Curcumin and LOXblock-1 ameliorate ischemia-reperfusion induced inflammation and acute kidney injury by suppressing the semaphorin-plexin pathway.

AIMS: Ischemia/reperfusion (I/R) is one of the most important causes of acute kidney injury (AKI), a clinical syndrome with kidney dysfunction and high mortality rates. New diagnostic biomarkers need to be defined to better illuminate the pathophysiology of AKI. For the first time, we aim to investigate the protective effects of Curcumin which is known for its antioxidant and anti-inflammatory properties and 12/15 lipoxygenase inhibitor LOXblock-1 on I/R induced AKI by modulating inflammatory processes, oxidative stress, apoptosis and semaphorin-plexin pathway. MAIN METHODS: The rats were divided into five groups, with eight animals per group: Sham, I/R, I/R + DMSO (1%, i.p.), I/R + Curcumin (100 mg/kg, i.p.), I/R + LOXblock-1 (2 µg/kg, i.p.). KEY FINDINGS: The renal function biomarkers (BUN, CREA and UA) in serum were significantly increased in the I/R group. The inflammatory (TNF-α, IL-6 and MCP-1), apoptotic (CYCS and CASP3) and oxidative stress parameters (MDA, MPO, TAS and TOS) measured by ELISA were significantly increased in the I/R group. In histopathological analysis, it was observed that I/R caused serious damage to kidney tissue. SEMA3A was found to increase both serum level and mRNA expression in I/R group. It was observed that curcumin and LOXblock-1 reduce inflammatory processes, oxidative stress and apoptosis via the semaphorin-plexin pathway by both measurements and histopathological analysis. Curcumin was proved more effective than LOXblock-1 with its antioxidant feature in I/R injury. SIGNIFICANCE: The current study reveals the protective effects of Curcumin and LOXblock-1 on acute kidney injury by suppressing SEMA3A as a new biomarker.

Gene expression of semaphorin-3A, semaphorin-7A, neuropilin-1, plexin-C1, and ß1 integrin in treated-multiple sclerosis patients.

OBJECTIVE: Recently, members of the semaphorin family have received major attention in various medical fields, especially autoimmunity. In this study, we selected semaphorin-3A (Sema3A), semaphorin-7A (Sema7A), and their receptors to determine the possible relationship between these molecules and multiple sclerosis (MS). METHOD: We measured the gene expression of Sema3A, Sema7A, neuropilin-1 (NP-1), plexin-C1, and ß1 integrin in the blood samples of relapsing-remitting multiple sclerosis (RRMS) patients, treated with high-dose interferon-ß1a (IFN-ß1a), low-dose IFN-ß1a, IFN-ß1b, and glatiramer acetate (GA) via quantitative real-time polymerase chain reaction (qRT-PCR) assay, and then, compared the results of treatment-naive patients with the healthy controls. RESULTS: The gene expression of Sema3A (P = 0.02), NP-1 (P < 0.001), and plexin-C1 (P < 0.01) significantly decreased in the treatment-naive group, compared to the healthy controls. Sema3A significantly increased in all treated patients, compared to the treatment-naive patients (P < 0.001). However, expression of NP-1 (P < 0.001), plexin-C1 (P < 0.001), and ß1 integrin (P < 0.05) only increased in patients receiving high-dose IFN-ß1a, IFN-ß1b, and GA. Expression of Sema7A increased in only two groups of patients treated with IFN-ß1b (P < 0.001) and GA (P = 0.018), without any significant decrease in the treatment-naive group, compared to the healthy controls (P > 0.05). CONCLUSION: Our findings confirm that the presence of Sema3A, Sema7A, and their receptors can play critical roles in the treatment of MS patients. Therefore, they can be potential target molecules for MS treatment in the future.

The Prognostic Value of Serum Semaphorin3A and VEGF Levels in Patients with Metastatic Colorectal Cancer.

