Effects of the commensal microbiota on spleen and mesenteric lymph node immune function: investigation in a germ-free piglet model.

Commensal microbial-host interaction is crucial for host metabolism, growth, development, and immunity. However, research on microbial-host immunity in large animal models has been limited. This study was conducted to investigate the effects of the commensal microbiota on immune function in two model groups: germ-free (GF) and specific-pathogen-free (SPF) piglets. The weight and organ index of the spleen of the GF piglet were larger than those in the SPF piglet (P < 0.05). The histological structure of the red pulp area and mean area of germinal centers were larger in the SPF piglet than in the GF piglet (P < 0.05), whereas the areas of staining of B cells and T cells in the spleen and mesenteric lymph nodes (MLNs) were lower in the GF piglet (P < 0.05). We identified immune-related genes in the spleen and MLNs using RNA sequencing, and used real-time quantitative PCR to analyze the expression of core genes identified in gene set enrichment analysis. The expression levels of genes in the transforming growth factor-ß/SMAD3 signaling pathway, Toll-like receptor 2/MyD88/nuclear factor-κB signaling pathway, and pro-inflammatory factor genes IL-6 and TNF-α in the spleen and MLNs were higher in the SPF piglet and in splenic lymphocytes compared with those in the GF and control group, respectively, under treatment with acetic acid, propionic acid, butyric acid, lipopolysaccharide (LPS), or concanavalin A (ConA). The abundances of plasma cells, CD8++ T cells, follicular helper T cells, and resting natural killer cells in the spleen and MLNs were significantly greater in the SPF piglet than in the GF piglet (P < 0.05). In conclusion, the commensal microbiota influenced the immune tissue structure, abundances of immune cells, and expression of immune-related pathways, indicating the importance of the commensal microbiota for spleen and MLNs development and function. In our study, GF piglet was used as the research model, eliminating the interference of microbiota in the experiment, and providing a suitable and efficient large animal research model for exploring the mechanism of "microbial-host" interactions.

Acetate Alleviates Gut Microbiota Depletion-Induced Retardation of Skeletal Muscle Growth and Development in Young Mice.

The normal growth and development of skeletal muscle is essential for the health of the body. The regulation of skeletal muscle by intestinal microorganisms and their metabolites has been continuously demonstrated. Acetate is the predominant short-chain fatty acids synthesized by gut microbiota through the fermentation of dietary fiber; however, the underlying molecular mechanisms governing the interaction between acetate and skeletal muscle during the rapid growth stage remains to be further elucidated. Herein, specific pathogen-free (SPF) mice, germ-free (GF) mice, and germ-free mice supplemented with sodium acetate (GS) were used to evaluate the effects of acetate on the skeletal muscle growth and development of young mice with gut microbiota deficiency. We found that the concentration of serum acetate, body mass gain, succinate dehydrogenase activity, and expression of the myogenesis maker gene of skeletal muscle in the GS group were higher than those in the GF group, following sodium acetate supplementation. Furthermore, the transcriptome analysis revealed that acetate activated the biological processes that regulate skeletal muscle growth and development in the GF group, which are otherwise inhibited due to a gut microbiota deficiency. The in vitro experiment showed that acetate up-regulated Gm16062 to promote skeletal muscle cell differentiation. Overall, our findings proved that acetate promotes skeletal muscle growth and development in young mice via increasing Gm16062 expression.

The effect of canagliflozin on gut microbiota and metabolites in type 2 diabetic mice.

BACKGROUND: Sodium glucose cotransporter 2 inhibitor (SGLT2i) represent a new type of hypoglycemic medicine that can cause massive loss of glucose from the urine, which have several benefits of reducing body weight and improving the prognosis of cardiovascular and kidney diseases. Although they are oral medicated hypoglycemic agents, their effects on the gut microbiome and function have been unclear. OBJECTIVE: In order to describe the effects of canagliflozin on intestinal flora and metabolites, diabetic mice were randomized to receive canagliflozin or isoconcentration carboxymethylcellulose sodium by gavage for 8 weeks. Feces were collected for 16 S rRNA gene and LC-MS/MS analysis and enriched metabolic pathways through Kyoto Encyclopedia of Genes and Genomes (KEGG). Liver, muscle, intestinal, fat were collected for qRT-PCR according to KEGG enriched metabolic pathways. RESULTS: Our results showed that canagliflozin significantly increased GLP-1 level and impacted on the composition of gut microbiota and metabolites. It mainly increased Muribaculum, Ruminococcaceae_UCG_014, Lachnospiraceae-UCG-001, decreased ursodeoxycholic acids (UDCA) and hyodeoxycholic acids (HDCA), and increased fatty acids metabolites in feces. CONCLUSION: In conclusion, we analyzed the changes of intestinal microbial composition and metabolites in diabetic mice after canagliflozin intervention and found that canagliflozin influenced intestinal fatty acid and bile acid (BA) metabolism. This study will provide reference for subsequent SGLT2i and intestinal related research.

