The protective effort of GPCR kinase 2-interacting protein-1 in neurons via promoting Beclin1-Parkin induced mitophagy at the early stage of spinal cord ischemia-reperfusion injury.

In spinal cord ischemia-reperfusion (I/R) injury, large amounts of reactive oxygen species can cause mitochondrial damage. Therefore, mitophagy acts as the main mechanism for removing damaged mitochondria and protects nerve cells. This study aimed to illustrate the important role of GPCR kinase 2-interacting protein-1 (GIT1) in mitophagy in vivo and in vitro. The level of mitophagy in the neurons of Git1 knockout mice was significantly reduced after ischemia-reperfusion. However, the overexpression of adeno-associated virus with Git1 promoted mitophagy and inhibited the apoptosis of neurons. GIT1 regulated the phosphorylation of Beclin-1 in Thr119, which could promote the translocation of Parkin to the mitochondrial outer membrane. This process was independent of PTEN-induced kinase 1 (PINK1), but it could not rescue the role in the absence of PINK1. Overall, GIT1 enhanced mitophagy and protected neurons against ischemia-reperfusion injury and, hence, might serve as a new research site for the protection of ischemia-reperfusion injury.

Macrophage MSR1 promotes the formation of foamy macrophage and neuronal apoptosis after spinal cord injury.

BACKGROUND: A sustained inflammatory response following spinal cord injury (SCI) contributes to neuronal damage, inhibiting functional recovery. Macrophages, the major participants in the inflammatory response, transform into foamy macrophages after phagocytosing myelin debris, subsequently releasing inflammatory factors and amplifying the secondary injury. Here, we assessed the effect of macrophage scavenger receptor 1 (MSR1) in phagocytosis of myelin debris after SCI and explained its possible mechanism. METHODS: The SCI model was employed to determine the critical role of MSR1 in phagocytosis of myelin debris in vivo. The potential functions and mechanisms of MSR1 were explored using qPCR, western blotting, and immunofluorescence after treating macrophages and RAW264.7 with myelin debris in vitro. RESULTS: In this study, we found improved recovery from traumatic SCI in MSR1-knockout mice over that in MSR1 wild-type mice. Furthermore, MSR1 promoted the phagocytosis of myelin debris and the formation of foamy macrophage, leading to pro-inflammatory polarization in vitro and in vivo. Mechanistically, in the presence of myelin debris, MSR1-mediated NF-κB signaling pathway contributed to the release of inflammatory mediators and subsequently the apoptosis of neurons. CONCLUSIONS: Our study elucidates a previously unrecognized role of MSR1 in the pathophysiology of SCI and suggests that its inhibition may be a new treatment strategy for this traumatic condition.

3M syndrome patient with a novel mutation: A case report.

BACKGROUND: A rare autosomal recessive genetic disorder, 3M syndrome, is characterized by severe intrauterine and postnatal growth retardation. Children with 3M syndrome typically exhibit short stature, facial deformities, long tubular bones, and high vertebral bodies but generally lack mental abnormalities or other organ damage. Pathogenic genes associated with 3M syndrome include CUL7, OBSL1 and CCDC8. The clinical and molecular characteristics of patient with 3M syndrome are unique and serve as important diagnostic indicators. CASE SUMMARY: In this case, the patient displayed square shoulders, scoliosis, long slender tubular bones, and normal neurological development. Notably, the patient did not exhibit the typical dysmorphic facial features, relative macrocephaly, or growth retardation commonly observed in individuals with 3M syndrome. Whole exon sequencing revealed a novel heterozygous c.56681+1G>C (Splice-3) variant and a previously reported nonsense heterozygous c.3341G>A (p.Trp1114Ter) variant of OBSL1. Therefore, it is important to note that the clinical features of 3M syndrome may not always be observable, and genetic confirmation is often required. Additionally, the identification of the c.5683+1G>C variant in OBSL1 is noteworthy because it has not been previously reported in public databases. CONCLUSION: Our study identified a new variant (c.5683+1G>C) of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.

Advances in Phytochemistry and Modern Pharmacology of Saposhnikovia Divaricata (Turcz.) Schischk.

