Process Of Adipogenesis Research Articles

Semaglutide modulates adipogenic differentiation and extracellular acidification in epicardial (EAT) and subcutaneous (SAT) adipose tissue stromal cells from patients with cardiovascular disease

Abstract Backround Cardiovascular disease (CVD) is the main cause of death in the world. One of the known risk factors is the epicardial fat (EAT) accumulation, which is around the myocardium and coronaries playing a paracrine role over them. Although mature and functional adipocytes are involved in energy balance and glucose metabolism, the hypertrophic state increases the production of fatty acid binding protein 4 (FABP4), which is a pro-inflammatory adipokine, with consequences on extracellular acidification. Recent data shows that glucagon-like peptide receptor agonists 1 (GLP1ra) drug improves the insulin response and reduces EAT thickness. Although GLP1ra has a direct effect on hypothalamus for reducing food intake, this drug might play a direct role on adipogenesis process in this fat stromal cells. Purpose Our study aims to demonstrate the effect of semaglutide on adipogenesis and metabolism in epicardial and subcutaneous stromal cells from patients with cardiovascular disease. Methods The study was approved by the Galician Research Ethics Committee, and subcutaneous adipose tissue (SAT) and EAT samples from 17 patients were obtained undergoing open-heart surgery with informed consent. Stromal cells from biopsies were isolated and cultured. Adipogenesis was induced for 15 days with or without 1 nM semaglutide, given by Novo-Nordisk (Bagsværd, Denmark), using an adipogenesis cocktail. Cells were lysed and RNA was isolated for RT-qPCR. Target genes were amplified for Glucagon like peptide 1- receptor (GLP1R), differentiation, adipogenesis, glucose metabolism and cellular markers. Extracellular acidification rate was measured with glycolytic rate assay on Seahorse. Lipids accumulation was tested by AdipoRed staining. Results Stromal cells from both tissues express GLP1R but higher differentiation factor (PGC1α) was detected in SAT compared to EAT (p=0.02), as well as adipogenesis induction. After semaglutide treatment, we observed a downregulation of FABP4 and GLUT1 in EAT (p=0.01 and p=0.02, respectively). Despite FABP4 was not modulated on SAT, there was a reduction of PGC1α levels. (p=0.02). Since glitazones upregulate PGC1α, which is used for adipogenesis induction, these results might suggest the counteract mechanism of semaglutide. The metabolism assay showed that semaglutide reduces extracellular acidification rate in EAT cells (p=0.04) and oxidative glycolysis with semaglutide treatment (p=0.003) but not in SAT cells. Conclusions Semaglutide reduces adipogenesis, through modulation of PGC1α transcription factor in EAT from patients with cardiovascular disease and extracellular acidification and oxidative glycolysis. These results might help to understand one of the mechanisms associated with EAT reduction in patients with semaglutide treatment.

7004 Systems genetics analysis to identify candidate genes for fat distribution in BXD mice

Abstract Disclosure: N. Kim: None. D. Ryu: None. C. Oh: None. Obesity is defined as the accumulation of excess fat in the body. Although obesity is the main cause of metabolic disorders, not all obese people have metabolic disorders. Among many factors identified, the ratio of visceral (vWAT) to subcutaneous white adipose tissue (sWAT), representing body fat distribution, has been elucidated to be closely associated with metabolic health. Body fat distribution has been proposed as a possible explanation for this discrepancy. To investigate the regulation of body fat distribution, we performed a genetic analysis using the phenotype data and male subcutaneous fat microarray data from the BXD mouse genetic reference population. Our analysis identified H2-Ke6 (Hsd17b8), encoding hydroxysteroid 17-beta dehydrogenase, as a candidate target for adipose tissue plasticity. To further explore its role, we employed multiple approaches to reveal the effect of Hsd17b8 inhibition. First, lipid accumulation was attenuated in 3T3-L1 preadipocytes where Hsd17b8 was inhibited by CRISPER/Cas9 as well as lasalocid. Furthermore, we confirmed that the expression of adipogenesis-related transcription factor as well as mature adipocyte marker was decreased in terminally differentiated 3T3-L1. Specifically, CCAAT/enchancer binding protein α (Cebpa), peroxisome proliferator-activated receptor γ (Pparg), adiponectin (Adipoq), and fatty acid binding protein 4 (Fabp4) were transcriptionally downregulated. Consistently, in C. elegans, we used RNA interference (RNAi) to inhibit the expression of the Hsd17b8 ortholog, dhs-25, and observed a reduction in lipid accumulation. All these data suggest that the reduction in lipid accumulation in differentiated 3T3-L1 cells by the inhibition of Hsd17b8 is attributed to the suppression of early differentiation during the adipogenesis process. On top of that, to determine whether Hsd17b8 indeed influences body fat distribution in vitro, we utilized IngWAT Mouse Immortalized Preadipocyte Cell Line derived from subcutaneous white adipose tissue (sWAT) of a wild-type mouse. In contrast to the previous findings, we observed an increase in lipid accumulation of IngWAT when Hsd17b8 was inhibited. Surprisingly, the elevation of lipid accumulation in sWAT, as seen in gynoid obesity, has been revealed to be indicative of robust metabolic health compared to android obesity. Collectively, these data suggest that Hsd17b8 may represent a novel therapeutic target for the treatment of obesity. Our study provides valuable insights into the mechanisms underlying metabolic health in obesity and highlights the potential of Hsd17b8 as a therapeutic target for modulating adipose tissue plasticity. Presentation: 6/3/2024

