周围神经损伤后再生与修复机制研究进展

周围神经损伤是一种由于压迫、牵引、切割、缺血等原因引起的外周神经细胞损伤或坏死的疾病。周围神经损伤病理学变化包括轴浆运输受损、轴突变性、施万细胞损伤、节段性脱髓鞘和完全瓦勒氏变性。神经损伤后修复成为了现代医学研究中的热点与难点。本文对干细胞移植、神经营养因子、新型材料和生物电刺激在周围神经损伤修复中的作用及机制做了综述,并且对其在临床中的应用进行展望。     

RGS1 silencing inhibits the inflammatory response and angiogenesis in rheumatoid arthritis rats through the inactivation of Toll-like receptor signaling pathway

Emerging evidence shows that rheumatoid arthritis (RA) progression can be induced by the activation of Toll-like receptor (TLR) signaling pathway. Regulator of G-protein signaling 1 (RGS1) is observed to be a candidate biomarker for arthritis. Accordingly, the present study aims to determine the potential effects of RGS1 mediating TLR on RA. A rat model of collagen-induced arthritis (CIA) was established to mimic the features of RA by injection of bovine type II collagen. The rats with CIA were treated with short hairpin RNA (shRNA) against RGS1 or TLR pathway activator Poly I:C to elucidate the role of RGS1 in RA progression. The inflammatory factors were measured, and the thoracic gland and spleen indexes as well as the vascular density were determined. The expression levels of RGS1, TLR3, vascular endothelial growth factor (VEGF), metalloproteinase-2 (MMP-2), MMP-9, and interleukin 1 receptor-associated kinase-4 (IRAK4) were determined. RGS1 was robustly increased in RA. The TLR signaling pathway was suppressed by RGS1 silencing. shRNA-mediated depletion of RGS1 was shown to significantly enhance thoracic gland index and inhibit the serum levels of TNF-α, IL-1β, and IL-17, spleen index, vascular density, and the expression levels of TLR3, VEGF, MMP-2, MMP-9, and IRAK4. However, when the rats with CIA were treated with Poly I:C, the trend of effects was opposite. These findings highlight that functional suppression of RGS1 inhibits the inflammatory response and angiogenesis by inactivating the TLR signaling pathway in rats with CIA, thereby providing a novel therapeutic target for RA treatment.     

Exosomal microRNA-155-5p from PDLSCs regulated Th17/Treg balance by targeting sirtuin-1 in chronic periodontitis

The mechanism of local inflammation and systemic injury in chronic periodontitis is complicated, in which and exosomes play an important role. In our study, we found that T helper cell 17 (Th17)/regulatory T cell (Treg) balance is destabilized in the peripheral blood of patients with periodontitis, with upregulated Th17 or downregulated Treg, respectively. Porphyromonas gingivalis lipopolysaccharide (LPS) was used to simulate the inflammatory microenvironment of chronic periodontitis. The exosomes were extracted from periodontal ligament stem cells (PDLSCs) in LPS-induced periodontitis environment, which inversely effected on CD4+ T cells under normal and inflammatory conditions. Furthermore, compared with exosomes from normal PDLSCs, lower expression of microRNA-155-5p (miR-155-5p) and higher expression of Sirtuin-1 (SIRT1) were observed in exosomes from LPS-stimulated PDLSCs. Exosomes from PDLSCs alleviated inflammatory microenvironment through Th17/Treg/miR-155-5p/SIRT1 regulatory network. This study aimed to find the “switching” factors that affected the further deterioration of periodontitis to maximally control the multiple downstream damage signal factors to further understand periodontitis and find new targets for its treatment.     

Scutellarin exerts protective effects against atherosclerosis in rats by regulating the Hippo–FOXO3A and PI3K/AKT signaling pathways

