Chloride intracellular channel 5 modulates adipocyte accumulation in skeletal muscle by inhibiting preadipocyte differentiation

Targeting the T-type calcium channel Cav3.2 in GABAergic arcuate nucleus neurons to treat obesity

OBJECTIVE

Cav3.2, a T-type low voltage-activated calcium channel widely expressed throughout the central nervous system, plays a vital role in neuronal excitability and various physiological functions. However, the effects of Cav3.2 on energy homeostasis remain unclear. Here, we examined the role of Cav3.2 expressed by hypothalamic GABAergic neurons in the regulation of food intake and body weight in mice and explored the underlying mechanisms.

METHODS

Male congenital Cana1h (the gene coding for Cav3.2) global knockout (Cav3.2KO) mice and their wild type (WT) littermates were first used for metabolic phenotyping studies. By using the CRISPR-Cas9 technique, Cav3.2 was selectively deleted from GABAergic neurons in the arcuate nucleus of the hypothalamus (ARH) by specifically overexpressing Cas9 protein and Cav3.2-targeting sgRNAs in ARH Vgat (Vgat^ARH) neurons. These male mutants (Cav3.2KO-Vgat^ARH) were used to determine whether Cav3.2 expressed by Vgat^ARH neurons is required for the proper regulation of energy balance. Subsequently, we used an electrophysiological patch-clamp recording in ex vivo brain slices to explore the impact of Cav3.2KO on the cellular excitability of Vgat^ARH neurons.

RESULTS

Male Cav3.2KO mice had significantly lower food intake than their WT littermate controls when fed with either a normal chow diet (NCD) or a high-fat diet (HFD). This hypophagia phenotype was associated with increased energy expenditure and decreased fat mass, lean mass, and total body weight. Selective deletion of Cav3.2 in Vgat^ARH neurons resulted in similar feeding inhibition and lean phenotype without changing energy expenditure. These data provides an intrinsic mechanism to support the previous finding on ARH non-AgRP GABA neurons in regulating diet-induced obesity. Lastly, we found that naringenin extract, a predominant flavanone found in various fruits and herbs and known to act on Cav3.2, decreased the firing activity of Vgat^ARH neurons and reduced food intake and body weight. These naringenin-induced inhibitions were fully blocked in Cav3.2KO-Vgat^ARH mice.

CONCLUSION

Our results identified Cav3.2 expressed by Vgat^ARH neurons as an essential intrinsic modulator for food intake and energy homeostasis, which is a potential therapeutic target in the treatment of obesity.

Squalene epoxidase plays a critical role in determining pig meat quality by regulating adipogenesis, myogenesis, and ROS scavengers

In mammals, Squalene epoxidase (SQLE) is an enzyme that converts squalene to 2,3-oxidosqualene, in the early stage of cholesterol generation. Here, we identified single nucleotide polymorphisms (SNPs) in the SQLE gene (c.2565 G > T) by RNA Sequencing from the liver tissue of Berkshire pigs. Furthermore, we found that homozygous GG pigs expressed more SQLE mRNA than GT heterozygous and TT homozygous pigs in longissimus dorsi tissue. Next, we showed that the SNP in the SQLE gene was associated with several meat quality traits including backfat thickness, carcass weight, meat colour (yellowness), fat composition, and water-holding capacity. Rates of myogenesis and adipogenesis induced in C2C12 cells and 3T3-L1 cells, respectively, were decreased by Sqle knockdown. Additionally, the expression of myogenic marker genes (Myog, Myod, and Myh4) and adipogenic marker genes (Pparg, Cebpa, and Adipoq) was substantially downregulated in cells transfected with Sqle siRNA. Moreover, mRNA expression levels of ROS scavengers, which affect meat quality by altering protein oxidation processes, were significantly downregulated by Sqle knockdown. Taken together, our results suggest the molecular mechanism by which SNPs in the SQLE gene can affect meat quality.

Evidence for an important role of host microRNAs in regulating hepatic fibrosis in humans infected with Schistosoma japonicum

MicroRNAs (miRNAs) are short, non-coding RNAs that repress the translation of target gene transcripts. They have been implicated in various activities such as cell proliferation, survival, differentiation, migration and metabolism. We report here the first known miRNome and transcriptome analysis of human livers displaying advanced fibrosis due to Schistosoma japonicum infection. We present evidence that hsa-miR-150-5p, hsa-miR-10a-5p, hsa-miR-199a-3p, hsa-miR-4521, hsa-miR-222/221, hsa-miR-663b and hsa-miR-143-3p (associated without correction) play an important role in hepatic fibrosis by acting on metabolism, organization of the extracellular matrix proteins, lipid mobilization and limitation of oxidative damage stress.

Co-Expression of Ezrin-CLIC5-Podocalyxin Is Associated with Migration and Invasiveness in Hepatocellular Carcinoma

Background and Aim

Prognostic markers are important for predicting the progression and staging of hepatocellular carcinoma (HCC). Ezrin (EZR) and Podocalyxin (PODXL) are proteins associated with invasion, migration and poor prognosis in various types of cancer. Recently, it has been observed that chloride intracellular channel 5 (CLIC5) forms a complex with EZR and PODXL and that it is required for podocyte structure and function. In this study, we evaluated the overexpression of EZR, PODXL and CLIC5 in HCC.

Methods

The modified resistant hepatocyte model (MRHR), human biopsies and HCC cell lines (HepG2, Huh7 and SNU387) were used in this study. Gene and protein expression levels were evaluated in the MRHR by qRT-PCR, Western blot and immunohistochemistry analyses, and protein expression in the human biopsies was evaluated by immunohistochemistry. Protein expression in the HCC cell lines was evaluated by immunofluorescence and Western blot, also the migration and invasive abilities of Huh7 cells were evaluated using shRNA-mediated inhibition.

Results

Our results indicated that these genes and proteins were overexpressed in HCC. Moreover, when the expression of CLIC5 and PODXL was inhibited in Huh7 cells, we observed decreased migration and invasion.

Conclusion

This study suggested that EZR, CLIC5 and PODXL could be biological markers to predict the prognosis of HCC and that these proteins participate in migration and invasion processes.