Regenerated Fat Induced by a Decellularized Adipose Matrix Can Survive Long-term In Vivo

Decellularized adipose matrix (DAM) is considered to be the most potential biological scaffold for soft tissue repair and reconstruction, as it is able to induce the regeneration of adipose tissue in situ in adulthood. But how does this adipose tissue regeneration happen and develop in vivo? Is it the same as the original autologous one? Temporary existence or long-term survival? These are the key questions that will determine the future applications of DAM. In this study, we investigated the composition, structure and biomechanical properties of DAM before implanting it into the subcutaneous back of immunodeficient mice. The entire regeneration process in vivo was closely monitored histologically from 3 days to 1 year after implantation, including fat regeneration, vascular growth, inflammatory responses, and matrix degradation and remodeling. Transcriptome sequencing was used to analyze the difference in gene expression between regenerated fat and autologous fat at different periods. The results showed that the DAM-induced regenerated fat first appeared at 1w and remained stable over 6m, indicating remarkable similarity to autologous fat at the later stages of implantation. And about (18.3 ± 29.3) % of the regenerated adipocytes were still viable after one year. The process of adipogenesis was enhanced by the decrease in inflammatory infiltration and proceeded in parallel with angiogenesis. Statement of significance: The decellularized adipose matrix (DAM) is the only biological scaffold that can spontaneously generate adipocytes in vivo without the need to add exogenous cells. However, in the previous studies, the longest DAM-related animal experiments were about 3 months. The different stages and characteristics of DAM implantation cannot be fully captured. Comprehensive preclinical researches on the initiation, characteristics, and long-term outcomes of DAM-induced adipose tissue regeneration in adulthood is crucial.In this study, we closely observed various aspects of the entire process in vivo from 3 days to 1 year after implantation including fat regeneration, vascular growth, inflammatory reactions as well as matrix degradation and remodeling. The thorough research will contribute to the understanding of stability and dynamic remodeling of DAM regeneration models.

Addressing chemically-induced obesogenic metabolic disruption: selection of chemicals for in vitro human PPARα, PPARγ transactivation, and adipogenesis test methods.

Whilst western diet and sedentary lifestyles heavily contribute to the global obesity epidemic, it is likely that chemical exposure may also contribute. A substantial body of literature implicates a variety of suspected environmental chemicals in metabolic disruption and obesogenic mechanisms. Chemically induced obesogenic metabolic disruption is not yet considered in regulatory testing paradigms or regulations, but this is an internationally recognised human health regulatory development need. An early step in the development of relevant regulatory test methods is to derive appropriate minimum chemical selection lists for the target endpoint and its key mechanisms, such that the test method can be suitably optimised and validated. Independently collated and reviewed reference and proficiency chemicals relevant for the regulatory chemical universe that they are intended to serve, assist regulatory test method development and validation, particularly in relation to the OECD Test Guidelines Programme. To address obesogenic mechanisms and modes of action for chemical hazard assessment, key initiating mechanisms include molecular-level Peroxisome Proliferator-Activated Receptor (PPAR) α and γ agonism and the tissue/organ-level key event of perturbation of the adipogenesis process that may lead to excess white adipose tissue. Here we present a critical literature review, analysis and evaluation of chemicals suitable for the development, optimisation and validation of human PPARα and PPARγ agonism and human white adipose tissue adipogenesis test methods. The chemical lists have been derived with consideration of essential criteria needed for understanding the strengths and limitations of the test methods. With a weight of evidence approach, this has been combined with practical and applied aspects required for the integration and combination of relevant candidate test methods into test batteries, as part of an Integrated Approach to Testing and Assessment for metabolic disruption. The proposed proficiency and reference chemical list includes a long list of negatives and positives (20 chemicals for PPARα, 21 for PPARγ, and 11 for adipogenesis) from which a (pre-)validation proficiency chemicals list has been derived.

