Vitamin C inhibits NLRP3 inflammasome activation and delays the development of age-related hearing loss in male C57BL/6 mice.

The efficacy of vitamin C in age-related hearing loss, i.e., presbycusis, remains debatable. On a separate note, inflammation induced by the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is involved in the progression of presbycusis. In this study, we investigated the effect of vitamin C on male C57BL/6 mice's presbycusis and NLRP3 inflammasome. The results showed that vitamin C treatment improved hearing, reduced the production of inflammatory factors, inhibited NLRP3 inflammasome activation, and decreased cytosolic mitochondrial DNA (mtDNA) in the C57BL/6 mouse cochlea, inferior colliculus, and auditory cortex. According to this study, vitamin C protects auditory function in male C57BL/6 presbycusis mice through reducing mtDNA release, inhibiting the NLRP3 inflammasome activation in the auditory pathway. Our study provides a theoretical basis for applying vitamin C to treat presbycusis.

[Expression of neuronal marker protein gene product 9.5 and its clinicopathologic significance in breast cancer].

OBJECTIVE: To detect the expression of pan-neuronal marker protein gene product (PGP)9.5 and its clinicopathologic significance in breast cancer. METHODS: The expression of PGP9.5 was examined by immunohistochemistry EnVision method in 196 cases during 2007 to 2011, including 20 normal tissues, 14 cases of fibroadenoma, 18 cases of ductal carcinoma in situ (DCIS) and 144 cases of invasive ductal carcinoma (IDC) of the breast. The relationship between PGP9.5 expression and clinicopathologic characteristics of IDC was assessed. RESULTS: PGP9.5 expression was localized in the stroma of all normal breast tissues, but there was no expression observed in all fibroadenomas and DCIS. Overall, the expression rate of PGP9.5 in IDC was 61.8% (89/144). PGP9.5 expression increased from grade 1 tumors (29.4%, 10/34) to grade 2-3 tumors (71.8%, 79/110; P = 0.000). In addition, patients with less than 3 years disease-free survival tended to show higher PGP9.5 expression (64.8%, 35/54), compared to patients with equal to and/or more than 3 years disease-free survival (46.7%, 42/90; P = 0.035). However, there was no correlation between PGP9.5 expression and tumor size, tumor stage, lymph metastasis, hormone receptor expression. CONCLUSION: PGP9.5 expression is correlated with tumor grade and prognosis in IDC of the breast.

The clinicopathological significance of neurogenesis in breast cancer.

BACKGROUND: Recent reports support a novel biological phenomenon about cancer related neurogenesis. However, little is known about the clinicopathological significance of neurogenesis in breast cancer. METHODS: A total of 196 cases, including 20 of normal tissue, 14 of fibroadenoma, 18 of ductal carcinoma in situ (DCIS) and 144 of invasive ductal carcinoma (IDC) of the breast were used. The tissue slides were immunostained for protein gene product (PGP) 9.5 and S 100 to identify nerves. The correlation between the expression of PGP 9.5 and clinicopathological characteristics in IDC of the breast was assessed. RESULTS: While the PGP 9.5 positive nerve fibers are identified in all cases of normal breast tissue controls and in the tumor stroma of 61% (89/144) cases of invasive ductal carcinomas, PGP 9.5 positive nerve fibers are not seen in the tumor stroma of cases of fibroadenoma and DCIS. The percentage of tumors that exhibited neurogenesis increased from tumor grade I to tumor grade II and III (29.4% vs 71.8%, p < 0.0001). In addition, patients with less than 3 years of disease-free survival tended to have a higher positive expression of PGP 9.5 compared to patients with an equal or more than 3 years of disease-free survival (64.8% vs 46.7%, p = 0.035). Furthermore, moderate/strong expression of PGP 9.5 was found to be significantly related to microvessel density (MVD, p = 0.014). Interestingly, PGP 9.5 expression was significantly associated with higher MVD in the ER-negative (p = 0.045) and node-negative (p = 0.039) subgroups of IDC of the breast. CONCLUSIONS: This data indicates that neurogenesis is associated with some aggressive features of IDC including tumor grade and patient survival as well as angiogenesis, especially in ER-negative and node-negative subtypes of IDC of the breast. Thus, neurogenesis appears to be associated with breast cancer progression and may play a role in therapeutic guidance for patients with ER-negative and node-negative invasive breast cancer.