Saposhnikovia divaricata (Turcz.) Schischk (S. divaricata, Fangfeng) is a herb in the Apiaceae family, and its root has been used since the Western Han Dynasty (202 B.C.). Chromones and coumarins are the pharmacologically active substances in S. divaricata. Modern phytochemical and pharmacological studies have demonstrated their antipyretic, analgesic, anti-inflammatory, antioxidant, anti-tumor, and anticoagulant activities. Technological and analytical strategy theory advancements have yielded novel results; however, most investigations have been limited to the main active substances-chromones and coumarins. Hence, we reviewed studies related to the chemical composition and pharmacological activity of S. divaricata, analyzed the developing trends and challenges, and proposed that research should focus on components' synergistic effects. We also suggested that, the structure-effect relationship should be prioritized in advanced research.

Fatty acids derived from apoptotic chondrocytes fuel macrophages FAO through MSR1 for facilitating BMSCs osteogenic differentiation.

The nonunion following a fracture is associated with severe patient morbidity and economic consequences. Currently, accumulating studies are focusing on the importance of macrophages during fracture repair. However, details regarding the process by which macrophages facilitate endochondral ossification (EO) are largely unknown. In this study, we present evidence that apoptotic chondrocytes (ACs) are not inert corpses awaiting removal, but positively modulate the osteoinductive ability of macrophages. In vivo experiments revealed that fatty acid (FA) metabolic processes up-regulated following EO. In vitro studies further uncovered that FAs derived from ACs are taken up by macrophages mainly through macrophage scavenger receptor 1 (MSR1). Then, our functional experiments confirmed that these exogenous FAs subsequently activate peroxisome proliferator-activated receptor α (PPARα), which further facilitates lipid droplets generation and fatty acid oxidation (FAO). Mechanistically, elevated FAO is involved in up-regulating the osteoinductive effect by generating BMP7 and NAD+/SIRT1/EZH2 axis epigenetically controls BMP7 expression in macrophages cultured with ACs culture medium. Our findings advanced the concept that ACs could promote bone regeneration by regulating metabolic and function reprogram in macrophages and identified macrophage MSR1 represents a valuable target for fracture treatments.

Macrophage GIT1 Contributes to Bone Regeneration by Regulating Inflammatory Responses in an ERK/NRF2-Dependent Way.

Despite the best treatment, approximately 10% of fractures still face undesirable repair. Recently, many studies have focused on the importance of macrophages in bone repair; however, the cellular mechanisms by which they work are not yet fully understood. In this study, we explored the functions of macrophage G-protein-coupled receptor interacting protein 1 (GIT1) in healing a tibial monocortical defect model. Using GIT1flox/flox Lyz2-Cre (GIT1 CKO) mice, we observed that a GIT1 deficiency in the macrophages led to an exacerbation of interleukin 1ß (IL1ß) production, more M1-like macrophage infiltration, and impaired intramembranous ossification in vivo. The results of in vitro assays further indicated that the macrophage GIT1 plays a critical role in several cellular processes in response to lipopolysaccharide (LPS), such as anti-oxidation, IL1ß production alleviation, and glycolysis control. Although GIT1 has been recognized as a scaffold protein, our data clarified that GIT1-mediated extracellular-signal-regulated kinase (ERK) phosphorylation could activate nuclear factor (erythroid-derived 2)-like 2 (NRF2) in macrophages after LPS treatment. Moreover, we demonstrated that macrophage GIT1-activated ERK/NRF2 negatively regulates the 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), facilitating the decrease of glycolysis. Our findings uncovered a previously unrecognized role of GIT1 in regulating ERK/NRF2 in macrophages to control the inflammatory response, suggesting that macrophage GIT1 could be a potential target to improve bone regeneration. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research..

Macrophage MSR1 promotes BMSC osteogenic differentiation and M2-like polarization by activating PI3K/AKT/GSK3ß/ß-catenin pathway.

Approximately 10% of bone fractures do not heal satisfactorily, leading to significant clinical and socioeconomic implications. Recently, the role of macrophages in regulating bone marrow stem cell (BMSC) differentiation through the osteogenic pathway during fracture healing has attracted much attention. Methods: The tibial monocortical defect model was employed to determine the critical role of macrophage scavenger receptor 1 (MSR1) during intramembranous ossification (IO) in vivo. The potential functions and mechanisms of MSR1 were explored in a co-culture system of bone marrow-derived macrophages (BMDMs), RAW264.7 cells, and BMSCs using qPCR, Western blotting, immunofluorescence, and RNA sequencing. Results: In this study, using the tibial monocortical defect model, we observed delayed IO in MSR1 knockout (KO) mice compared to MSR1 wild-type (WT) mice. Furthermore, macrophage MSR1 mediated PI3K/AKT/GSK3ß/ß-catenin signaling increased ability to promote osteogenic differentiation of BMSCs in the co-culture system. We also identified proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) as the target gene for macrophage MSR1-activated PI3K/AKT/GSK3ß/ß-catenin pathway in the co-culture system that facilitated M2-like polarization by enhancing mitochondrial oxidative phosphorylation. Conclusion: Our findings revealed a previously unrecognized function of MSR1 in macrophages during fracture repair. Targeting MSR1 might, therefore, be a new therapeutic strategy for fracture repair.

