Pirfenidone ameliorates liver steatosis by targeting the STAT3-SCD1 axis.

OBJECTIVE: Previous studies reported that pirfenidone (PFD) is associated with liver disease. However, the effects of pirfenidone on energy metabolism and hepatic lipid accumulation are still poorly understood. METHODS: In this study, C57BL/6J mice were randomly divided into two groups, and fed a normal chow diet (NCD) or a high-fat diet (HFD) for 16 weeks. At the end of the eighth week, half of the mice fed on both diets were treated with PFD. Biochemical and lipid metabolism-related indices were analyzed. Furthermore, Hepa 1-6 cells and mouse primary hepatocytes (MPHs) were incubated with PFD with or without free fatty acid (FFA) treatment. Then, stattic (a p-STAT3 inhibitor) or Ad-shSTAT3 was used to further elucidate the effects of Signal Transducer and Activator of Transcription 3 (STAT3) signaling on PFD regulation of hepatic steatosis. RESULTS: PFD ameliorated obesity and hepatic lipid deposition in HFD mice by decreasing stearoyl-CoA desaturase 1 (SCD1) expression and upregulating p-STAT3 in the liver. In Hepa 1-6 cells and MPHs, PFD also down-regulated the expression of SCD1. STAT3 inhibition treatment eliminated the benefits of PFD on both SCD1 and hepatic steatosis. CONCLUSION: In summary, our data reveal that PFD may play an important role in mitigating hepatic steatosis in a STAT3-SCD1-dependent manner.

Decreased Circulating MANF in Women with PCOS is Elevated by Metformin Therapy and is Inversely Correlated with Insulin Resistance and Hyperandrogenism.

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a novel neurotrophic factor. Although recent studies have suggested that MANF appeared to be associated with insulin resistance, the results have been inconsistent. The aim of our study was to determine the serum MANF levels in women with PCOS and controls, to investigate their relationship to insulin resistance, and to evaluate circulating MANF changes with metformin intervention in PCOS women. We conducted a series of cross-sectional and interventional studies in 90 newly diagnosed patients with PCOS and 60 age- and gender-matched controls. Oral glucose tolerance test and euglycemic-hyperinsulinemic clamps were performed to assess the glucose tolerance and insulin sensitivity. Forty-three women with PCOS were randomly assigned to six months of oral metformin therapy. Serum MANF levels were significantly lower in women with PCOS than in controls. Serum MANF levels were positively correlated with M-value and negatively correlated with body mass index (BMI), body fat percentage (FAT), homeostatic model assessment of insulin resistance (HOMA-IR), and free androgen index (FAI). Multivariate stepwise regression demonstrated that serum MANF levels were independently associated with M-value and FAI. After six months of metformin treatment, there was a significant increase in serum MANF levels in PCOS women. Serum MANF levels are decreased in women with PCOS, and are reversely related to insulin resistance and hyperandrogenism. Metformin treatment elevates serum MANF levels and alleviates insulin resistance and hyperandrogenism in PCOS women.

Causal Relationship Between Sleep Traits and Hypothalamic-Pituitary-Target Gland Axis Function: A Mendelian Randomization Study.

Background: In recent years, multiple observational studies have confirmed the association between sleep traits and various human physiopathological states. However, the causal relationship between sleep traits and hypothalamic-pituitary-target gland axis (HPTGA) function remains unknown. Methods: We obtained summary statistics on sleep traits (insomnia, chronotype, and sleep duration (long and short)) from the UK Biobank database. Data related to the HPTGA functions were obtained from the publicly available database. Subsequently, a two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationship between different sleep traits and the HPTGA function. Reverse MR analysis was conducted to examine the direction of causality. Results: The MR analysis results suggested that chronotype is associated with decreased levels of six hormones in HPTGA. Sleep duration was causally associated with decreased levels of free thyroxine and progesterone. Both long and short sleep durations are detrimental to the secretion of prolactin-releasing peptide, somatostatin, and plasma cortisol, while short sleep duration can promote progesterone secretion. After gender stratification, we found that female reproductive function is more susceptible to the influence of unfavorable sleep traits. Conclusion: Our MR analysis indicated a significant causal association between chronotype and suppressed gonadal function in healthy adult humans, with no apparent gender-specific effect. Extreme sleep durations were also found to be detrimental to the maintenance of normal HPTGA secretion function. Compared to males, gonadal function in the female cohort is more susceptible to extreme sleep habits. Subsequent observational studies are urgently needed to confirm the underlying mechanisms.

Effect of Umbilical Cord Mesenchymal Stem Cell Transplantation Under LIFPUS Pretreatment on Thyroid Function in EAT Rats.

