The present study was designed to test the hypothesis that cADP-ribose (cADPR) increases Ca(2+) release through activation of ryanodine receptors (RYR) on the sarcoplasmic reticulum (SR) in coronary arterial smooth muscle cells (CASMCs). We reconstituted RYR from the SR of CASMCs into planar lipid bilayers and examined the effect of cADPR on the activity of these Ca(2+) release channels. In a symmetrical cesium methanesulfonate configuration, a 245 pS Cs(+) current was recorded. This current was characterized by the formation of a subconductance and increase in the open probability (NP(o)) of the channels in the presence of ryanodine (0.01-1 microM) and imperatoxin A (100 nM). A high concentration of ryanodine (50 microM) and ruthenium red (40-80 microM) substantially inhibited the activity of RYR/Ca(2+) release channels. Caffeine (0.5-5 mM) markedly increased the NP(o) of these Ca(2+) release channels of the SR, but D-myo-inositol 1,4,5-trisphospate and heparin were without effect. Cyclic ADPR significantly increased the NP(o) of these Ca(2+) release channels of SR in a concentration-dependent manner. Addition of cADPR (0.01 microM) into the cis bath solution produced a 2.9-fold increase in the NP(o) of these RYR/Ca(2+) release channels. An eightfold increase in the NP(o) of the RYR/Ca(2+) release channels (0.0056 +/- 0.001 vs. 0.048 +/- 0.017) was observed at a concentration of cADPR of 1 microM. The effect of cADPR was completely abolished by ryanodine (50 microM). In the presence of cADPR, Ca(2+)-induced activation of these channels was markedly enhanced. These results provide evidence that cADPR activates RYR/Ca(2+) release channels on the SR of CASMCs. It is concluded that cADPR stimulates Ca(2+) release through the activation of RYRs on the SR of these smooth mucle cells.

The endocannabinoid system (CS) has been implicated in the development of hepatic fibrosis such as schistosomiasis-associated liver fibrosis (SSLF). However, the mechanisms mediating the action of the CS in hepatic fibrosis are unclear. The present study hypothesized that Schistosoma J. infection upregulates cannabinoid receptor 1 (CB1) due to activation of NADPH oxidase leading to a fibrotic phenotype in hepatic stellate cells (HSCs). The SSLF model was developed by infecting mice with Schistosoma J. cercariae in the skin, and HSCs from control and infected mice were then isolated, cultured, and confirmed by analysis of HSC markers α-SMA and desmin. CB1 significantly increased in HSCs isolated from mice with SSLF, which was accompanied by a greater expression of fibrotic markers α-SMA, collagen I, and TIMP-1. CB1 upregulation and enhanced fibrotic changes were also observed in normal HSCs treated with soluble egg antigen (SEA) from Schistosoma J. Electron spin resonance (ESR) analysis further demonstrated that superoxide (O2(-)) production was increased in infected HSCs or normal HSCs stimulated with SEA. Both Nox4 and Nox1 siRNA prevented SEA-induced upregulation of CB1, α-SMA, collagen I, and TIMP-1 by inhibition of O2(-) production, while CB1 siRNA blocked SEA-induced fibrotic changes without effect on O2(-) production in these HSCs. Taken together, these data suggest that the fibrotic activation of HSCs on Schistosoma J. infection or SEA stimulation is associated with NADPH oxidase-mediated redox regulation of CB1 expression, which may be a triggering mechanism for SSLF.

Recent evidence has indicated that overexpression of the epigenetic reader bromodomain‐containing protein 4 (BRD4) contributes to a poor prognosis of lung cancers, and the suppression of its expression promotes cell apoptosis and leads to tumor shrinkage. Proteolysis targeting chimera (PROTAC) has recently emerged as a promising therapeutic strategy with the capability to precisely degrade targeted proteins. Herein, a novel style of versatile nano‐PROTAC (CREATE (CRV‐LLC membrane/DS‐PLGA/dBET6)) is developed, which is constructed by using a pH/GSH (glutathione)‐responsive polymer (disulfide bond‐linked poly(lactic‐co‐glycolic acid), DS‐PLGA) to load BRD4‐targeted PROTAC (dBET6), followed by the camouflage with engineered lung cancer cell membranes with dual targeting capability. Notably, CREATE remarkably confers simultaneous targeting ability to lung cancer cells and tumor‐associated macrophages (TAMs). The pH/GSH‐responsive design improves the release of dBET6 payload from nanoparticles to induce pronounced apoptosis of both cells, which synergistically inhibits tumor growth in both subcutaneous and orthotopic tumor‐bearing mouse model. Furthermore, the efficient tumor inhibition is due to the direct elimination of lung cancer cells and TAMs, which remodels the tumor microenvironment. Taken together, the results elucidate the construction of a versatile nano‐PROTAC enables to eliminate both lung cancer cells and TAMs, which opens a new avenue for efficient lung cancer therapy via PROTAC.

Bone marrow-derived mesenchymal stem cells (BMSCs) are widely used in tissue engineering for regenerative medicine due to their multipotent differentiation potential. However, their poor migration ability limits repair effects. Icariin (ICA), a major component of the Chinese medical herb Herba Epimedii, has been reported to accelerate the proliferation, osteogenic, and chondrogenic differentiation of BMSCs. However, it remains unknown whether ICA can enhance BMSC migration, and the possible underlying mechanisms need to be elucidated. In this study, we found that ICA significantly increased the migration capacity of BMSCs, with an optimal concentration of 1 μmol/L. Moreover, we found that ICA stimulated actin stress fiber formation in BMSCs. Our work revealed that activation of the MAPK signaling pathway was required for ICA-induced migration and actin stress fiber formation. In vivo, ICA promoted the recruitment of BMSCs to the cartilage defect region. Taken together, these results show that ICA promotes BMSC migration in vivo and in vitro by inducing actin stress fiber formation via the MAPK signaling pathway. Thus, combined administration of ICA with BMSCs has great potential in cartilage defect therapy.

Background This study focused on the mechanisms where icariin inhibited chondrocyte apoptosis and angiogenesis by regulating the TDP‐43 signaling pathway. Methods A rat osteoarthritis (OA) model was established by collagenase injection. Histological examination of the articular cartilage and synovial tissue was performed 6 weeks after operation. Cartilage cell line overexpressing TDP‐43 and mesenchymal stem cell line (TDP43‐MSCs) of the rat TDP43 gene were established. Results In OA rats transplanted with TDP43‐mMSCs, TDP43 was highly expressed in chondrocytes (TDP43‐HC), while TDP43 expression was low in HC and MSCs‐HC (p < 0.05). After the intervention of MSCs‐TDP43, high expression of TDP43 induced the apoptosis and death of chondrocytes. After the addition of icariin, late apoptosis and death of TDP43‐HC were significantly attenuated. Apoptosis and death of HC, MSCs‐HC, and TDP43‐HC cells were effectively controlled with icariin, and no apparent cell death was found. ELISA showed that the VEGF and HIF‐1 alpha were significantly higher in the rat OA model than the normal control rats. Conclusion TDP43‐MSC transplantation interfered with the expression of TDP43 in the articular chondrocytes of OA rats, which may impact on inducing apoptosis of chondrocytes as well as inhibiting the proliferation of chondrocytes. Additionally, TDP43‐MSCs appeared to promote the formation of neovascularization in the synovial tissue, which could be significantly attenuated by icariin.