Sirtuins are a family of deacetylases that modify structural proteins, metabolic enzymes, and histones to change cellular protein localization and function. In mammals, there are seven sirtuins involved in processes like oxidative stress or metabolic homeostasis associated with aging, degeneration or cancer. We studied gene expression of sirtuins by qRT-PCR in human mural granulosa-lutein cells (hGL) from IVF patients in different infertility diagnostic groups and in oocyte donors (OD; control group). Study 1: sirtuins genes’ expression levels and correlations with age and IVF parameters in women with no ovarian factor. We found significantly higher expression levels of SIRT1, SIRT2 and SIRT5 in patients ≥40 years old than in OD and in women between 27 and 39 years old with tubal or male factor, and no ovarian factor (NOF). Only SIRT2, SIRT5 and SIRT7 expression correlated with age. Study 2: sirtuin genes’ expression in women poor responders (PR), endometriosis (EM) and polycystic ovarian syndrome. Compared to NOF controls, we found higher SIRT2 gene expression in all diagnostic groups while SIRT3, SIRT5, SIRT6 and SIRT7 expression were higher only in PR. Related to clinical parameters SIRT1, SIRT6 and SIRT7 correlate positively with FSH and LH doses administered in EM patients. The number of mature oocytes retrieved in PR is positively correlated with the expression levels of SIRT3, SIRT4 and SIRT5. These data suggest that cellular physiopathology in PR’s follicle may be associated with cumulative DNA damage, indicating that further studies are necessary.

An excess of oxidative stress (OS) may affect several physiological processes fundamental to reproduction. SIRT1, SIRT6 and SIRT7 are involved in protection stress systems caused by OS, and they can be activated by antioxidants such as celastrol or melatonin. In this study, we evaluate SIRT1, SIRT6 and SIRT7 gene expression in cultured human granulosa-lutein (hGL) cells in response to OS inductors (glucose or peroxynitrite) and/or antioxidants. Our results show that celastrol and melatonin improve cell survival in the presence and absence of OS inductors. In addition, melatonin induced SIRT1, SIRT6 and SIRT7 gene expression while celastrol only induced SIRT7 gene expression. This response was not altered by the addition of OS inductors. Our previous data for cultured hGL cells showed a dual role of celastrol as a free radical scavenger and as a protective agent by regulating gene expression. This study shows a direct effect of celastrol on SIRT7 gene expression. Melatonin may protect from OS in a receptor-mediated manner rather than as a scavenger. In conclusion, our results show increased hGL cells survival with melatonin or celastrol treatment under OS conditions, probably through the regulation of nuclear sirtuins’ gene expression.

Regulation of oxidative stress (OS) is important to prevent damage to female reproductive physiology. While normal OS levels may have a regulatory role, high OS levels may negatively affect vital processes such as folliculogenesis or embryogenesis. The aim of this work was to study OS induced by glucose, a reactive oxygen species generator, or peroxynitrite, a reactive nitrogen species generator, in cultured human granulosa-lutein (hGL) cells from oocyte donors, analyzing expression of genes involved in oocyte maturation (FSHR, PAPP, and CYP19A1) and OS damage response (ALDH3A2). We also evaluated the effect of celastrol as an antioxidant. Our results showed that although both glucose and peroxynitrite produce OS increments in hGL cells, only peroxynitrite treatment increases ALDH3A2 and PAPP gene expression levels and decreases FSHR gene expression levels. Celastrol pre-treatment prevents this effect of peroxynitrite. Interestingly, when celastrol alone was added, we observed a reduction of the expression of all genes studied, which was independent of both OS inductors. In conclusion, regulation of OS imbalance by antioxidant substances such as celastrol may prevent negative effects of OS in female fertility. In addition to the antioxidant activity, celastrol may well have an independent role on regulation of gene expression in hGL cells.

