Maternal Immune Activation Disrupts Autophagy and Glucose Homeostasis: Experimental Evidence for the Protective Effects of N‐Acetylcysteine on Maternal and Offspring Outcomes in a Rat Model

Maternal immune activation during pregnancy has been shown to disrupt maternal glucose regulation, predisposing the mother to postpartum diabetic conditions while also exerting long-lasting metabolic effects on the offspring. This study aimed to investigate the impact of lipopolysaccharide (LPS)-induced maternal immune activation on glucose homeostasis at different postpartum stages, the modulatory role of N-acetylcysteine (NAC), and the effects on the offspring, including sex-specific differences. Albino Wistar female and male rats were used; pregnant females received a single intraperitoneal injection of LPS (0.5 mg/kg) on gestational day 16, with a subset pretreated with NAC (300 mg/kg). Mothers were sacrificed at the end of gestation or on postpartum day 21 (PP21), and offspring were analyzed at PP21. Maternal glucose tolerance was assessed using OGTT, and HOMA-IR and HOMA-β indices were used to determine insulin resistance and β-cell function. Maternal and offspring tissues were analyzed for key markers of signaling, autophagy, proliferation, apoptosis, and inflammation. Phosphorylated protein kinase B (p-Akt), mammalian target of rapamycin (mTOR), Ki-67 (a proliferation marker), phosphorylated AMP-activated protein kinase (p-AMPK), Beclin-1, and microtubule-associated protein 1 light chain 3 beta (LC3B) were measured in tissue homogenates; pancreatic insulin and pro-insulin levels were determined; plasma cytokines, including interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ), as well as cleaved caspase-3. All of them were quantified using enzyme-linked immunosorbent assay (ELISA) kits. Total antioxidant capacity (TAC) and total oxidant status (TOS) were measured in plasma using colorimetric assays. At PP0, LPS decreased muscle glucose uptake, increased hepatic gluconeogenesis and glucose output, and enhanced pancreatic insulin production, autophagy, apoptosis, and proliferation while maintaining plasma glucose levels, indicating an adaptive response. NAC improved muscle glucose uptake, suppressed hepatic gluconeogenesis, and normalized pancreatic changes. At PP21, LPS exposure led to increased hepatic gluconeogenesis, impaired pancreatic function, and higher plasma glucose levels. NAC reduced hepatic gluconeogenesis but did not restore glucose balance and worsened pancreatic dysfunction. In offspring of LPS-treated dams, IL-6, TNF-α, and IFN-γ levels decreased, whereas IL-10 increased only in females. Markers of pancreatic apoptosis, autophagy, and proliferation were reduced in both sexes. NAC exposure decreased IL-10 and increased IL-6, TNF-α, and IFN-γ in all offspring and selectively enhanced pancreatic markers in males. Maternal LPS exposure differentially affected glucose regulation through the muscle, liver, and pancreas across postpartum stages. NAC exerted beneficial effects mainly in the early postpartum period but was insufficient later. Furthermore, NAC induced sex-specific effects in the offspring, with a more substantial impact observed in males.