Commensal microbiota modulates phenotypic characteristics and gene expression in piglet Peyer's patches.

The gastrointestinal tract contains a complex microbial community. Peyer's patches (PPs) play an important role in inducing mucosal immune responses in the gastrointestinal tract. However, little is known about the effect of commensal microbiota on the host's PPs. Here, we analyzed the phenotypic-to-transcriptome changes in the intestine PPs of specific pathogen-free (SPF) and germ-free (GF) piglets (fed in an environment with and without commensal microbiota, respectively) to elucidate the role of commensal microbiota in host intestine mucosal immunity. Analyses of anatomical and histological characteristics showed that commensal microbiota deficiency led to PP hypoplasia, especially regarding B and T cells. A total of 12,444 mRNAs were expressed in 12 libraries; 2,156 and 425 differentially expressed (DE) mRNAs were detected in the jejunal PP (JPP) and ileal PP (IPP), respectively (SPF vs. GF). The shared DE mRNAs of the JPP and IPP were mainly involved in basic physiological and metabolic processes, while the specific DE mRNAs were enriched in regulating immune cells in the JPP and microbial responses and cellular immunity in the IPP. Commensal microbiota significantly modulated the expression of genes related to B-cell functions, including activation, proliferation, differentiation, apoptosis, receptor signaling, germinal center formation, and IgA isotype class switching, particularly in the JPP. TLR4 pathway-related genes were induced in response to microbial colonization and in LPS/SCFA-treated B cells. We also detected 69 and 21 DE lncRNAs in the JPP and IPP, respectively, and four one-to-one lncRNA-mRNA pairs were identified. These findings might represent key regulatory axes for host intestine mucosal immunity development during microbial colonization. Overall, the findings of this study revealed that commensal microbiota modulated phenotypic characteristics and gene expression in the piglet intestine PPs and underscored the importance of early microbial colonization for host mucosal immunity development.

A longitudinal cohort study on benefit finding evolution in Chinese women breast cancer survivals.

Even though the prevalence of benefit finding (BF) has been empirically shown to exist among breast cancer (BC) survivals, how does benefit finding evolve over time remains inadequately investigated. The objective of this cohort study is to examine how BF evolves over time among Chinese breast cancer survivals and determine the demographic, medical and psychosocial factors that can sustain BF increase over time. Participants were 486 women with different stages of breast cancer (stages I, II and III) followed from completion of primary treatment. Analysis were performed on the data collected during 2014-2019. During the assessment, each participant completed self-report questionnaires of characteristics and benefit finding at six time points with the interval of 6 months since BC diagnosis. The relationships between demographic, medical and psychosocial characteristics and benefit finding evolution over time were examined using mixed models. Participants reported mixed results on the evolving patterns of benefit finding: 28% reported an upward trend in BF scoring over time, 49% instead reported an downward trend, and the remaining 23% reported no obvious change. Our study has shown that some well-known covariates of benefit finding, e.g. education, income, and social support, are not associated with BF trends. In comparison, levels of spirituality and disease coping at diagnosis can more reliably predict BF evolution over time. Identifying the sustaining factors of benefit finding in the experience of breast cancer is the key to design effective psycho clinical solutions for patients' long-term post-traumatic growth. As time goes by, breast cancer patients may experience less benefit finding. Our results strongly indicate that benefit finding can be sustained and increased by encouraging attempts at meaning-making and active disease coping during breast cancer treatment. To the best of our knowledge, this study is among the first to examine the evolution trends of benefit finding over time on breast cancer survivals and determine their psychosocial predictors in developing countries.