PURPOSE: Despite new treatment options in metastatic colorectal cancer (mCRC), new prognostic markers are still needed to determine optimal chemoregimen especially for anti-angiogenesis drugs. In this study, we evaluated the serum semaphorin and VEGF-A levels as prognostic factors in patients with mCRC. METHODS: Patients with diagnosed mCRC who were treated with first-line bevacizumab plus chemotherapy were included in the study. Venous blood samples of 37 patients with metastatic colon cancer were taken, and serum semaphorin 3A and VEGF-A levels were studied in pre-treatment and the 1st and third months after the treatment was initiated. RESULTS: Totally, 37 patients were enrolled in the study. The patients' mean age was 62 years. Twenty-eight (49%) of the patients were male, and 19 (51%) were female. Serum semaphorin3A (sema3A) levels of the patients were 5.4 ± 7.4 ng/ml before the treatment, 3.5 ± 3.3 ng/ml at the first month, and 3.5 ± 3.7 ng/ml at the third month. Serum VEGF-A levels were 27.7 ± 32.9 ng/l before the treatment, 23.1 ± 28.1 ng/l at the first month, and 28.9 ± 30.2 ng/l at the third month. There was no significant correlation between the survival and pre-treatment VEGF-A level (p = 0.064). Overall survival (OS) was statistically significantly higher in patients with pre-treatment semaphorin 3A levels below 5.4 ng/ml than higher than 5.4 ng/ml (10.5 months vs 4.5 months, respectively, HR 0.23, 95% CI 19.635-11,391, p = 0.012). CONCLUSION: Pre-treatment semaphorin 3A level can be a prognostic marker for the mCRC patients who were treated with bevacizumab in patients with metastatic colorectal cancer.

Decreased Expression of Semaphorin 3A and Semaphorin 7A Levels and Its Association with Systemic Lupus Erythematosus.

A growing body of data suggests that semaphorins are involved in both normal and pathological immune responses, as well as autoimmune pathologies. To investigate the plasma semaphorin 3A (Sema3A) and semaphorin 7A (Sema7A) levels in systemic lupus erythematosus (SLE) patients and their correlation with clinical manifestations and laboratory indexes, a two-step method was applied. First, 80 SLE patients and 80 healthy controls were recruited for comparing serum Sema3A and Sema7A concentrations. Second, 40 rheumatoid arthritis (RA) patients and 40 sjögren's syndrome (SS) patients were then included as disease controls. Plasma Sema3A and Sema7A concentrations were detected by ELISA. There were significant differences in Sema3A and Sema7A among four groups. When compared to healthy controls, both Sema3A and Sema7A levels were decreased in SLE and increased in RA; increased Sema3A level and decreased Sema7A level were found in SS. There were significant differences in Sema3A concentration between SLE and RA, SLE and SS. Moreover, there were significant differences in Sema7A level between SLE and RA, SS and RA. However, no significant differences in Sema3A between SS and RA and no significant differences in Sema7A between SS and SLE were observed. Both plasma Sema3A and Sema7A levels were correlated with anti-SSA and IgM. Area under curve (AUC) of the receiver operating characteristic (ROC) curve for Sema3A and Sema7A were 0.535 (0.455-0.613) and 0.671 (0.594-0.742), respectively. Aberrant Sema3A and Sema7A expression and their clinical associations in SLE suggest their important role in this disease.

Semaphorin 3A inhibits allergic inflammation by regulating immune responses in a mouse model of allergic rhinitis.

BACKGROUND: It has been reported that semaphorin 3A (sema3A) could improve allergic symptoms in allergic rhinitis (AR) mice. However, the immunomodulatory roles of sema3A in AR remain unclear. This study was performed to determine the immunoregulatory effects of sema3A on airway inflammation in an AR mice model. METHODS: First, sema3A expression was measured in the serum of AR patients and also in a mice model. Then, nasal symptoms, ovalbumin (OVA)-specific immunoglobulin E (IgE) production, cytokine levels, and histologic structure were analyzed in OVA-sensitized mice, sema3A mice, mice given saline, and controls. The percentages of CD4+ IL-4+ IFN-γ- Th2 cells, CD4+ IFN-γ+ IL-4- Th1 cells, CD4+ IL-17+ Th17 cells, and CD4+ CD25+ Foxp3+ Treg cells in the spleen were also analyzed. RESULTS: Serum sema3A levels in both AR patients and OVA-sensitized mice decreased significantly compared with controls. The intranasal administration of sema3A reduced allergic symptom scores, eosinophil infiltration, and OVA-specific IgE production in OVA-sensitized mice. In addition, levels of IL-4 and IL-17 as well as percentages of CD4+ IL-17+ Th17 cells were suppressed by sema3A administration. Levels of IFN-γ and IL-10 and ratios of CD4+ IFN-γ+ IL-4- Th1/CD4+ IL-4+ IFN-γ- Th2 cells, as well as percentages of CD4+ CD25+ Foxp3+ Treg cells, were increased by administration of sema3A. CONCLUSION: Our results demonstrate that sema3A suppressed allergic inflammation in AR via inhibition of Th2/Th17 responses and enhancement of Th1/Treg responses.

