GSK3-activated STAT5 regulates expression of SFRPs to modulate adipogenesis

A positive correlation of serum SFRP1 levels with the risk of developing type 2 diabetes mellitus: a case-control study

OBJECTIVE

Secreted frizzled-related protein 1 (SFRP1) is an adipokine whose production is significantly altered in metabolic disorders. Considering the relationship between dysfunction of Wnt/β-catenin signaling and metabolic disorders as well as the inhibitory effects of SFRP1 on this signaling pathway, the present work aimed to investigate the correlation between serum SFRP1 levels and type 2 diabetes mellitus (T2DM) and its developing risk factors for the first time.

METHODS

This case-control study measured serum levels of SFRP1, tumor necrosis factor (TNF)-α, interleukin (IL)-6, adiponectin, and fasting insulin using enzyme-linked immunosorbent assay kits in 80 T2DM patients and 80 healthy individuals. Biochemical parameters were determined using the AutoAnalyzer instrument.

RESULTS

The T2DM group had higher levels of SFRP1 compared with the controls (146.8100 ± 43.61416 vs 81.9531 ± 32.78545 pg/mL; P < .001). There was a positive correlation between SFRP1 and insulin (r = 0.327, P = .003), TNF-α (r = 0.420, P < .001) as well as homeostatic model assessment for insulin resistance (r = 0.328, P = .003) in the T2DM group. In addition, 10-unit changes in SFRP1 levels showed the risk of T2DM in both the unadjusted (odds ratio [OR] [95% CI] = 1.564 [1.359-1.800]) and adjusted models accounting for age, gender, and body mass index (OR [95% CI] = 1.564 [1.361-1.799]; P < .001). A cut-off value of SFRP1 (105.83 pg/mL) was identified to distinguish between the T2DM patients and the healthy subjects, with sensitivity of 75.0% and specificity of 80.0%.

CONCLUSION

According to our research, there was a significant and positive link between the amount of SFRP1 and the likelihood of developing T2DM as well as the related factors like insulin resistance index and TNF-α. These results indicated that SFRP1 might have a potential role in the development of T2DM.

Adipocyte hypertrophy associates with in vivo postprandial fatty acid metabolism and adipose single-cell transcriptional dynamics

Adipocyte hypertrophy is associated with metabolic complications independent of obesity. We aimed to determine: 1) the association between adipocyte size and postprandial fatty acid metabolism; 2) the potential mechanisms driving the obesity-independent, hypertrophy-associated dysmetabolism in vivo and at a single-cell resolution. Tracers with positron emission tomography were used to measure fatty acid metabolism in 40 men and women with normal or impaired glucose tolerance (NCT02808182), and single nuclei RNA-sequencing (snRNA-seq) to determine transcriptional dynamics of subcutaneous adipose tissue (AT) between individuals with AT hypertrophy vs. hyperplasia matched for sex, ethnicity, glucose-tolerance status, BMI, total and percent body fat, and waist circumference. Adipocyte size was associated with high postprandial total cardiac fatty acid uptake and higher visceral AT dietary fatty acid uptake, but lower lean tissue dietary fatty acid uptake. We found major shifts in cell transcriptomal dynamics with AT hypertrophy that were consistent with in vivo metabolic changes.

Unlocking Prognostic Genes and Multi-Targeted Therapeutic Bioactives from Herbal Medicines to Combat Cancer-Associated Cachexia: A Transcriptomics and Network Pharmacology Approach

