The First Thousand Days: Kidney Health and Beyond

Advocacy for DOHaD research optimizing child kidney health

Emerging antenatal risk factors have been associated with an increased risk of kidney disease throughout the offspring's life course. However, the intricate kidney programming mechanisms underlying these risks remain complex and are incompletely understood, but they are rooted in structural and functional alterations within the kidneys. The Developmental Origins of Health and Disease (DOHaD) theory underscores the significance of elucidating core mechanisms initiated through the maternal-fetal interface, which trigger kidney programming. Furthermore, it offers a promising avenue for preventing kidney disease at its earliest stages through a process known as reprogramming. This concise review aims to synthesize existing knowledge regarding the impact of kidney programming on offspring kidney disease and to provide an overview of documented reprogramming strategies as observed in animal models of kidney programming. By consolidating this information, we aim to expedite the translation of research breakthroughs into practical clinical solutions, ultimately resulting in enhanced outcomes for children facing kidney-related issues.

Prenatal morphogenic and histogenic development of the kidney in rabbits (Oryctolagus cuniculus)

Background

Rabbits are easily available and docile animals; thus, they are a promising model for medical research. White New Zealand rabbits are usually employed for research.

Aim

This study aimed to determine the kidney's histological structure using rabbit embryos and fetuses at various stages of gestation.

Methods

Morphogenesis and histogenesis of the kidney were assessed using Harris's hematoxylin and eosin staining at different gestational periods in rabbits.

Results

Around the 10th day of gestation, the intermediate mesoderm started to differentiate into kidney tissue. The first primitive form of the kidney was the pronephros, which consisted of pronephric tubules and ducts. Large mesonephroi occupied a large part of the abdominal cavity from the 13th day of gestation and persisted for several days. At 15th day of gestation, the permanent kidney, the metanephros, began its differentiation and then persevered until formation of the adult kidney tissue at 24th day of gestation.

Conclusion

This study clarified normal kidney histogenesis in rabbits; this would provide better understanding of kidney diseases aid in kidney transplant.

Gestational Exposure to Nonsteroidal Anti-Inflammatory Drugs and Risk of Chronic Kidney Disease in Childhood

Importance

Gestational exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of adverse fetal kidney outcomes. However, details regarding timing, specific NSAIDs, and long-term childhood kidney outcomes are limited.

Objective

To evaluate the association between gestational exposure to NSAIDs and the risk of chronic kidney disease (CKD) in childhood.

Design, Setting, and Participants

This national cohort study assessed 1 025 255 children born alive in Taiwan from January 1, 2007, to December 31, 2017, with follow-up until December 31, 2021. Children without valid maternal-child linkage and with incomplete birth information were excluded. Data analysis was performed from November 30, 2023, to April 30, 2024.

Exposure

Maternal prescriptions for NSAIDs from the last menstrual period to birth.

Main Outcomes and Measures

The main outcome was childhood CKD, including congenital anomalies of the kidney and urinary tract and other kidney diseases. Cox proportional hazards regression models with stabilized inverse probability of treatment weighting (weighted hazard ratio [wHR]) and a robust sandwich estimator were used to estimate the relative risk of NSAID exposure in pregnancy, adjusted for newborn characteristics.

Results

This study included 163 516 singleton-born children (24.0%) whose mothers (mean [SD] age at birth of child, 31.25 [4.92] years) used at least 1 dispensing of an NSAID during pregnancy. Gestational NSAID exposure was significantly associated with a higher risk of childhood CKD (wHR, 1.10; 95% CI, 1.05-1.15). No association was observed between NSAID use and fetal nephrotoxicity in sibling comparisons. Elevated risks were revealed for exposure during the second trimester (wHR, 1.19; 95% CI, 1.11-1.28) and the third trimester (wHR, 1.12; 95% CI, 1.03-1.22) in singleton-born children. Specific NSAID exposures associated with higher CKD risk included indomethacin (wHR, 1.69; 95% CI, 1.10-2.60) and ketorolac (wHR, 1.28; 95% CI, 1.01-1.62) in the first trimester, diclofenac (wHR, 1.27; 95% CI, 1.13-1.42) and mefenamic acid (wHR, 1.29; 95% CI, 1.15-1.46) in the second trimester, and ibuprofen (wHR, 1.34; 95% CI, 1.07-1.68) in the third trimester.

Conclusions and Relevance

In this study, gestational exposure to NSAIDs was not associated with a substantial increase in the risk of childhood CKD when comparing between siblings. However, the findings underscore the need for caution when prescribing NSAIDs during pregnancy, particularly indomethacin and ketorolac in the first trimester, mefenamic acid and diclofenac in the second trimester, and ibuprofen in the third trimester, to ensure the safety of the offspring's kidneys.