Semaphorin 3A in Ankylosing Spondylitis.

BACKGROUND/PURPOSE: To determine serum semaphorin 3A (Sema 3A) levels in ankylosing spondylitis (AS). METHODS: Serum Sema 3A was measured in 46 AS patients and 30 healthy controls (HCs). For the patients, we recorded demographic data, disease activity, functional index & global assessment, detected human leukocyte antigen-B27 (HLA-B27), and measured erythrocyte sedimentation rate (ESR) & C-reactive protein (CRP). RESULTS: Sema 3A was higher in AS patients than in HCs (3.98 ± 2.57 vs. 1.34 ± 0.48 ng/ml, p = 0.013). Area under the curve (AUC) of standard receiver operating characteristic (ROC) has suggested that Sema 3A > 2 ng/ml is better to predict the higher Bath Ankylosing Spondylitis Disease Activity Index (BASDAI, > 4) than ESR or CRP. There were good correlations between higher Sema 3A and uveitis, Schöber's test, as well as interstitial lung disease. AS patients undergoing anti-tumor necrosis factor therapies for 3 months exhibited a positive correlation of change in Sema 3A (ΔSema 3A) with disease activity fluctuation [ΔBASDAI, ΔBath Ankylosing Spondylitis Functional Index (BASFI) and ΔBath Ankylosing Spondylitis - Global score (BAS-G)]. CONCLUSION: Serum Sema 3A level was increased in AS patients and was inversely correlated to Schöber's test. Serum Sema 3A is better as a bio-marker than ESR or CRP to correlate with high disease activity in AS patients, and it is also a good indicator for monitoring disease activity and functional status during anti-TNF treatment. Also, Sema 3A may be taken as a predictor for extra-articular presentations in AS, but this needs further study to elucidate.

Circulating Semaphorin 4D as a Marker for Predicting Radiographic Progression in Patients with Rheumatoid Arthritis.

Semaphorin 3A (Sema3A) and semaphorin 4D (Sema4D) are molecules which regulate immune responses as well as bone remodeling process. The aim of this study was to evaluate the serum levels of Sema3A and Sema4D and to investigate their clinical significance in rheumatoid arthritis (RA). The serum levels of Sema3A and Sema4D were measured in 130 patients with RA and 65 sex- and age-matched healthy individuals. Circulating levels of biomarkers of RA-related inflammation and bone turnover such as tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-22, IL-34, osteopontin, Dkk-1, and sclerostin were also measured. Disease activity was determined by the 28-joint disease activity score (DAS28), and radiographic joint damage was assessed by the modified Sharp van der Heijde score (SHS). The serum levels of Sema3A were significantly higher in patients with RA than those in healthy controls (p < 0.001), whereas serum4D levels did not differ between the two groups. The levels of Sema4D showed a positive correlation with C-reactive protein (p = 0.001) and IL-6 (p < 0.001) levels, whereas the levels of Sema3A showed a negative correlation with Dkk-1 (p = 0.007) and TNF-α (p = 0.001). Even though Sema3A and Sema4D levels were comparable between RA patients with DAS28> 3.2 and with DAS28 ≤ 3.2, RA patients with radiographic progression (ΔSHS change/year ≥ 1) had significantly higher baseline levels of Sema4D than those without progression (p = 0.029). Additionally, when RA patients were divided into 3 groups using tertiles of Sema4D levels, the percentage of progressors was significantly increased (p = 0.045). In multivariate logistic regression analysis, serum Sema4D levels were an independent risk factor for radiographic progression. Our results suggest that the baseline levels of Sema4D might be a useful marker to identify RA patients with subsequent radiographic progression and that Sema4D may be an active mediator involved in RA-induced joint damage.

Semaphorin-3A inhibits multiple myeloma progression in a mouse model.

