Novel Role of Gestational Hydralazine in Limiting Maternal and Dietary Obesity-Related Chronic Kidney Disease

Cross-Generational Impact of Maternal Exposure to Low Level of PM2.5 on Kidney Health

INTRODUCTION

Inhaled fine and ultrafine particulate matter may affect organs other than the lung, including the kidney. Recent studies have consistently shown the possibility of air pollution in highly polluted countries to be nephrotoxic. However, in countries like Australia, where air quality generally adheres to or remains below the WHO standards, the subtle yet consequential impacts of chronic exposure to seemingly safe levels of traffic PM2.5, are a subject of increasing significance. However, how such exposures in the peri-pregnancy period affect kidney health in mothers and the offspring is unclear, which formed the aims of this study.

METHODS

Female Balb/c mice were exposed to PM2.5 (5 μg/day) delivered nasally for 6 weeks prior to mating, during gestation and lactation (PM group). In a subgroup, PM2.5 was switched to saline from mating until offspring were weaned to model mothers moving to areas with clean air. Kidneys were analysed in dams and adult offspring at 13 weeks of age.

RESULTS

PM2.5 induced oxidative stress without histological changes in the dam's kidney. However, male PM offspring displayed in utero underdevelopment, characterised by reduced body weight and kidney-to-body weight at birth compared to control offspring, and lower glomerular numbers, with a marked increase in albuminuria, glomerulosclerosis, inflammation, oxidative stress, and mitochondrial injury. Female PM offspring had delayed postnatal development, lower glomerular numbers, increased glomerulosclerosis, and oxidative stress injury markers. Removal of PM2.5 from conception significantly reduced DNA oxidation and kidney damage in the offspring.

CONCLUSION

There is no safe level of ambient PM2.5 for kidney health when exposed in utero. Maternal PM2.5 exposure equally impacts the kidney health of male and female offspring. Removal of PM2.5 from conception was overall protective to the offspring.

Sex differences in fetal kidney reprogramming: the case in the renin-angiotensin system

During the early stages of the development of the living multiorgan systems, genome modifications other than sequence variation occur that guide cell differentiation and organogenesis. These modifications are known to operate as a fetal programming code during this period, and recent research indicates that there are some tissue-specific codes in organogenesis whose effects may persist after birth until adulthood. Consequently, the events that disrupt the pre-established epigenetic pattern could induce shifts in organ physiology, with implications on health from birth or later in adult life. Chronic kidney disease (CKD) is one of the main causes of mortality worldwide; its etiology is multifactorial, but diabetes, obesity, and hypertension are the main causes of CKD in adults, although there are other risk factors that are mainly associated with an individual's lifestyle. Recent studies suggest that fetal reprogramming in the developing kidney could be implicated in the susceptibility to kidney disease in both childhood and adulthood. Some epigenetic modifications, such as genome methylation status, dysregulation of miRNA, and histone coding alterations in genes related to the regulation of the renin-angiotensin axis, a common denominator in CKD, may have originated during fetal development. This review focuses on epigenetic changes during nephrogenesis and their repercussions on kidney health and disease. In addition, the focus is on the influence of environmental factors during pregnancy, such as maternal metabolic diseases and dietary and metabolic conditions, as well as some sex differences in fetal kidney reprogramming during which dysregulation of the renin-angiotensin system is involved.

Maternal High-Fat Diet Controls Offspring Kidney Health and Disease

A balanced diet during gestation is critical for fetal development, and excessive intake of saturated fats during gestation and lactation is related to an increased risk of offspring kidney disease. Emerging evidence indicates that a maternal high-fat diet influences kidney health and disease of the offspring via so-called renal programming. This review summarizes preclinical research documenting the connection between a maternal high-fat diet during gestation and lactation and offspring kidney disease, as well as the molecular mechanisms behind renal programming, and early-life interventions to offset adverse programming processes. Animal models indicate that offspring kidney health can be improved via perinatal polyunsaturated fatty acid supplementation, gut microbiota changes, and modulation of nutrient-sensing signals. These findings reinforce the significance of a balanced maternal diet for the kidney health of offspring.

Hesperidin inhibits methylation and autophagy in LPS and high glucose-induced human villous trophoblasts

INTRODUCTION

Gestational diabetes mellitus (GDM) is the first occurrence of diabetes due to abnormal maternal sugar metabolism after pregnancy, which may lead to adverse pregnancy outcomes. Hesperidin is known to decrease in the cord blood of GDM with obesity, but its role is unknown. This study aims to explore the potential function of hesperidin in GDM with obesity to develop new therapeutic ideas.

METHODS

Peripheral blood and placental tissues from GDM and GDM with obesity patients were collected to isolate human villous trophoblasts and detection. Bioinformatics was used to analyze the differential methylation genes between GDM and GDM with obesity. Immunofluorescence was applied for the detection of CK7 expression. Cells vitality was detected by CCK8 and transwell. Molecular docking was applied to predict the binding of hesperidin and ATG7 protein. Inflammation and m6A levels was analyzed by ELISA. ATG7, LC3, TLR4 and P62 proteins was analyzed by Western blot.