Cachexia is a devastating fat tissue and muscle wasting syndrome associated with every major chronic illness, including cancer, chronic obstructive pulmonary disease, kidney disease, AIDS, and heart failure. Despite two decades of intense research, cachexia remains under-recognized by oncologists. While numerous drug candidates have been proposed for cachexia treatment, none have achieved clinical success. Only a few drugs are approved by the FDA for cachexia therapy, but a very low success rate is observed among patients. Currently, the identification of drugs from herbal medicines is a frontier research area for many diseases. In this milieu, network pharmacology, transcriptomics, cheminformatics, and molecular docking approaches were used to identify potential bioactive compounds from herbal medicines for the treatment of cancer-related cachexia. The network pharmacology approach is used to select the 32 unique genes from 238 genes involved in cachexia-related pathways, which are targeted by 34 phytocompounds identified from 12 different herbal medicines used for the treatment of muscle wasting in many countries. Gene expression profiling and functional enrichment analysis are applied to decipher the role of unique genes in cancer-associated cachexia pathways. In addition, the pharmacological properties and molecular interactions of the phytocompounds were analyzed to find the target compounds for cachexia therapy. Altogether, combined omics and network pharmacology approaches were used in the current study to untangle the complex prognostic genes involved in cachexia and phytocompounds with anti-cachectic efficacy. However, further functional and experimental validations are required to confirm the efficacy of these phytocompounds as commercial drug candidates for cancer-associated cachexia.

Preliminary identification and analysis of differential RNA editing between higher and lower backfat thickness pigs using DNA-seq and RNA-seq data

RNA editing is an essential post-transcriptional regulatory mechanism. However, few studies have investigated the functional RNA edits in the economic traits of livestock on a genome-wide scale. Pigs are one of the most important livestock species and their fat is the principal organ involved in the regulation of adipose deposition. Here, we used three full-sibling pairs, with each pair comprising a pig with higher backfat (BF) thickness and lower backfat thickness, to identify RNA editing events based on whole-genome and transcriptome sequencing data. A total of 60,903 non-redundant RNA editing sites with 59,472 (97.7%) A-to-G edits were detected using a revised bioinformatics pipeline. A specific sequence context with G preference was found one base downstream of the edited site, and the editing level was associated with the distribution of nucleotides across nearly sites. Moreover, the A-to-G editing sites mostly occurred in the pig-special short interspersed nuclear elements, Pre0_SS. Comparing the difference between pigs with higher BF and lower BF, we found 211 differentially edited sites (DESites). Functional enrichment analyses revealed a significant enrichment of genes containing DESites in terms of adipose deposition. The DESites located in the six adipose-related genes (SKP1, GSK3B, COL5A3, MDM4, NT5C2, and DENND2A) were selected as candidate RNA editing sites associated with adipose deposition, and thus require further evaluation. This study mined the potentially functional RNA editing sites in pig adipose tissue and indicated that RNA editing may play an important role in adipose deposition, which provides a new insight into the post-transcriptionally mediated regulation mechanism of fat development.

Early-Onset Diabetes Mellitus in Chromosome 8p11.2 Deletion Syndrome Combined With Becker Muscular Dystrophy - A Case Report

BACKGROUND

Chromosome 8p11.2 includes several key genes in development such as the FGFR1, ANK1, KAT6A, and SLC20A2 genes. Deletion of this fragment causes a contiguous gene syndrome. Currently, few cases of interstitial deletion of whole 8p11.2 have been reported. We report a rare case of 8p11.2 deletion syndrome with the unique phenotypes, presenting with early-onset diabetes.

CASE DESCRIPTION

A 20-year-old man with a 1-year history of diabetes mellitus was admitted to the Endocrinology Clinic. Physical examination revealed the dysmorphic facial features, and broad and foreshortened halluces. Laboratory examination indicated spherocytosis anemia, and hypogonadotropic hypogonadism. Bone mineral density analysis showed decreased bone density in the lumbar vertebrae. Brain CT showed calcification. Whole-exome sequencing revealed a 7.05-Mb deletion in 8p11 containing 43 OMIM genes, and a large in-frame deletion of exons 48-55 in the DMD gene. Metformin was given to the patient after which his blood glucose was well controlled. HCG was injected subcutaneously and was supplemented with calcium and vitamin D, which led to an improvement in the patient's quality of life.

CONCLUSION

We report a rare case of 8p11.2 deletion syndrome with unique phenotypes, and early-onset diabetes. It is challenging for endocrinologists to simultaneously reconcile a combination of these diseases across multiple disciplines. We discussed the influencing factors of early-onset diabetes in this patient and speculated that it was caused by complex interactions of known and unknown genetic backgrounds and environmental factors.

