BACKGROUND:Indolepropionic acid has been shown to reduce diabetes-induced central nervous system inflammation.However,there is a lack of research on whether to inhibit microglia M1 polarization for the treatment of spinal cord injury. OBJECTIVE:To investigate the mechanism of indolepropionic acid inhibition of microglial cell M1 polarization for the treatment of spinal cord injury through cell and animal experiments. METHODS:(1)In vitro experiments:BV2 cell viability was assessed using the CCK-8 assay to determine optimal concentrations of indolepropionic acid.Subsequently,BV2 cells were categorized into control group,administration group(50 μmol/L indolepropionic acid),lipopolysaccharide group(100 ng/mL lipopolysaccharide),and treatment group(100 ng/mL lipopolysaccharide + 50 μmol/L indolepropionic acid).Nitric oxide content was quantified using the Griess method.Real-time quantitative PCR and western blot assay were employed to measure mRNA and protein levels of pro-inflammatory factors.Cell immunofluorescence staining was conducted to assess inducible nitric oxide synthase expression.The Seahorse assay was employed to assess glycolytic stress levels in BV2 cells.(2)In vivo experiments:30 SD rats were randomly divided into three groups:sham surgery group,spinal cord injury group,and indolepropionic acid group.Motor function recovery in rats after spinal cord injury was assessed using BBB scoring and the inclined plane test.Immunofluorescence staining of spinal cord tissue was conducted to evaluate the expression of inducible nitric oxide synthase in microglial cells.ELISA was employed to measure protein expression levels of the pro-inflammatory cytokines interleukin-1β and tumor necrosis factor-α in spinal cord tissue. RESULTS AND CONCLUSION:(1)In vitro experiments:Indolepropionic acid exhibited significant suppression of BV2 cell viability when its concentration exceeded 50 μmol/L.Indolepropionic acid achieved this by inhibiting the activation of the nuclear factor κB signaling pathway,thereby suppressing the mRNA and protein expression levels of pro-inflammatory cytokines(interleukin-1β and tumor necrosis factor-α),as well as the M1 polarization marker,inducible nitric oxide synthase,in BV2 cells.Additionally,indolepropionic acid notably reduced the glycolytic level in BV2 cells induced by lipopolysaccharides.(2)In vivo experiments:Following indolepropionic acid intervention in spinal cord injury rats,there was a noticeable increase in BBB scores and the inclined plane test angle.There was also a significant decrease in the number of M1-polarized microglial cells in spinal cord tissue,accompanied by a marked reduction in the protein expression levels of pro-inflammatory cytokines(interleukin-1β and tumor necrosis factor-α).(3)These results conclude that indolepropionic acid promotes functional recovery after spinal cord injury by improving the inflammatory microenvironment through inhibition of microglia M1 polarization.

Spinal cord injury (SCI) causes motor, sensory, and autonomic dysfunctions. The gut microbiome has an important role in SCI, while short-chain fatty acids (SCFAs) are one of the main bioactive mediators of microbiota. In the present study, we explored the effects of oral administration of exogenous SCFAs on the recovery of locomotor function and tissue repair in SCI. Allen's method was utilized to establish an SCI model in Sprague-Dawley (SD) rats. The animals received water containing a mixture of 150 mmol/L SCFAs after SCI. After 21 d of treatment, the Basso, Beattie, and Bresnahan (BBB) score increased, the regularity index improved, and the base of support (BOS) value declined. Spinal cord tissue inflammatory infiltration was alleviated, the spinal cord necrosis cavity was reduced, and the numbers of motor neurons and Nissl bodies were elevated. Enzyme-linked immunosorbent assay (ELISA), real-time quantitative polymerase chain reaction (qPCR), and immunohistochemistry assay revealed that the expression of interleukin (IL)‍-10 increased and that of IL-17 decreased in the spinal cord. SCFAs promoted gut homeostasis, induced intestinal T cells to shift toward an anti-inflammatory phenotype, and promoted regulatory T (Treg) cells to secrete IL-10, affecting Treg cells and IL-17⁺ γδ T cells in the spinal cord. Furthermore, we observed that Treg cells migrated from the gut to the spinal cord region after SCI. The above findings confirm that SCFAs can regulate Treg cells in the gut and affect the balance of Treg and IL-17⁺ γδ T cells in the spinal cord, which inhibits the inflammatory response and promotes the motor function in SCI rats. Our findings suggest that there is a relationship among gut, spinal cord, and immune cells, and the "gut-spinal cord-immune" axis may be one of the mechanisms regulating neural repair after SCI.
Animals ; Rats ; Interleukin-17 ; Rats, Sprague-Dawley ; Recovery of Function ; Spinal Cord Injuries/drug therapy* ; T-Lymphocytes, Regulatory ; Receptors, Antigen, T-Cell, gamma-delta/immunology*

