Fat accumulation in differentiated brown adipocytes is linked with expression of Hox genes

Homeobox (Hox) genes are involved in body plan of embryo along the anterior–posterior axis. Presence of several Hox genes in white adipose tissue (WAT) and brown adipose tissue (BAT) is indicative of involvement of Hox genes in adipogenesis. We propose that differentiation inducing agents viz. isobutyl-methyl-xanthine (IBMX), indomethacin, dexamethasone (DEX), triiodothyronine (T3) and insulin may regulate differentiation in brown adipose tissue through Hox genes. In vitro culture of brown fat stromalvascular fraction (SVF) in presence or absence of differentiation inducing agents was used for establishing relationship between fat accumulation in differentiated adipocytes and expression of Hox genes. Relative expression of Pref1, UCP1 and Hox genes was determined in different stages of adipogenesis. Presence or absence of IBMX, indomethacin and DEX during differentiation of proliferated pre-adipocytes resulted in marked differences in expression of Hox genes and lipid accumulation. In presence of these inducing agents, lipid accumulation as well as expression of HoxA1, HoxA5, HoxC4 & HoxC8 markedly enhanced. Irrespective of presence or absence of T3, insulin down regulates HoxA10. T3 results in over expression of HoxA5, HoxC4 and HoxC8 genes, whereas insulin up regulates expression of only HoxC8. Findings suggest that accumulation of fat in differentiated adipocytes is linked with expression of Hox genes.     

Long‐lived hypopituitary Ames dwarf mice are resistant to the detrimental effects of high‐fat diet on metabolic function and energy expenditure

Growth hormone (GH) signaling stimulates the production of IGF‐1; however, increased GH signaling may induce insulin resistance and can reduce life expectancy in both mice and humans. Interestingly, disruption of GH signaling by reducing plasma GH levels significantly improves health span and extends lifespan in mice, as observed in Ames dwarf mice. In addition, these mice have increased adiposity, yet are more insulin sensitive compared to control mice. Metabolic stressors such as high‐fat diet (HFD) promote obesity and may alter longevity through the GH signaling pathway. Therefore, our objective was to investigate the effects of a HFD (metabolic stressor) on genetic mechanisms that regulate metabolism during aging. We show that Ames dwarf mice fed HFD for 12 weeks had an increase in subcutaneous and visceral adiposity as a result of diet‐induced obesity, yet are more insulin sensitive and have higher levels of adiponectin compared to control mice fed HFD. Furthermore, energy expenditure was higher in Ames dwarf mice fed HFD than in control mice fed HFD. Additionally, we show that transplant of epididymal white adipose tissue (eWAT) from Ames dwarf mice fed HFD into control mice fed HFD improves their insulin sensitivity. We conclude that Ames dwarf mice are resistant to the detrimental metabolic effects of HFD and that visceral adipose tissue of Ames dwarf mice improves insulin sensitivity in control mice fed HFD.     

Dietary fat composition influences glomerular and proximal convoluted tubule cell structure and autophagic processes in kidneys from calorie‐restricted mice

Calorie restriction (CR) has been repeatedly shown to prevent cancer, diabetes, hypertension, and other age‐related diseases in a wide range of animals, including non‐human primates and humans. In rodents, CR also increases lifespan and is a powerful tool for studying the aging process. Recently, it has been reported in mice that dietary fat plays an important role in determining lifespan extension with 40% CR. In these conditions, animals fed lard as dietary fat showed an increased longevity compared with mice fed soybean or fish oils. In this paper, we study the effect of these dietary fats on structural and physiological parameters of kidney from mice maintained on 40% CR for 6 and 18 months. Analyses were performed using quantitative electron microcopy techniques and protein expression in Western blots. CR mitigated most of the analyzed age‐related parameters in kidney, such as glomerular basement membrane thickness, mitochondrial mass in convoluted proximal tubules and autophagic markers in renal homogenates. The lard group showed improved preservation of several renal structures with aging when compared to the other CR diet groups. These results indicate that dietary fat modulates renal structure and function in CR mice and plays an essential role in the determination of health span in rodents.     