Previous studies revealed that progression of multiple myeloma (MM) is associated with downregulation of semaphorin-3A (sema3A) expression in bone marrow endothelial cells. We therefore determined if serum sema3A concentrations are correlated with MM progression and if sema3A can affect MM progression. We find that the concentration of sema3A in sera of MM patients is strongly reduced and that the decrease is correlated with disease progression. A similar depletion is found in patients having acute myeloid leukemia and acute lymphoblastic leukemia but not in cancer forms that do not involve the bone marrow such as in colon cancer. Expression of a modified sema3A [furin-resistant sema3A (FR-sema3A)] stabilized against cleavage by furin-like proprotein convertases in CAG MM cells did not affect their behavior in-vitro. CAG cells injected into the tail vein of severe combined immunodeficient (SCID) mice home to the bone marrow and proliferate, mimicking MM disease progression. Disease progression in mice injected with CAG cells expressing FR-sema3A was inhibited, resulting in prolonged survival and a lower incidence of bone lesions. Histological examination and fluorescence-activated cell sorting analysis revealed that FR-sema3A expression reduced the infiltration of the CAG cells into the bone marrow, reduced bone marrow necrosis and reduced angiogenesis induced by the MM cells in the bone marrow. Our results suggest that measurement of sema3A serum concentrations may be of use for the diagnosis and for the monitoring of malignancies of the bone marrow such as MM. Furthermore, our results suggest that FR-sema3A may perhaps find use as an inhibitor of MM disease progression.

Expression of circulating Semaphorin3A and its association with inflammation and bone destruction in rheumatoid arthritis.

To determine the expression of Semaphorin3A (Sema3A) in rheumatoid arthritis (RA) patients, and analyze the correlation between serum Sema3A and the pathogenesis of RA. The concentration of serum Sema3A and its mRNA expression level were detected in RA patients. The association of serum Sema3A level with clinical and laboratory features of RA were analyzed. Serum Sema3A of 130 RA patients (15.89 ± 8.58 ng/ml) was significantly higher than that of 150 HC (6.96 ± 2.62 ng/ml) and 215 patients with other rheumatic diseases (P < 0.05). Consistent with the serum level, the Sema3A mRNA level was also higher in RA patients' PBMC than that in HC (1.8-fold increase, P < 0.01). The serum level of Sema3A was correlated with platelet counts (r = 0.229), ESR (r = 0.172), RF (r = 0.230), IgM (r = 0.254) and Sharp score (r = 0.254), and bone mineral density (BMD) of lumbar spine (r = 0.263). Serum Sema3A was also fundamentally higher in AKA-, APF-, anti-CCP-positive groups compared with negative groups (P < 0.05). The ROC curve showed that the optimum diagnostic cutoff value for Sema3A was 10.881 ng/ml. RF level and antibodies (anti-CCP, APF, AKA, and GPI) positive rates were significantly higher in Sema3A positive group. Sharp score was also higher, although without significance. The expression of Sema3A is significantly elevated in RA patients. The level of serum Sema3A is positively correlated with inflammatory factors (including ESR, IgM, and RF) and is associated with auto-antibody production and bone destruction.

Assessment of plasma biomarkers for their association with Multiple Sclerosis progression.

In a cross-sectional study involving 160 Multiple Sclerosis (MS) patients and 70 healthy controls we set out to determine the association of five blood biomarkers with MS risk and progression scores. High levels of Semaphorin3A (SEMA3A) in females, and low levels of prolactin and estradiol in males associated with MS risk. High MS disability correlated with higher SEMA3A levels in females. Our findings suggest the clinical applicability of SEMA3A, and prolactin as biomarkers for MS progression. However, these biomarkers had sex-specific associations with MS, and any therapeutic approaches utilizing them should take that into consideration.

Decreased expression of Sema3A, an immune modulator, in blood sample of multiple sclerosis patients.