BACKGROUND: Osteoporosis (OP) has become a major public health issue, threatening the bone health of middle-aged and elderly people from all around the world. Changes in the gut microbiota (GM) are correlated with the maintenance of bone mass and bone quality. However, research results in this field remain highly controversial, and no systematic review or meta-analysis of the relationship between GM and OP has been conducted. This paper addresses this shortcoming, focusing on the difference in the GM abundance between OP patients and healthy controls based on previous 16S ribosomal RNA (rRNA) gene sequencing results, in order to provide new clinical reference information for future customized prevention and treatment options of OP. METHODS: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we comprehensively searched the databases of PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI). In addition, we applied the R programming language version 4.0.3 and Stata 15.1 software for data analysis. We also implemented the Newcastle-Ottawa Scale (NOS), funnel plot analysis, sensitivity analysis, Egger's test, and Begg's test to assess the risk of bias. RESULTS: This research ultimately considered 12 studies, which included the fecal GM data of 2033 people (604 with OP and 1429 healthy controls). In the included research papers, it was observed that the relative abundance of Lactobacillus and Ruminococcus increased in the OP group, while the relative abundance for Bacteroides of Bacteroidetes increased (except for Ireland). Meanwhile, Firmicutes, Blautia, Alistipes, Megamonas, and Anaerostipes showed reduced relative abundance in Chinese studies. In the linear discriminant analysis Effect Size (LEfSe) analysis, certain bacteria showed statistically significant results consistently across different studies. CONCLUSIONS: This observational meta-analysis revealed that changes in the GM were correlated with OP, and variations in some advantageous GM might involve regional differences.
Middle Aged ; Aged ; Humans ; Gastrointestinal Microbiome/genetics* ; RNA, Ribosomal, 16S/genetics* ; Genes, rRNA ; Osteoporosis ; Feces

BACKGROUND: miRNA-136-5 p plays a crucial regulatory role in pathological changes, inflammatory response and regeneration after spinal cord injury. OBJECTIVE: To investigate the effect of miRNA-136-5 p on the expression of cytokines in serum and NF-κB protein in spinal cord in rats with spinal cord injury and to explore the molecular mechanism. METHODS: Thirty-six male Sprague-Dawley rats, of SPF grade were provided by Laboratory Animal Center of Guangxi Medical University. The lentiviral vector system was prepared and transfected into spinal cord injured rats. Thirty-six rat models of spinal cord injury were established by modified Allen's method. Basso Beattie Bresnahan scores were performed. Rats were randomly divided into normal control, modeling (LV-ctrl plus spinal cord injury), overexpression (spinal cord injury plus LV-miRNA-136-5 p), and inhibition (spinal cord injury plus LV-sponge) groups (n=9/group). Seven days before surgery and the day of surgery, the overexpression and inhibition groups were continuously injected with the lentivirus suspension into the injured area, and the normal control and modeling groups were injected with the same amount of normal saline. Three rats were sacrificed at 1, 3 and 7 days, and blood and spinal cord tissues were taken. The levels of interleukin-1β, interleukion-6 and interferon-α in rat serum were determined by ELISA. The expression of NF-κB protein was detected by western blot assay and double immunofluorescence. RESULTS AND CONCLUSION: (1) There was no significant difference in preoperative Basso Beattie Bresnahan scores (P＞ 0.05). In the modeling group, the rats showed prone walking, vary degrees of urinary retention, and spinal shock, with complete loss of function of both hind limbs and muscle strength of 0. (2) Compared with the normal control group, the levels of inflammatory factors in the other groups were increased significantly (P ＜ 0.05). The expression levels of inflammatory factors were highest in the overexpression group, followed by modeling group, and lowest in the inhibition group. (3) Results of western blot assay and double immunofluorescence showed that the expression level of NF-κB protein in the modeling, overexpression and inhibition groups was significantly higher than that in the normal control group (P ＜ 0.05), and the level was highest in the overexpression group. (4) In summary, miRNA-136-5 p can affect inflammatory factors and NF-κB in rats with acute spinal cord injury.