The Function and Mechanism of Long Noncoding RNAs in Adipogenic Differentiation.

Adipocytes are crucial for maintaining energy balance. Adipocyte differentiation involves distinct stages, including the orientation stage, clone amplification stage, clone amplification termination stage, and terminal differentiation stage. Understanding the regulatory mechanisms governing adipogenic differentiation is essential for comprehending the physiological processes and identifying potential biomarkers and therapeutic targets for metabolic diseases, ultimately improving glucose and fat metabolism. Adipogenic differentiation is influenced not only by key factors such as hormones, the peroxisome proliferator-activated receptor (PPAR) family, and the CCATT enhancer-binding protein (C/EBP) family but also by noncoding RNA, including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA). Among these, lncRNA has been identified as a significant regulator in adipogenic differentiation. Research has demonstrated various ways in which lncRNAs contribute to the molecular mechanisms of adipogenic differentiation. Throughout the adipogenesis process, lncRNAs modulate adipocyte differentiation and development by influencing relevant signaling pathways and transcription factors. This review provides a brief overview of the function and mechanism of lncRNAs in adipogenic differentiation.

Thymus in Cardiometabolic Impairments and Atherosclerosis: Not a Silent Player?

The thymus represents a primary organ of the immune system, harboring the generation and maturation of T lymphocytes. Starting from childhood, the thymus undergoes involution, being replaced with adipose tissue, and by an advanced age nearly all the thymus parenchyma is represented by adipocytes. This decline of thymic function is associated with compromised maturation and selection of T lymphocytes, which may directly impact the development of inflammation and induce various autoinflammatory disorders, including atherosclerosis. For a long time, thymus health in adults has been ignored. The process of adipogenesis in thymus and impact of thymic fat on cardiometabolism remains a mysterious process, with many issues being still unresolved. Meanwhile, thymus functional activity has a potential to be regulated, since islets of thymopoeisis remain in adults even at an advanced age. The present review describes the intricate process of thymic adipose involution, focusing on the issues of the thymus' role in the development of atherosclerosis and metabolic health, tightly interconnected with the state of vessels. We also review the recent information on the key molecular pathways and biologically active substances that may be targeted to manipulate both thymic function and atherosclerosis.

An alkaloid enriched fraction from Murraya koenigii (L.) Spreng. Leaves ameliorate HFD-induced obesity and metabolic complexities in C57BL/6J mice

Ethnopharmacological relevanceMurraya koenigii commonly known as curry leaf, is traditionally used in India to manage various ailments including diabetes mellitus. Curry leaves are well documented in Indian Ayurvedic system of medicine for beneficial effects in skin eruptions, dysentery, emesis, poisonous bites and bruises. The anti-hyperglycemic and anti-hyperlipidemic effects of curry leaf extracts have been demonstrated through several in vitro and in vivo experiments previously. Aim of the studyTo prepare an alkaloid enriched fraction (AEF) from M. koenigii and its evaluation on i) in vitro adipogenesis process and ii) in vivo high fat diet-induced obesity in C57BL/6J mice. Materials and methodsMKME and AEF were prepared from M. koenigii leaves. The four carbazole alkaloids (bioactive markers) isolated from AEF were quantitatively determined in the leaves by RP-HPLC method. MKME and AEF were studied for anti-obesogenic activity in adipocytes in vitro and in HFD-induced C57BL/6J obese mice in vivo. At the termination of the in vivo study, lipid profile, hepatic and renal injury and glucose levels were analyzed in the blood samples. Animal tissues were examined histopathologically to determine any signs of damage. Repeated dose oral toxicity study for 28 days on Sprague-Dawley rats was also performed to determine the safety profile of AEF. ResultsBoth MKME and AEF displayed anti-obesogenic activity at 25 μg/ml concentration in vitro and showed 54.06 ± 3.86% and 37.46 ± 3.17% lipid accumulation, respectively compared to control. Further, supplementation of AEF and MKME in HFD-fed C57BL/6J mice helped in controlling weight gain, improved dyslipidemia and glucose intolerance significantly. AEF showed better anti-obesity activity than MKME both in vitro and in vivo study. Repeated administration of AEF up to 1 g/kg dose for 28 days showed no pathological tissue damage. Both MKME and AEF were standardized using a simple and validated RP-HPLC method. ConclusionPresent study was aimed at preparation of a novel alkaloid-enriched fraction from methanolic extract of M. koenigii leaf and its evaluation for anti-diabesity effect. Our results demonstrated AEF to be a promising plant-based therapy for ameliorating obesity and related metabolic complications in HFD-fed C57BL/6J mice.