Carbonic anhydrase inhibition for the management of cerebral ischemia: in vivo evaluation of sulfonamide and coumarin inhibitors

Ischemia of brain areas is a global health problem, causing death or long-term disability. Current pharmacological options have limited impact on ischemic damages. Recently, a relationship between hypoxia and carbonic anhydrase (CA) over-expression has been highlighted suggesting CA inhibition as a possible target. This study aimed to evaluate the pharmacological profile of sulfonamide and coumarin CA inhibitors in rats underwent permanent middle cerebral artery occlusion (pMCAO). The neurological score of pMCAO rats was dramatically reduced 24?h after occlusion. Repeated subcutaneous injections of the CA inhibitors 4 and 7 (1?mg kg^?1) were able to increase the neurological score by 40%. Compound 7 showed the tendency to reduce the volume of hemisphere infarction. The standard CA inhibitor acetazolamide was ineffective. The properties of novel CA inhibitors to improve neurological functionalities after cerebral ischemic insult are shown. The CA involvement in cerebral hypoxic phenomena deserves deeper investigations.     

Sexual dimorphism in activation of placental autophagy in obese women with evidence for fetal programming from a placenta-specific mouse model

The incidence of maternal obesity and its co-morbidities (diabetes, cardiovascular disease) continues to increase at an alarming rate, with major public health implications. In utero exposure to maternal obesity has been associated with development of cardiovascular and metabolic diseases in the offspring as a result of developmental programming. The placenta regulates maternal-fetal metabolism and shows significant changes in its function with maternal obesity. Autophagy is a cell-survival process, which is responsible for the degradation of damaged organelles and misfolded proteins. Here we show an activation of autophagosomal formation and autophagosome-lysosome fusion in placentas of males but not females from overweight (OW) and obese (OB) women vs. normal weight (NW) women. However, total autophagic activity in these placentas appeared to be decreased as it showed an increase in SQSTM1/p62 and a decrease in lysosomal biogenesis. A mouse model with a targeted deletion of the essential autophagy gene Atg7 in placental tissue showed significant placental abnormalities comparable to those seen in human placenta with maternal obesity. These included a decrease in expression of mitochondrial genes and antioxidants, and decreased lysosomal biogenesis. Strikingly, the knockout mice were developmentally programmed as they showed an increased sensitivity to high-fat diet-induced obesity, hyperglycemia, hyperinsulinemia, increased adiposity, and cardiac remodeling. In summary, our results indicate a sexual dimorphism in placental autophagy in response to maternal obesity. We also show that autophagy plays an important role in placental function and that inhibition of placental autophagy programs the offspring to obesity, and to metabolic and cardiovascular diseases.     

Development and evaluation of the herd dynamic milk model with focus on the individual cow component

The herd dynamic milk (HDM) model is a dynamic model capable of simulating the performance of individual dairy animals (from birth to death), with a daily time step. Within this study, the HDM model is described and evaluated in relation to milk production, body condition score (BCS) and BCS change throughout lactation by comparing model simulations against data from published experimental studies. The model’s response to variation in genetic potential, herbage allowance and concentrate supplementation was tested in a sensitivity analysis. Data from experiments in Ireland and France over a 3-year period (2009–11) were used to complete the evaluation. The aim of the Irish experiment was to determine the impact of different stocking rates (SRs) (SR1: 3.28 cow/ha, SR2: 2.51 cow/ha) on key physical, biological and economic performance. The aim of the French experiment was to evaluate over a prolonged time period, the ability of two breeds of dairy cows (Holstein and Normande) to produce and to reproduce under two feeding strategies (high level and low level) in the context of compact calving. The model evaluation was conducted at the herd level with separate evaluations for the primiparous and multiparous cows. The evaluation included the two extreme SRs for the Irish experiment, and an evaluation at the overall herd and individual animal level for the different breeds and feeding levels for the French data. The comparison of simulation and experimental data for all scenarios resulted in a relative prediction error, which was consistently <15% across experiments for weekly milk production and BCS. In relation to BCS, the highest root mean square error was 0.27 points of BCS, which arose for Holstein cows in the low feeding group in late lactation. The model responded in a realistic fashion to variation in genetic potential for milk production, herbage allowance and concentrate supplementation.     

