Genetic polymorphisms, biomarkers and signaling pathways associated with septic shock: from diagnosis to therapeutic targets.

Septic shock is a severe form of sepsis characterized by high global mortality rates and significant heritability. Clinicians have long been perplexed by the differential expression of genes, which poses challenges for early diagnosis and prompt treatment of septic shock. Genetic polymorphisms play crucial roles in determining susceptibility to, mortality from, and the prognosis of septic shock. Research indicates that pathogenic genes are known to cause septic shock through specific alleles, and protective genes have been shown to confer beneficial effects on affected individuals. Despite the existence of many biomarkers linked to septic shock, their clinical use remains limited. Therefore, further investigation is needed to identify specific biomarkers that can facilitate early prevention, diagnosis and risk stratification. Septic shock is closely associated with multiple signaling pathways, including the toll-like receptor 2/toll-like receptor 4, tumor necrosis factor-α, phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, nuclear factor κB, Janus kinase/signal transducer and activator of transcription, mammalian target of rapamycin, NOD-like receptor thermal protein domain-associated protein 3 and hypoxia-induced-factor-1 pathways. Understanding the regulation of these signaling pathways may lead to the identification of therapeutic targets for the development of novel drugs to treat sepsis or septic shock. In conclusion, identifying differential gene expression during the development of septic shock allows physicians to stratify patients according to risk at an early stage. Furthermore, auxiliary examinations can assist physicians in identifying therapeutic targets within relevant signaling pathways, facilitating early diagnosis and treatment, reducing mortality and improving the prognosis of septic shock patients. Although there has been significant progress in studying the genetic polymorphisms, specific biomarkers and signaling pathways involved in septic shock, the journey toward their clinical application and widespread implementation still lies ahead.

TGM2 accelerates migration and differentiation of BMSCs by activating Wnt/ß-catenin signaling.

BACKGROUND: Transglutaminase 2 (TGM2) is a gene previously reported to be associated with the differentiation of bone marrow mesenchymal stem cells (BMSCs). The study was developed to reveal the impact of TGM2 on the migration and differentiation of BMSCs. METHODS: Cells were isolated from bone marrow of mice and then the surface antigens were identified by flow cytometry. Wound healing assays were conducted to assess the migratory ability of BMSCs. The mRNA levels of TGM2 and osteoblast-associated genes (ALP, OCN, and RUNX2) were subjected to RT-qPCR analysis, and protein levels of these genes as well as ß-catenin were quantitated by western blotting. Alizarin red staining was conducted for detection of osteogenic ability. The activation of Wnt signaling was assessed by TOP/FOP flash assays. RESULTS: Surface antigens were positively identified in MSCs, indicating good multidirectional differentiation ability of cells. TGM2 silencing suppressed BMSC migration while weakening mRNA and protein levels of osteoblast-associated genes. While TGM2 overexpression exerts the opposite impact on cell migration and expression levels of osteoblast-associated genes. Additionally, overexpressed TGM2 promotes the mineralization of BMSCs according to results of Alizarin red staining. Moreover, TGM2 activated the Wnt/ß-catenin signaling, and DKK1 (an inhibitor of Wnt signaling) reversed the promoting influence of TGM2 on cell migration and differentiation. CONCLUSION: TGM2 promotes the migration and differentiation of BMSCs via activation of the Wnt/ß-catenin signaling.

MiR-145-5p restrains chondrogenic differentiation of synovium-derived mesenchymal stem cells by suppressing TLR4.