Secreted Frizzled Related Proteins in Cardiovascular and Metabolic Diseases

Abnormal gene expression and secreted protein levels are accompanied by extensive pathological changes. Secreted frizzled related protein (SFRP) family members are antagonistic inhibitors of the Wnt signaling pathway, and they were recently found to be involved in the pathogenesis of a variety of metabolic diseases, which has led to extensive interest in SFRPs. Previous reports highlighted the importance of SFRPs in lipid metabolism, obesity, type 2 diabetes mellitus and cardiovascular diseases. In this review, we provide a detailed introduction of SFRPs, including their structural characteristics, receptors, inhibitors, signaling pathways and metabolic disease impacts. In addition to summarizing the pathologies and potential molecular mechanisms associated with SFRPs, this review further suggests the potential future use of SFRPs as disease biomarkers therapeutic targets.

Glycogen Synthase Kinase-3β Mediates Proinflammatory Cytokine Secretion and Adipogenesis in Orbital Fibroblasts from Patients with Graves' Orbitopathy

Purpose

We sought to determine the role of glycogen synthase kinase-3β (GSK-3β) in the pathogenesis of Graves’ orbitopathy(GO).

Methods

Expression of the GSK-3β gene in whole orbital tissue explants was compared between GO and non-GO donors using quantitative real-time PCR (RT-PCR). The expression of proinflammatory molecules in the presence of the GSK-3β inhibitor CHIR 99021 was analyzed using RT-PCR, western blot, and ELISA. Adipogenic differentiation was identified using Oil Red O staining, and the levels of peroxisome proliferator activator gamma (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPs) α and β were determined by western blot.

Results

The expression of GSK-3β was significantly higher in GO tissues than in control tissues. The addition of CHIR 99021 led to a decrease in the active form of the kinase in which the Y216 residue is phosphorylated. When GO and non-GO fibroblasts were stimulated with IL-1β or TNF-α, IL-6, IL-8, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-1 (COX-1), and monocyte chemoattractant protein 1 (MCP-1) showed increased production, which was blunted when CHIR 99021 was added. The activation of Akt, PI3K, nuclear factor (NF)-κB, Erk, Jnk, and p38 kinase by IL-1β and TNF-α was diminished with CHIR 99021 in GO cells. A decrease in lipid droplets and expression of PPARγ and c/EBPα and -β was noted in fibroblasts treated with CHIR 99021 during adipocyte differentiation. The inhibition of Wnt and β-catenin in adipogenesis was reversed by CHIR 99021.

Conclusions

GSK-3β plays a significant role in GO pathogenesis. The inhibition of the kinase attenuated the proinflammatory cytokines production and fibroblast differentiation into adipocytes. GSK-3β may be a potential target for anti-inflammatory and anti-adipogenic treatment of GO.

Bta-miR-376a Targeting KLF15 Interferes with Adipogenesis Signaling Pathway to Promote Differentiation of Qinchuan Beef Cattle Preadipocytes

Intramuscular fat (IMF) is a quality index associated with the taste and juiciness of meat. The deposition of IMF is affected by genetic and non-genetic factors, such as age, slaughter location, gender of the animal, and diet. Micro-ribonucleic acids (miRNA) are transcriptional regulators involved in adipogenesis, but the specific role of miR-376a in regulation of bovine adipocytes remains unknown. Our findings indicated that miR-376a was a potential negative regulator of bovine adipocyte differentiation. A bta-miR-376a mimic inhibited mRNA and protein expression of the marker genes, CDK1, CDK2, PCNA, C/EBPα, FAS, and PPAR γ, and significantly reduced ratios (%) of S-phase cells, the number of cells stained with 5-ethynyl-2'-deoxyuridine, and adipocyte proliferation. Oil red O staining and triglyceride content analysis also confirmed that bta-miR-376a was involved in adipocyte differentiation. Luciferase activities confirmed that Krüppel-like transcription factor 15 (KLF15) was a direct target gene of bta-miR-376a, and that KLF15 was a key transcription factor in adipogenesis. Therefore, bta-miR-376a might be a target for increasing beef IMF.