Research progress in regulation of hair growth by dermal adipose tissue

To summarize the dynamic and synchronized changes between the hair cycle and dermal adipose tissue as well as the impact of dermal adipose tissue on hair growth, and to provide a new research idea for the clinical treatment of hair loss. An extensive review of relevant literature both domestic and international was conducted, analyzing and summarizing the impact of dermal adipose precursor cells, mature dermal adipocytes, and the processes of adipogenesis in dermal adipose tissue on the transition of hair cycle phases. Dermal adipose tissue is anatomically adjacent to hair follicles and closely related to the changes in the hair cycle. The proliferation and differentiation of dermal adipose precursor cells promote the transition of hair cycle from telogen to anagen, while mature adipocytes can accelerate the transition from anagen to catagen of the hair cycle by expressing signaling molecules, with adipogenesis in dermal adipose tissue and hair cycle transition signaling coexistence. Dermal adipose tissue affects the transition of the hair cycle and regulates hair growth by secreting various signaling molecules. However, the quantity and depth of existing literature are far from sufficient to fully elucidate its prominent role in regulating the hair cycle, and the specific regulatory mechanisms needs to be further studied.

Antiadipogenic activity of homoeopathic preparation of Chelidonium Majus employing3T3-L1 cell line as a model.

Adipocytes are derived from mesenchymal stem cells through the process of adipogenesis. Adipocyte metabolism is abnormal in a range of disorders like obesity, nutritional insufficiency and diabetes. The 3T3-L1 preadipocytes are most often used to create adipocyte models, and they can be differentiated into adipocyte cells under the right conditions. Homeopathic preparation of Chelidonium majus (HPCM) in management of Obesity and T2DM has many evidences in clinical practice.3T3-L1 preadipocyte cells were differentiated into adipocytes by using differentiation cocktail. Cell were treated with HPCM attenuation at the concentration of 0.5%, 1% and 2% for 15 days. Oil O Red Staining was used to assess LD accumulation. In order to determine the lipid content in 3T3-L1 adipocytes, cells were dissolved in isopropanol and the absorbance values were measured. Images were captured and analysed using software imageJ.We investigated the action of Homeopathic preparations of Chelidonium majus (HPCM) in obesity using the 3T3-L1 adipogenesis model employing huMSC’s.After differentiation of adipocytes many LDs were formed in 3T3-L1 preadipocytes which can be compared with no lipid droplet in 3T3-L1nondifferentiated cells. Further, area of differentiated adipocytes was mapped and then compared for LD accumulation in control and HPCM for checking its antiadipogenic activity.A significant reduction in accumulation of lipid droplets was seen in 0.5%, 1% and 2% concentration of HPCM as compared to control during the differentiation of 3T3-L1 preadipocytes into adipocytes. Excessive differentiation of cells and high fat accumulation in the adipose tissue are closely linked to obesity. Preadipocyte differentiation inhibitors may have preventive and therapeutic potential as anti-obesity drugs. HPCM has potential to act as an antiadipogenic agent which can be used to combat various diseases like obesity, T2DM and cardiovascular diseases

Impaired Remodeling of White Adipose Tissue in Obesity and Aging: From Defective Adipogenesis to Adipose Organ Dysfunction.

