A role for Rho kinase in vascular contraction evoked by sodium fluoride

Agonist and depolarization-induced vascular smooth muscle contractions involve the activation of Rho-kinase pathway. However, there are no reports addressing the question whether this pathway is involved in NaF-induced vascular contractions. We hypothesized that Rho-kinase plays a role in vascular contraction evoked by sodium fluoride in rat aortae. In both physiological salt solution and calcium-free solution with 2 mM EGTA, cumulative addition of NaF increased vascular tension in concentration-dependent manners. Effects of Rho-kinase inhibitor (Y27632) on phosphorylation of myosin light chain (MLC20) and myosin targeting subunit (MYPT1(Thr696)) of myosin light chain phosphatase as well as NaF-induced contractions were determined using isolated tissue and the Western blot experiments. Y27632 inhibited NaF-induced contractions in a concentration-dependent manner. NaF increased phosphorylation of MLC20 and MYPT1(Thr696), which were also inhibited by Y27632. However, MLCK inhibitor (ML-7) or PKC inhibitor (Ro31-8220) did not inhibit the NaF-induced contraction. These results indicate that activation of Rho-kinase and the subsequent phosphorylation of MYPT1(Thr696) play important roles in NaF-induced contraction of rat aortae.     

Two circadian timing circuits in Neurospora crassa cells share components and regulate distinct rhythmic processes

In Neurospora crassa, FRQ, WC-1, and WC-2 proteins comprise the core circadian FRQ-based oscillator that is directly responsive to light and drives daily rhythms in spore development and gene expression. However, physiological and biochemical studies have demonstrated the existence of additional oscillators in the cell that function in the absence of FRQ (collectively termed FRQ-less oscillators [FLOs]). Whether or not these represent temperature-compensated, entrainable circadian oscillators is not known. The authors previously identified an evening-peaking gene, W06H2 (now called clock-controlled gene 16 [ccg-16]), which is expressed with a robust daily rhythm in cells that lack FRQ protein, suggesting that ccg-16 is regulated by a FLO. In this study, the authors provide evidence that the FLO driving ccg-16 rhythmicity is a circadian oscillator. They find that ccg-16 rhythms are generated by a temperature-responsive, temperature-compensated circadian FLO that, similar to the FRQ-based oscillator, requires functional WC-1 and WC-2 proteins for activity. They also find that FRQ is not essential for rhythmic WC-1 protein levels, raising the possibility that this WCFLO is involved in the generation of WC-1 rhythms. The results are consistent with the presence of 2 circadian oscillators within Neurospora cells, which the authors speculate may interact with each other through the shared WC proteins.     

Microglial MERTK eliminates phosphatidylserine‐displaying inhibitory post‐synapses

Glia contribute to synapse elimination through phagocytosis in the central nervous system. Despite the important roles of this process in development and neurological disorders, the identity and regulation of the "eat‐me" signal that initiates glia‐mediated phagocytosis of synapses has remained incompletely understood. Here, we generated conditional knockout mice with neuronal‐specific deletion of the flippase chaperone Cdc50a, to induce stable exposure of phosphatidylserine, a well‐known "eat‐me" signal for apoptotic cells, on the neuronal outer membrane. Surprisingly, acute Cdc50a deletion in mature neurons causes preferential phosphatidylserine exposure in neuronal somas and specific loss of inhibitory post‐synapses without effects on other synapses, resulting in abnormal excitability and seizures. Ablation of microglia or the deletion of microglial phagocytic receptor Mertk prevents the loss of inhibitory post‐synapses and the seizure phenotype, indicating that microglial phagocytosis is responsible for inhibitory post‐synapse elimination. Moreover, we found that phosphatidylserine is used for microglia‐mediated pruning of inhibitory post‐synapses in normal brains, suggesting that phosphatidylserine serves as a general "eat‐me" signal for inhibitory post‐synapse elimination.     