Semaphorin 3A (Sema3A) as an immune modulator could participate in the pathogenesis of autoimmune diseases. In the current study, we aimed to investigate Sema3A expression in peripheral blood mononuclear cells (PBMCs) and its serum level in relapsing-remitting multiple sclerosis (RRMS) patients. Fifteen newly determined and untreated RRMS patients were chosen and assessed in relapsing and remitting phases in compare with fifteen healthy individuals. In consistent with previous findings in other autoimmune diseases, our results revealed that serum level of Sema3A and its expression in PBMCs of RRMS patients were significantly lower than in normal subjects. We also evaluated this down regulation predictive value with ROC analysis. According to our data, we suggest that Sema3A could be involved in pathogenesis of MS and might be a potential diagnostic biomarker for the disease.

Assessment of semaphorin 3A and its role in bone remodelling in a group of ankylosing spondylitis patients.

OBJECTIVES: Several molecules are involved in the pathogenesis of new bone formation in ankylosing spondylitis (AS). The aim of the present study was to evaluate serum levels of semaphoring 3A in AS and to investigate any correlations with radiographic damage, disease activity, function and treatment. METHODS: AS patients who fulfilled the modified New York criteria were enrolled for this study. Healthy subjects were also enrolled as control group. BASDAI, ASDAS-CRP, BASMI, BASFI, patients and physician VAS, C-reactive protein and erythrocyte sedimentation rate were evaluated at baseline visit. Radiographs of the spine and pelvis performed within six months from the enrolment in the study were collected in all patients. Spinal damage was assessed using the mSASSS. Serum concentrations of semaphorin3A were assessed at baseline and after four months of therapy in patients who started an anti-TNF. RESULTS: Twenty healthy subjects and forty AS patients were enrolled in the study. Of these patients, 15 started anti-TNF therapy the day of baseline visit. Semaphorin3A serum concentrations [median (25th-75th)] were similar in AS patients [0.26 (0.20-0.31) ng/ml] and controls [0.28 (0.26-0.3) ng/ml; p=ns). No significant correlation was found between semaphorin 3A serum levels and radiographic damage index. Semaphorin 3A serum levels positively correlated with ESR values (rho=0.37, p=0.049) and with disease activity assessed by the physician VAS (rho=0.47, p<0.01). No differences were found in the semaphorin3A serum levels after 4 months, compared to baseline values. CONCLUSIONS: The results of the present study could contribute to the intriguing topic of bone remodelling in AS.

Semaphorin 3A, a potential immune regulator in familial Mediterranean fever.

OBJECTIVES: Semaphorin 3A (sema3A) plays a regulatory role in immune responses with effects on both T and B regulatory cells. Familial Mediterranean fever (FMF) is an autoinflammatory disease, yet a possible role for regulatory T and B cells has been described. METHODS: 17 FMF patients during attack and then in remission, 8 FMF patients with smoldering disease and 12 healthy controls were enrolled. Sema3A in serum and its expression on regulatory T and B cells was evaluated. Clinical parameters of FMF patients were assessed. RESULTS: Semaphorin 3A serum level was lower in FMF patients during attack, smoldering disease or remission than healthy controls, (242.3±9.8 ng/ ml vs. 258.9±11.5 ng/ml vs. 232.5±22.7 ng/ml vs. 323.3±160.2 ng/ml, respectively p<0.05). This decrease was specifically noted on regulatory B and T cells in FMF patients during attack and in smoldering disease and normalized in remission. CONCLUSIONS: Sema3A expression on T and B regulatory lymphocytes is low in FMF patients during attack and in smoldering disease compared to the expression in remission and healthy controls. These results are in line with previous descriptions suggesting a possible role of regulatory T cells in termination of FMF attacks. Further studies are needed to verify these preliminary findings.

Decreased expression of neuropilin-1 as a novel key factor contributing to peripheral microvasculopathy and defective angiogenesis in systemic sclerosis.