New insights of Krüppel-like transcription factors in adipogenesis and the role of their regulatory neighbors

Obesity is a serious public health problem associated with predisposition to develop metabolic diseases. Over the past decade, several studies in vitro and in vivo have shown that the activity of Krüppel-like factors (KLFs) regulates adipogenesis, adipose tissue function and metabolism. Comprehension of both the origin and development of adipocytes and of adipose tissue could provide new insights into therapeutic strategies to contend against obesity and related metabolic diseases. This review focus on the transcriptional role that KLF family members play during adipocyte differentiation, describes their main interactions and the mechanisms involved in this fine-tuned developmental process. We also summarize new findings of the involvement of several effectors that modulate KLFs expression during adipogenesis, including growth factors, circadian clock proteins, interleukins, nuclear receptors, protein kinases and importantly, microRNAs. Thus, KLFs regulation by these factors and emerging molecules might constitute a potential therapeutic target for anti-obesity intervention.

Brown Adipose Expansion and Remission of Glycemic Dysfunction in Obese SM/J Mice

We leverage the SM/J mouse to understand glycemic control in obesity. High-fat-fed SM/J mice initially develop poor glucose homeostasis relative to controls. Strikingly, their glycemic dysfunction resolves by 30 weeks of age despite persistent obesity. The mice dramatically expand their brown adipose depots as they resolve glycemic dysfunction. This occurs naturally and spontaneously on a high-fat diet, with no temperature or genetic manipulation. Removal of the brown adipose depot impairs insulin sensitivity, indicating that the expanded tissue is functioning as an insulin-stimulated glucose sink. We describe morphological, physiological, and transcriptomic changes that occur during the brown adipose expansion and remission of glycemic dysfunction, and focus on Sfrp1 (secreted frizzled-related protein 1) as a compelling candidate that may underlie this phenomenon. Understanding how the expanded brown adipose contributes to glycemic control in SM/J mice will open the door for innovative therapies aimed at improving metabolic complications in obesity.

Inhibition of GSK-3β restores delayed gastric emptying in obesity-induced diabetic female mice

Diabetic gastroparesis (DG) is a clinical syndrome characterized by delayed gastric emptying (DGE). Loss of nuclear factor erythroid 2-related factor 2 (Nrf2) is associated with reduced neuronal nitric oxide synthase-α (nNOSα)-mediated gastric motility and DGE. Previous studies have shown that nuclear exclusion and inactivation of Nrf2 is partly regulated by glycogen synthase kinase 3β (GSK-3β). In the current study, the molecular signaling of GSK-3β-mediated Nrf2 activation and its mechanistic role on DG were investigated in high-fat diet (HFD)-induced obese/Type 2 diabetes (T2D) female mice. Adult female C57BL/6J mice were fed with HFD or normal diet (ND) with or without GSK-3β inhibitor (SB 216763, 10 mg/kg body wt ip) start from the 14th wk and continued feeding mice for an additional 3-wk time period. Our results show that treatment with GSK-3β inhibitor SB attenuated DGE in obese/T2D mice. Treatment with SB restored impaired gastric 1) Nrf2 and phase II antioxidant enzymes through PI3K/ERK/AKT-mediated pathway, 2) tetrahydrobiopterin (BH₄, cofactor of nNOS) biosynthesis enzyme dihydrofolate reductase, and 3) nNOSα dimerization in obese/T2 diabetic female mice. SB treatment normalized caspase 3 activity and downstream GSK-3β signaling in the gastric tissues of the obese/T2 diabetic female mice. In addition, GSK-3β inhibitor restored impaired nitrergic relaxation in hyperglycemic conditions. Finally, SB treatment reduced GSK3 marker, pTau in adult primary enteric neuronal cells. These findings emphasize the importance of GSK-3β on regulating gastric Nrf2 and nitrergic mediated gastric emptying in obese/diabetic rodents.NEW & NOTEWORTHY Inhibition of glycogen synthase kinase 3β (GSK-3β) with SB 216763 attenuates delayed gastric emptying through gastric nuclear factor erythroid 2-related factor 2 (Nrf2)-phase II enzymes in high-fat diet-fed female mice. SB 216763 restored impaired gastric PI3K/AKT/ β-catenin/caspase 3 expression. Inhibition of GSK-3β normalized gastric dihydrofolate reductase, neuronal nitric oxide synthase-α expression, dimerization and nitrergic relaxation. SB 216763 normalized both serum estrogen and nitrate levels in female obese/Type 2 diabetes mice. SB 216763 reduced downstream signaling of GSK-3β in enteric neuronal cells in vitro.

