OBJECTIVE: To explore the role of semaphorin 4D (Sema4D) in immunoglobulin A (IgA) -mediated immune abnormalities in B lymphocytes of pediatric Henoch-Schonlein purpura (HSP). METHODS: One hundred HSP children admitted to Hengshui People's Hospital from January 2022 to January 2023 were selected as HSP group, and one hundred healthy children as control group. Sema4D expression was detected, and the relationship between Sema4D expression in children's serum and skin lesions and clinical characteristics of children was analyzed. Sema4D expression on the surface of lymphocytes of HSP children was detected. Different concentrations of human recombinant Sema4D protein was used to stimulate peripheral blood mononuclear cells in HSP children in vitro. The expression level of IgA in the supernatant was detected to verify whether Sema4D mediates immune abnormalities through IgA secreted by B lymphocytes. RESULTS: The Sema4D level in the HSP group was significantly higher than that in the control group (P <0.001). Sema4D level in HSP children with severe, renal involvement, and joint involvement was higher than those with mild to moderate disease, and no renal or joint involvement (all P <0.001). Compared with control group, IgA level, CD8 ⁺ T lymphocyte proportion, and CD19 ⁺ B lymphocyte proportion in the HSP group were significantly higher but CD4 ⁺ T lymphocyte proportion was lower (all P <0.001). The expression levels of Sema4D on the surface of CD4 ⁺ T lymphocytes, CD8 ⁺ T lymphocytes, and CD19 ⁺ B lymphocytes in the HSP group were significantly higher than those in the control group (all P <0.001). With the increase of human recombinant Sema4D protein concentration, the level of IgA expression in HSP children gradually increased (P <0.05). Correlation analysis showed that Sema4D was significantly positively correlated with IgA (r =0.667). CONCLUSION HSP children show high expression of Sema4D, especially on the surface of T and B lymphocytes. The shedding of Sema4D from membrane surface may stimulate B lymphocytes to secrete IgA by binding to CD72, leading to immune abnormalities.
Humans ; IgA Vasculitis/immunology* ; Semaphorins/metabolism* ; B-Lymphocytes/metabolism* ; Immunoglobulin A/immunology* ; Child ; Antigens, CD/metabolism* ; Male ; Female ; Child, Preschool

OBJECTIVES: To establish a prognostic model for primary liver cancer (PLC) using bioinformatics methods. METHODS: Based on the data from 404 patients in the Cancer Genome Atlas (TCGA) database, we constructed a prognostic model integrating the differentially expressed genes, anoikis, and immune-related genes (DAIs) using univariate Cox regression and the LASSO-Cox approach. The predictive ability of the model was evaluated using Kaplan-Meier method and receiver-operating characteristic curves, and a nomogram was developed to facilitate its clinical applications. Gene set enrichment analysis (GSEA) was performed to explore the associated pathways and relationship between the DAIs and the tumor immune microenvironment, and the half-maximal inhibitory concentration (IC₅₀) of liver cancer drugs was calculated using the "pRRophetic" R package. We also detected the expression of SEMA7A in paired tumor and adjacent tissues from liver cancer patients. RESULTS: We constructed and validated a prognostic model based on 7 DAIs (NR4A3, SEMA7A, IL11, AR, BIRC5, EGF, and SPP1), and obtained consistent results in both the TCGA training cohort and GEO validation cohort (GSE14520), where the patients in the low-risk group were characterized by more favorable clinical outcomes and immune status. By integrating this prognostic signature with clinical information, a composite nomogram was generated. Somatic mutation analysis showed that TTN, TP53, and CTNNB1 mutations accounted for the largest proportion of total mutations, and the patients in the low-risk-low-TMB group had higher survival rate. Drug sensitivity analysis revealed differences in sensitivity to chemotherapeutic agents between high- and low-risk groups and between TP53 mutations and non-mutations. In clinical tissue specimens, SEMA7A expression was significantly higher in liver cancer tissues than in the adjacent tissues. CONCLUSIONS We established a new prognostic model based on DAIs for predicting clinical outcomes and therapeutic response of patients with primary liver cancer.
Humans ; Liver Neoplasms/diagnosis* ; Prognosis ; Anoikis ; Nomograms ; Computational Biology ; Tumor Microenvironment ; Semaphorins/metabolism*

Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of the extremity, such as joint pain, joint stiffness, bone deformity, etc. Differentiation and maturation of osteoblasts were regulated by osteoclasts via Sema4D/Plexin-B1 signaling pathway. Furthermore, the differentiation and maturation of osteoclasts are conducted by osteoblasts via RANKL/RANK/OPG pathway. Both of these processes form a feedback circuit which is a key link in skeletal fluorosis. In this study, an osteoblast-osteoclast co-culture model in vitro was developed to illustrate the mechanism of skeletal fluorosis. With the increase of fluoride concentration, the expression level of Sema4D was decreased and TGF-β1 was increased continuously. OPG/RANKL mRNA level, however, increased gradually. On the basis of that, the inhibition of Sema4D/Plexin-B1/RhoA/ROCK signaling pathway caused by fluoride promoted the level of TGF-β1 and activated the proliferation of osteoblasts. In addition, osteroprotegerin (OPG) secreted by osteoblasts was up-regulated by fluoride. The competitive combination of OPG and RANKL was strengthened and the combination of RANKL and RANK was hindered. And then the differentiation and maturation of osteoclasts were inhibited, and bone absorption was weakened, leading to skeletal fluorosis.
Animals ; Antigens, CD ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Feedback, Physiological ; Fetus ; Fluorides ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Gene Expression Regulation, Developmental ; Osteoblasts ; drug effects ; metabolism ; pathology ; Osteoclasts ; drug effects ; metabolism ; pathology ; Osteogenesis ; drug effects ; genetics ; Osteoprotegerin ; genetics ; metabolism ; RANK Ligand ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Receptor Activator of Nuclear Factor-kappa B ; genetics ; metabolism ; Receptors, Cell Surface ; genetics ; metabolism ; Semaphorins ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; genetics ; metabolism ; rho-Associated Kinases ; genetics ; metabolism ; rhoA GTP-Binding Protein ; genetics ; metabolism

OBJECTIVETo compare the expressions of hypoxia-inducible factor 1 alpha(HIF-1α) and Semaphorin 4D(Sema4D) in colorectal carcinoma and normal colorectal tissues, and to investigate their correlation and clinical significance.

METHODSThe expressions of HIF-1α and Sema4D were examined in 86 cases of colorectal carcinoma and 52 normal colorectal tissues by SP immunohistochemical staining. Correlation between these two expressions and association of the expressions with clinicopathological characters and prognosis were analyzed.

RESULTSThe positive rates of HIF-1α and Sema4D protein in colorectal carcinoma tissues were significantly higher than those in normal colorectal tissues(58.1% vs. 7.7%, χ(2)=34.624, P<0.01; 60.5% vs. 11.5%, χ(2)=31.839, P<0.01). HIF-1α and Sema4D protein expressions were closely associated with colorectal carcinoma histological types(P=0.003, P=0.010), TNM staging (P=0.003, P=0.017) and lymphatic metastasis (P=0.003, P=0.020), and a significant correlation was observed between the expressions of HIF-1α and Sema4D protein (r=0.567, P<0.01). The 5-year overall survival rate was 37%. Univariate analysis showed that 5-year survival rates of patients with positive and negative HIF-1α protein expression were 24% and 56%(P=0.003), and those with positive and negative Sema4D protein expression were 23% and 59%(P=0.001). Multivariate Cox analysis showed that expression of Sema4D was an independent prognostic factor of colorectal cancer patients(P=0.026), while expression of HIF-1α was not(P=0.501).

CONCLUSIONCombined detection of HIF-1α and Sema4D has the potential to predict the development trend of colorectal carcinoma and prognosis of patients.

Antigens, CD ; metabolism ; Colorectal Neoplasms ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Lymphatic Metastasis ; Neoplasm Staging ; Prognosis ; Semaphorins ; metabolism ; Survival Rate

BACKGROUNDHypoxia promotes tumor angiogenesis and hypoxia-inducible factor-1 alpha (HIF-1α) plays a pivotal role in this process. Recently identified pro-angiogenic factor, semaphorin4D (Sema4D) also promotes angiogenesis and enhances invasive proliferation in some tumors. Furthermore, tumor-associated macrophages (TAMs) can increase the expression of HIF-1α and Sema4D in cancer cells and thus influence tumor growth and progression. The purpose of this study was to evaluate the effect of TAMs on the expression of Sema4D and HIF-1α and the impact of biologic behavior in colon cancer cells.

METHODSImmunohistochemistry was used to analyze HIF-1α and Sema4D expression in 86 curatively resected colon cancer samples and 52 normal colon tissues samples. The relationship between their expression and clinicopathological factors was analyzed. Furthermore, macrophage-tumor cell interactions, such as metastasis, angiogenesis, were also studied using in vitro co-culture systems. Statistical analysis was performed using SPSS 17.0 software (SPSS Inc., USA). Differences between two groups were analyzed with Student's t test.