The adipose organ adapts and responds to internal and environmental stimuli by remodeling both its cellular and extracellular components. Under conditions of energy surplus, the subcutaneous white adipose tissue (WAT) is capable of expanding through the enlargement of existing adipocytes (hypertrophy), followed by de novo adipogenesis (hyperplasia), which is impaired in hypertrophic obesity. However, an impaired hyperplastic response may result from various defects in adipogenesis, leading to different WAT features and metabolic consequences, as discussed here by reviewing the results of the studies in animal models with either overexpression or knockdown of the main molecular regulators of the two steps of the adipogenesis process. Moreover, impaired WAT remodeling with aging has been associated with various age-related conditions and reduced lifespan expectancy. Here, we delve into the latest advancements in comprehending the molecular and cellular processes underlying age-related changes in WAT function, their involvement in common aging pathologies, and their potential as therapeutic targets to influence both the health of elderly people and longevity. Overall, this review aims to encourage research on the mechanisms of WAT maladaptation common to conditions of both excessive and insufficient fat tissue. The goal is to devise adipocyte-targeted therapies that are effective against both obesity- and age-related disorders.

Potential probiotic Lactobacillus delbrueckii subsp. lactis KUMS-Y33 suppresses adipogenesis and promotes osteogenesis in human adipose-derived mesenchymal stem cell

Today, probiotics are considered to be living microorganisms whose consumption has a certain number of beneficial effects on the consumer. The present study aimed to investigate the effect of a new probiotic extract (Lactobacillus delbrueckii subsp. lactis KUMS Y33) on the differentiation process of human adipose-derived stem cells (hADSCs) into adipocytes and osteocytes and, as a result, clarify its role in the prevention and treatment of bone age disease. Several bacteria were isolated from traditional yogurt. They were evaluated to characterize the probiotic’s activity. Then, the isolated hADSCs were treated with the probiotic extract, and then osteogenesis and adipogenesis were induced. To evaluate the differentiation process, oil red O and alizarin red staining, a triglyceride content assay, an alkaline phosphatase (ALP) activity assay, as well as real-time PCR and western blot analysis of osteocyte- and adipocyte-specific genes, were performed. Ultimately, the new strain was sequenced and registered on NBCI. In the probiotic-treated group, the triglyceride content and the gene expression and protein levels of C/EBP-α and PPAR-γ2 (adipocyte-specific markers) were significantly decreased compared to the control group (P < 0.05), indicating an inhibited adipogenesis process. Furthermore, the probiotic extract caused a significant increase in the ALP activity, the expression levels of RUNX2 and osteocalcin, and the protein levels of collagen I and FGF-23 (osteocyte-specific markers) in comparison to the control group (P < 0.05), indicating an enhanced osteogenesis process. According to the results of the present study, the probiotic extract inhibits adipogenesis and significantly increases osteogenesis, suggesting a positive role in the prevention and treatment of osteoporosis and opening a new aspect for future in-vivo study.

Effect of metabolically divergent pig breeds and tissues on mesenchymal stem cell expression patterns during adipogenesis

BackgroundUnraveling the intricate and tightly regulated process of adipogenesis, involving coordinated activation of transcription factors and signaling pathways, is essential for addressing obesity and related metabolic disorders. The molecular pathways recruited by mesenchymal stem cells (MSCs) during adipogenesis are also dependent on the different sources of the cells and genetic backgrounds of donors, which contribute to the functional heterogeneity of the stem cells and consequently affect the developmental features and fate of the cells.MethodsIn this study, the alteration of transcripts during differentiation of synovial mesenchymal stem cells (SMSCs) derived from fibrous synovium (FS) and adipose synovial tissue (FP) of two pig breeds differing in growth performance (German Landrace (DL)) and fat deposition (Angeln Saddleback (AS)) was investigated. SMSCs from both tissues and breeds were stimulated to differentiate into adipocytes in vitro and sampled at four time points (day 1, day 4, day 7 and day 14) to obtain transcriptomic data.ResultsWe observed numerous signaling pathways related to the cell cycle, cell division, cell migration, or cell proliferation during early stages of adipogenesis. As the differentiation process progresses, cells begin to accumulate intracellular lipid droplets and changes in gene expression patterns in particular of adipocyte-specific markers occur. PI3K-Akt signaling and metabolic pathways changed most during adipogenesis, while p53 signaling and ferroptosis were affected late in adipogenesis. When comparing MSCs from FS and FP, only a limited number of differentially expressed genes (DEGs) and enriched signaling pathways were identified. Metabolic pathways, including fat, energy or amino acid metabolism, were highly enriched in the AS breed SMSCs compared to those of the DL breed, especially at day 7 of adipogenesis, suggesting retention of the characteristic metabolic features of their original source, demonstrating donor memory in culture. In contrast, the DL SMSCs were more enriched in immune signaling pathways.ConclusionsOur study has provided important insights into the dynamics of adipogenesis and revealed metabolic shifts in SMSCs associated with different cell sources and genetic backgrounds of donors. This emphasises the critical role of metabolic and genetic factors as important indications and criteria for donor stem cell selection.