Preterm Birth and Kidney Health: From the Womb to the Rest of Life

Chronic kidney disease (CKD) is a widespread condition often resulting from multiple factors, including maternal influences. These risk factors not only heighten the likelihood of developing CKD but increase the risk of a preterm birth. Adverse events during nephrogenesis can disrupt kidney development, leading to a reduced number of nephrons. As survival rates for preterm infants improve, more individuals are living into adulthood, thereby elevating their risk of CKD later in life. This review aims to explore the connections between preterm birth, kidney development, and the increased risk of CKD, while proposing practical solutions for the future through a multidisciplinary approach. We examine human studies linking preterm birth to negative kidney outcomes, summarize animal models demonstrating kidney programming and reduced nephron numbers, and consolidate knowledge on common mechanisms driving kidney programming. Additionally, we discuss factors in the postnatal care environment that may act as secondary insults contributing to CKD risk, such as acute kidney injury (AKI), the use of nephrotoxic drugs, preterm nutrition, and catch-up growth. Finally, we outline recommendations for action, emphasizing the importance of avoiding modifiable risk factors and implementing early CKD screening for children born preterm. Together, we can ensure that advancements in kidney health keep pace with improvements in preterm care.

Lactoferrin in Pediatric Chronic Kidney Disease and Its Relationship with Cardiovascular Risk

BACKGROUND

Pediatric CKD is associated with a high risk of cardiovascular disease (CVD). Early detection of subclinical CVD in childhood CKD can be achieved through various cardiovascular (CV) assessments, including carotid intima-media thickness (cIMT), ambulatory blood pressure monitoring (ABPM), and arterial stiffness indices. Lactoferrin (LF), a key functional glycoprotein found in breast milk, has been linked to several diseases and has potential as a biomarker.

METHODS

In our study of 102 children with CKD stages G1-G4, we explored the relationship between LF and CV risk markers.

RESULTS

We found that LF concentration was not related to the severity or underlying causes of childhood CKD, but was positively correlated with overweight/obesity. Lower LF levels were correlated with increased cIMT and elevated arterial stiffness indices. Notably, abnormalities in ABPM profiles were observed in up to 60% of the children with CKD, with low LF levels linked to nighttime hypertension, nocturnal non-dipping, and ABPM abnormalities.

CONCLUSIONS

In conclusion, LF shows promise as a biomarker for detecting subclinical CVD in children with CKD. Its potential utility in early detection could be instrumental in guiding timely interventions and improving long-term CV outcomes, although further research is needed to clarify the underlying mechanisms.

Effects of Nutrition on Maternal Health, Fetal Development, and Perinatal Outcomes

The early life theory states that the first 1000 days of a person's life are highly influential, as lasting health impacts can be attained during this period [...].

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.

Sulfur-Containing Amino Acids, Hydrogen Sulfide, and Sulfur Compounds on Kidney Health and Disease

Hydrogen sulfide (H₂S) plays a decisive role in kidney health and disease. H₂S can ben synthesized via enzymatic and non-enzymatic pathways, as well as gut microbial origins. Kidney disease can originate in early life induced by various maternal insults throughout the process, namely renal programming. Sulfur-containing amino acids and sulfate are essential in normal pregnancy and fetal development. Dysregulated H₂S signaling behind renal programming is linked to deficient nitric oxide, oxidative stress, the aberrant renin-angiotensin-aldosterone system, and gut microbiota dysbiosis. In animal models of renal programming, treatment with sulfur-containing amino acids, N-acetylcysteine, H₂S donors, and organosulfur compounds during gestation and lactation could improve offspring's renal outcomes. In this review, we summarize current knowledge regarding sulfide/sulfate implicated in pregnancy and kidney development, current evidence supporting the interactions between H₂S signaling and underlying mechanisms of renal programming, and recent advances in the beneficial actions of sulfide-related interventions on the prevention of kidney disease. Modifying H₂S signaling is the novel therapeutic and preventive approach to reduce the global burden of kidney disease; however, more work is required to translate this into clinical practice.

Melatonin and Kidney Health: From Fetal Stage to Later Life

Melatonin, an endogenous hormone mainly released at night by the pineal gland, has multifaceted biofunctions. Emerging evidence points to melatonin having a crucial role in kidney health and disease. As the prevalence of chronic kidney disease (CKD) is still rising, a superior strategy to advance global kidney health is needed to not just treat CKD, but prevent it early on. Adult kidney disease can have its origins in early life. This review aims to evaluate the recent literature regarding melatonin's effect on kidney development, its clinical uses in the early stage of life, animal models documenting preventive applications of melatonin on offspring's kidney-related disease, and a thorough summary of therapeutic considerations concerning melatonin supplementation.

