Prenatal blood lead levels and reduced preadolescent glomerular filtration rate: Modification by body mass index

The Impact of the Aryl Hydrocarbon Receptor on Antenatal Chemical Exposure-Induced Cardiovascular-Kidney-Metabolic Programming

Early life exposure lays the groundwork for the risk of developing cardiovascular-kidney-metabolic (CKM) syndrome in adulthood. Various environmental chemicals to which pregnant mothers are commonly exposed can disrupt fetal programming, leading to a wide range of CKM phenotypes. The aryl hydrocarbon receptor (AHR) has a key role as a ligand-activated transcription factor in sensing these environmental chemicals. Activating AHR through exposure to environmental chemicals has been documented for its adverse impacts on cardiovascular diseases, hypertension, diabetes, obesity, kidney disease, and non-alcoholic fatty liver disease, as evidenced by both epidemiological and animal studies. In this review, we compile current human evidence and findings from animal models that support the connection between antenatal chemical exposures and CKM programming, focusing particularly on AHR signaling. Additionally, we explore potential AHR modulators aimed at preventing CKM syndrome. As the pioneering review to present evidence advocating for the avoidance of toxic chemical exposure during pregnancy and deepening our understanding of AHR signaling, this has the potential to mitigate the global burden of CKM syndrome in the future.

Prenatal Metal Exposures and Associations with Kidney Injury Biomarkers in Children

Prenatal exposure to arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) may be nephrotoxic, yet limited studies have examined subclinical kidney injury biomarkers in children. We assessed whether metal exposure in the second trimester (2T), a crucial time of kidney development, is associated with altered urine kidney injury and function biomarkers in preadolescent children. Analyses included 494 children participating in a birth cohort study in Mexico City. Concentrations of As, Cd, and Pb were measured from pregnant women in 2T blood and urine, and Hg in urine only. Kidney biomarkers were measured from children in urine at age 8-12 years. We assessed the associations between individual metals and (1) kidney biomarkers using linear regression and (2) a multi-protein kidney mixture using weighted quantile sum (WQS) regression. Associations of separate urine and blood metal mixtures with individual kidney biomarkers were assessed via WQS. Within the multi-protein mixture, the association with increased urinary As was predominated by urine alpha-1-microglobulin (A1M), interferon gamma-induced protein 10 (IP10), and fatty acid binding protein 1; the association with increased urinary Cd was predominated by A1M, clusterin, and albumin. The urine metal mixture was associated with increased albumin (0.23 ng/mL; 95% confidence interval (CI): 0.10, 0.37), IP10 (0.15 ng/mL; 95% CI: 0.02, 0.28), and cystatin C (0.17 ng/mL; 95% CI: 0.04, 0.31); these associations were mainly driven by urinary As and Cd. We observed null associations between prenatal blood or urine metal mixtures and estimated glomerular filtration rate. Higher prenatal urinary metals, individually and as a mixture were associated with altered kidney injury biomarkers in children. Further research and longer participant follow-up are required to ascertain the risk of kidney disease later in life.

Metabolite profiling and nephroprotective potential of Glycyrrhiza glabra L. roots against cisplatin-induced nephrotoxicity in vitro and in vivo

OBJECTIVES

The present study was conducted to investigate the phytochemical analysis and demonstrate the nephroprotective potential of root extract of Glycyrrhiza glabra L. against cisplatin (CP) -induced nephrotoxicity in vitro and in vivo.

MATERIALS AND METHODS

The HPTLC analysis and UPLC-MS were carried out for standardizing and metabolite profiling of methanolic extract of roots of G. glabra (GGE). Further, in vitro studies were conducted in human embryonic kidney (HEK)-293 cells to evaluate the cytotoxicity and anti-oxidant potential of GGE with CP as a toxicant and ascorbic acid as standard. Also, in vivo nephroprotective potential at doses of 31.5, 63, and 126 mg/kg/day on CP (6 mg/kg, bw, IP) induced nephrotoxicity was evaluated on rodents.