Dysregulation of adipogenesis and disrupted lipid metabolism by the antidepressants citalopram and sertraline

Selective Serotonin Reuptake Inhibitors (SSRIs) are widely used medications for the treatment of major depressive disorder. However, long-term SSRI use has been associated with weight gain and altered lipid profiles. These findings suggest that SSRIs may have negative effects on metabolism. Exposure to certain chemicals called ‘obesogens’ is known to promote lipid accumulation and obesity by modulating adipogenesis. Here, we investigated whether citalopram (CIT) and sertraline (SER) interfere with the process of adipogenesis, using human mesenchymal stem cells (MSCs) in a 2D and a 3D model. Assessment of intracellular lipid accumulation by fluorescence staining was used as a measure for enhanced adipogenesis. To explore possible mechanisms behind SSRIs' effects, receptor mediated activity was studied using responsive cell lines for various nuclear receptors. Furthermore, RNA sequencing was performed in the 3D model, followed by differential gene expression and pathway analysis. A dose dependent increase in lipid accumulation was observed in both models with CIT and SER. For the 3D model, the effect was seen in a range close to reported steady-state plasma concentrations (0.065–0.65 μM for SER and 0.12–0.92 μM for CIT). Pathway analysis revealed unexpected results of downregulation in adipogenesis-related pathways and upregulation in phospholipids and lysosomal pathways. This was confirmed by an observed increase in lysosomes in the 2D model. Our findings suggest lysosomal dysfunction and disrupted lipid metabolism in mature adipocytes, leading to excessive phospholipid synthesis. Moreover, important adipogenic processes are inhibited, potentially leading to dysfunctional adipocytes, which might have implications in the maintenance of a healthy metabolic balance.

Effects of Chronic Sleep Restriction on Transcriptional Sirtuin 1 Signaling Regulation in Male Mice White Adipose Tissue.

Chronic sleep restriction (CSR) is a prevalent issue in modern society that is associated with several pathological states, ranging from neuropsychiatric to metabolic diseases. Despite its known impact on metabolism, the specific effects of CSR on the molecular mechanisms involved in maintaining metabolic homeostasis at the level of white adipose tissue (WAT) remain poorly understood. Therefore, this study aimed to investigate the influence of CSR on sirtuin 1 (SIRT1) and the peroxisome proliferator-activated receptor γ (PPARγ) signaling pathway in the WAT of young male mice. Both genes interact with specific targets involved in multiple metabolic processes, including adipocyte differentiation, browning, and lipid metabolism. The quantitative PCR (qPCR) results demonstrated a significant upregulation of SIRT-1 and some of its target genes associated with the transcriptional regulation of lipid homeostasis (i.e., PPARα, PPARγ, PGC-1α, and SREBF) and adipose tissue development (i.e., leptin, adiponectin) in CSR mice. On the contrary, DNA-binding transcription factors (i.e., CEBP-β and C-myc), which play a pivotal function during the adipogenesis process, were found to be down-regulated. Our results also suggest that the induction of SIRT1-dependent molecular pathways prevents weight gain. Overall, these findings offer new, valuable insights into the molecular adaptations of WAT to CSR, in order to support increased energy demand due to sleep loss.

Transcriptional profile of human thymus reveals IGFBP5 is correlated with age-related thymic involution.