Perinatal Oxidative Stress and Kidney Health: Bridging the Gap between Animal Models and Clinical Reality

Oxidative stress arises when the generation of reactive oxygen species or reactive nitrogen species overwhelms antioxidant systems. Developing kidneys are vulnerable to oxidative stress, resulting in adult kidney disease. Oxidative stress in fetuses and neonates can be evaluated by assessing various biomarkers. Using animal models, our knowledge of oxidative-stress-related renal programming, the molecular mechanisms underlying renal programming, and preventive interventions to avert kidney disease has grown enormously. This comprehensive review provides an overview of the impact of perinatal oxidative stress on renal programming, the implications of antioxidant strategies on the prevention of kidney disease, and the gap between animal models and clinical reality.

Chronic Kidney Disease and Gut Microbiota: What Is Their Connection in Early Life?

The gut-kidney interaction implicating chronic kidney disease (CKD) has been the focus of increasing interest in recent years. Gut microbiota-targeted therapies could prevent CKD and its comorbidities. Considering that CKD can originate in early life, its treatment and prevention should start in childhood or even earlier in fetal life. Therefore, a better understanding of how the early-life gut microbiome impacts CKD in later life and how to develop ideal early interventions are unmet needs to reduce CKD. The purpose of the current review is to summarize (1) the current evidence on the gut microbiota dysbiosis implicated in pediatric CKD; (2) current knowledge supporting the impact of the gut-kidney axis in CKD, including inflammation, immune response, alterations of microbiota compositions, short-chain fatty acids, and uremic toxins; and (3) an overview of the studies documenting early gut microbiota-targeted interventions in animal models of CKD of developmental origins. Treatment options include prebiotics, probiotics, postbiotics, etc. To accelerate the transition of gut microbiota-based therapies for early prevention of CKD, an extended comprehension of gut microbiota dysbiosis implicated in renal programming is needed, as well as a greater focus on pediatric CKD for further clinical translation.

The developmental origins of health and chronic kidney disease: Current status and practices in Japan

The concept of the developmental origins of health and disease (DOHaD) views unfavorable perinatal circumstances as contributing to the development of diseases in later life. It is well known that such unfavorable circumstances play an important role as a risk factor for chronic kidney disease (CKD) in infants born with prematurity. Low birthweight (LBW) is believed to be a potential contributor to CKD in adulthood. Preterm and/or LBW infants are born with incomplete nephrogenesis. As a result, the number of nephrons is low. The poor intrauterine environment also causes epigenetic changes that adversely affect postnatal renal function. After birth, hyperfiltration of individual nephrons due to low nephron numbers causes proteinuria and secondary glomerulosclerosis. Furthermore, the risk of CKD increases as renal damage takes a second hit from exposure to nephrotoxic substances and acquired insults such as acute kidney injury after birth among infants in neonatal intensive care. Meanwhile, unfortunately, recent studies have shown that the number of nephrons in healthy Japanese individuals is approximately two-thirds lower than that in previous reports. This means that Japanese premature infants are clearly at a high risk of developing CKD in later life. Recently, several DOHaD-related CKD studies from Japanese researchers have been reported. Here, we summarize the relevance of CKD in conjunction with DOHaD and review recent studies that have examined the impact of the upward LBW trend in Japan on renal health.

Early-Life Origins of Metabolic Syndrome: Mechanisms and Preventive Aspects

One of the leading global public-health burdens is metabolic syndrome (MetS), despite the many advances in pharmacotherapies. MetS, now known as "developmental origins of health and disease" (DOHaD), can have its origins in early life. Offspring MetS can be programmed by various adverse early-life conditions, such as nutrition imbalance, maternal conditions or diseases, maternal chemical exposure, and medication use. Conversely, early interventions have shown potential to revoke programming processes to prevent MetS of developmental origins, namely reprogramming. In this review, we summarize what is currently known about adverse environmental insults implicated in MetS of developmental origins, including the fundamental underlying mechanisms. We also describe animal models that have been developed to study the developmental programming of MetS. This review extends previous research reviews by addressing implementation of reprogramming strategies to prevent the programming of MetS. These mechanism-targeted strategies include antioxidants, melatonin, resveratrol, probiotics/prebiotics, and amino acids. Much work remains to be accomplished to determine the insults that could induce MetS, to identify the mechanisms behind MetS programming, and to develop potential reprogramming strategies for clinical translation.