Characterization and Treatment of Inflammation and Insulin Resistance in Obese Adipose Tissue

Tissue-Level Effect of Andrographis and Ashwagandha Metabolites on Metabolic and Inflammatory Gene Expression in Skeletal Muscle and Adipose Tissue: An Ex Vivo/In Vitro Investigation

Adipose tissue and skeletal muscle dysfunction play a central role in cardiometabolic morbidity. Ashwagandha and Andrographis are purported to have anti-inflammatory and antioxidant activity, but this is based on exposure of cells to the parent compounds ignoring phytochemical absorption and metabolism. We explored the anti-inflammatory/antioxidant effects of ashwagandha and Andrographis in ex vivo human models of skeletal muscle and adipose tissue. Healthy participants supplemented with 2000 mg/day Andrographis (n = 10) or 1100 mg/day ashwagandha (n = 10) for 28 days. Sera collected pre (D0) and post (D28) supplementation were pooled by timepoint and added to adipose explant (AT) and primary human myotube (SKMC) culture media (15% v/v) for treatment. A Taqman panel of 56 genes was used to quantify these. In AT, treatment with ashwagandha sera decreased the expression of genes involved in antioxidant defence and inflammatory response (CCL5, CD36, IL6, IL10, ADIPOQ, NFEL2, UCP2, GPX3, GPX4; geometric 95% CI for fold change > 1) and altered the expression of genes involved in fatty acid metabolism. In SKMC, ashwagandha sera altered FOXO1 and SREBF1 expression. Andrographis sera decreased IL18 and SERPINEA3 expression in AT. This physiologically relevant in vitro screening characterises the effects of ashwagandha in AT to guide future clinical trials.

Patrinoside and Patrinoside A from Patrinia scabiosaefolia Improve Insulin Resistance by Inhibiting NF-κB, MAPK Pathways and Oxidative Stress in RAW264.7 and 3 T3-L1 Cells

Patrinia scabiosaefolia, as traditional food and medicine plant, was used to treat appendicitis, enteritis, and hepatitis for thousand years in China. Patrinoside and patrinoside A isolated from P. scabiosaefolia could significantly improve insulin resistance (IR) by activating PI-3 K/AKT signaling pathway in our previous study. Since IR is closely related to inflammation, their anti-inflammatory activities in RAW264.7 inflammatory model induced by LPS and in 3 T3-L1 IR inflammatory model induced by TNF-α were evaluated to identify whether the effects on improving IR related to anti-inflammatory activity. In RAW264.7 cells, patrinoside and patrinoside A significantly inhibited the transcription and secretion of inflammatory mediators NO, TNF-α, and IL-6. Western blot analysis showed that the significant inhibition of phosphorylation of IκB and P65 and P38, ERK and JNK suggested that the effects were exerted through NF-κB pathway and MAPK pathway. In 3 T3-L1 cells, patrinoside and patrinoside A also inhibited the activation of NF-κB and MAPK pathways through inhibiting the transcriptions of inflammatory cytokines IL-6 and chemokines MCP-1 and MIP-1α. These events resulted in the inhibition of macrophages migration to adipocytes. In addition, patrinoside and patrinoside A ameliorated oxidative stress by inhibiting ROS release in LPS-stimulated RAW264.7 cells. In conclusion, patrinoside and patrinoside A could active PI-3 K/AKT pathway, inhibit NF-κB pathway, MAPK pathway, and improve oxidative stress, which showed multipathways on improving IR. These results provided the scientific basis for material basis and mechanism on improving IR of P. scabiosaefolia.

Delivery of miRNAs to the adipose organ for metabolic health

Despite the increasing prevalence of obesity and diabetes, there is no efficient treatment to combat these epidemics. The adipose organ is the main site for energy storage and plays a pivotal role in whole body lipid metabolism and energy homeostasis, including remodeling and dysfunction of adipocytes and adipose tissues in obesity and diabetes. Thus, restoring and balancing metabolic functions in the adipose organ is in demand. MiRNAs represent a novel class of drugs and drug targets, as they are heavily involved in the regulation of many cellular and metabolic processes and diseases, likewise in adipocytes. In this review, we summarize key regulatory activities of miRNAs in the adipose organ, discuss various miRNA replacement and inhibition strategies, promising delivery systems for miRNAs and reflect the future of novel miRNA-based therapeutics to target adipose tissues with the ultimate goal to combat metabolic disorders.