MiR-1-3p regulates the differentiation of mesenchymal stem cells to prevent osteoporosis by targeting secreted frizzled-related protein 1

Osteoporosis (OP) is a systemic skeletal disorder with the characteristics of bone mass reduction and microarchitecture deterioration, resulting in bone fragility and increased fracture risk. A reduction in the osteoblast-differentiation of bone marrow mesenchymal stem cells (BMSCs) is considered as a basic pathogenesis of osteoporosis. miRNAs play a substantial role in the development and differentiation of BMSCs. In the present study, we found that miR-1-3p was significantly downregulated in the bones of Chinese osteoporotic patients (n = 29). Secreted frizzled-related protein 1 (SFRP1) was predicted as a target gene of miR-1-3p via the TargetScan and PicTar softwares and validated by dual-luciferase reporter assays. The findings revealed that the expression of SFRP1 was inversely correlated with miR-1-3p in osteoporotic patients. We induced mouse MSCs (mMSCs) to osteogenesis or adipogenesis and found that miR-1-3p was upregulated during osteogenesis but downregulated during adipogenesis. The overexpression of miR-1-3p stimulated osteogenesis and inhibited adipogenesis of mMSCs. In addition, ovariectomized (OVX) mice were tested and the function of miR-1-3p in vivo was explored. Immunohistochemistry and histomorphometric assays showed that in vivo inhibition of miR-1-3p increased the expression level of SFRP1 and reduced bone formation and bone mass. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining indicated that the in vivo suppression of miR-1-3p promoted osteoclast activity, suggesting that miR-1-3p may influence bone mass by regulating bone resorption. It can be concluded that miR-1-3p plays a pivotal role in the pathogenesis of osteoporosis via targeting SFRP1 and may be a potential therapeutic target for osteoporosis.

Latest advances in STAT signaling and function in adipocytes

Adipocytes and adipose tissue are not inert and make substantial contributions to systemic metabolism by influencing energy homeostasis, insulin sensitivity, and lipid storage. In addition to well-studied hormones such as insulin, there are numerous hormones, cytokines, and growth factors that modulate adipose tissue function. Many endocrine mediators utilize the JAK-STAT pathway to mediate dozens of biological processes, including inflammation and immune responses. JAKs and STATs can modulate both adipocyte development and mature adipocyte function. Of the seven STAT family members, four STATs are expressed in adipocytes and regulated during adipogenesis (STATs 1, 3, 5A, and 5B). These STATs have been shown to play influential roles in adipose tissue development and function. STAT6, in contrast, is highly expressed in both preadipocytes and mature adipocytes, but is not considered to play a major role in regulating adipose tissue function. This review will summarize the latest research that pertains to the functions of STATs in adipocytes and adipose tissue.

Role of Secreted Frizzled-Related Protein 1 in Early Mammary Gland Tumorigenesis and Its Regulation in Breast Microenvironment

In mice, the lack of secreted frizzled-related protein 1 (SFRP1) is responsible for mammogenesis and hyperplasia, while, in bovines, its overexpression is associated with post-lactational mammary gland involution. Interestingly, there are no reports dealing with the role of SFRP1 in female involution. However, SFRP1 dysregulation is largely associated with human tumorigenesis in the literature. Indeed, the lack of SFRP1 is associated with both tumor development and patient prognosis. Considering the increased risk of breast tumor development associated with incomplete mammary gland involution, it is crucial to demystify the "grey zone" between physiological age-related involution and tumorigenesis. In this review, we explore the functions of SFRP1 involved in the breast involution processes to understand the perturbations driven by the disappearance of SFRP1 in mammary tissue. Moreover, we question the presence of recurrent microcalcifications identified by mammography. In bone metastases from prostate primary tumor, overexpression of SFRP1 results in an osteolytic response of the tumor cells. Hence, we explore the hypothesis of an osteoblastic differentiation of mammary cells induced by the lack of SFRP1 during lobular involution, resulting in a new accumulation of hydroxyapatite crystals in the breast tissue.