BACKGROUND: A growing number of studies have demonstrated that mesenchymal stem cells (MSCs) can effectively regulate the progression of multiple autoimmune diseases and can respond positively to mechanical stimulation by ultrasound in an in vitro setting to improve transplantation efficacy. OBJECTIVE: The aim of this study was to activate hUC-MSCs by pretreatment with low-intensity focused pulsed ultrasound (LIFPUS) in an in vitro environment and transplant them into a rat model of EAT via tail vein. To investigate the efficacy and potential mechanism of action of hUC-MSCs in the treatment of EAT. METHODS: In this study, 40 female lewis rats were divided into control, EAT, hUC-MSCs treatment and LIFPUS pretreatment transplantation group. EAT models were established by subcutaneous multi-point injection of PTG+Freund's adjuvant, and the primary hUC-MSCs were treated with different gradients of LIFPUS irradiation or sham irradiation in an in vitro environment and screened by Western Blot (WB), flow cytology cycle analysis, and cellular immunofluorescence to find the optimal treatment parameters for LIFPUS to promote cell proliferation. After tail vein injection of different pretreatment groups of hUC-MSCs, Homing sites of hUC-MSCs in vivo, circulating autoantibody expression levels and local thyroid histopathological changes were assessed by enzyme-linked immunosorbent assay (ELISA), spleen index, tissue hematoxylin-eosin (HE) staining and immunohistochemistry. The expression levels of apoptotic proteins Bcl-2, Bax and endoplasmic reticulum stress-related proteins Chop and EIF2α in thyroid tissue were also examined by WB. RESULTS: LIFPUS can effectively stimulate hUC-MSCs in vitro to achieve the most optimal proliferative and secretory activity. In the EAT model, hUC-MSCs can effectively reduce thyroid cell apoptosis, improve thyroid function and reduce excessive accumulation of autoimmune antibodies in the body. in comparison, the LIFPUS pretreatment group showed a more favorable treatment outcome. Further experiments demonstrated that hUC-MSCs transplantation may effectively inhibit the apoptotic state of thyroid follicles and follicular epithelial cells by down-regulating the unfolded protein reaction (UPR) of the PERK pathway, thus providing a therapeutic effect for AIT. CONCLUSION: hUC-MSCs can effectively reverse the physiological function of EAT thyroid tissue and reduce the accumulation of circulating antibodies in the body. in comparison, hUC-MSCs under LIFPUS pretreatment showed more desirable therapeutic potential. hUC-MSCs transplanted under LIFPUS pretreatment may be a new class of safe therapeutic modality for the treatment of AIT.

TXNIP Exacerbates the Senescence and Aging-Related Dysfunction of ß Cells by Inducing Cell Cycle Arrest Through p38-p16/p21-CDK-Rb Pathway.

Aims: Thioredoxin-interacting protein (TXNIP) is a crucial molecular promoter of oxidative stress and has been identified to be associated with cellular senescence. It is an important mediator of ß cell insulin secretion and has effects on ß cell mass. However, its role in ß cell senescence is unclear. The present study was designed to investigate the effects and mechanisms of TXNIP on the senescence and aging- and diet-related dysfunction of ß cells. Methods: Human pancreatic paraffin tissues and serum samples from different ages were collected to detect TXNIP expression. TXNIP-/- and C57BL/6J mice were fed either a normal chow diet (NCD) or a high-fat diet (HFD) until 5, 11, 14, or 20 months. The recapitulation experiment was conducted with TXNIP protein injection. MIN6 cells were transfected with LV-TXNIP and LV-siTXNIP. The biochemical indexes, ageing-related markers, cell cycle proteins, and pathways were examined both in vivo and in vitro. Results: TXNIP expression showed an age-related increase in ß cells and serum samples from humans. TXNIP significantly impaired glucose metabolism and insulin secretion in an age-dependent manner. TXNIP aggravated age-related and obesity-induced structural failure, oxidative stress, decreased proliferation, increased apoptosis in ß cells, and induced the cell cycle arrest. TXNIP interacted with p38 mitogen-activated protein kinase (p38MAPK) and modulated the p16/p21-CDK-Rb axis to accelerate ß cell senescence. Innovation and Conclusions: The present study demonstrated that TXNIP may exacerbate pancreatic ß cell senescence and age-related dysfunction by inducing cell cycle arrest through the p38-p16/p21-CDK-Rb pathway, in natural and pathological states. Antioxid. Redox Signal. 38, 480-495.

Role and mechanism of TXNIP in ageing-related renal fibrosis.