RESULTSHIF-1α (58%) and Sema4D (60%) were expressed at a significantly higher level in tumors than in normal tissues (P < 0.01, for both). Furthermore, HIF-1α and Sema4D expression was significantly correlated with lymphatic metastasis, specific histological types and TNM stages (P < 0.05), but not with age and tumor size (P > 0.05). Sema4D expression was correlated with that of HIF-1α (r = 0.567, P < 0.01). TAMs markedly induced HIF-1α and Sema4D expression in colon cancer cells and subsequently increased their migration and invasion.

CONCLUSIONSHIF-1α and Sema4D expression are closely related to lymphatic metastasis, specific histological types and TNM stages in colon cancer. Furthermore, TAMs promote migration and invasion of colon cancer cells and endothelial tube formation, possibly through up-regulation of HIF-1α and Sema4D.

Adult ; Aged ; Antigens, CD ; genetics ; metabolism ; Cell Line, Tumor ; Colonic Neoplasms ; genetics ; metabolism ; Female ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Immunohistochemistry ; Macrophages ; immunology ; metabolism ; Male ; Middle Aged ; Neoplasm Metastasis ; genetics ; pathology ; Semaphorins ; genetics ; metabolism

This study aimed to explore Semaphrin4D (Sema4D) expression and clinical significance in non-small cell lung cancer (NSCLC), and to define the roles and mechanisms of Sema4D in regulating the malignant behaviors of A549 cells by small interfering RNA (siRNA). Firstly, immunohistochemistry revealed that Sema4D was more frequently expressed in NSCLC than in lung benign lesion (P<0.05) and its overexpression was associated with low differentiation (P<0.05), poor pTNM staging (P<0.05) and occurrence of lymph node (LN) metastasis (P<0.05). Endogenous Sema4D expression was suppressed by Sema4D siRNA in A549 cells overexpressing Sema4D. Protein levels of Sema4D, total Akt and p-Akt were examined by Western blotting. Cell proliferation, migration and invasion abilities were measured by MTT assay and Transwell assay respectively. Results showed that Sema4D siRNA significantly suppressed phosphorylation of AKT in A549 cells, but it did not alter total AKT expression. In addition, efficient down-regulation of SemaD significantly inhibit cell proliferation (P<0.05), migration (P<0.05) and invasion (P<0.05) in A549 cells. These findings suggest that Sema4D might serve as a reliable tool for early prediction of NSCLC poor prognosis. Sema4D could play an important role in promoting tumor proliferation, migration and metastasis in the NSCLC, by influencing the Akt protein phosphorylation. Inhibition of Sema4D may be a useful approach for the treatment of NSCLC.
Aged ; Antigens, CD ; biosynthesis ; Carcinoma, Non-Small-Cell Lung ; metabolism ; mortality ; pathology ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease-Free Survival ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; metabolism ; mortality ; pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Invasiveness ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Semaphorins ; biosynthesis ; Survival Rate

Erbin, a member of Leucine-rich repeat and PDZ-containing protein family, was found to inhibit TGF-β-induced epithelial-mesenchymal transition (EMT) in our previous study. However, the mechanism of Erbin in regulating EMT is unclear. Semaphorin protein Sema4C, with PDZ binding site at C-terminal has been recognized as a positive regulator of EMT. Here, we aimed to examine the interaction between Erbin and Sema4C. HK2 cells were treated with TGF-β1, or transfected with Erbin and (or) Sema4C. Interaction of Erbin and Sema4C was identified by immunoprecipitation. RT-PCR was used to detect the expression of Erbin and Sema4C at mRNA level after transfection. The expression levels of Erbin, Sema4C, and markers of EMT were measured by using Western blotting or ELISA. After HK2 cells were stimulated with 10 ng/mL TGF-β1 for 72 h, the protein expression levels of Erbin and Sema4C were both up-regulated, and immunoprecipitation results showed Erbin interacted with Sema4C in HK2 cells both at endogenous and exogenous levels. Furthermore, overexpression of Sema4C suppressed E-cadherin, induced vimentin and promoted fibronectin secretion, indicating Sema4C promotes the process of EMT. However, HK2 cells overexpressing Erbin were resistant to Sema4C-induced EMT. In contrast, Erbin specific siRNA promoted EMT induced by Sema4C. Taken together, these results suggest that Erbin can interact with Sema4C, and co-expression of Erbin blocks the process of Sema4C-induced EMT.
Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Blotting, Western ; Cadherins ; metabolism ; Cell Line ; Epithelial-Mesenchymal Transition ; Humans ; Immunoprecipitation ; Kidney Tubules, Proximal ; cytology ; drug effects ; metabolism ; Protein Binding ; RNA Interference ; Reverse Transcriptase Polymerase Chain Reaction ; Semaphorins ; genetics ; metabolism ; Transfection ; Transforming Growth Factor beta1 ; pharmacology ; Vimentin ; metabolism