Atherosclerosis (AS), a progressive disorder, is one of the tough challenges in the clinic. Scutellarin, an extract from Herba Erigerontis, is found to have oxygen-free radicals scavenging effects and antioxidant effects. In this study, we aimed to investigate the anti-AS effects of scutellarin is related to controlling the Hippo–FOXO3A and PI3K/AKT signal pathway. To establish an AS model, the rats in the scutellarin and model groups were intraperitoneally injected with vitamin D ₃ and then fed a high-fat diet for 12 weeks. In addition, in vitro angiotensin II-induced apoptosis of human aortic endothelial cells (HAECs) were used to establish models. Scutellarin significantly reduced blood lipid levels and increased antioxidase levels in both models. Additionally, scutellarin inhibited reactive oxygen species generation and apoptosis in HAECs. The impaired vascular barrier function was restored by using scutellarin in AS rats and in HAECs cells characterized by inhibiting mammalian sterile-20-like kinases 1 (Mst1) phosphorylation, Yes-associated protein (YAP) phosphorylation, forkhead box O3A (FOXO3A) phosphorylation at serine 207, nuclear translocation of FOXO3A, and upregulating protein expression of AKT and FOXO3A phosphorylation at serine 253. Scutellarin significantly reduced Bcl-2 interacting mediator of cell death (Bim), caspase-3, APO-1, CD95 (Fas), and Bax: Bcl-2-associated X (Bax) levels and activated Bcl-2: B-cell lymphoma-2 (Bcl-2). Scutellarin also significantly inhibited the expression of Mst1, YAP, FOXO3A at the messenger RNA level. When Mst1 was overexpressed or phosphoinositide 3-kinases suppressed, the effects of scutellarin were significantly blocked. In conclusion, the results of the present study suggest that scutellarin exerts protective effects against AS by inhibiting endothelial cell injury and apoptosis by regulating the Hippo–FOXO3A and PI3K/AKT signal pathways.     

高通量测序分析实验性脑脊髓炎肠道微生物变化及与IL-17、IFN-γ相关性

【目的】通过建立实验性脑脊髓膜炎(EAE)小鼠模型,观察小鼠肠道菌群在不同发病时间点的变化和炎症因子IL-17、IFN-γ的表达情况,探讨肠道菌群的变化在EAE发病中的免疫调节作用。【方法】将48只C57BL/6小鼠按照随机数字表法分为正常对照组、EAE模型组各24只。EAE组采用MOG35-55与完全弗氏佐剂的混合物制备模型,进行神经功能评分,记录体重变化。分别取免疫后7、14、21、30 d的小鼠粪便,对样本DNA的16S rDNA V3/V4区基因测序。ELASE法检测IL-17、IFN-γ的表达。【结果】EAE组小鼠血液中IL-17、IFN-γ的表达从第7天开始逐渐升高,21 d时达到高峰。14 d时,EAE组与正常对照组相比,物种丰度有显著性差异(P0.05)的菌种有:Alistipes、布牢特氏菌属、毛螺菌科_NK4A136_group等。30dEAE组与正常对照组相比,物种丰度有显著性差异(P0.05)的菌种有:Allobaculum、真细菌属、螺杆菌等。通过LefSe分析,在7、14、21 d中分别主要作用的微生物菌种逐渐减少,在21d时最少。Odoribacter在21d时起了主要作用。【结论】与正常对照组相比,14、21、30dEAE小鼠肠道菌种的丰度均发生了变化,产生了肠道菌群的紊乱;其中普雷沃氏菌属_NK3B31_group的丰度均较正常对照组降低,与IFN-γ呈负相关(r=–0.537,P0.01)。普雷沃氏菌属_NK3B31_group可能是导致MS脱髓鞘发生的关键菌属。EAE组各个时间点相比起主要作用的肠道菌群种类减少,多样性降低。其中,Odoribacter是在21 d高峰期起主要作用的菌种,但其作用机制需要深入研究。EAE组中炎症因子IL-17、IFN-γ表达的升高,促进了MOG35-55诱发的炎症反应。     

In vivo surveillance and elimination of teratoma-forming human embryonic stem cells with monoclonal antibody 2448 targeting annexin A2