Osteoarthritis (OA) is a progressive degeneration of articular cartilage with involvement of synovial membrane, and subchondral bone. Recently, cell-based therapies, including the application of stem cells such as mesenchymal stem cells (MSCs), have been introduced for restoration of the articular cartilage. Toll-like receptors (TLRs) were reported to participate in OA progression and MSC chondrogenesis. Here, the role and molecular mechanism of toll like receptor 4 (TLR4) in chondrogenic differentiation of synovium-derived MSCs (SMSCs) were investigated. Molecular markers (CD44, CD90, CD45 and CD14) on SMSC surfaces were identified by flow cytometry. Multi-potential differentiation capacities of SMSCs for chondrogenesis, adipogenesis and osteogenesis were examined by Alcian blue, oil red O and Alizarin red staining, respectively. TLR4 and miR-145-5p levels in SMSCs were assessed using RT-qPCR. The protein expression of TGFB3, Col II, SOX9 and Aggrecan in SMSCs was tested by western blotting. Cytokine secretions were analyzed with ELISA for IL-1ß and IL-6. Intracellular NAD+ content and NAD+/NADH ratio were assessed. The interaction between miR-145-5p and TLR4 was confirmed by RNA pulldown and luciferase reporter assays. In this study, SMSCs were identified to have immunophenotypic characteristics of MSCs. TLR4 knockdown inhibited chondrogenic and osteogenic differentiation of SMSCs. Mechanistically, TLR4 was targeted by miR-145-5p in SMSCs. Moreover, TLR4 elevation offset the inhibitory impact of miR-145-5p upregulation on chondrogenic differentiation of SMSCs. Overall, miR-145-5p restrains chondrogenesis of SMSCs by suppressing TLR4.

Negative pressure wound therapy enhances bone regeneration compared with conventional therapy in a rabbit radius gap-healing model.

Negative pressure wound therapy (NPWT) has been recognized as an effective method for the treatment of intractable wounds. However, its effects on bone healing remain to be elucidated. Our previous study demonstrated that NPWT induced cell proliferation and osteoblastic differentiation of rat periosteum-derived mesenchymal stem cells (P-MSCs). It was reported that following NPWT treatment, the expression of the mechanotransduction molecule integrin ß5 is increased, indicating that NPWT may serve an active role in fracture healing by enhancing bone formation and reducing bone resorption. The present study sought to further investigate the efficacy of NPWT on the bone regeneration process in a rabbit radial gap-healing model. All rabbits with radial defects were randomly divided into two groups: NPWT and control groups. Continuous negative pressure at -125 mmHg was applied to all rabbits. Furthermore, X-ray imaging and scoring on day 7, 14, 21 and 28 postoperatively were performed to evaluate new bone formation. Histological changes were determined via hematoxylin and eosin and Masson's trichrome staining at 2- and 4-weeks following surgery. In addition, vimentin-positive cells located in the periosteum were detected via immunohistochemical examination on day 3 post operation. Finally, protein expression levels of vascular endothelial growth factor (VEGF), bone morphogenetic protein (BMP)-2 and osteopontin (OPN) were evaluated using western blot analysis on the 2nd and 4th week following NPWT. X-ray and histological examination revealed that the bone-healing processes in the NPWT group were faster compared with the control group. Additionally, compared with the control group, the NPWT group exhibited higher X-ray scores, increased percentage of positive vimentin-stained cells and upregulated expression of VEGF, BMP-2 and OPN proteins. The aforementioned findings suggest that NPWT, under a continuous negative pressure of -125 mmHg, may accelerate bone regeneration by enhancing MSC proliferation, osteoblastic differentiation and VEGF, BMP-2 and OPN expression.

Salidroside Suppresses IL-1ß-Induced Apoptosis in Chondrocytes via Phosphatidylinositol 3-Kinases (PI3K)/Akt Signaling Inhibition.

BACKGROUND Salidroside, a natural dietary isothiocyanate, has been widely studied for its multiple effects, including promoting proliferation, anti-inflammation, and anti-apoptosis. In the present study, these effects of Salidroside were explored to assess whether it could prevent osteoarthritis (OA) in vitro. MATERIAL AND METHODS The cytotoxic and proliferating effects of Salidroside on chondrocytes were detected by use of the Cell Counting Kit 8 assay. The expression levels of proteins were detected by Western blot. The cell apoptosis level was assessed by flow cytometry, and the levels of ROS, NO, caspase 3, and caspase 9 were assessed to evaluate the level of apoptosis. The expression level of pro-inflammatory factors was detected by ELISA. RESULTS Our results demonstrated that Salidroside promotes chondrocytes proliferation, inhibits IL-1ß-induced apoptosis and inflammation, and scavenges reactive oxygen species (ROS) and NO of chondrocytes. Salidroside upregulates the level of Bcl-2 and downregulates the level of Bax. Salidroside also inhibits the production of caspase 3/9 and suppresses the phosphorylation of PI3K and AKT. CONCLUSIONS Our results suggest that Salidroside prevents OA by its powerful pro-proliferating, anti-phlogistic, and anti-apoptotic effects by inhibiting PI3K/AKT.