RESULTS

Phytochemical analysis by HPTLC and UPLC-MS revealed the presence of glycyrrhizin, glabridin, and liquiritin along with other bioactive constituents. The in vitro assay of GGE showed significant (P<0.001 nephroprotective, cellular anti-oxidant potential and improvement in morphological changes induced by CP. Further, administration of CP caused significant (P<0.001) elevation in biochemical, inflammatory, oxidative stress, caspase-3, as well as histopathological changes in kidney tissue. Pre-treatment with GGE attenuated the elevated biochemical markers significantly, improved histopathological damage, and showed a comparable result to ascorbic acid and α-ketoanalogue.

CONCLUSION

Present study concluded the nephroprotective potential of GGE which supports the traditional claim of G. glabra roots in various kidney and its related disorders. The nephroprotective activity may be attributed to its anti-oxidant, anti-inflammatory, and anti-apoptosis effects. Thus, it holds promising potential in management of nephrotoxicity.

Early childhood fluoride exposure and preadolescent kidney function

BACKGROUND

Early-life renal maturation is susceptible to nephrotoxic environmental chemicals. Given the widespread consumption of fluoride and the global obesity epidemic, our main aim was to determine whether childhood fluoride exposure adversely affects kidney function in preadolescence, and if adiposity status modifies this association.

METHODS

Our study included 438 children from the PROGRESS cohort. Urinary fluoride (uF) was assessed at age 4 by diffusion analysis; outcomes studied included estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), selected kidney proteins and blood pressure measured at age 8-12 years. We modeled the relationship between uF and outcomes, and adjusted for body mass index (BMI), age, sex, and socioeconomic status.

RESULTS

The median uF concentration was 0.67 μg/mL. We observed null associations between 4-year uF and preadolescent eGFR, although effect estimates were in the expected inverse direction. A single unit increase in ln-transformed uF was associated with a 2.2 mL/min decrease in cystatin C-based eGFR (95% CI: 5.8, 1.4; p = 0.23). We observed no evidence of sex-specific effects or effect modification by BMI status. Although uF was not associated with BMI, among children with obesity, we observed an inverse association (β: 4.8; 95% CI: 10.2, 0.6; p = 0.08) between uF and eGFR.

CONCLUSIONS

Low-level fluoride exposure in early childhood was not associated with renal function in preadolescence. However, given the adverse outcomes of chronic fluoride consumption it is possible that the preadolescent age was too young to observe any effects. Longitudinal follow-up in this cohort and others is an important next step.

Nephroprotective Effects of Alhagi camelorum against Cisplatin-Induced Nephrotoxicity in Albino Wistar Rats

Alhagi camelorum (AC) is an old plant with a significant therapeutic value throughout Africa, Asia, and Latin America. The overuse of cisplatin (Cis > 50 mg/m²) is associated with observed nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. Remedial measures are needed for the protection of nephrotoxicity against cisplatin. Thus, we investigated the nephroprotective effects of AC plant extract to prevent cisplatin-induced nephrotoxicity in albino Wistar rats. The presence of polyphenols, phenolic compounds, tannins, and saponins was revealed during phytochemical investigation, and a significantly intense antioxidant activity was recorded. There were no toxicological symptoms in the treated rats, and no anatomical, physiological, or histological abnormalities were found compared to the control rats. The results of correcting cisplatin-induced nephrotoxicity revealed that the extract has a significant ability to treat kidney damage, with most parameters returning to normal after only three weeks of therapy. It is concluded that co-administration of cisplatin with AC extract showed exceptional nephroprotective effects at a dose of 600 mg/kg for Cis-induced nephrotoxicity.