Gastrointestinal (GI) toxicity is a common side effect in patients undergoing oxaliplatin (OxPt)-based chemotherapy for colorectal cancer (CRC). Frequently, this complication persists in the long term and could affect the efficacy of the treatment and the patient’s life quality. This long-term GI toxicity is thought to be related to OxPt-induced enteral neuropathy. AmotL2 is a member of the Angiomotin family of proteins, which play a role in cell survival, neurite outgrowth, synaptic maturation, oxidative stress protection, and inflammation. In order to assess the role of AmotL2 in OxPt-induced enteral neuropathy, we studied the expression of AmotL2 in cells of the enteric nervous system (ENS) of untreated and OxPt-treated CRC patients and its relationship with inflammation, using immunofluorescence confocal microscopy. Our results in human samples show that the total number of neurons and glial cells decreased in OxPt-treated patients, and TNF-α and AmotL2 expression was increased and colocalized in both neurons and glia. AmotL2 differential expression between OxPt-treated and untreated CRC patients shows the involvement of this scaffold protein in the inflammatory component and toxicity by OxPt in the ENS.

Oxaliplatin-induced peripheral neurotoxicity (OIPN) represents a major challenge in cancer therapy, characterized by dorsal root ganglia (DRG) inflammation and disruption of neuro-glio-vascular unit function. In this study, we investigated the involvement of the scaffold protein IQ Motif Containing GTPase Activating Protein 1 (IQGAP1) and dehydropeptidase-1 (DPEP1) in the DRG response to oxaliplatin (OxPt) and the modulatory effect of cilastatin. Behavioral assessment showed a robust nocifensive response to cold stimuli in OxPt-treated rats, attenuated by cilastatin co-treatment. Our confocal study revealed different cellular and subcellular expression patterns of IQGAP1 and DPEP1 in neurons, glia, and endothelial cells, where both signals overlap approximately one-third. OxPt enhanced cytosolic aggregation of IQGAP1 in neurons and upregulation of signal in glia, accompanied by co-expression of TNFα and IL-6, indicating involvement in the inflammatory process. DPEP1 showed altered subcellular distribution in OxPt-treated animals, suggesting a potential role in the inflammatory cascade. Notably, IQGAP1 expression was diminished in endothelial membranes under OxPt, while cilastatin preserved endothelial IQGAP1-CD31 colocalization, suggesting partial restoration of blood-nerve barrier integrity. These findings identify IQGAP1 and DPEP1 as key players in DRG inflammation and position cilastatin as a promising modulator of OIPN through neuro-glio-vascular stabilization.

Background/Objectives: Truncating mutations in PALB2, a critical component of the BRCA1-PALB2-BRCA2 homologous recombination repair complex, are associated with increased risk and aggressiveness of breast cancer. The consequences of PALB2 truncation on the expression, localization, and functional dynamics of the scaffold protein IQGAP1 were investigated in this study based on two cases of truncated PALB2 human breast invasive ductal carcinoma (IDC), specifically, c.1240C>T (p.Arg414*) and c.2257C>T (p.Arg753*). Methods: Using confocal microscopy, we examined co-expression patterns of IQGAP1 with PALB2, PCNA, CK7, and β-tubulin in tumor tissues from both control cancer and PALB2-mutated cases. Results: In PALB2-truncated tumors, IQGAP1 exhibited enhanced peripheral and plasma membrane localization with elevated co-localization levels compared to controls, suggesting altered cytoskeletal organization. PALB2 truncation increased nuclear and cytoplasmic N-terminal PALB2 immunoreactivity, indicating the presence of truncated isoforms disrupting the homologous recombination repair system. Co-expression analyses with PCNA revealed an inverse expression pattern between IQGAP1 and proliferation markers, suggesting S-phase cell cycle-dependent heterogeneity. Furthermore, the loss of IQGAP1 dominance over CK7 and β-tubulin in mutant tumors, along with persistent intercellular spacing, implied a loss of cell–cell cohesion and the acquisition of invasive traits. Conclusions: These data support a model where PALB2 truncation triggers a reorganization of IQGAP1 that disrupts its canonical structural functions and facilitates tumor progression via enhanced motility and impaired cell–cell interaction. IQGAP1 thus serves as both a functional effector and potential biomarker in PALB2-mutated IDC, opening novel paths for diagnosis and targeted therapeutic intervention.