Ubiquitinated gasdermin D mediates arsenic-induced pyroptosis and hepatic insulin resistance in rat liver

As an environmental toxicant, arsenic exposure may cause insulin resistance (IR). Previous studies have shown that pyroptosis plays an important role in the occurrence and development of IR. Although gasdermin D (GSDMD) functions as an executor of pyroptosis, the relationship between GSDMD-mediated pyroptosis and hepatic IR remains unclear. Here, we observed that sodium arsenite (NaAsO₂) activated NOD-like receptors containing pyrin domain 3 (NLRP3) inflammasomes, promoted GSDMD activation, induced pyroptosis and hepatic IR, while GSDMD knockdown attenuated pyroptosis and hepatic IR caused by NaAsO₂. However, GSDMD interference did not affect NLRP3 activation. Ubiquitination modification is widely involved in protein regulation and intracellular signal transduction, and whether it regulates GSDMD and affects its degradation, and exerts effects on arsenic-induced pyroptosis remain unclear. We observed that NaAsO₂ reduced the K48- and K63-linked ubiquitination of GSDMD, thereby inhibiting its degradation through the ubiquitin-proteasome system (UPS) and the autophagy-lysosome pathway (ALP), causing GSDMD to accumulate and lyse into GSDMD-N, which promoted pyroptosis. In summary, we demonstrated that GSDMD participated in arsenic-induced hepatic IR. Moreover, NaAsO₂ reduced GSDMD ubiquitination and decreased its intracellular degradation, aggravating pyroptosis and hepatic IR. We have revealed the molecular mechanism underpinning arsenic-induced IR, and we provide potential solutions for the prevention and treatment of type 2 diabetes (T2D).

Insulin resistance and potential modulators of ovarian reserve in young reproductive-aged women with obesity and type 1 diabetes

INTRODUCTION

Both obesity and diabetes play a significant role in reproductive disorders in women and insulin resistance (IR) is a confirmed trait d'union. We evaluated the relationship between IR and an established ovarian reserve biomarker such as anti-mullerian hormone (AMH) together with other potential modulators of ovarian physiology (adiponectin and kisspeptin) in young reproductive-aged group women with obesity and type 1 diabetes (T1D).

PATIENTS AND METHODS

We recruited 32 female youths: 14 of them presented with T1D (14.6 ± 2.6 years) and 18 with obesity (15.1 ± 2.6 years). The control group included 20 age-matched normal weight females. Each patient underwent physical examination and hormonal assessment. AMH, kisspeptin and adiponectin levels were also measured. IR was calculated as the homeostasis model assessment for insulin resistance (HOMA-IR) and the glucose disposal rate (eGDR) in patients with obesity and with T1D, respectively.

RESULTS

adiponectin and kisspeptin levels were significantly different into groups (p ≤ .001), whereas AMH levels were not. Adiponectin values were higher in controls compared to patients with obesity (p < .001) and T1D (p = .02). Kisspeptin levels were lower in controls compared to patients with obesity (p = .001), without reaching statistical significance when compared to T1D (p = .06). IR was associated with lower adiponectin and higher kisspeptin levels (p < .001 and p = .02, respectively), but not with AMH.

CONCLUSIONS

IR displays a relationship with adiponectin and kisspeptin in young reproductive-aged women with obesity and T1D. Interventions to correct IR in adolescents could be part of an early approach to prevent reproductive disorders and to promote factors associated with longevity in adult women.

Crtc1 Deficiency Causes Obesity Potentially via Regulating PPARγ Pathway in White Adipose

Obesity is characterized by excessive fat accumulation and associated with glucose and lipid metabolism disorders. Crtc1, a transcription cofactor regulating CREB activity, has been involved in the pathogenesis of metabolic syndrome; however, the underlying mechanism remains under debate. Here we generated a Crtc1^-/- mouse line using the CRISPR/Cas9 system. Under normal feeding conditions, Crtc1^-/- mice exhibited an obese phenotype resultant from the abnormal expansion of the white adipocytes. The development of obesity in Crtc1^-/- mice is independent of alterations in food intake or energy expenditure. Moreover, Crtc1^-/- mice were more prone to insulin resistance and dyslipidemia, as evidenced by higher levels of plasma glucose, insulin and FABP4 than wildtype mice. Transcriptome analysis in liver and epididymal white adipose tissue (eWAT) showed that the fat accumulation caused by Crtc1 deletion was mainly related to lipid metabolism in adipose tissue, but not in liver. GSEA and KEGG analysis identified PPAR pathway to be of the highest impact on lipid metabolism in eWAT. This regulation was independent of a direct interaction between CRTC1 and PPARγ. Our findings demonstrate a crucial role of Crtc1 in regulating lipid metabolism in adipose during development, and provide novel insights into obesity prevention and therapeutics.