Heavy metal ion concentration in the amniotic fluid of preterm and term pregnancies from two cities with different industrial output

The growth and development of the fetus is a complex phenomenon that can be influenced by several variables. High quantities of heavy metal ions in the amniotic fluid have been linked to poor health, especially in industrial, polluted and poor areas. The aim of the present study was to assess the differences in the concentration of these ions between preterm (weeks 15-37) and term pregnancies (starting at week 37). Another objective was to compare pregnancies from two cities with different industry levels. Two sample lots from two Romanian cities were analyzed. A total of 100 patients from Timisoara were compared with 60 from Petrosani, a heavy industry city in Romania. Demographic data were collected, and amniocentesis was performed on all women. Lead (Pb), copper (Cu), nickel (Ni), cadmium (Cd), arsenic (As), iron (Fe) and zinc (Zn) concentrations were assessed. Descriptive and analytical statistics were performed using the Mann-Whitney U test for non-parametric data and the Fisher's exact test for categorical data. In addition, categorical data was represented graphically. In the Timisoara cohort, the differences in heavy metal concentrations between preterm and term pregnancies were not statistically significant. In the Petrosani cohort, however, the concentrations of Zn (P=0.02606) and Cd (P=0.01512) were higher in preterm than in term pregnancies. When comparing the two cohorts as a whole, the concentration of Pb (P=0.04513), Cd (P=0.00002), As (P=0.03027) and Zn (P<0.00001) were higher in the patients from Petrosani than in those from Timisoara. Only Cu concentrations were higher in the Timisoara cohort (P<0.00001). The concentrations of Ni (P=0.78150) and Fe (P=0.44540) did not differ statistically. Thus, amniocentesis is an important diagnostic and exploratory tool in determining differences in the concentrations of elements such as heavy metal ions. Research over a longer period of time should be carried out to examine the relation between heavy metal ions concentration and possible postnatal health outcomes.

A review of studies on blood lead concentrations of traditional Mexican potters

BACKGROUND

Traditional Mexican potters and their families have been occupationally exposed to lead for centuries; however, studies on blood lead levels (BLL) and their adverse health impact on this population are scarce. There is no safe BLL, even at 1 μg/dL there are associated health effects.

OBJECTIVE

To systematize and characterize Mexican potters' historic lead exposure through their BLL and associated health outcomes.

METHODS

Using PRISMA guidelines, we conducted a systematic review through January 2021 of published studies on BLL and associated health outcomes in Mexican potters.

RESULTS

Fifteen studies containing data from 1980 to 2013 met the inclusion criteria and were published between 1980 and 2018. Study populations ranged from n = 5 to n = 457, and included adult potters (mean BLL 37.9 ± 16.2 μg/dL) and/or their children (mean BLL 22.5 ± 10.5 μg/dL). Studies reported on general lead poisoning symptoms, neurotoxic and nephrotoxic outcomes as well as correlated biomarkers.

CONCLUSIONS

Our results confirm high occupational and para-occupational lead exposure. Despite governmental and non-governmental initiatives to promote lead-free glazes, lead continues to be used by traditional potters and their families.

The nephroprotective effects of Daucus carota and Eclipta prostrata against cisplatin-induced nephrotoxicity in rats

The overuse of cisplatin (>50 mg/m2) is limited to nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. The objective of this study was to investigate the nephroprotective effects of Daucus carota and Eclipta prostrata extracts on cisplatin-induced nephrotoxicity in Wistar albino rats. The study involved male Wistar albino rats of 8 weeks weighing 220-270 g. A single injection of 5 mg/kg was injected into the rats for nephrotoxicity. Rats were divided into four groups based on dose conentrations. Blood and urine samples of rats were collected on the 0, 7th, 14th, and 21st days for nephrological analysis. The results showed that Cis + DC/Cis + EP (600 mg/kg) significantly (p < 0.001) increased the body weight and reduced the kidney weight of cisplatin-induced nephrotoxicity in rats (p < 0.001) as compared to Cis group. The results showed that 600 mg/kg administration of Cis + DC/Cis +EP successfully (p < 0.005) improved the urine and plasmin creatinine, Na, and K level compared to the Cis group. Histopathological results confirmed that Cis + EP/Cis + DC effectively improved the renal abnormalities. It is concluded that the co-administration of Cis + EP extract showed exceptional nephroprotective effects at a dose rate of 600 mg/kg.