OBJECTIVES: In systemic sclerosis (SSc), vascular involvement is characterised by vascular endothelial growth factor (VEGF)-A/VEGF receptor (VEGFR) system disturbances. Neuropilin-1 (NRP1), a receptor for both class-3 semaphorins (Sema3s) and VEGF-A, is required for optimal VEGF-A/VEGFR-2 signalling. Here, we investigated the possible involvement of Sema3A/NRP1 axis in SSc. METHODS: Circulating Sema3A and soluble NRP1 (sNRP1) were measured in patients with SSc and controls. NRP1 and Sema3A expression in skin biopsies was evaluated by immunofluorescence and western blotting. NRP1 expression was assessed in SSc and healthy dermal microvascular endothelial cells (SSc-MVECs and H-MVECs), and in SSc and control endothelial progenitor cell (EPC)-derived endothelial cells (ECs). The possible impact of transcription factor Friend leukaemia integration 1 (Fli1) deficiency on endothelial NRP1 expression was investigated by gene silencing. The binding of Fli1 to NRP1 gene promoter was evaluated using chromatin immunoprecipitation. Capillary morphogenesis was performed on Matrigel. RESULTS: Decreased sNRP1 levels in SSc were associated with active and late nailfold videocapillaroscopy patterns and digital ulcers. No difference in Sema3A was found between patients and controls. NRP1 was significantly decreased in SSc-MVECs both ex vivo and in vitro. NRP1 and Fli1 significantly decreased in H-MVECs challenged with SSc sera, while they were not different in SSc and control EPC-derived ECs. Fli1 occupied the NRP1 gene promoter and Fli1 gene silencing reduced NRP1 expression in H-MVECs. NRP1 gene silencing in H-MVECs resulted in a significantly impaired angiogenic capacity comparable to that of cells treated with SSc sera. CONCLUSION: In SSc, NRP1 deficiency may be an additional factor in the perturbed VEGF-A/VEGFR-2 system contributing to peripheral microvasculopathy and defective angiogenesis.

The Involvement of Immune Semaphorins in the Pathogenesis of Inflammatory Bowel Diseases (IBDs).

BACKGROUND AND AIMS: Immune semaphorins are a large family of proteins involved in the pathogenesis of inflammatory diseases through the regulation of immune homeostasis and tissue inflammation. We aim to assess the possible involvement of semaphorin3A (sema3A) and 4A (sema4A) in peripheral immune responses and bowel tissue inflammation of patients suffering from Crohn's disease (CD) and ulcerative colitis (UC). PATIENTS AND METHODS: Twenty-seven CD patients and 10 UC patients were studied and compared to 10 patients followed for acute diverticulitis (disease control) and 12 healthy individuals. All were evaluated for sema3A expression on T regulatory cells (Tregs), serum levels of sema3A and sema4A, and tissue expression of sema3A and sema4A in bowel biopsies. RESULTS: The percentage (%) of T regulatory cells (Tregs) expressing sema3A in patients with active CD (64.5% ± 14.49%) and active UC (49.8% ± 16.45%) was significantly lower when compared to that of healthy controls (88.7% ± 3.6%, p< 0.001 and p< 0.0001, respectively). This expression was seen to be in negative correlation with CD activity. Serum levels of Sema4A were significantly lower in patients with CD and UC when compared to that of controls (5.69 ± 1 .48 ng\ml for CD, 5.26 ± 1.23 ng/ml for UC patients vs 9.74 ± 2.73 ng/ml for normal controls, P<0.001). Sema4A was highly expressed in lymphocytes of the lamina propria of CD and UC patients but absent in patients with diverticulitis or in normal individuals. CONCLUSIONS: Altered % of Tregs expressing sema3A in patients with inflammatory bowel diseases (IBD) is partially responsible for their failure in preventing CD4+ effector T cell induced inflammation in IBD in peripheral blood. The increased expression of sema4A in bowel biopsies from CD and UC patients is suggestive of its central role in regulating local tissue inflammation in the bowel.

Semaphorin 3A: an immunoregulator in systemic sclerosis.

ABSTARCT: Semaphorin 3A (sema3A) plays a regulatory role in immune responses, mainly affecting the activation of regulatory T cells. It has been found to correlate with disease activity in rheumatoid arthritis and systemic lupus erythematosus (SLE). To investigate the expression of sema3A in patients with systemic sclerosis (SSc) compared to healthy controls and SLE disease controls and to correlate it with clinical characteristics, 27 SSc patients, 42 SLE patients and 28 healthy controls were enrolled. Serum level of sema3A was measured by ELISA, and expression of sema3A on regulatory T cells was evaluated by FACS analysis. SSc patients were evaluated for demographics, clinical manifestations, routine laboratory results, nailfold videocapillaroscopy, pulmonary function tests, echocardiograms, modified Rodnan skin score, and disease activity and severity scores. Serum levels of semaphorin 3A were lower in SSc compared to healthy controls 14.38 ± 5.7 versus 27.14 ± 8.4 ng/ml, p < 0.0001 and similar to SLE 15.7 ± 4.3 ng/ml. The expression of semaphorin 3A on regulatory T cells was also lower in SSc compared to healthy controls 61.7 ± 15.7 versus 88.7 ± 3. 7 % (p < 0.0001). Semaphorin 3A serum level inversely correlated with the duration of disease: r = -0.4, p = 0.036 and with low C4 level r = 0.66, p = 0.026. SCL-70 antibody positivity was associated with a lower semaphorin 3A level (difference in mean of 3.44, p = 0.06). Sema3A expression is low in SSc serum and more specifically on regulatory T cells. This may help explain the reduced activation of regulatory T cells in SSc.

