Fangfei Li,Jie Zhang,Xiaoli Ma,Hao Chen,Guiqiang Liang,Yunfeng Zou
Excessive accumulation of manganese (Mn) can cause neuroinflammation, impairing cognitive function. SPON1, a secreted glycoprotein in the extracellular matrix, is implicated in neuroinflammation, but its role in activating pro-inflammatory pathways in Mn-induced neuroinflammation remains unclear. This study employed in vivo and in vitro models to investigate Mn neuroinflammation. The expression levels of SPON1 and the ERK1/2/NF-κB pathway associated with inflammation were measured in male C57BL/6 mice after gavage of Mn at different doses (0, 25, 50, 100 mg/kg) for 12 weeks. SPON1 levels were measured after primary hippocampal neurons, primary cortical neurons, neuroblastoma cells (N2a), and microglial cells (BV2) were exposed to various concentrations of Mn for 24 h. We observed that in vivo Mn exposure significantly decreased SPON1 expression in the cortex but not in the hippocampus. Similarly, in vitro experiments demonstrated that Mn exposure significantly reduced SPON1 levels in primary cortical neurons, N2a, and BV2. In addition, Mn exposure increased the expression levels of ERK1/2 and NF-κB pathway proteins in the mouse cortex. Because BV2 cells are susceptible to inflammatory signals, they were chosen to elucidate how SPON1 induces neuroinflammation during Mn exposure. SPON1 knockdown increases the expression of inflammatory factors, whereas SPON1 overexpression inhibits the activation of the ERK1/2/NF-κB pathway and reduces inflammatory factor levels. In summary, these results suggest that Mn may affect the activation of ERK1/2/NF-κB pathway and the expression of inflammatory factors by inhibiting SPON1, ultimately promoting neuroinflammation.
Ovarian cancer (OC) is one of the three major gynecologic malignancies and has the highest mortality rate because of the late diagnosis. Liquid biopsy based on serum protein biomarkers has demonstrated great potential for early diagnosis but remains limited by the analysis performance of conventional immunoassay technologies, such as chemiluminescence, and biomarkers, such as CA125. To address this challenge and achieve accurate early-stage diagnosis of OC, we developed a digital immunoassay on a SlipChip (DiSC) for quantitative analysis of a potential serum protein biomarker, Spondin-1 (SPON1). The DiSC system achieved a limit of detection (LoD) of 23 fg/μL for digital quantification of SPON1. The DiSC system was utilized to quantify the serum level of SPON1 in 357 clinical serum samples, including 63 from patients with benign ovarian tumors and 294 from patients with malignant ovarian cancer, ranging from stages I to IV. SPON1 concentrations were significantly different in samples from patients with malignant ovarian cancer. Notably, significantly different SPON1 levels were observed in early stages (I and II), in lymph node-negative cases (N 0 ), and before metastasis (M 0 ), suggesting that SPON1 could serve as a sensitive diagnostic biomarker for early-stage OC. The differential diagnostic model based on SPON1 levels quantified using DiSC demonstrated an area under the curve (AUC) of 0.8187 for early-stage OC, a significant improvement over CA-125 (AUC = 0.6967). For OC of all stages, the AUC was 0.8225, which could be further increased to 0.8750 when combined with CA-125. This showcases the potential of SPON1 as a novel biomarker for sensitive early-stage diagnosis of ovarian cancer and the capability of the DiSC system in discovering low-abundance biomarkers for disease diagnosis.
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