Thymus is the main immune organ which is responsible for the production of self-tolerant and functional T cells, but it shrinks rapidly with age after birth. Although studies have researched thymus development and involution in mouse, the critical regulators that arise with age in human thymus remain unclear. We collected public human single-cell transcriptomic sequencing (scRNA-seq) datasets containing 350,678 cells from 36 samples, integrated them as a cell atlas of human thymus. Clinical samples were collected and experiments were performed for validation. We found early thymocyte-specific signaling and regulons which played roles in thymocyte migration, proliferation, apoptosis and differentiation. Nevertheless, signaling patterns including number, strength and path completely changed during aging, Transcription factors (FOXC1, MXI1, KLF9, NFIL3) and their target gene, IGFBP5, were resolved and up-regulated in aging thymus and involved in promoting epithelial-mesenchymal transition (EMT), responding to steroid and adipogenesis process of thymic epithelial cell (TECs). Furthermore, we validated that IGFBP5 protein increased at TECs and Hassall's corpuscle in both human and mouse aging thymus and knockdown of IGFBP5 significantly increased the expression of proliferation-related genes in thymocytes. Collectively, we systematically explored cell-cell communications and regulons of early thymocytes as well as age-related differences in human thymus by using both bioinformatic and experimental verification, indicating IGFBP5 as a functional marker of thymic involution and providing new insights into the mechanisms of thymus involution.

IGF2BP3-mediated enhanced stability of MYLK represses MSC adipogenesis and alleviates obesity and insulin resistance in HFD mice

Mesenchymal stem cells (MSCs) hold immense potential as multipotent stem cells and serve as a primary source of adipocytes. The process of MSC adipogenesis plays a crucial role in maintaining systemic metabolic homeostasis and has garnered significant attention in tissue bioengineering. N6-methyladenosine (m6A), the most prevalent RNA modification, is known to regulate cell fate and disease. However, the precise involvement of m6A readers in MSC adipogenesis remains unclear. In this study, we investigated the impact of IGF2BP3, a prominent m6A reader, on MSC adipogenesis. Our findings revealed a decrease in IGF2BP3 expression during the natural adipogenic differentiation of MSCs. Furthermore, IGF2BP3 was found to repress MSC adipogenesis by augmenting the levels of MYLK, a calcium/calmodulin-dependent kinase. Mechanistically, IGF2BP3 interacted with MYLK mRNA in an m6A-dependent manner, extending its half-life and subsequently inhibiting the phosphorylation of the ERK1/2 pathway, thereby impeding the adipogenic differentiation of MSCs. Additionally, we successfully achieved the overexpression of IGF2BP3 through intraperitoneal injection of adeno-associated virus serotype Rec2, which specifically targeted adipose tissue. This intervention resulted in reduced body weight and improved insulin resistance in high-fat diet mice. Overall, our study provides novel insights into the role of IGF2BP3 in MSC adipogenesis, shedding light on adipocyte-related disorders and presenting potential targets for related biomedical applications.

Presence of active AKT in the nucleus upon adipocyte differentiation of 3T3-L1 cells.

AKT is an essential player in the phosphoinositide 3-kinase (PI3K) signalling pathway. Although the mechanisms of its action are well understood at the plasma membrane, AKT can also be found in the nucleus. In adipocytes, this pathway is activated during the process of adipogenesis and solicits both plasma membrane and nuclear AKT activity. However, the endogenous presence of active AKT in the nucleus during adipogenesis has not been shown. Here, we show that the levels of active AKT phosphorylated at Ser-473 increase rapidly after the induction of differentiation in 3T3-L1 cells, both in the cytoplasm and in the nucleus, and tend to remain elevated over the course of differentiation. In conclusion, these results support the notion that nuclear AKT plays an important role in this process.

Anti-adipogenic effect of Malva parviflora on 3T3-L1 adipocytes.

Malva parviflora has shown anti-inflammatory, antihypertensive, antihyperlipidemic, and hypoglycemic effects. This study is aimed to evaluate the anti-adipogenic effect of M. parviflora on 3T3-L1 adipocytes. Fibroblast differentiation was induced either in the absence or presence of M. parviflora fractions (F3, F4, F7, F12, F13, F17, F18 and F19) for 4 days; F17 and 18 were the most effective fractions in reducing intracellular lipid accumulation (by 25.6% and 23.1%, respectively). EC50 of F17 and F18 (14 μg/mL and 17 μg/mL, respectively) were used to evaluate their anti adipogenic effect. After 10 days of inducing differentiation in the absence or presence of the extracts at the EC50 of F17 and F18, lipid accumulation, the concentration of interleukin 6 (IL-6) were measured in the culture medium; the presence of PPAR-γ, AKT, and p-AKT was also determined. In differentiated adipocytes (C2), F17 maintained intracellular lipid concentration at levels comparable to metformin, while decreasing PPAR-γ and increasing p-AKT presence; it also prevented IL-6 expression. F17 consists of alanine, valine, phenylalanine, and proline. On the other hand, F18 reduced intracellular lipid concentrations, prevented the increase of PPAR-γ and p-AKT, and maintained IL-6 expression at similar levels as metformin. F18 is mainly constituted by alanine, valine, proline, and sucrose. In conclusion, M. parviflora fractions (F17 and F18) control the process of adipogenesis, lipogenesis, and cellular dysfunction.