Plexins and semaphorins are a large family of proteins that are involved in cell movement and response. The importance of plexins and semaphorins has been emphasized by their discovery in many organ systems including the nervous (Nkyimbeng-Takwi and Chapoval, 2011; McCormick and Leipzig, 2012; Yaron and Sprinzak, 2012), epithelial (Miao et al., 1999; Fujii et al., 2002), and immune systems (Takamatsu and Kumanogoh, 2012) as well as diverse cell processes including angiogenesis (Serini et al., 2009; Sakurai et al., 2012), embryogenesis (Perala et al., 2012), and cancer (Potiron et al., 2009; Micucci et al., 2010). Plexins and semaphorins are transmembrane proteins that share a conserved extracellular semaphorin domain (Hota and Buck, 2012). The plexins and semaphorins are divided into four and eight subfamilies respectively based on their structural homology. Semaphorins are relatively small proteins containing the extracellular semaphorin domain and short intracellular tails. Plexins contain the semaphorin domain and long intracellular tails (Hota and Buck, 2012). The majority of plexin and semaphorin research has focused on the nervous system, particularly the developing nervous system, where these proteins are found to mediate many common neuronal cell processes including cell movement, cytoskeletal rearrangement, and signal transduction (Choi et al., 2008; Takamatsu et al., 2010). Their roles in the immune system are the focus of this review.
Animals ; Cell Adhesion Molecules ; immunology ; metabolism ; Humans ; Immunity ; Nerve Tissue Proteins ; immunology ; metabolism ; Semaphorins ; immunology ; metabolism

OBJECTIVETo explore the expression and clinical significance of Semaphorin4D (Sema4D) mRNA in peripheral blood lymphocyte, Sema4D on platelet surface, soluble Sema4D (sSema4D) in plasma in patients with cerebral infarction.

METHODSTaking 299 patients with cerebral infarction as the case group while 195 healthy adults as the control group. The mRNA expression of Sema4D was detected by Real-time PCR, and Sema4D expression on platelet by flow cytometry, sSema4D by ELISA. Then, the expression of Sema4D on platelet surface and the concentration of sSema4D in plasma of the 195 selected patients following 2 weeks' treatment were tested.

RESULTSThe expression of Sema4D mRNA significantly increased in the case group \[(2.23, 2.66)×10(4) IU/ml\] than in the control group \[(0.49, 0.53)×10(4)IU/ml\] (P < 0.01). The level of Sema4D on platelet surface in the case group (191.62 ± 46.56) significantly decreased than in the control group (303.33 ± 112.66) (P < 0.01). But the concentration of sSema4D in plasma in the case group \[(1.34 ± 0.56) µg/L\] was obviously higher than in the control group \[(0.61 ± 0.31) µg/L\] (P < 0.01). The expression of Sema4D on platelet was obviously relevant with the concentration of sSema4D in plasma in the case group with the correlation coefficient as 0.328 (P < 0.01). The expression of Sema4D on platelet obviously peaked up following 2 weeks' routine therapy in the case group, which was close to that in the control group. Meanwhile the concentration of sSema4D in plasma was downward corrected to the normal in the case group.

CONCLUSIONThe increased expressions and plasma levels, and reduced expressions on platelet of Sema4D in acute period, which returned to normal 2 weeks after treatment in the case group may be related to the occurrence of acute cerebral infarction, reflecting the development process of cerebral infarction.

Aged ; Antigens, CD ; blood ; metabolism ; Blood Platelets ; metabolism ; Case-Control Studies ; Cerebral Infarction ; blood ; Female ; Humans ; Lymphocytes ; metabolism ; Male ; Middle Aged ; Semaphorins ; blood ; metabolism

Adult ; Cytokines ; metabolism ; Female ; Gene Expression ; Humans ; Interleukin-2 ; blood ; Interleukin-4 ; blood ; Male ; Semaphorins ; genetics ; metabolism ; T-Lymphocytes, Helper-Inducer ; metabolism ; Thrombocytopenia ; genetics ; metabolism