N‐glycan maturation is crucial for cytokinin‐mediated development and cellulose synthesis in Oryza sativa

To explore the physiological significance of N‐glycan maturation in the plant Golgi apparatus, gnt1, a mutant with loss of N‐acetylglucosaminyltransferase I (GnTI) function, was isolated in Oryza sativa. gnt1 exhibited complete inhibition of N‐glycan maturation and accumulated high‐mannose N‐glycans. Phenotypic analyses revealed that gnt1 shows defective post‐seedling development and incomplete cell wall biosynthesis, leading to symptoms such as failure in tiller formation, brittle leaves, reduced cell wall thickness, and decreased cellulose content. The developmental defects of gnt1 ultimately resulted in early lethality without transition to the reproductive stage. However, callus induced from gnt1 seeds could be maintained for periods, although it exhibited a low proliferation rate, small size, and hypersensitivity to salt stress. Shoot regeneration and dark‐induced leaf senescence assays indicated that the loss of GnTI function results in reduced sensitivity to cytokinin in rice. Reduced expression of A‐type O. sativa response regulators that are rapidly induced by cytokinins in gnt1 confirmed that cytokinin signaling is impaired in the mutant. These results strongly support the proposed involvement of N‐glycan maturation in transport as well as in the function of membrane proteins that are synthesized via the endomembrane system.     

Capture of Bactrocera fruit flies in traps baited with liquid versus solid formulations of male lures in Malaysia

Approximately 70 species of Bactrocera fruit flies (Diptera: Tephritidae) are polyphagous economic pests that attack many important agricultural crops. Several of these Bactrocera species are also highly invasive, and many countries operate continuous, large-scale trapping programs to detect incipient infestations. Detection programs rely heavily on traps baited with male lures, with males of some species responding to raspberry ketone (RK; or its synthetic analogue cue-lure [CL]) and males of other species responding to methyl eugenol (ME). These lures (plus naled, an insecticide) are currently applied as liquids, although this procedure is time-consuming and may expose workers to health risks. Recent field tests, conducted largely in Hawaii, have shown that traps baited with a solid formulation (termed a wafer) that contains both RK and ME (plus dichlorvos, an insecticide) capture as many or more B. dorsalis (Hendel) and B. cucurbitae (Coquillett) males as traps baited with the standard liquid lures. While these results are promising, a more complete evaluation of the solid formulation requires testing in a region with a diverse assemblage of Bactrocera species, since interspecific variation in male response to lures has been reported. The objective of the present investigation was to assess the relative effectiveness of liquid versus solid formulations of male lures in Malaysia, a country known to harbor a large assemblage of Bactrocera species. Based on a 12-week sampling period, we found that, contrary to the Hawaiian results, traps baited with the wafer captured significantly fewer males than traps baited with liquid lures for all five ME-responding taxa analyzed and for one of the three RK/CL-responding species analyzed. Possible explanations for the discrepancy between these and earlier findings are offered.     

Implication of Progranulin and C1q/TNF-Related Protein-3 (CTRP3) on Inflammation and Atherosclerosis in Subjects with or without Metabolic Syndrome

Objective

Progranulin and C1q/TNF-related protein-3 (CTRP3) were recently discovered as novel adipokines which may link obesity with altered regulation of glucose metabolism, chronic inflammation and insulin resistance.

Research Design and Methods

We examined circulating progranulin and CTRP3 concentrations in 127 subjects with (n = 44) or without metabolic syndrome (n = 83). Furthermore, we evaluated the relationship of progranulin and CTRP3 levels with inflammatory markers and cardiometabolic risk factors, including high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), estimated glomerular filtration rate (eGFR), and adiponectin serum concentrations, as well as carotid intima-media thickness (CIMT).

