Jiali Mo

Perfluorooctane sulfonate (PFOS), an environmental endocrine‐disrupting compound, can adversely affect offspring lung development following gestational exposures. However, the underlying cellular and molecular mechanisms have yet to be fully elucidated. In our research, dams were orally administered PFOS (0.1 mg/kg BW) from gestational days 11 to 20, and the offspring lungs were assessed at postnatal days 0, 7, 14, and 21. It was shown that gestational PFOS exposure induced bronchopulmonary dysplasia (BPD)–like pathology, characterized by simplified alveolar structure, glycogen retention, and collagen deposition. Single‐cell RNA sequencing analysis of newborn rat lungs revealed that PFOS profoundly remodeled the pulmonary cellular landscape, resulting in a pronounced accumulation of transitional alveolar epithelial type II cells (AECIIs), and a shift of alveolar macrophages toward pro‐inflammatory and pro‐fibrotic phenotypes. Intercellular communication analysis indicated that molecules originating from monocytes and alveolar macrophages, including the FN1–CD44 axis, may be the major signals responsible for epithelial defects. Overall, these findings identify the disruption of AECII differentiation as a pivotal event in alveolar developmental defects and provide novel insights into the role of immune–epithelial crosstalk in PFOS‐induced pulmonary toxicity.

Perfluorooctane sulfonate (PFOS) is widely used in industry and consumer products. Previous studies have showed that PFOS gestational exposure is associated with offspring lung damage in rat. However, the underlying mechanisms remain poorly understood. In this study, we investigated the role of gasdermin E (GSDME) in lung injury of offspring and its underlying mechanisms using in vivo and in vitro approaches. Pregnant SD rats were exposed to PFOS (1 mg/kg BW/d) between gestational day 12–18, and the lung tissue of the offspring was evaluated on postnatal day 7. PFOS treated animals exhibited alveolar septal thickening and inflammation-related damages, with an increased expression of GSDME in alveolar type II epithelial cells (AECII). Furthermore, in vitro experiments demonstrated that PFOS exposure (with 225 μM and up) upregulated the caspase-3/GSDME signaling pathway in AECII. Also, ultrastructure analysis revealed significant changes in the endoplasmic reticulum (ER) structure in PFOS-induced pyroptotic cells, which is consistent with the ER stress detected in these cells. Additionally, PFOS exposure led to increased expression of ER stress-related proteins, including p-PERK, p-eIF2α, ATF4, and CHOP. Subsequently, using specific inhibitors, we found that the PERK/ATF4 pathway acted as an upstream signal regulating GSDME-dependent pyroptosis. Overall, our findings show that GSDME-dependent pyroptosis plays a crucial role in the lung injury induced by gestational PFOS exposure, and the PERK/ATF4 pathway may function as a possible mediator of this process.

Podocyte abnormalities are common mechanism driving the progression of glomerular diseases, which account for most chronic kidney diseases (CKDs). However, the role of podocyte in the mechanism of high-risk long-term CKD caused by prematurity has not been well clarified. In present study, urine samples of 86 preterm infants and 32 full-term infants were collected, and podocyte-specific podocin mRNA levels in urine pellet were applied to indicate urinary podocyte mRNA excretion. In addition, in a preterm animal rat model, preterm rats were identified by delivery 2 days early. From the age of 3 weeks–12 months, urine samples were collected to examine podocyte mRNA excretion by measuring podocyte-specific podocin mRNA levels. Kidney samples at the age of 3 weeks, 2 months, and 12 months were collected from 8, 5 and 6 preterm rats and 9, 6 and 8 full-term rats, respectively, to examine podocyte density and podocyte area by measuring the podocyte specific nuclear marker WT-1 and the podocyte specific marker synaptopodin. As results, a more than threefold increase of urinary podocyte-specific podocin mRNA excretion rate was found in preterm infants compared with full-term infants. In addition, there was negative correlation between gestational age at birth and urinary podocin mRNA excretion. In preterm rats, a reduction in the total number of differentiated podocytes in glomeruli and an increased podocyte podocin mRNA excretion rate in urine were detected at the end of kidney differentiation. Moreover, long-term follow-up data in preterm rats showed there was an increased the risk of renal disease indicated by persistent podocyte mRNA loss, proteinuria, and enlarged glomeruli. In conclusion, increasing podocyte mRNA excretion in urine and podocyte loss in kidney led by prematurity drive the progression of long-term abnormal kidney function and could potentially explain the high risk of long-term CKD in preterm infants.

Recent single-cell RNA sequencing (scRNA-seq) analyses have offered much insight into the gene expression profiles in early-stage kidney development. However, comprehensive gene expression profiles from mid- and late-stage kidney development are lacking. In the present study, by using the scRNA-seq technique, we analyzed 54,704 rat kidney cells from just after birth to adulthood (six time points: postnatal days 0, 2, 5, 10, 20, and 56) including the mid and late stages of kidney development. Twenty-five original clusters and 13 different cell types were identified during these stages. Gene expression in these 13 cell types was mapped, and single cell atlas of the rat kidney from birth to maturity (http://youngbearlab.com) was built to enable users to search for a gene of interest and to evaluate its expression in different cells. The variation trend of six major types of kidney cells—intercalated cells of the collecting duct (CD-ICs), principal cells of the collecting duct (CD-PCs), cells of the distal convoluted tubules (DCTs), cells of the loop of Henle (LOH), podocytes (PDs), and cells of the proximal tubules (PTs)—during six postnatal time points was demonstrated. The trajectory of rat kidney development and the order of induction of the six major types of kidney cells from just after birth to maturity were determined. In addition, features of the dynamically changing genes as well as transcription factors during postnatal rat kidney development were identified. The present study provides a resource for achieving a deep understanding of the molecular basis of and regulatory events in the mid and late stages of kidney development.