BACKGROUND: Change of microenvironment after acute spinal cord injury is the main factor causing secondary injury, so it is of great significance to investigate the changes of microenvironment after acute spinal cord injury for clinical diagnosis and treatment. OBJECTIVE: To investigate the expression levels and clinical significance of interleukin-6, brain derived neurotrophic factor, basic fibroblast growth factor, neurotrophin-3 and neurotrophin-4 in peripheral blood within 48 hours after acute spinal cord injury. METHODS: Twenty-nine patients with acute spinal cord injury admitted at the Department of Spinal Osteopathia, the First Affiliated Hospital of Guangxi Medical University from October 2016 to June 2018 were enrolled, and were divided into two groups according to American Spinal Injury Association impairment scale: complete spinal cord injury (n=11) and incomplete spinal cord injury (n=18). Thirteen patients with avascular necrosis of the femoral head were selected as controls. The expression levels of interleukin-6, brain derived neurotrophic factor, basic fibroblast growth factor, neurotrophin-3 and neurotrophin-4 in peripheral blood of 42 patients were determined by ELISA and compared. RESULTS AND CONCLUSION: The ELISA results showed that the expression levels of interleukin-6, brain derived neurotrophic factor, basic fibroblast growth factor, neurotrophin-3 and neurotrophin-4 in peripheral blood in the spinal cord injury group were significantly higher than those in the control group (P ＜ 0.05). The expression levels of all above cytokines in the complete spinal cord injury group were significantly higher than those in the incomplete spinal cord injury group (P ＜ 0.05). In summary, increased expression of interleukin-6, brain derived neurotrophic factor, basic fibroblast growth factor, neurotrophin-3, neurotrophin-4 after acute spinal cord injury indicates that it may participate in the important pathophysiological process after acute spinal cord injury.

BACKGROUND/AIMS: The Rome III criteria separated chronic constipation into functional constipation (FC) and constipation-predominant irritable bowel syndrome (IBS-C), but some researchers questioned the partitioning and treated both as distinct parts of a continuum. The study aims to explore the similarity and diversity of brain white matter between FC and IBS-C. METHODS: The voxel-wise analysis of the diffusion parameters was used to quantify the white matter changes of female brains in 18 FC patients and 20 IBS-C patients compared with a comparison group with 19 healthy controls by tract-based spatial statistics. The correlations between diffusive parameters and clinical symptoms were evaluated using a Pearson’s correlation. RESULTS: In comparison to healthy controls, FC patients showed a decrease of fractional anisotropy (FA) and an increase of radial diffusivity (RD) in multiple major fibers encompassing the corpus callosum (CC, P = 0.001 at peak), external capsule (P = 0.002 at peak), corona radiata (CR, P = 0.001 at peak), and superior longitudinal fasciculus (SLF, P = 0.002 at peak). In contrast, IBS-C patients showed FA and RD aberrations in the CC (P = 0.048 at peak). Moreover, the direct comparison between FC and IBS-C showed only RD differences in the CR and SLF. In addition, FA and RD in the CC were significantly associated with abdominal pain for all patients, whereas FA in CR (P = 0.016) and SLF (P = 0.040) were significantly associated with the length of time per attempt and incomplete evacuation separately for FC patients. CONCLUSION: These results may improve our understanding of the pathophysiological mechanisms underlying different types of constipation.
Abdominal Pain ; Anisotropy ; Brain ; Constipation ; Corpus Callosum ; Diffusion ; Diffusion Tensor Imaging ; External Capsule ; Female ; Humans ; Irritable Bowel Syndrome ; White Matter

