p62, Bcl-2, Bax and Cleaved-caspase-3 induced by ISO were resumed by PASE treatment. Consistently, PASE demonstrated similar effects on ISO-induced H9c2 cells as it did in vivo. In addition, PASE could counteract the increased autophagy induced by the autophagy inducer, rapamycin.ConclusionPASE attenuated ISO-induced cardiac hypertrophy in mice by inhibiting excessive autophagy and apoptosis in cardiomyocytes. The novel findings may pave the way for the clinical usage of PASE for the prevention of heart diseases related with cardiac hypertrophy.     

Role of Muscle c-Jun NH2-Terminal Kinase 1 in Obesity-Induced Insulin Resistance

Obesity caused by feeding of a high-fat diet (HFD) is associated with an increased activation of c-Jun NH₂-terminal kinase 1 (JNK1). Activated JNK1 is implicated in the mechanism of obesity-induced insulin resistance and the development of metabolic syndrome and type 2 diabetes. Significantly, Jnk1^−/− mice are protected against HFD-induced obesity and insulin resistance. Here we show that an ablation of the Jnk1 gene in skeletal muscle does not influence HFD-induced obesity. However, muscle-specific JNK1-deficient (M^KO) mice exhibit improved insulin sensitivity compared with control wild-type (M^WT) mice. Thus, insulin-stimulated AKT activation is suppressed in muscle, liver, and adipose tissue of HFD-fed M^WT mice but is suppressed only in the liver and adipose tissue of M^KO mice. These data demonstrate that JNK1 in muscle contributes to peripheral insulin resistance in response to diet-induced obesity.Obesity is a major risk factor for the development of insulin resistance, hyperglycemia, and metabolic syndrome that can lead to β-cell dysfunction and type 2 diabetes (8). The prevalence of human obesity represents a serious health problem in the United States. It is therefore important that we obtain a detailed understanding of the molecular mechanism that accounts for obesity-induced insulin resistance. Recent progress has led to the identification of signal transduction pathways that may mediate the effects of obesity on insulin resistance (14, 23).c-Jun NH₂-terminal kinase 1 (JNK1) represents one signaling pathway that has been implicated in the pathogenesis of metabolic syndrome and type 2 diabetes (21). JNK1 is activated when mice are fed a high-fat diet (HFD) (7). Moreover, Jnk1^−/− mice are protected against HFD-induced insulin resistance (7). The mechanism of protection is mediated, in part, by the failure of Jnk1^−/− mice to develop HFD-induced obesity (7). However, JNK1 can regulate insulin resistance independently of obesity. Thus, mice with an adipose tissue-specific JNK1 deficiency develop normal diet-induced obesity but exhibit selective protection against HFD-induced insulin resistance in both the liver and adipose tissue (16). These data indicate that adipose tissue JNK1 plays a critical role during the development of HFD-induced insulin resistance.The liver plays a key role in the insulin-stimulated disposal of blood glucose during the postprandial state because of reduced gluconeogenesis and increased glycogen synthesis (17). However, glucose uptake by skeletal muscle also makes a major contribution to insulin-stimulated glucose disposal (17). Muscle may therefore be an important target of obesity-induced JNK1 signaling and the regulation of glucose homeostasis.The purpose of this study was to test the role of JNK1 in muscle. Our approach was to examine the effect of a muscle-specific ablation of the Jnk1 gene in mice. We found that HFD-fed control wild-type (M^WT) mice and muscle-specific JNK1-deficient (M^KO) mice became similarly obese. However, M^KO mice were selectively protected against HFD-induced insulin resistance. This analysis demonstrates that muscle JNK1 contributes to the effects of obesity on insulin resistance.