GSK3β inhibition suppresses the hepatic lipid accumulation in Schizothorax prenanti

Glycogen synthase kinase-3β (GSK3β) is a serine/threonine kinase involved in the regulation of embryonic development, glycogen metabolism, protein synthesis, mitosis, and apoptosis. To understand the role of GSK3β in hepatic lipid accumulation of Schizothorax prenanti, we used lithium chloride (LiCl), a GSK3β inhibitor, to inhibit the expression and activity of GSK3β. LiCl increased levels of phosphorylation of GSK3β (Ser9) and decreased the protein level of GSK3β. Plasma TG, TC, and LDL-C levels were greatly decreased after LiCl treatment. Additionally, GSK3β inhibition significantly reduced the levels of hepatic triglyceride (TG) and decreased the expression of lipogenesis-related genes in liver. Interestingly, LiCl decreased levels of phosphorylation of STAT3 (Tyr705), and then inhibited the activity of STAT3. These results indicate that in vivo LiCl treatment, which inhibited GSK3β activity, effectively decreased hepatic lipid accumulation through STAT3 in Schizothorax prenanti.

miR-1185-1 and miR-548q Are Biomarkers of Response to Weight Loss and Regulate the Expression of GSK3B

The aim of the present investigation was to identify putative miRNAs involved in the response to weight loss. Reverse-transcribed RNA isolated from white blood cells (WBCs) of a subpopulation from the Reduction of the Metabolic Syndrome in Navarra-Spain (RESMENA-S) study (low-responders (LR) and high-responders (HR)) was hybridized in a gene expression microarray. Moreover, miRNAs were sequenced by miRNA-Seq. It was found that miR-548q and miR-1185-1 were overexpressed in HR, both in the microarray and in the miRNA-Seq. A bioinformatic prediction of putative target genes of the selected miRNAs found that GSK3B, a putative target for miR-548q and miR-1185-1, was downregulated in HR. Particular 3′-UTR binding regions of GSK3B were cloned downstream of the firefly luciferase gene. HEK-293T cells were co-transfected with either 0.25 μg of empty pmiR-GLO or pmiR-GLO-548q-3′-UTR/pmiR-GLO-1185-1-3′-UTR, and 7.5 pmol of miR-548q/miR-1185-1 mimics, demonstrating that miR-1185-1 bound to the 3′-UTR region of GSK3B. THP-1 cells were transfected with either 20/40 nM of miR-548q/miR-1185-1 mimics, evidencing that miR-1185-1inhibited the expression of the gene when transfected at doses of 20/40 nM, whereas miR-548q inhibited GSK3B expression at a dose of 40 nM. As a conclusion, miR-548q and miR-1185-1 levels in WBCs are biomarkers of response to weight-loss diets and could be involved in the regulation of the proinflammatory gene GSK3B.

Inhibition of GSK3β Reduces Ectopic Lipid Accumulation and Induces Autophagy by the AMPK Pathway in Goat Muscle Satellite Cells

Ectopic lipid accumulation in muscle is important not only for obesity and myopathy treatment, but also for meat quality improvement in farm animals. However, the molecular mechanisms involved in lipid metabolism in muscle satellite cells are still elusive. In this study, SB216763 reduced GSK3β activation by increasing the level of pGSK3β (Ser9) and decreasing the level of total GSK3β protein. GSK3β inhibition decreased lipid accumulation and downregulated the expression level of lipogenesis-related genes in the adipogenic differentiation of goat muscle satellite cells. Furthermore, SB216763 treatment increased the levels of pAMPKα (T172) and pACC (Ser79). Further, we found that GSK3β inhibition promoted levels of LC3B-II and reduced the protein levels of p62 to induce the autophagy in muscle satellite cells. Taken together, our results provide new insight into a critical function for GSK3β: modulating lipid accumulation in goat muscle satellite cells through activating the AMPK pathway.