BACKGROUND: Bone marrow-derived mononuclear cells (BM-MNCs) hold the potential of differentiating into osteoclasts. Polygonatum sibiricum polysaccharide (PSP) may inhibit the differentiation of BM-MNCs into osteoclasts and it is expected to become a new drug for the treatment of osteoporosis. OBJECTIVE: To investigate the effect of PSP on the differentiation of mouse BM-MNCs into osteoclasts induced by receptor activator of nuclear factor kappa-B ligand (RANKL) and bone resorption in vivo. METHODS: Mouse bone marrow-derived macrophages cultured in vitro, the effect of macrophage colony stimulating factor and PSP (5, 10, 20, 40, 80,160, 320, 640, 1280, 2560 mg/L) on the proliferation of mouse BM-MNCs was detected by cell counting kit-8 assay to determine the PSP concentration range; the mouse BMMs were cultured and induced in DMEM medium containing macrophage colony stimulating factor, RANKL and 5, 10, 20, 40, 80,160, 320, 640 mg/L PSP, respectively; those cultured without PSP served as control group. The morphological changes of cells were observed under an inverted microscope.; the number of osteoclasts was detected by tartrate-resistant acid phosphatase staining; the mRNA expression levels of osteoclast-related genes including tartrate-resistant acid phosphatase, matrix metalloproteinase-9, cathepsin K, and nuclear factor of activated T cells c1 were evaluated by quantitative real-time PCR. A mouse model of calvarial osteolysis induced by lipopolysaccharide was established to receive PSP intervention, and then micro CT scanning, three-dimensional reconstruction and relevants software were used for quantitative analysis of bone volume/volume percentage, trabecular number, trabecular bone spacing and thickness. The number of osteoclasts was identified by tartrate-resistant acid phosphatase staining and quantitative analysis of bone resorption area was conducted. RESULTS AND CONCLUSION: Compared with the control group, the concentration of PSP below 640 mg/L showed no significant effect on the proliferation of BMMs (P > 0.05). Different concentrations of PSP (40-640 mg/L) significantly reduced the number of osteoclasts, osteoclast differentiation and maturation, and the mRNA expression levels of tartrate-resistant acid phosphatase, matrix metalloproteinase-9, cathepsin K, and nuclear factor of activated T cells c1 TRAP, MMP-9, CtsK and NFATc1 (P < 0.05). Compared with lipopolysaccharide, PSP could effectively alleviate the lipopolysaccharide-induced calvarial osteolysis, and the bone volume/volume percentage, trabecular number, and trabecular bone spacing were significantly decreased (P < 0.05); additionally, the number of osteoclasts and the area of bone resorption were decreased significantly (P < 0.01). To conclude, PSP can inhibit the differentiation and maturation of mouse BMMs to osteoclasts and alleviate lipopolysaccharide-induced calvarial osteolysis.

Objective To investigate PSP on bone microstructures,Ca,P,OPG and RANKL of osteoporotic rat model.Methods Thirty female rats randomly divided into five groups:Sham,OVX,H-,M-,L-PSP.Sham and OVX were irrigated stomachsaline;PSP solution was gavaged to other groups.After 8-week,bone microstructures of tibial metaphyseal,Ca,P,OPG and RANKL were measured.Results Body weight,Ca,P,RANKL,Tb.Sp of OVX were significantly increased compared to Sham,OPG,BV/TV,Tb.Th,Tb.N decreased.Body weight of H-,M-PSP,Ca and Tb.Sp of PSP,P and RANKL in H-PSP were decreased compared to OVX,OPG in H-,M-PSP,BV/TV,Tb.Th,Tb.N of PSP group increased.The differences were statistically significant (P ＜ 0.05).Conclusion PSP prevents osteoporosis by improving the microstructure of trabecular bone,reducing bone turnover,increasing OPG and reducing RANKL expression.