This study describes the use of a previously reported chimerised monoclonal antibody (mAb), ch2448, to kill human embryonic stem cells (hESCs) in vivo and prevent or delay the formation of teratomas. ch2448 was raised against hESCs and was previously shown to effectively kill ovarian and breast cancer cells in vitro and in vivo. The antigen target was subsequently found to be Annexin A2, an oncofetal antigen expressed on both embryonic cells and cancer cells. Against cancer cells, ch2448 binds and kills via antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody-drug conjugate (ADC) routes. Here, we investigate if the use of ch2448 can be extended to hESC. ch2448 was found to bind specifically to undifferentiated hESC but not differentiated progenitors. Similar to previous study using cancer cells, ch2448 kills hESC in vivo either indirectly by eliciting ADCC or directly as an ADC. The treatment with ch2448 post-transplantation eliminated the in vivo circulating undifferentiated cells and prevented or delayed the formation of teratomas. This surveillance role of ch2448 adds an additional layer of safeguard to enhance the safety and efficacious use of pluripotent stem cell-derived products in regenerative medicine. Thereby, translating the use of ch2448 in the treatment of cancers to a proof of concept study in hESC (or pluripotent stem cell [PSC]), we show that mAbs can also be used to eliminate teratoma forming cells in vivo during PSC-derived cell therapies. We propose to use this strategy to complement existing methods to eliminate teratoma-forming cells in vitro. Residual undifferentiated cells may escape in vitro removal methods and be introduced into patients together with the differentiated cells.     

MicroRNA-32 targeting PTEN enhances M2 macrophage polarization in the glioma microenvironment and further promotes the progression of glioma

Molecular and Cellular Biochemistry - T cells are involved in bone marrow failure in aplastic anemia (AA). MEG3 is a long, non-coding RNA that can modulate target gene expression and T cell...     

Analysis of VEGF gene polymorphisms and serum VEGF protein levels contribution in polycystic ovary syndrome of patients

Vascular endothelial growth factor (VEGF) is a well-known factor in reproductive function and contributes to the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in VEGFA gene were suggested to contribute alterations in VEGF secretion and PCOS. This study evaluated the association of VEGFA SNPs with altered VEGF secretion level and PCOS among ethnically-matched control women. This prospective case–control study was conducted from 2016 to 2018 and comprised of 55 women with PCOS and 52 control subjects. ELISA was used to measure VEGF levels; and various other related bio chemicals whereas the genotyping of VEGFA variants was performed through the analysis of nine SNPs of VEGF. PRL, E2, PRGE testosterone and glucose level were found to be insignificantly different. The levels of FSH, LH, LH/FSH, TT, insulin, SHBG and HOMA-IR were significantly higher in the study group. Among the nine tested variants of VEGF SNPs, two SNPs rs3025020 and rs833061, consisted of TT (Recessive and Dominant homozygous, respectively) which were marginally higher in test. The SNP rs1570360 had significantly higher GG allele (32.73%) which was recessive homozygous. There was no significant difference observed in genotype frequencies related to higher value of VEGF. The genotype frequencies for the studied SNPs were in alignment with Hardy–Weinberg equilibrium (HWE). The mean serum VEGF levels got significantly increased in PCOS group. No significant association was found between VEGF genotypes and its serum levels. VEGF levels in rs699947 (AA-major homozygous), rs3025039 (CC-major homozygous) and rs833061 (TT & CC-major & minor homozygous) genotypes were significantly higher in PCOS. The study results evidently proved that the allelic variants in genes may be a factor for PCOS and VEGF serum levels with respect to few SNP variants only. These findings indicated that VEGF may be involved in PCOS status and confirmed the previous association between genetic variants in VEGF, serum level of VEGF protein and PCOS.

     

MicroRNA-506-3p initiates mesenchymal-to-epithelial transition and suppresses autophagy in osteosarcoma cells by directly targeting SPHK1

Osteosarcoma (OS) is the most common malignant bone tumor. In cancer cells, autophagy is related to epithelial-to-mesenchymal transition (EMT). Although microRNA (miR)-506-3p has been demonstrated to act as a tumor suppressor in OS, its role in regulating the EMT process and autophagy remains unknown. The results showed that miR-506-3p directly inhibited the expression of sphingosine kinase 1 (SPHK1) in 143B and SaOS-2 cells. The invasive capability of OS cells was reduced following miR-506-3p mimics transfection, and restored when SPHK1 was overexpressed simultaneously. Further, miR-506-3p mimics initiated mesenchymal-to-epithelial transition (MET) – E-cadherin expression was upregulated, whilst vimentin and fibronectin were downregulated. The basal autophagy flux (LC3II/I) was suppressed by miR-506-3p mimics. The alterations induced by miR-506-3p mimics were partly reversed by SPHK1 overexpression or treatment of rapamycin. Meanwhile, treatment of SPHK1-transfected cells with 3-methyladenine inhibited EMT. The data suggest that miR-506-3p initiates MET and suppresses autophagy in OS cells by targeting SPHK1.