The balance of inflammation is critical to the repair of spinal cord injury (SCI), which is one of the most devastating traumas in human beings. Inflammatory cytokines, the direct mediators of local inflammation, have differential influences on the repair of the injured spinal cord. Some inflammatory cytokines are demonstrated beneficial to spinal cord repair in SCI models, while some detrimental. Various animal researches have revealed that local delivery of therapeutic agents efficiently regulates inflammatory cytokines and promotes repair from SCI. Quite a few clinical studies have also shown the promotion of repair from SCI through regulation of inflammatory cytokines. However, local delivery of a single agent affects only a part of the inflammatory cytokines that need to be regulated. Meanwhile, different individuals have differential profiles of inflammatory cytokines. Therefore, future studies may aim to develop personalized strategies of locally delivered therapeutic agent cocktails for effective and precise regulation of inflammation, and substantial functional recovery from SCI.

Rho GTPase-activating protein 26 (ARHGAP26) is a negative regulator of the Rho family that converts the small GTP-binding protein RhoA (GTP-RhoA) to its inactive GDP-bound form and is a putative tumor suppressor gene associated with cell growth and migration. Here, the involvement of ARHGAP26 in ovarian cancer cell proliferation and migration was investigated. In this study, low ARHGAP26 expression was observed in ovarian cancer tissues and was associated with a poor overall survival and higher β-catenin expression in patients with ovarian cancer. A2780 and HEY cells with ARHGAP26 upregulation showed decreased cell proliferation, migration, and invasion, along with decreased GTP-RhoA, β-catenin, VEGF, MMP2, and MMP7 expression. ARHGAP26 upregulation in A2780 cells also inhibited lung metastasis in vivo. SKOV3 cells with ARHGAP26 downregulation demonstrated an inverse effect, which was inhibited by ARHGAP26 overexpression or DKK1, an antagonist of the β-catenin pathway. SMURF1, an E3 ubiquitin ligase, interacted with and induced ubiquitination of ARHGAP26. ARHGAP26 upregulation in SKOV3 cells significantly inhibited SMURF1 upregulation-induced cell migration and invasion. Overall, SMURF1-mediated ubiquitination of ARHGAP26 may promote invasion and migration of ovarian cancer cells via the β-catenin pathway.

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Background Osteoarthritis (OA), a prevalent degenerative disease characterized by degradation of extracellular matrix (ECM), still lacks effective disease-modifying therapy. Mesenchymal stem cells (MSCs) transplantation has been regarded as the most promising approach for OA treatment while engrafting cells alone might not be adequate for effective regeneration. Genetic modification has been used to optimize MSC-based therapy; however, there are still significant limitations that prevent the clinical translation of this therapy including low efficacy and safety concerns. Recently, chemically modified mRNA (modRNA) represents a promising alternative for the gene-enhanced MSC therapy. In this regard, we hypothesized that adipose derived stem cells (ADSCs) engineered with modRNA encoding insulin-like growth factor 1 (IGF-1) were superior to native ADSCs on ameliorating OA development. Methods Mouse ADSCs were acquired from adipose tissue and transfected with modRNAs. First, the kinetics and efficacy of modRNA-mediated gene transfer in mouse ADSCs were analyzed in vitro. Next, we applied an indirect co-culture system to analyze the pro-anabolic potential of IGF-1 modRNA engineered ADSCs (named as IGF-1-ADSCs) on chondrocytes. Finally, we evaluated the cell retention and chondroprotective effect of IGF-1-ADSCs in vivo using fluorescent labeling, histology and immunohistochemistry. Results modRNA transfected mouse ADSCs with high efficiency (85 ± 5%) and the IGF-1 modRNA-transfected ADSCs facilitated burst-like production of bio-functional IGF-1 protein. In vitro, IGF-1-ADSCs induced increased anabolic markers expression of chondrocytes in inflammation environment compared to untreated ADSCs. In a murine OA model, histological and immunohistochemical analysis of knee joints harvested at 4 weeks and 8 weeks after OA induction suggested IGF-1-ADSCs had superior therapeutic effect over native ADSCs demonstrated by lower histological OARSI score and decreased loss of cartilage ECM. Conclusions These findings collectively supported the therapeutic potential of IGF-1-ADSCs for clinical OA management and cartilage repair.