BACKGROUND: miRNA plays a critical regulatory role in the development and plasticity of spinal cord, and pathological changes after spinal cord injury. OBJECTIVE: To study the effect of miR-136-5p on the A20 expression in mouse astrocytes stimulated by interleukin-17 (IL-17). METHODS: C57BL/6 mouse astrocytes were cultured in vitro, identified by immunofluorescence staining, and then stimulated by 100 μg/L IL-17 for 0, 3, 6, 12 and 24 hours, respectively. The relative mRNA expression levels of IL-6 and tumor necrosis factor-α were detected by RT-PCR to determine the optimal stimulation time of IL-17. The mouse astrocytes were respectively stimulated by 10, 20, 50, 100 and 200 μg/L IL-7 for 6 hours, and similarly, the relative mRNA expression levels of IL-6 and tumor necrosis factor-α were detected to determine the optimal concentration of IL-17. At 6 hours after IL-17 (50 μg/L) stimulation, the mRNA expression levels of miR-136-5p and A20 in mouse astrocytes were detected by RT- PCR, and the protein expression level of A20 was detected by western blot assay. In addition, the lentiviral expression vector (miR-136-5p-inhibition) was constructed and transfected into the mouse astrocytes that were also stimulated by IL-7 to detect the expression levels of miR-136-5p, A20 mRNA and A20 protein. RESULTS AND CONCLUSION: Compared with the blank control group, the expression level of miR-136-5p in the miR-136-5p-inhibition group was significantly decreased after 6-hour IL-17 stimulation (P < 0.05). The expression levels of A20 mRNA and protein in each group were significantly decreased after 6-hour IL-17 (50 μg/L) stimulation (P < 0.05). The expression levels of A20 mRNA and protein in the miR-136-5p-inhibition group were significantly higher than those in the blank control group (P < 0.05), while there were no significant differences in the expression level of A20 protein between blank control and negative groups (P > 0.05). To conclude, miR-136-5p makes certain effect on the expression of A20 protein in astrocytes after IL-17 stimulation.

BACKGROUND:Our previous studies have found that polygonatum sibiricum polysaccharide (PSP) promotes osteogenic differentiation of bone marrow mesenchymal stem cel s (BMSCs) by Wnt/β-catenin signaling pathway, but the molecular mechanism is unclear.OBJECTIVE:To investigate the effect of PSP promoting the osteogenic differentiation via Wnt signaling pathways in BMSCs after LRP5 silencing. METHODS:LRP5 interference vectors were constructed and then transfected into C57BL/6 mouse BMSCs cultured in vitro. The transfection efficiency of cel s was calculated under fluorescence inverted microscope and the expression of LRP5 protein was detected by western blot assay. The osteogenic potential of BMSCs after LRP5-siRNA transfection was analyzed by alkaline phosphatase staining, alizarin red staining and western blot assay. Effect of PSP on the osteogenic differentiation of LIRP5-silenced mouse BMSCs was detected by real-time PCR and dual luciferase assay. RESULTS AND CONCLUSION:Compared with the control group, the mineralization ability, the mRNA expressions of Runx2 and Osterix, and the protein expression of LRP5 were significantly decreased in the LRP5-siRNA group (P<0.05). PSP could promote LRP5-siRNA transfected mouse BMSCs differentiating into osteoblasts and significantly upregulated the expressions ofβ-catenin and Osterixin, and also induced the high expression of luciferase reporter gene (TOPFlash) containing wild type TCF binding sites (P<0.05). To conclude, LRP5 plays an important role in the process of mouse BMSCs differentiating into osteoblasts. PSP can promote the osteogenic differentiation of mouse BMSCs by activating the Wnt/β-catenin signaling pathway independent on LRP5.