Expression of S100A6 in rat hippocampus after traumatic brain injury due to lateral head acceleration.

In a rat model of traumatic brain injury (TBI), we investigated changes in cognitive function and S100A6 expression in the hippocampus. TBI-associated changes in this protein have not previously been reported. Rat S100A6 was studied via immunohistochemical staining, Western blot, and reverse transcription-polymerase chain reaction (RT-PCR) after either lateral head acceleration or sham. Reduced levels of S100A6 protein and mRNA were observed 1 h after TBI, followed by gradual increases over 6, 12, 24, and 72 h, and then a return to sham level at 14 day. Morris water maze (MWM) test was used to evaluate animal spatial cognition. TBI- and sham-rats showed an apparent learning curve, expressed as escape latency. Although TBI-rats displayed a relatively poorer cognitive ability than sham-rats, the disparity was not significant early post-injury. Marked cognitive deficits in TBI-rats were observed at 72 h post-injury compared with sham animals. TBI-rats showed decreased times in platform crossing in the daily MWM test; the performance at 72 h post-injury was the worst. In conclusion, a reduction in S100A6 may be one of the early events that lead to secondary cognitive decline after TBI, and its subsequent elevation is tightly linked with cognitive improvement. S100A6 may play important roles in neuronal degeneration and regeneration in TBI.

Antisense oligodeoxynucleotides targeting connexin43 reduce cerebral astrocytosis and edema in a rat model of traumatic brain injury.

OBJECTIVE: Brain injury induces an acute increase in the expression of gap junction protein connexin43 (Cx43). It also leads to cerebral edema, probably due to the swelling and proliferation of astrocytes reactive to the injury. Antisense oligodeoxynucleotides (AS-ODN) targeting Cx43 were tested for their ability to reduce reactive astrocytosis and cerebral edema in a rat model of traumatic brain injury (TBI). METHODS: The brains of experimental animals were intraventricularly injected with these AS-ODNs, while sham rats and normal controls were administered saline in the same way. Controlled cortical impact (CCI) injury was induced in both experimental and sham rats, then the damaged brain tissue was stained for glial fibrillary acidic protein (GFAP) immunofluorescein, measured for water content using the wet-dry weight method, and examined for Cx43 protein expression by western blotting. RESULTS: The brains of both experimental and sham groups were found to have a higher level of Cx43 expression, higher water content, and more swollen and proliferative astrocytes than the normal controls at 6 hours, 24 hours, and 48 hours post-trauma. But compared with the sham animals, brains of experimental rats showed less Cx43 expression, lower water content, and less swollen and proliferative astrocytes. These two brain-injured groups displayed a similar pattern of changes in these outcomes over the 48-hour time period studied. DISCUSSION: Antisense oligodeoxynucleotides targeting Cx43 reduced reactive astrocytosis and cerebral edema following TBI, indicating that Cx43 might be involved in regulating the water imbalance between brain cells.

Expression of candidate plasticity-related gene 15 is increased following traumatic brain injury.

OBJECTIVES: Candidate plasticity-related gene 15 (cpg15) is an activity-regulated gene that mediates synaptic plasticity; this study assesses the potential link between cpg15 expression levels and repair and regeneration following traumatic brain injury (TBI). METHODS: We investigated the expression of cpg15 in the frontal lobe of rats subjected to TBI and sham rats, using the following methods: immunohistochemical analysis, Western blotting, and reverse transcription-polymerase chain reaction. RESULTS: CPG15(+) neurons were present in coronal sections of the frontal lobe at Day 1, reached the highest level around Day 14, and maintained elevated levels through Day 21. CPG15 protein and mRNA levels were noticed to increase in a similar temporal pattern. In contrast, rats in the sham group had undetectable levels of CPG15. CONCLUSIONS: Elevated cpg15 expression in the frontal cortex suggests its possible involvement in regenerative and reparative processes that follow TBI.

SDR9C7 promotes lymph node metastases in patients with esophageal squamous cell carcinoma.