Semaphorin 3A serum levels are influenced by haemodialysis: what clinical significance?

AIM: Semaphorin 3A urinary levels represent an early, predictive biomarker of acute kidney injury and positively correlate with albumin-to-creatinine ratio and serum creatinine in hypertensive patients with chronic kidney disease. Our purpose has been to evaluate semaphorin 3A serum levels in a cohort of haemodialysis (HD) patients, the influence of a single HD session on its concentrations, and the potential correlation with clinical and biochemical parameters. METHODS: We enrolled 18 patients receiving HD with Acetate-Free Biofiltration technique and 16 healthy subjects as controls. Peripheral venous blood samples were obtained from patients at different intervals: start of dialysis (pre-HD), middle, and end of the treatment (post-HD). We also collected dialysate samples by the Quantiscan monitoring system (Hospal, Bologna, Italy). RESULTS: Semaphorin 3A was significantly lower in HD patients at baseline compared to controls (median 19.50 (interquartile range 1.00-65.00) versus 97.50 (23.50-161.00) ng/mL, P = 0.0237). A statistically significant reduction was seen during a single HD session (from 19.50 (1.00-65.00) to 0.86 (0.82-4.21) ng/mL, P < 0.0001), with a reduction ratio of 65.92 ± 33.51%. The median concentration in dialysate was 54.00 (15.00-102.00) ng/mL. Pre-HD values were directly related to serum vitamin D (r = 0.872; P = 0.001) and inversely correlated with calcium levels (r = -0.426; P = 0.012) and calcium × phosphate product (r = -0.422; P = 0.0252). CONCLUSION: Semaphorin 3A removal during HD may be clinically relevant due to its involvement in different aspects of cell physiology and in bone remodelling. Semaphorin 3A both inhibits osteoclastic bone reabsorption and increases osteoblastic new bone formation, thus playing a dual osteoprotective role.

Semaphorin3a promotes advanced diabetic nephropathy.

The onset of diabetic nephropathy (DN) is highlighted by glomerular filtration barrier abnormalities. Identifying pathogenic factors and targetable pathways driving DN is crucial to developing novel therapies and improving the disease outcome. Semaphorin3a (sema3a) is a guidance protein secreted by podocytes. Excess sema3a disrupts the glomerular filtration barrier. Here, using immunohistochemistry, we show increased podocyte SEMA3A in renal biopsies from patients with advanced DN. Using inducible, podocyte-specific Sema3a gain-of-function (Sema3a(+)) mice made diabetic with streptozotocin, we demonstrate that sema3a is pathogenic in DN. Diabetic Sema3a(+) mice develop massive proteinuria, renal insufficiency, and extensive nodular glomerulosclerosis, mimicking advanced DN in humans. In diabetic mice, Sema3a(+) exacerbates laminin and collagen IV accumulation in Kimmelstiel-Wilson-like glomerular nodules and causes diffuse podocyte foot process effacement and F-actin collapse via nephrin, αvß3 integrin, and MICAL1 interactions with plexinA1. MICAL1 knockdown and sema3a inhibition render podocytes not susceptible to sema3a-induced shape changes, indicating that MICAL1 mediates sema3a-induced podocyte F-actin collapse. Moreover, sema3a binding inhibition or podocyte-specific plexinA1 deletion markedly ameliorates albuminuria and abrogates renal insufficiency and the diabetic nodular glomerulosclerosis phenotype of diabetic Sema3a(+) mice. Collectively, these findings indicate that excess sema3a promotes severe diabetic nephropathy and identifies novel potential therapeutic targets for DN.