Bioinformatics analysis of the molecular mechanisms underlying traumatic spinal cord injury.

Spinal cord injury (SCI) is a cause of disability. The present study aimed to investigate the molecular mechanisms involved in traumatic SCI. Transcriptome data under accession no. GSE5296, including 96 chips, were downloaded from the Gene Expression Omnibus database. The raw data were normalized and differentially expressed genes (DEGs) were identified. Furthermore, Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology enrichment analysis of up­ and downregulated DEGs was performed. Additionally, a protein­protein interaction network was constructed and the expression patterns of different genes were determined. Compared with sham samples, there were 374, 707, 1,322, 1,475, 1,724 and 1,342 DEGs identified at 0.5, 4, 24 and 72 h, and 7 and 28 days post­injury, respectively. At 24 and 72 h, and 7 days following injury, the upregulated DEGs were markedly enriched in 'inflammatory response' and 'immune process'. Downregulated DEGs were predominantly enriched in neuronal function­associated pathways and 'steroid biosynthesis' process. Protein­protein interaction network analysis demonstrated similar results. Trend charts further demonstrated that the inflammatory and neuronal functions were altered in a temporal and site­specific manner. The present study provided an insight into the molecular mechanisms underlying traumatic SCI, which may benefit future SCI research and aid in therapy development.

Bioinformatics Analysis of the Molecular Mechanism of Aging on Fracture Healing.

Increasing age negatively affects different phases of bone fracture healing. The present study aimed to explore underlying mechanisms related to bone fracture repair in the elderly. GSE17825 public transcriptome data from the Gene Expression Omnibus database were used for analysis. First, raw data were normalized and differentially expressed genes (DEGs) were identified. Next, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were implemented to evaluate pathways and DEGs. A protein-protein interaction (PPI) network was then constructed. A total of 726, 861, and 432 DEGs were identified between the young and elderly individuals at 1, 3, and 5 days after fracture, respectively. The results of GO, KEGG, and PPI network analyses suggested that the inflammatory response, Wnt signaling pathway, vascularization-associated processes, and synaptic-related functions of the identified DEGs are markedly enriched, which may account for delayed fracture healing in the elderly. These findings provide valuable clues for investigating the effects of aging on fracture healing but should be validated through further experiments.

GIT1 contributes to autophagy in osteoclast through disruption of the binding of Beclin1 and Bcl2 under starvation condition.

Approximately 10-15% of all bone fractures do not heal properly, causing patient morbidity and additional medical care expenses. Therefore, better mechanism-based fracture repair approaches are needed. In this study, a reduced number of osteoclasts (OCs) and autophagosomes/autolysosomes in OC can be observed in GPCR kinase 2-interacting protein 1 (GIT1) knockout (KO) mice on days 21 and 28 post-fracture, compared with GIT1 wild-type (GIT1 WT) mice. Furthermore, in vitro experiments revealed that GIT1 contributes to OC autophagy under starvation conditions. Mechanistically, GIT1 interacted with Beclin1 and promoted Beclin1 phosphorylation at Thr119, which induced the disruption of Beclin1 and Bcl2 binding under starvation conditions, thereby, positively regulating autophagy. Taken together, the findings suggest a previously unappreciated role of GIT1 in autophagy of OCs during fracture repair. Targeting GIT1 may be a potential therapeutic approach for bone fractures.

SLIT2/ROBO1 axis contributes to the Warburg effect in osteosarcoma through activation of SRC/ERK/c-MYC/PFKFB2 pathway.

Cellular metabolic reprogramming is the main characteristic of cancer cells and identification of targets using this metabolic pattern is extremely important to treat cancers, such as osteosarcoma (OS). In this study, SLIT2 and ROBO1 were upregulated in OS, and higher expression of ROBO1 was associated with worse overall survival rate. Furthermore, in vitro and in vivo experiments demonstrated that the SLIT2/ROBO1 axis promotes proliferation, inhibits apoptosis, and contributes to the Warburg effect in OS cells. Mechanistically, the SLIT2/ROBO1 axis exerted cancer-promoting effects on OS via activation of the SRC/ERK/c-MYC/PFKFB2 pathway. Taken together, the findings reveal a previously unappreciated function of SLIT2/ROBO1 signaling in OS, which is intertwined with metabolic alterations that promote cancer progression. Targeting the SLIT2/ROBO1 axis may be a potential therapeutic approach for patients with OS.