Results

Circulating progranulin levels are significantly related with inflammatory markers, hsCRP (r = 0.30, P = 0.001) and IL-6 (r = 0.30, P = 0.001), whereas CTRP3 concentrations exhibit a significant association with cardiometabolic risk factors, including waist circumference (r = −0.21), diastolic blood pressure (r = −0.21), fasting glucose (r = −0.20), triglyceride (r = −0.34), total cholesterol (r = −0.25), eGFR (r = 0.39) and adiponectin (r = 0.26) levels. Serum progranulin concentrations were higher in patients with metabolic syndrome than those of the control group (199.55 [179.33, 215.53] vs. 185.10 [160.30, 204.90], P = 0.051) and the number of metabolic syndrome components had a significant positive correlation with progranulin levels (r = 0.227, P = 0.010). In multiple regression analysis, IL-6 and triglyceride levels were significant predictors of serum progranulin levels (R ² = 0.251). Furthermore, serum progranulin level was an independent predictor for increased CIMT in subjects without metabolic syndrome after adjusting for other cardiovascular risk factors (R ² = 0.365).

Conclusions

Serum progranulin levels are significantly associated with systemic inflammatory markers and were an independent predictor for atherosclerosis in subjects without metabolic syndrome.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01668888","term_id":"NCT01668888"}}NCT01668888     

TXNIP Deficiency Exacerbates Endotoxic Shock via the Induction of Excessive Nitric Oxide Synthesis

Thioredoxin-interacting protein (TXNIP) has multiple functions, including tumor suppression and involvement in cell proliferation and apoptosis. However, its role in the inflammatory process remains unclear. In this report, we demonstrate that Txnip^−/− mice are significantly more susceptible to lipopolysaccharide (LPS)-induced endotoxic shock. In response to LPS, Txnip^−/− macrophages produced significantly higher levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS), and an iNOS inhibitor rescued Txnip^−/− mice from endotoxic shock-induced death, demonstrating that NO is a major factor in TXNIP-mediated endotoxic shock. This susceptibility phenotype of Txnip^−/− mice occurred despite reduced IL-1β secretion due to increased S-nitrosylation of NLRP3 compared to wild-type controls. Taken together, these data demonstrate that TXNIP is a novel molecule that links NO synthesis and NLRP3 inflammasome activation during endotoxic shock.     

Effect of Sodium Bicarbonate Administration on Mortality in Patients with Lactic Acidosis: A Retrospective Analysis

Background

Lactic acidosis is a common cause of high anion gap metabolic acidosis. Sodium bicarbonate may be considered for an arterial pH <7.15 but paradoxically depresses cardiac performance and exacerbates acidosis by enhancing lactate production. This study aimed to evaluate the cause and mortality rate of lactic acidosis and to investigate the effect of factors, including sodium bicarbonate use, on death.

Methods

We conducted a single center analysis from May 2011 through April 2012. We retrospectively analyzed 103 patients with lactic acidosis among 207 patients with metabolic acidosis. We used SOFA and APACHE II as severity scores to estimate illness severity. Multivariate logistic regression analysis and Cox regression analysis models were used to identify factors that affect mortality.

Results

Of the 103 patients with a mean age of 66.1±11.4 years, eighty-three patients (80.6%) died from sepsis (61.4%), hepatic failure, cardiogenic shock and other causes. The percentage of sodium bicarbonate administration (p = 0.006), catecholamine use, ventilator care and male gender were higher in the non-survival group than the survival group. The non-survival group had significantly higher initial and follow-up lactic acid levels, lower initial albumin, higher SOFA scores and APACHE II scores than the survival group. The mortality rate was significantly higher in patients who received sodium bicarbonate. Sodium bicarbonate administration (p = 0.016) was associated with higher mortality. Independent factors that affected mortality were SOFA score (Exp (B) = 1.72, 95% CI = 1.12–2.63, p = 0.013) and sodium bicarbonate administration (Exp (B) = 6.27, 95% CI = 1.10–35.78, p = 0.039).

Conclusions

Lactic acidosis, which has a high mortality rate, should be evaluated in patients with metabolic acidosis. In addition, sodium bicarbonate should be prescribed with caution in the case of lactic acidosis because sodium bicarbonate administration may affect mortality.