Adverse Impact of Environmental Chemicals on Developmental Origins of Kidney Disease and Hypertension

Chronic kidney disease (CKD) and hypertension are becoming a global health challenge, despite developments in pharmacotherapy. Both diseases can begin in early life by so-called "developmental origins of health and disease" (DOHaD). Environmental chemical exposure during pregnancy can affect kidney development, resulting in renal programming. Here, we focus on environmental chemicals that pregnant mothers are likely to be exposed, including dioxins, bisphenol A (BPA), phthalates, per- and polyfluoroalkyl substances (PFAS), polycyclic aromatic hydrocarbons (PAH), heavy metals, and air pollution. We summarize current human evidence and animal models that supports the link between prenatal exposure to environmental chemicals and developmental origins of kidney disease and hypertension, with an emphasis on common mechanisms. These include oxidative stress, renin-angiotensin system, reduced nephron numbers, and aryl hydrocarbon receptor signaling pathway. Urgent action is required to identify toxic chemicals in the environment, avoid harmful chemicals exposure during pregnancy and lactation, and continue to discover other potentially harmful chemicals. Innovation is also needed to identify kidney disease and hypertension in the earliest stage, as well as translating effective reprogramming interventions from animal studies into clinical practice. Toward DOHaD approach, prohibiting toxic chemical exposure and better understanding of underlying mechanisms, we have the potential to reduce global burden of kidney disease and hypertension.

The First Thousand Days: Kidney Health and Beyond

The global burden of chronic kidney disease (CKD) is rising. A superior strategy to advance global kidney health is required to prevent and treat CKD early. Kidney development can be impacted during the first 1000 days of life by numerous factors, including malnutrition, maternal illness, exposure to chemicals, substance abuse, medication use, infection, and exogenous stress. In the current review, we summarize environmental risk factors reported thus far in clinical and experimental studies relating to the programming of kidney disease, and systematize the knowledge on common mechanisms underlying renal programming. The aim of this review is to discuss the primary and secondary prevention actions for enhancing kidney health from pregnancy to age 2. The final task is to address the potential interventions to target renal programming through updating animal studies. Together, we can enhance the future of global kidney health in the first 1000 days of life.

Nephrotoxic Metal Mixtures and Preadolescent Kidney Function

Exposure to metals including lead (Pb), cadmium (Cd), and arsenic (As), may impair kidney function as individual toxicants or in mixtures. However, no single medium is ideal to study multiple metals simultaneously. We hypothesized that multi-media biomarkers (MMBs), integrated indices combining information across biomarkers, are informative of adverse kidney function. Levels of Pb, Cd, and As were quantified in blood and urine in 4–6-year-old Mexican children (n = 300) in the PROGRESS longitudinal cohort study. We estimated the mixture effects of these metals, using weighted quantile sum regression (WQS) applied to urine biomarkers (Umix), blood biomarkers (Bmix), and MMBs, on the cystatin C-based estimated glomerular filtration rate (eGFR) and serum cystatin C assessed at 8–10 years of age, adjusted for covariates. Quartile increases in Umix and the MMB mixture were associated with 2.5% (95%CI: 0.1, 5.0) and 3.0% (95%CI: 0.2, 5.7) increased eGFR and −2.6% (95% CI: −5.1%, −0.1%) and −3.3% (95% CI: −6.5%, −0.1%) decreased cystatin C, respectively. Weights indicate that the strongest contributors to the associations with eGFR and serum cystatin C were Cd and Pb, respectively. MMBs detected mixture effects distinct from associations with individual metals or media-type, highlighting the benefits of incorporating information from multiple exposure media in mixtures analyses.