Corticosteroid therapy for severe acute pancreatitis: a meta-analysis of randomized, controlled trials.

BACKGROUND: Recent reports about the benefits of corticosteroid therapy in patients with severe acute pancreatitis (SAP) have shown conflicting results. We aimed to explore the effects of corticosteroid therapy in SAP patients on patient outcomes by performing a meta-analysis. METHODS: Databases (Medline, EMBASE, Web of Science, PubMed, Cochrane Library, Chinese Biomedicine Database, and China Academic Journal Full-Text Database) were queried for all relevant, randomized, controlled trials investigating corticosteroid therapy in patients with SAP. RESULTS: Six randomized, controlled trials including 430 SAP patients were identified. Corticosteroid therapy for SAP was associated with reductions in the length of hospital stay, the need for surgical intervention, and the mortality rate (weighted mean difference [WMD]: -9.47, 95% confidence interval [CI]: -16.91 to -2.04, P = 0.01; odds ratio [OR]: 0.35, 95% CI: 0.18-0.67, P = 0.002; OR: 0.45, 95% CI: 0.22-0.94, P = 0.03). There were no significant differences in the complication rates or Physiology and Chronic Health Evaluation II (APACHE II) scores in patients with or without corticosteroid therapy. CONCLUSION: Corticosteroid therapy may improve outcomes in patients with SAP.

Measuring both procalcitonin and C-reactive protein for a diagnosis of sepsis in critically ill patients.

BACKGROUND: The usefulness of procalcitonin (PCT) and C-reactive protein (CRP) as individual biomarkers, and in combination, for the identification of infections in a critically ill patient cohort was evaluated retrospectively. METHODS: Best cut-off values for PCT and CRP for a diagnosis of sepsis in critically ill patients were determined using receiver operator characteristic (ROC) curve analysis. Both combined tests and individual tests were performed for PCT and CRP, with positive and negative results recorded, and accuracy evaluated using odds ratios (OR). RESULTS: In the 55 critically ill patients studied, the best cut-off value for PCT for a diagnosis of sepsis was 1.1 ng/ml (sensitivity, specificity and negative predictive values [NPV] were 82%, 68% and 71%, respectively). In addition, the best cut-off value for CRP was 50.7 mg/l ( sensitivity, specificity and NPV of 90%, 68% and 83%, respectively). Measuring PCT and CRP in combination provided a sensitivity of 79%, a specificity of 86%, and a positive predictive value (PPV) of 90%. Diagnostic OR for the combination of biomarkers versus CRP alone (19 and 18, respectively) were greater than that for PCT (9). CONCLUSION: For critically ill patients, CRP and CRP in combination with PCT were found to be suitable biomarkers for diagnosing sepsis, based on their NPV and PPV.

Effect of intestinal function-recovering decoction on treatment of multiple organ dysfunction syndrome in rats.

OBJECTIVE: To analyze the effect of intestinal function-recovering decoction on multiple organ dysfunction syndrome in rats, and to investigate a novel solution to multiple organ dysfunction syndrome. METHODS: Multiple organ dysfunction syndrome was induced in 60 Sprague-Dawley rats by intestinal ischemia-reperfusion combined with cecal ligation and puncture. Then these rats were intragastrically administered physiological saline (group I, n=20), ampicillin (group II, n=20) or intestinal function-recovering decoction (group III, n=20). After treatment, serum malondialdehyde and superoxide dismutase levels were compared among three groups. Simultaneously, bacterial culture of various organ tissues was performed and bacterial and endotoxin translocation were observed. RESULTS: Compared with group I, serum malondialdehyde, alanine aminotransferase and aspartate aminotransferase levels were significantly decreased (all P<0.05) and serum superoxide dismutase level was significantly increased (P<0.05) in the group III. However, there were no significant differences in these indices between groups II and III (P>0.05). The rate of bacterial translocation in the groups II and III was significantly lower than in the group I (P<0.05), and no significant difference was observed between groups II and III (P>0.05). CONCLUSIONS: Intestinal function-recovering decoction can significantly reduce endotoxin and bacterial translocation and stabilize enteral oxidative-antioxidative balance.