Kidney ageing, which is always accompanied by renal fibrosis, drives the progression of renal fibrosis. Thioredoxin-interacting protein (TXNIP) is an endogenous suppressor of the reactive oxygen species-scavenging protein thioredoxin, which has been implicated in the ageing of some organs and is involved in renal fibrosis. However, the expression of TXNIP in ageing kidneys has not been examined, and the relationship between TXNIP and ageing-related renal fibrosis is unclear. We found that TXNIP expression was upregulated in aged mouse kidneys, and this upregulation was accompanied by ageing-related renal fibrosis phenotypes. We demonstrated that the ageing biomarkers were downregulated in TXNIP-knockout mice, and these effects resulted in the alleviation of renal fibrosis and impairments in kidney function. TXNIP overexpression in tubular cells upregulated senescence markers, promoted a profibrotic response and activated STAT3 signalling, and these parameters were inhibited by the silencing of TXNIP. Similarly, the TXNIP-mediated profibrotic response was significantly suppressed by a STAT3 inhibitor. By coimmunoprecipitation, we verified that TXNIP directly bound to STAT3, which suggested that TXNIP exacerbates renal tubular epithelial fibrosis by activating the STAT3 pathway. In summary, TXNIP plays an important role in age-related renal fibrosis and might be a therapeutic target for preventing ageing-associated renal fibrosis.

Thioredoxin-interacting protein: a critical link between autophagy disorders and pancreatic ß-cell dysfunction.

Thioredoxin-interacting protein (TXNIP) is a known important regulatory protein of islet ß-cell biology and function, but the detailed mechanism is not clear. Autophagy plays a pivotal role in maintaining cellular homoeostasis. This study aimed to elucidate the influence of TXNIP on the autophagy of ß-cell. In this study, C57BL/6 mice and TXNIP-/- mice were fed with a standard diet (SD) or a high-fat and high-sugar diet (HFSD), and then we analysed biochemical and autophagy related indexes in the mice. We infected MIN6 cells with LV-TXNIP and siRNA TXNIP, then the cells were treated with free fatty acid (FFA), autophagic activator rapamycin (RAP), inhibitors of autophagy chloroquine (CQ) and bafilomycin A1(BAF), finally, we examined the changes of autophagy in MIN6 cells. The results showed that HFSD led to ß-cell dysfunction and autophagy dysregulation, which was improved by TXNIP knockout in mice. In vitro experiments, TXNIP gene silencing enhanced LC3B-I conversion to LC3B-II, reduced the protein level of P62, decreased autophagosome accumulation induced by FFA treatment, increased the glucose-stimulated insulin secretion (GSIS) and autophagic flux inhibited by treatment with CQ. TXNIP overexpression induced upregulation of LC3B-I, LC3B-II and P62, accentuating the increase in autophagy and organelle destruction induced by FFA, and exacerbated the effect of BAF on the accumulation of autophagy proteins. Increasing TXNIP levels reduced GSIS, which was reversed by treatment with RAP. In summary, our study suggested that TXNIP is a critical link between autophagy disorders and pancreatic ß-cell dysfunction.

[Over-expression of thioredoxin-interacting protein promotes apoptosis of MIN6 cells via activating p38MAPK pathway].

Objective To investigate the effect of thioredoxin interacting protein (TXNIP) over-expression on the apoptosis of MIN6 ß-cells and the mechanism involved. Methods Lentivirus carrying TXNIP gene was used to infect MIN6 ß-cells in logarithmic growth phase, and the infection efficiency was evaluated by fluorescence microscope and Western blotting. Then MIN6 ß-cells were divided into three groups: control group, empty lentivirus vector (LV-GFP) group and TXNIP over-expression (LV-GFP-TXNIP) group. CCK-8 assay was used to detect cell proliferation. AnnexinV-FITC/PI double staining was utilized to measure the apoptosis of MIN6 cells. Western blotting was applied to detect the expressions of TXNIP protein, TRX, Bax, Bcl2, cleaved caspase-3 (c-caspase-3), p38 mitogen-activated protein kinase (p38MAPK), phospho-p38MAPK (p-p38MAPK) proteins in the MIN6 ß-cells before and after treated with p38MAPK inhibitor SP169316. Results At 72 hours after the infection, the infection rate reached (87.10±2.30)% and (92.21±0.54)% in LV-GFP group and LV-GFP-TXNIP group, respectively, suggesting that lentivirus-mediated TXNIP over-expression was desirable. Compared with control group and LV-GFP group, the cell viability markedly decreased, and cell apoptosis, Bax/Bcl2 ratio, expression of c-caspased-3 and p38MAPK phosphorylation significantly increased in LV-GFP-TXNIP group. However, both the Bax/Bcl2 ratio and c-caspase-3 protein expression in LV-GFP-TXNIP group were obviously reduced after treated with p38MAPK inhibitor. Conclusion TXNIP over-expression might promote the apoptosis of MIN6 cells via activating the p38 MAPK pathway.