Genetic association of marbling score with intragenic nucleotide variants at selection signals of the bovine genome

Selection signals of Korean cattle might be attributed largely to artificial selection for meat quality. Rapidly increased intragenic markers of newly annotated genes in the bovine genome would help overcome limited findings of genetic markers associated with meat quality at the selection signals in a previous study. The present study examined genetic associations of marbling score (MS) with intragenic nucleotide variants at selection signals of Korean cattle. A total of 39 092 nucleotide variants of 407 Korean cattle were utilized in the association analysis. A total of 129 variants were selected within newly annotated genes in the bovine genome. Their genetic associations were analyzed using the mixed model with random polygenic effects based on identical-by-state genetic relationships among animals in order to control for spurious associations produced by population structure. Genetic associations of MS were found (P<3.88×10⁻⁴) with six intragenic nucleotide variants on bovine autosomes 3 (cache domain containing 1, CACHD1), 5 (like-glycosyltransferase, LARGE), 16 (cell division cycle 42 binding protein kinase alpha, CDC42BPA) and 21 (snurportin 1, SNUPN; protein tyrosine phosphatase, non-receptor type 9, PTPN9; chondroitin sulfate proteoglycan 4, CSPG4). In particular, the genetic associations with CDC42BPA and LARGE were confirmed using an independent data set of Korean cattle. The results implied that allele frequencies of functional variants and their proximity variants have been augmented by directional selection for greater MS and remain selection signals in the bovine genome. Further studies of fine mapping would be useful to incorporate favorable alleles in marker-assisted selection for MS of Korean cattle.     

Ossification score is a better indicator of maturity related changes in eating quality than animal age

Ossification score and animal age are both used as proxies for maturity-related collagen crosslinking and consequently decreases in beef tenderness. Ossification score is strongly influenced by the hormonal status of the animal and may therefore better reflect physiological maturity and consequently eating quality. As part of a broader cross-European study, local consumers scored 18 different muscle types cooked in three ways from 482 carcasses with ages ranging from 590 to 6135 days and ossification scores ranging from 110 to 590. The data were studied across three different maturity ranges; the complete range of maturities, a lesser range and a more mature range. The lesser maturity group consisted of carcasses having either an ossification score of 200 or less or an age of 987 days or less with the remainder in the greater maturity group. The three different maturity ranges were analysed separately with a linear mixed effects model. Across all the data, and for the greater maturity group, animal age had a greater magnitude of effect on eating quality than ossification score. This is likely due to a loss of sensitivity in mature carcasses where ossification approached and even reached the maximum value. In contrast, age had no relationship with eating quality for the lesser maturity group, leaving ossification score as the more appropriate measure. Therefore ossification score is more appropriate for most commercial beef carcasses, however it is inadequate for carcasses with greater maturity such as cull cows. Both measures may therefore be required in models to predict eating quality over populations with a wide range in maturity.     

Verification of suitable and reliable reference genes for quantitative real-time PCR during adipogenic differentiation in porcine intramuscular stromal-vascular cells

Intramuscular fat (IMF) is an important trait influencing meat quality, and intramuscular stromal-vascular cell (MSVC) differentiation is a key factor affecting IMF deposition. Quantitative real-time PCR (qPCR) is often used to screen the differentially expressed genes during differentiation of MSVCs, where proper reference genes are essential. In this study, we assessed 31 of previously reported reference genes for their expression suitability in porcine MSVCs derived form longissimus dorsi with qPCR. The expression stability of these genes was evaluated using NormFinder, geNorm and BestKeeper algorithms. NormFinder and geNorm uncovered ACTB, ALDOA and RPS18 as the most three stable genes. BestKeeper identified RPL13A, SSU72 and DAK as the most three stable genes. GAPDH was found to be the least stable gene by all of the three software packages, indicating it is not an appropriate reference gene in qPCR assay. These results might be helpful for further studies in pigs that explore the molecular mechanism underlying IMF deposition.     

Investigation of the differentiation of ex vivo nerve and fat tissues using laser‐induced breakdown spectroscopy (LIBS): Prospects for tissue‐specific laser surgery

In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser‐Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions. The performed measurements suggest that the two tissue types show a high similarity in terms of qualitative elemental composition while at the same time revealing a distinct difference in the concentration of the constituent elements. Different analysis approaches are evaluated and discussed to optimize the tissue‐differentiation performance of the LIBS approach.

Plasma mediated laser tissue ablation.