👤 Franziska Rother

Neurological disorders cause over 11 million deaths annually worldwide, highlighting the urgent need for new therapeutic strategies to improve current treatment outcomes. Nerve growth factor (NGF) is a key regulator of neuronal survival, and modifying mesenchymal stem cells (MSC) to enhance their neurotrophic activity is a promising therapeutic strategy. However, the broader molecular consequences of NGF overexpression in MSC remain unclear. This study examined how NGF overexpression affects neurotrophin secretion and apoptosis-related protein expression in Wharton's jelly MSC (WJ-MSC). WJ-MSC were lentivirally transduced to overexpress NGF and differentiated for 12 days. NGF, BDNF, TrkA, TrkB, IL-13, and TNF-α were quantified using ELISA (n = 3 biological replicates; assays in duplicate). Thirty-five apoptosis-related proteins were assessed using the Proteome Profiler Human Apoptosis Array (assays in duplicate). Data were analyzed using one-way ANOVA or multiple t-test. NGF overexpression increased extracellular NGF (↑∼220 %, p < 0.0001) and reduced BDNF secretion (↓∼35 %, p < 0.05). Soluble phosphorylated TrkA/TrkB increased significantly in supernatants (↑30-60 %, p < 0.05). IL-13 rose modestly without statistical significance, and TNF-α remained undetectable. Early proteome changes showed upregulation of pro-apoptotic proteins (p21 ↑97 %, phospho-p53 ↑30 %) with concurrent reductions in anti-apoptotic markers (BCL2 ↓66 %, HSP60 ↓58 %). After 12 days, the apoptotic profile remained predominantly pro-apoptotic, despite selective increases in BCLXL (↑92 %), clusterin (↑102 %), and survivin (↑38 %) indicating only partial compensatory responses. NGF overexpression enhances neurotrophin-related signaling but produces a sustained pro-apoptotic shift in WJ-MSC, suggesting limited benefit for cell survival. These findings require confirmation using functional apoptosis assays and in vivo models. Show less

Lipodystrophy syndromes cause hypertriglyceridemia that improves with leptin treatment using metreleptin. Mechanisms causing hypertriglyceridemia and improvements after metreleptin are incompletely understood. Determine relationship of circulating lipoprotein lipase (LPL) modulators with hypertriglyceridemia in healthy controls and in patients with lipodystrophy before and after metreleptin. Cross-sectional comparison of patients with lipodystrophy (generalized lipodystrophy n = 3; partial lipodystrophy n = 11) vs age/sex-matched healthy controls (n = 28), and longitudinal analyses in patients before and after 2 weeks and 6 months of metreleptin. The study was carried out at the National Institutes of Health, Bethesda, Maryland. Outcomes were LPL stimulators apolipoprotein (apo) C-II and apoA-V and inhibitors apoC-III and angiopoietin-like proteins (ANGPTLs) 3, 4, and 8; ex vivo activation of LPL by plasma. Patients with lipodystrophy were hypertriglyceridemic and had higher levels of all LPL stimulators and inhibitors vs controls except for ANGPTL4, with >300-fold higher ANGPTL8, 4-fold higher apoC-III, 3.5-fold higher apoC-II, 1.9-fold higher apoA-V, 1.6-fold higher ANGPTL3 ( Elevations in LPL inhibitors apoC-III and ANGPTL8 may contribute to hypertriglyceridemia in lipodystrophy, and may mediate reductions in circulating and hepatic triglycerides after metreleptin. These therefore are strong candidates for therapies to lower triglycerides in these patients. Show less

Spermatogenesis is driven by an ordered series of events, which rely on trafficking of specific proteins between nucleus and cytoplasm. The karyopherin α family of proteins mediates movement of specific cargo proteins when bound to karyopherin β. Karyopherin α genes have distinct expression patterns in mouse testis, implying they may have unique roles during mammalian spermatogenesis. Here, we use a loss-of-function approach to determine specifically the role of Kpna6 in spermatogenesis and male fertility. We show that ablation of Kpna6 in male mice leads to infertility and has multiple cumulative effects on both germ cells and Sertoli cells. Kpna6-deficient mice exhibit impaired Sertoli cell function, including loss of Sertoli cells and a compromised nuclear localization of the androgen receptor. Furthermore, our data demonstrate devastating defects on spermiogenesis, including incomplete sperm maturation and a massive reduction in sperm number, accompanied by disturbed histone-protamine exchange, differential localization of the transcriptional regulator BRWD1 and altered expression of RFX2 target genes. Our work uncovers an essential role of Kpna6 in spermatogenesis and, hence, in male fertility. Show less