BACKGROUND: The major reason for the poor prognosis of esophageal squamous cell carcinoma (ESCC) patients is lymph node (LN) metastases. METHODOLOGY/PRINCIPAL: In the present study, gene expression profiling assay (GEP) was performed to identify the differences in gene expression profiles between primary ESCC tumors that were with LN metastases (N(+)) and those without LN metastases (N(-)). CONCLUSIONS/SIGNIFICANCE: A total of 23 genes were identified as being significantly elevated, and 30 genes were sharply decreased in ESCC tumors that were N(+) compared with N- tumors. Among these genes, two transcripts of the short chain dehydrogenase/reductase family 9C, member 7 (SDR9C7) were observed 7 times more frequently in N(+) compared with N(-) tumors. Immunohistochemical staining showed that SDR9C7 expression closely correlated with metastasis, and would be a prognostic marker for ESCC patients. To investigate the role of SDR9C7 in the ESCC metastasis, repeated transwell assays were adopted to establish highly and non-invasive ESCC sublines, and western blot showed that SDR9C7 expression was markedly higher in highly invasive cells compared with non-invasive ones. Down-regulation of SDR9C7 dramatically inhibited the metastatic abilities in vitro and in vivo, and repressed the expression of MMP11 in highly invasive cells, indicating that SDR9C7 promotes ESCC metastasis partly through regulation of MMP11, and might be a potential prognostic and therapeutic marker for ESCC patients.

MicroRNA-501 promotes HBV replication by targeting HBXIP.

MicroRNAs (miRNAs) can negatively regulate gene expression and also induce or inhibit viral replication. In the present study, we found 10 miRNAs were differentially expressed in a stable HBV-producing cell line (HepG2.2.15) compared with its control cell line (HepG2) by miRNA array analysis. miR-501 was significantly up-regulated in HepG2 cells and tissues with high-HBV replication. miR-501 expression was significantly up-regulated in hepatocellular carcinoma tissues, where HBV replication kept high. Down-regulating miR-501 could significantly inhibit HBV replication, but not influence the growth of HepG2.2.15 cells. Luciferase reporter and western blot assays revealed that HBXIP, an inhibitor of HBV replication, was a potential target of miR-501. Moreover, knockdown of HBXIP rescued the inhibition of HBV that occurred after the loss of miR-501 in HepG2.2.15 cells, suggesting that miR-501 induced HBV replication partially by targeting HBXIP. Thus, knockdown of miR-501 might provide a new mechanism and therapeutic target for inhibiting HBV replication.

PCP can enhance dendritic cells to present the HBsAg peptide.

AIM: To investigate the influence of paraclorophenol (pCP) on dendritic cells loading and presenting HBsAg from peripheral blood monocytes of healthy volunteers identified as hepatitis B vaccine nonresponders. METHODS: The density gradient centrifugation was performed to isolate mononuclear cells from 10 hepatitis B vaccine nonresponders. The adherent monocytes were incubated with HBsAg adding rhGM-CSF and rhIL-4 in the presence of absence of pCP for 7 days. Then the supernatant was collected for ELISA assays. The culture medium system without pCP was used as negative control and without pCP or HBsAG was named blank control. the matured DCs were co-incubated with autologous T lymphocytes for 72h and the supernatant was also collected for ELISA assays. RESULTS: In the presence of pCP, the level of IL-12 in supernate (265.68± 16.21) ng/L was significantly higher than the negative control (168.76±10.01) ng/L (P<0.05) and blank control (87±5.79)ng/L (P<0.05); after co-incubated with autologous T lymphocytes for 3 days, the level of IFN-γ with pCP (773.04±32.73) mg/L was also significantly higher than the negative control (573.59±26.11) mg/L (P<0.05) ans blank control (362.81±24.27)mg/L (P<0.05). CONCLUSION: pCP can effectively enhance the dendritic cells loading and presenting HBsAg from peripheral blood monocytes of healthy volunteers identified as hepatitis B vaccine nonresponders, which also can dramatically increase te autologous T lymphocytes response.7

Overexpression of a novel gene gankyrin correlates with the malignant phenotype of colorectal cancer.

