Single-cell sequencing reveals the antifibrotic effects of YAP/TAZ in systemic sclerosis.

Systemic sclerosis (SSc) is a heterogeneous disease with skin fibrosis. Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) is associated with fibrotic response. This work attempted to determine the precise mechanism of YAP/TAZ in SSc. Single-cell sequencing (scRNA-seq) was used to analyse the differential gene expression between SSc patients and healthy volunteers, showing that the YAP/TAZ signalling pathway was enriched in the fibroblasts of SSc patients. Subsequently, enzyme-linked immunosorbent assay and immunohistochemical analyses were conducted to examine the levels of YAP and TAZ in mild and severe SSc patients. YAP and TAZ were highly expressed in the serum and skin tissues of mild and severe SSc patients, especially severe SSc patients. Additionally, an SSc mouse model was induced by bleomycin, and the impacts of YAP/TAZ knockdown on the pathological changes in skin and lung tissues were detected by haematoxylin and eosin staining and Masson staining. Knockdown of YAP and TAZ inhibited α-SMA mRNA and protein expression in skin and lung tissues of SSc mice. Inhibition of YAP and TAZ reduced skin inflammation and thickness and repressed lung inflammation and fibrosis in SSc mice. Importantly, knockdown of YAP and TAZ synergistically inhibited inflammation and fibrosis in skin and lung tissues in SSc mice. In conclusion, this work demonstrated that knockdown of YAP and TAZ exerted a synergistic effect on alleviating SSc in mice. Thus, this work suggests that YAP/TAZ is a potential target for SSc treatment.

Cucurbitacin IIb improved active chromatin-induced systemic lupus erythematosus via balancing the percentage of Th17 and Treg cells.

The pathogenesis of systemic lupus erythematosus (SLE) is closely associated with aberrant immune system. Here, the aim of our study was to explore the regulation of cucurbitacin IIb (CuIIb) to Th17/Treg cells in SLE. Compared with normal mice, the percentage of Treg cells was downregulated in SLE mouse model, and Th17 was upregulated. Meantime, the production of Treg-related transcription factor (foxp3) in SLE model mouse was reduced, and the production of Th17-related transcription factor (RORγt) was increased. After treatment with CuIIb, the percentage of Treg cells in SLE mice was partly upregulated, and Th17 cells percentage was downregulated. The expression of foxp3 and RORγt in SLE mice were promoted and inhibited by CuIIb treatment, respectively. SLE-induced kidney injury also was improved by CuIIb treatment. In vitro, we demonstrated again that CuIIb upregulated the percentage of Treg cells in lymphocytes from SLE mice, and downregulated the percentage of Th17 cells. Highly expressed IL-6 and IL17, and lowly expressed IL-10 and TGF-ß in lymphocytes from SLE mice were repressed and facilitated by CuIIb treatment, respectively. Overall, our data proved that CuIIb improved kidney injury in SLE mice through balancing the percentage of Th17 and Treg cells. Our data provided a reliable evidence to support the potential of CuIIb in SLE treatment.

Adiponectin exerts a potent anti-arthritic effect and insulin resistance in collagen-induced arthritic rats.

AIM: Previous research has shown that adiponectin (AD) induces severe insulin resistance (IR) and exhibits pro-inflammatory effect, so it could serve as a useful risk biomarker in rheumatoid arthritis (RA). The present study aims to evaluate the effect of AD on IR and anti-arthritis in collagen-induced arthritic (CIA) rats. METHOD: After immunization with bovine type II collagen (CII), Wistar rats were administered with AD (60 µg/kg/day) or saline into the ankle joint cavity of the left hind leg for 15 days. The severity of arthritis was clinically and histologically assessed. Arthritis score was recorded every other day for each paw. Paw volume was measured on alternate days to monitor the progression of the disease in the arthritic control group. Tumor necrosis factor (TNF)-α, interleukin (IL)-1, AD, insulin and fasting glucose were measured in sera. Histopathology of joint synovial tissues was also examined. RESULTS: Treatment with AD resulted in significantly delayed onset of arthritis as well as decreased clinical arthritis and histopathological severity scores. AD reduced both serum fasting glucose, TNF-α, IL-1 and IR. Histological analysis confirmed treatment with AD suppressed joint synovial inflammation and immunohistochemical expression of TNF-α compared to the CIA group. Surprisingly, adiponectin levels measured by enzyme-linked immunosorbent assay in serum were significantly increased in CIA rats compared to the normal group. CONCLUSIONS: Adiponectin might display anti-inflammatory effects. These results suggest that AD may be a potential immunosuppressant for the treatment of RA linked to metabolic disease.

Investigation of PI3K/PKB/mTOR/S6K1 signaling pathway in relationship of type 2 diabetes and Alzheimer's disease.

The aim of this study was to investigate the roles of PI3K/PKB/mTOR/S6K1 signaling pathway in the risk-increasing mechanisms of type 2 diabetes mellitus (T2DM) towards the Alzheimer's disease (AD). Based on the high-sugar high-fat diet, the single intraperitoneal injection of streptozotocin was performed to induce the T2DM rat model; the immunohistochemistry and RT-PCR technique were then performed to detect the expression levels of mTOR, PI3K, PKB, S6K1 and phosphorylated Tau protein in the hippocampal tissues of each group. The related metabolic indicators of the T2DM group and the T2DM + AD group were significantly higher than the normal control group and the AD group (P<0.01); the Morris water maze test of the AD group and the learning and memory of the T2DM + AD group were than significantly decreased than the T2DM group (P<0.01); the T2DM + AD group exhibited significantly increased expression levels of mTOR, S6K1 and Tau protein in the hippocampal tissues than the AD group and the T2DM group (P<0.05), and while the expression levels of PI3K and PKB were decreased (P<0.05). Among the possible mechanisms through which T2DM increased the risk of AD, the dystransduction of insulin signaling pathway (PI3K/PKB/mTOR/S6K1) was the important cause of hyperphosphorylation of Tau protein, thus it prompted the AD occurrence.

mTOR and tau phosphorylated proteins in the hippocampal tissue of rats with type 2 diabetes and Alzheimer's disease.

This study explored the effects of mammalian target of rapamycin (mTOR) on the increased risk of developing Alzheimer's disease (AD) in rats with type 2 diabetes mellitus (T2DM). Male Sprague-Dawley rats were randomly divided into four groups: control, T2DM, AD and T2DM+AD. Changes in the learning and memory abilities of the rats were observed using the Morris water maze. mTOR activity and tau protein hyperphosphorylation in the hippocampus were analyzed by immunohistochemical staining and RT-PCR. The learning and memory abilities of the experimental rats were weakened compared with those of the control group. The T2DM+AD group revealed significant changes over the T2DM and AD groups. Compared with the control, T2DM and AD groups, the mTOR protein and mRNA levels, hyperphosphorylation of tau protein and total tau protein mRNA levels were significantly increased in the T2DM+AD group. T2DM may excessively activate mTOR in the hippocampal tissue by impairing insulin signaling, thereby increasing the extent of tau hyperphosphorylation and promoting the occurrence of AD.