RESULTS

The methylation of ATG7 gene was up-regulated in GDM with obesity compared with GDM. The m6A and autophagy proteins levels in GDM with obesity were higher than that in GDM. LPS with 2.5-25 mM glucose induced the increase of autophagy proteins, inflammation and m6A levels in human villous trophoblasts. Hesperidin formed hydrogen bonds and hydrophobic interactions with ATG7 proteins. Hesperidin (0.25 μM) inhibited the autophagy proteins and m6A level in LPS and 25 mM glucose-induced human villous trophoblasts.

DISCUSSION

GDM with obesity followed the increase of autophagy proteins and m6A levels. Hesperidin inhibited the autophagy proteins and m6A level in LPS and glucose-induced human villous trophoblasts.

Potential Impacts of Hydralazine as a Novel Antioxidant on Cardiovascular and Renal Disease-Beyond Vasodilation and Blood Pressure Lowering

Hydralazine is a traditional antihypertensive drug that was developed several decades ago. Its most well-known effect is blood pressure lowering by arterial vasodilation. While mainly used an adjunct treatment for clinical hypertension or chronic heart failure, this old drug has also shown potential as a repurposing drug for the atherosclerosis vascular disease and various kidney diseases. Recent experimental studies suggest that hydralazine exerts antioxidative, anti-apoptotic, and HIF-1α stabilization effects for angiogenesis and vascular protection. Hydralazine also exerts reno-protective effects via its antioxidation, DNA demethylation, and anti-inflammation abilities. The above evidence provides advanced rationales for new applications of this drug beyond blood pressure lowering and arterial vasodilation. Here, we summarized the recent experimental advances in the use of hydralazine for either a vascular disease or kidney diseases, or both. Given the wide populations of people with cardiovascular and/or kidney diseases, future studies are worth validating the potential impacts of hydralazine on the clinical outcomes in selected patients.

Low-dose hydralazine reduces albuminuria and glomerulosclerosis in a mouse model of obesity-related chronic kidney disease

AIM

To determine, using a mouse model of obesity, whether low-dose hydralazine prevents obesity-related chronic kidney disease (CKD).

METHODS

From 8 weeks of age, male C57BL/6 mice received a high-fat diet (HFD) or chow, with or without low-dose hydralazine (25 mg/L) in drinking water, for 24 weeks. Biometric and metabolic variables, renal function and structural changes, renal global DNA methylation, DNA methylation profile and markers of renal fibrosis, injury, inflammation and oxidative stress were assessed.

RESULTS

The HFD-fed mice developed obesity, with glucose intolerance, hyperinsulinaemia and dyslipidaemia. Obesity increased albuminuria and glomerulosclerosis, which were significantly ameliorated by low-dose hydralazine in the absence of a blood pressure-lowering effect. Obesity increased renal global DNA methylation and this was attenuated by low-dose hydralazine. HFD-induced changes in methylation of individual loci were also significantly reversed by low-dose hydralazine. Obese mice demonstrated increased markers of kidney fibrosis, inflammation and oxidative stress, but these markers were not significantly improved by hydralazine.

CONCLUSION

Low-dose hydralazine ameliorated HFD-induced albuminuria and glomerulosclerosis, independent of alterations in biometric and metabolic variables or blood pressure regulation. Although the precise mechanism of renoprotection in obesity is unclear, an epigenetic basis may be implicated. These data support repurposing hydralazine as a novel therapy to prevent CKD progression in obese patients.

Diet Modification before or during Pregnancy on Maternal and Foetal Outcomes in Rodent Models of Maternal Obesity

The obesity epidemic has serious implications for women of reproductive age; its rising incidence is associated not just with health implications for the mother but also has transgenerational ramifications for the offspring. Increased incidence of diabetes, cardiovascular disease, obesity, and kidney disease are seen in both the mothers and the offspring. Animal models, such as rodent studies, are fundamental to studying maternal obesity and its impact on maternal and offspring health, as human studies lack rigorous controlled experimental design. Furthermore, the short and prolific reproductive potential of rodents enables examination across multiple generations and facilitates the exploration of interventional strategies to mitigate the impact of maternal obesity, both before and during pregnancy. Given that obesity is a major public health concern, it is important to obtain a greater understanding of its pathophysiology and interaction with reproductive health, placental physiology, and foetal development. This narrative review focuses on the known effects of maternal obesity on the mother and the offspring, and the benefits of interventional strategies, including dietary intervention, before or during pregnancy on maternal and foetal outcomes. It further examines the contribution of rodent models of maternal obesity to elucidating pathophysiological pathways of disease development, as well as methods to reduce the impact of obesity on the mothers and the developing foetus. The translation of these findings into the human experience will also be discussed.