Gankyrin, a small and highly conserved protein which is identical to the p28 gene product, was found to be related with the malignant phenotypes in liver and esophageal carcinoma. However, the roles of gankyrin in colorectal carcinoma (CRC) are still unknown. In the present study, the gankyrin mRNA and protein expression in human CRC cell lines and clinical tissue samples were evaluated and correlated with clinicopathological features. Possible mechanisms by which gankyrin regulates the malignant phenotype of CRC cells were also investigated. The results demonstrated that gankyrin was obviously overexpressed in CRC tissues and cell lines compared to controls, and gankyrin expression was correlated with TNM stages and metastasis of CRC. Overexpression of gankyrin by PhkitNeo-hGankyrin plasmid transfected into Lovo cells could promote the cell proliferation and tumorigenicity. This finding was further strengthened by experiments that suppressing gankyrin expression by siRNA exerted the opposite effects on CRC cells SW620. In addition, our present study showed that the co-expression of cyclinD1 and beta-catenin were positive correlation with the alteration of gankyrin expression. This data suggested that gankyrin played significant roles in the pathogenesis of human CRC, and might be an important therapeutic target for CRC.

The expression of hypoxia-inducible factor-1alpha in hepatitis B virus-related hepatocellular carcinoma: correlation with patients' prognosis and hepatitis B virus X protein.

Hypoxia inducible factor-1alpha (HIF-1alpha) was well correlated with carcinogenesis and tumor progression in many kinds of cancer. In this study, high expression of HIF-1alpha was found in 37 of the 72 (51.39%) tumor specimens, and significantly correlated with venous invasion and lymphonode invasion. Patients with high expression of HIF-1alpha had a significantly shorter overall survival rate and disease-free survival rate than those with low expression. Multivariate analysis showed high HIF-1alpha expression was a borderline independent factor of overall survival. HIF-1alpha expression was also found to be significantly correlated with the expression of hepatitis B virus X protein (HBx), and over-expressed HBx upregulated HIF-1alpha protein expression in vitro. These results suggested that HIF-1alpha, which was partially regulated by HBx, might be a prognostic marker of HBV-related HCC patients.

[Construction of eukaryotic expression vector of siRNA specific for MAD2 and its effect on the growth of gastric cell line SGC7901].

AIM: To construct the RNA interference eukaryotic expression vector specific for human MAD2 gene and to observe its effect on the growth of gastric cancer cell line SGC7901. METHODS: The expression vectors of pSilencer3.1/MAD2-siRNA1 and pSilencer3.1/MAD2-siRNA2 were constructed by gene recombination and then were stably transfected into the gastric carcinoma cell line SGC7901 by liposome mediation. The expression of MAD2 on the levels of protein and mRNA was detected by Western blot and RT-PCR, and the monoclone with the highest inhibition efficiency was selected. The growth of the transfected cells was assessed by MTT. And the cells treated with 1.0 mg/L vincristine (VCR) for 24 h were analyzed by FCM for cell cycle. RESULTS: Sequence-specific siRNAs targeting MAD2 significantly down regulated the expression of MAD2 in SGC7901 cells. In MAD2-siRNA transfected cells, the rate of cell growth increased markedly and cell cycle couldn't be arrested in M phase induced by VCR, while the cells transfected with the mock vector could. CONCLUSION: Down regulation of MAD2 expression of SGC7901 bv sequence-specific siRNA could accelerate the cell growth and impair the mitosis arrest of SGC7901 induced by VCR.

Enhanced cell survival of gastric cancer cells by a novel gene URG4.

Upregulated gene 4 (URG4), a novel gene located on 7 chromosome (7p13), was found to contribute to hepatocarcinogenesis. However, the role of URG4 in the gastric carcinogenesis still remains unclear. In the present study, URG4 was found by immunohistochemistry to be upregulated in human gastric cancer tissues compared with matched adjacent nonneoplastic tissues. The proliferating cell nuclear antigen index is higher in gastric cancer tissues with high URG4 expression than in those with low URG4 expression. The growth of GES-1 cells, which are immortalized human gastric epithelial mucosa cells with baseline URG4 expression, was accelerated by URG4 induction. Downregulation of URG4 through URG4 small interfering RNA (siRNA) in SGC7901 and MKN28 cells, which had high endogenous URG4 expression, suppressed cell proliferation in both of these cells. URG4-siRNA also inhibited the proliferation of SGC7901 and MKN28 cells in soft agar and tumor formation in nude mice. Overexpression of URG4 in GES cells upregulated cyclin D1, whereas repression of URG4 in SGC7901 and MKN28 cells downregulated cyclin D1. The data suggested that URG4 played an important role in the development of human gastric cancer by regulating the expression of cyclin D1 and might be used as a potential therapeutic target for gastric cancer.