SEPT9 Upregulation in Satellite Glial Cells Associated with Diabetic Polyneuropathy in a Type 2 Diabetes-like Rat Model

Despite the worldwide prevalence and severe complications of type 2 diabetes mellitus (T2DM), the pathophysiological mechanisms underlying the development of diabetic polyneuropathy (DPN) are poorly understood. Beyond strict control of glucose levels, clinical trials for reversing DPN have largely failed. Therefore, understanding the pathophysiological and molecular mechanisms underlying DPN is crucial. Accordingly, this study explored biochemical and neuropathological deficits in a rat model of T2DM induced through high-fat diet (HFD) feeding along with two low-dose streptozotocin (STZ) injections; the deficits were explored through serum lipid, neurobehavioral, neurophysiology, neuropathology, and immunohistochemistry examinations. Our HFD/STZ protocol induced (1) mechanical hyperalgesia and depression-like behaviors, (2) loss of intraepidermal nerve fibers (IENFs) and reduced axonal diameters in sural nerves, and (3) decreased compound muscle action potential. In addition to hyperglycemia, which was correlated with the degree of mechanical hyperalgesia and loss of IENFs, we observed that hypertriglyceridemia was the most dominant deficit in the lipid profiles of the diabetic rats. In particular, SEPT9, the fourth component of the cytoskeleton, increased in the satellite glial cells (SGCs) of the dorsal root ganglia (DRG) in the T2DM-like rats. The number of SEPT9(+) SGCs/DRG was correlated with serum glucose levels and mechanical thresholds. Our findings indicate the putative molecular mechanism underlying DPN, which presumably involves the interaction of SGCs and DRG neurons; nevertheless, further functional research is warranted to clarify the role of SEPT9 in DPN.

Study on early diagnosis of epithelial ovarian cancer by analysis of plasma septin-9 and clusterin level

Background and Aim

To investigate the value of peripheral blood plasma levels of septin-9 and clusterin protein in the diagnosis of epithelial ovarian cancer (EOC).

Materials and Methods

The peripheral blood plasma samples were obtained from 137 EOC patients, 12 borderline ovarian tumor patients, 10 benign ovarian tumor patients, 41 benign pelvic lesion patients, and 58 healthy women. The peripheral plasma septin-9 and clusterin proteins levels were measured by enzyme-linked immunosorbent assay. The power of test was evaluated with the area under the receiver operating characteristic curve (ROC) (AUC).

Results

The mean levels of plasma septin-9 and clusterin in EOC patients were significantly higher than that in healthy women (P = 0.002, P = 0.021). The mean levels of plasma septin-9 in benign pelvic lesion patients were significantly higher than that in healthy women (P = 0.007). The mean levels of plasma septin-9 in epithelial ovarian carcinoma patients with tumor family history or distant metastases were significantly higher than that of patients without (P = 0.040, P = 0.025). The AUC of septin-9 protein was 0.712, when the optimal cut-off point was 0.28, the sensitivity and diagnostic specificity were 82.5% and 50.0%, respectively; the AUC of clusterin was 0.636, and when the optimal cut-off point was 87.96 ng/ml, the sensitivity and diagnostic specificity was 71.5% and 41.4%, respectively.

Conclusion

The plasma levels of septin-9 and clusterin in ovarian cancer patients were abnormally elevated, which might be used as potential candidates of peripheral blood tumor biomarkers for early diagnosis of EOC and septin-9 might be related to distal metastases of EOC. The septin-9 might play the promotion role, which protein level relates to not only the distal metastases but also the prognosis of EOC. Due to the limit of sample volume, further enlargement of the sample size and set up of the follow-up system is in need to in-depth study the relationship between plasma protein concentration with the distal metastases, and further explore its correlation with the prognosis of EOC.

A pooled analysis of the diagnostic efficacy of plasmic methylated septin-9 as a novel biomarker for colorectal cancer

The methylation status of septin-9 gene in plasma has been developed as a promising biomarker to aid in the diagnosis of colorectal cancer (CRC). In this study, we aimed to evaluate the overall diagnostic ability of septin-9 methylation for detection of CRC. Studies on the diagnostic performance of plasma septin-9 in CRC were searched from the online databases up to January 31st, 2017. Risk of bias among the studies was estimated according to the Quality Assessment of Studies of Diagnostic Accuracy included in the Systematic Reviews (QUADAS) II checklist. The aggregation of the effect sizes was enabled by utilizing a bivariate analysis model. A meta-regression test and influence analysis were conducted to determine the underlying sources of heterogeneity. According to the predefined criteria, 1,462 patients with CRC from 14 eligible trials were included. The quantitative meta-analyses showed that methylated septin-9 in plasma sustained a pooled sensitivity of 0.67 (95% CI, 0.61-0.73) and specificity of 0.89 (95% CI, 0.86-0.92) in discriminating CRC patients from cancer-free individuals, along with an area under the curve of 0.87. Moreover, the stratified analyses grouped by ethnicity demonstrated that methylayted septin-9 testing achieved a better sensitivity of 0.72 (95% CI, 0.68-0.76) in the European-based population group and a higher specificity of 0.90 (95% CI, 0.88-0.92) in the Asian-based population group. Plasmic methylated septin-9 suggests a promising diagnostic efficacy in confirming CRC. However, more studies are required to confirm our findings.