Inhibiting Glycogen Synthase Kinase 3 Reverses Obesity-Induced White Adipose Tissue Inflammation by Regulating Apoptosis Inhibitor of Macrophage/CD5L-Mediated Macrophage Migration

Objective- Obesity-induced inflammation in white adipose tissue, characterized by increased macrophage infiltration and associated with macrophage population shift from anti-inflammatory M2 to proinflammatory M1 macrophages, largely contributes to obesity-induced insulin resistance and influences type 2 diabetes mellitus pathogenesis. GSK3 (glycogen synthase kinase 3), a serine/threonine kinase, has been reported to participate in various cellular processes. We sought to examine the potential mechanism by which GSK3, a serine/threonine kinase implicated in various cellular processes, modulates obesity-induced visceral adipose tissue (VAT) inflammation. Approach and Results- Male C57BL/6J mice were fed a high-fat diet for 10 weeks while being treated with vehicle control or GSK3 inhibitors SB216763 or CHIR99021. RNA-sequencing results using VAT demonstrated that GSK3 inhibitor treatment reversed obesity-specific expression of genes associated with inflammation. Consistently, GSK3 inhibition reduced obesity-induced VAT inflammation as characterized by decreased proinflammatory M1 macrophages but increased anti-inflammatory M2 macrophages in the VAT and reduced circulatory inflammatory monocytes. These anti-inflammatory effects of GSK3 inhibition were found to be driven, at least in part, by inhibiting production of apoptosis inhibitor of macrophage in macrophages via inactivating STAT3 to reduce free fatty acid and chemokine level produced from VAT to suppress the migration/chemotaxis of macrophages and monocytes. Conclusions- Our findings suggest that GSK3 may act as an important regulator of obesity-induced inflammation and characterize the novel role of GSK3 in shifting macrophage polarization and reinforce its therapeutic potential for obesity-induced inflammation and its associated diabetes mellitus.

Sfrp5/Wnt Pathway: A Protective Regulatory System in Atherosclerotic Cardiovascular Disease

Adipose tissue stores energy and is the largest endocrine organ in the body, producing several adipokines. However, among these adipokines, few play a role in the positive metabolism that promotes good health. Secreted frizzled-related protein (Sfrp)-5, an antagonist that directly binds to Wnt, has attracted interest due to its favorable effects on atherosclerotic cardiovascular disease (ASCVD). This review focuses on Sfrp5 biology and the roles of the Sfrp5/Wnt system in ASCVD.

METTL3 inhibits BMSC adipogenic differentiation by targeting the JAK1/STAT5/C/EBPβ pathway via an m6A-YTHDF2-dependent manner

Bone marrow stem cells (BMSCs) are multipotent stem cells that can regenerate mesenchymal tissues, such as adipose tissue, bone, and muscle. Recent studies have shown that N⁶-methyladenosine (m⁶A) methylation, one of the most prevalent epigenetic modifications, is involved in the development process. However, whether it plays roles in BMSC differentiation is still elusive. Here, we found that the deletion of m⁶A "writer" protein methyltransferase-like (METTL)3 in porcine BMSCs (pBMSCs) could promote adipogenesis and janus kinase (JAK)1 protein expression via an m⁶A-dependent way. Knockdown of METTL3 decreased mRNA m⁶A levels of JAK1, leading to enhanced YTH m⁶A RNA binding protein 2 (YTHDF2)-dependent JAK1 mRNA stability. We further demonstrated that JAK1 activated signal transducer and activator of transcription (STAT) 5 through regulation of its phosphorylation to bind to the promoter of CCAAT/enhancer binding protein (C/EBP) β, which could ultimately lead to a modulated adipogenic process. Collectively, our results reveal an orchestrated network linking the m⁶A methylation and JAK1/STAT5/C/EBPβ pathway in pBMSCs adipogenic differentiation. Our findings provide novel insights into the underlying molecular mechanisms of m⁶A modification in the regulation of BMSCs differentiating into adipocytes, which may pave a way to develop more effective therapeutic strategies in stem cell regenerative medicine and the treatment of obesity.-Yao, Y., Bi, Z., Wu, R., Zhao, Y., Liu, Y., Liu, Q., Wang, Y., Wang, X. METTL3 inhibits BMSC adipogenic differentiation by targeting the JAK1/STAT5/C/EBPβ pathway via an m⁶A-YTHDF2-dependent manner.