MicroRNAs as Epigenetic Regulators of Obesity.

In obesity, the process of adipogenesis largely determines the number of adipocytes in body fat depots. Adipogenesis is regulated by several adipocyte-selective micro-ribonucleic acids (miRNAs) and transcription factors that modulate adipocyte proliferation and differentiation. However, some miRNAs block the expression of master regulators of adipogenesis. Since the specific miRNAs display different expressions during adipogenesis, in mature adipocytes and permanent obesity, their use as biomarkers or therapeutic targets is feasible. Upregulated miRNAs in persistent obesity are downregulated during adipogenesis. Moreover, some of the downregulated miRNAs in obese individuals are upregulated in mature adipocytes. Induction of adipocyte stress and hypertrophy leads to the release of adipocyte-derived exosomes (AdEXs) that contain the cargo molecules, miRNAs. miRNAs are important messengers for intercellular communication involved in metabolic responses and have very specific signatures that direct the metabolic activity of target cells. While each miRNA targets multiple messenger RNAs (mRNAs), which may coordinate or antagonize each other's functions, several miRNAs are dysregulated in other tissues during obesity-related comorbidities. Deletion of the miRNA-processing enzyme DICER in pro-opiomelanocortin-expressing cells results in obesity, which is characterized by hyperphagia, increased adiposity, hyperleptinemia, defective glucose metabolism, and alterations in the pituitary-adrenal axis. In recent years, RNA-based therapeutical approaches have entered clinical trials as novel therapies against overweight and its complications. Development of lipid droplets, macrophage accumulation, macrophage polarization, tumor necrosis factor receptor-associated factor 6 activity, lipolysis, lipotoxicity, and insulin resistance are effectively controlled by miRNAs. Thereby, miRNAs as epigenetic regulators are used to determine the new gene transcripts and therapeutic targets.

A Review of Mechanism of Action of Moringa oleifera as an Inhibitor of Adipogenesis in Obesity

Background: Obesity has been becoming a global health problem that could cause the emergence of many other diseases. Several strategies are used to treat obesity, including lifestyle modifications, anti-obesity medications (pharmacotherapy), bariatric surgery, and gut microbiota transplantation. Pharmacotherapy is an effective treatment method and is often chosen by obese people because it is quite simple and does not require invasive and expensive procedures. However, long-term usage of conventional medicines causes serious side effects. Therefore, studies about herbal medicine increased significantly, one of them is Moringa oleifera (MO). Objectives: This review provides information about the pathways involved in the adipogenesis processes in obesity and how MO can inhibit adipogenesis through several pathways. Methods: Data were collected from PubMed based on the keywords “moringa”, “obese”, “adipogenesis”, “adipocyte”, and “lipogenesis”. There were 16 journals in full text that met the inclusion criteria for conducting a literature study related to these keywords over the last 10 years (from 2013 to 2023). Results: The anti-obesity effect of MO is thought to come from several specific compounds isolated from this plant, including quercetin, isoquercetin, quercetin-3-O-malonylglucoside, astragalin, kaempferol, isothiocyanate, EGCG, and many others. These active compounds can be isolated from various parts of the MO plant, but the most widely used are the leaves and seeds. These compounds exert anti-obesity activity by inhibiting adipogenesis through multiple pathways, including the AMPK, PI3K/AKT, MAPK, JAK/STAT, TGF-β, and Wnt/β-catenin pathways. Conclusions: Several in vivo, in vitro, and clinical trial studies have been conducted to demonstrate the benefits and safety of MO as a medicinal plant with pharmacological potential to inhibit adipogenesis in obesity.Keywords: moringa; adipogenesis; adipocyte; lipogenesis; obese