Renal Metabolism Research Articles

Beyond SGLT2: proximal tubule transporters as potential drug targets for chronic kidney disease.

The proximal tubule is responsible for reabsorbing about 60% of filtered solutes and water and is critical for the secretion of metabolic waste products, drugs and toxins. A large number of highly specialized ion channels and transport proteins belonging to the SLC and ABC transporter families are involved. Their activity is directly or indirectly linked to ATP consumption and requires large quantities of energy and oxygen supply. Moreover, the activity of these transporters is often coupled to the movement of Na+ ions thus influencing also salt and water balance, as well as transport and regulatory processes in downstream segments. Because of their relevance for systemic ion balance, for renal metabolism or for affecting regulatory processes, proximal tubule transporters are attractive targets for existing drug and for novel strategies to reduce kidney disease progression or to alleviate the consequences of decreased kidney function. In this review, the relevance of some major proximal tubule transport systems as drug targets in individuals with chronic kidney disease (CKD) is discussed. Inhibitors of the sodium-glucose cotransporter 2, SGLT2, are now part of standard therapy in patients with CKD and/or heart failure. Also, indirect inhibition of Na+/H+-exchangers by carbonic anhydrase inhibitors and uricosuric drugs have been used for decades. Inhibition of phosphate and amino acid transporters have recently been proposed as novel principles to remove excess phosphate or to protect the proximal tubule metabolically, respectively. In addition, organic cation and anion transporters involved in drug and toxin excretion may serve as targets of new drugs. The advantages and challenges associated with (novel) drugs targeting proximal tubule transport are discussed.

Laminaria japonica polysaccharide protects against liver and kidney injury in diabetes mellitus through the AhR/CD36 pathway.

The lipid accumulation associated with diabetes causes continuous liver and kidney damage. Laminaria japonica polysaccharide (fucoidan) has been shown to regulate the disorder in lipid metabolism caused by diabetes. Herein, we established a diabetes mellitus (DM) rat model through a high-fat and high-sugar diet combined with streptozotocin. An automatic biochemical analyzer was used to detect serum lipid content, and hematoxylin and eosin, Masson, periodic acid-silver-methenamine, and Oil Red O staining were used to observe changes in the structure of the kidney and liver, including fibrosis and lipid accumulation. We confirmed that fucoidan could ameliorate renal injury, lipid metabolism, and oxidative stress in streptozotocin-induced diabetic rat models. Metabolomics analysis demonstrated that amino acid metabolism is an important process. We further demonstrated a novel role of fucoidan in regulating kidney and liver lipid metabolism through the aryl hydrocarbon receptor (AhR)-mediated CD36 signaling pathway. Similar results were found in DM rats treated with an AhR inhibitor, as well as in those treated with a combination of both an AhR inhibitor and fucoidan. Importantly, we observed a higher expression of AhR/CD36 in the kidneys and liver of rats with DM, and the level of AhR/CD36 correlated with lipid accumulation and kidney function, suggesting that AhR/CD36 signaling could be a promising therapeutic target for fucoidan in treating lipid metabolism in DM. PRACTICAL APPLICATION: As the main component of Laminaria japonica, fucoidan has excellent antioxidant properties and protective effects against liver and kidney damage in diabetes mellitus. It can play a protective role in the daily diet of diabetic patients. Alternatively, it could be developed as a potential therapeutic drug for the treatment of diabetes.

P-15 DIAGNOSTIC PITFALL - A RARE CASE OF HYPERCALCEMIA

Abstract Introduction Infantile hypercalcaemia type 1 (IIH) is an autosomal recessive disorder characterized by homozygous mutations in the CYP24A1 gene that encodes the 24-hydroxylase enzyme used to inactivate 1,25-(OH)2-vitamin D. Clinical Case A 24-year-old male was referred to our department for the evaluation of hypertension and nephrolithiasis, in the context of hypercalcemia. The general physical examination and the endocrinological assessment revealed no abnormalities. The patient was initially evaluated in nephrology & urology departments, where computed tomography (CT) revealed renal nephrocalcinosis and a lower right renal cyst, with no findings at thoracic level. Laboratory results confirmed hypercalcemia (total calcium 12.6 mg/dL, Ca++ at 5.49 mg/dL), alongside low parathyroid hormone (PTH) at 3 pg/mL. Malignancy was ruled out by normal PTH-related peptide levels (<0.5 pmol/L) and normal 25-hydroxyvitamin D levels (46 ng/mL), though 1,25-dihydroxyvitamin D was slightly elevated (81.8 pg/mL; Ref: 19.9−79.3 pg/mL). Bone metabolism markers, including FGF-23, serum crosslaps, and osteocalcin, were normal, excluding metabolic bone disease. Urine/24h: low urinary calcium (0.27 g/24h) and normal urinary phosphate (0.87 g/24h). In the diagnostic algorithm, hypercalcemia can be PTH-mediated, non-PTH-mediated, medication-induced, and miscellaneous causes. The patient's low PTH and suppressed PTH-rp excluded primary hyperparathyroidism and malignancy-related hypercalcemia. Normal 25(OH) vitamin D and slightly elevated 1,25(OH) vitamin D levels raised the suspicion of extrarenal 1-alpha-hydroxylation of vitamin D, a mechanism seen in granulomatous diseases such as sarcoidosis or tuberculosis, or in lymphomas. However, granulomatous diseases were excluded based on negative chest X-ray and thoracic CT findings and normal angiotensin-converting enzyme (ACE) levels. Other possible malignancies were excluded: germ cell tumors, such as non-seminomatous germ cell tumors, testicular cancers, particularly seminomas or choriocarcinomas, Hodgkin's lymphoma and multiple myeloma. Additionally, through medical history, clinical examination, and laboratory tests, we have also excluded hyperthyroidism, acromegaly, pheochromocytoma, adrenal insufficiency, bed rest/immobilization, parenteral nutrition, and supplements. Consequently, a genetic cause of abnormal renal calcium metabolism was suspected. Genetic testing revealed a heterozygous pathogenic mutation in the CYP24A1 gene, which is linked to Infantile Hypercalcemia Type 1. The patient's diagnosis of IIH was confirmed by the detection of the CYP24A1 mutation. Management of his condition focuses on controlling calcium levels through dietary intake and diuresis to prevent kidney stones, as there is no specific treatment available. Conclusion This case report highlights the importance of determining the etiology of hypercalcemia and the significance of genetic testing in clinical management.

A Clinical Drug as the Three-Photon Fluorescence Probe forInVivo Microscopic Imaging of Mouse Kidney.

Three-photon fluorescence (3PF) microscopy encounters significant challenges in biological research and clinical applications, primarily due to the limited availability of high-performance probes. We took a shortcut by exploring the excellent 3PF property of berberine hydrochloride (BH), a clinically utilized drug derived from the traditional Chinese medicine, Coptis. Capitalizing on its renal metabolism characteristics, we employed BH for invivo 3PF microscopic imaging of the mouse kidney. This approach enabled high-resolution structural observation of renal tubules and facilitated the diagnosis of drug-induced acute kidney injury (AKI) based on renal tubule morphology. The analytical capabilities of 3PF microscopy for renal physiology and pathological diagnosis suggest its potential for future clinical applications.

Curcumin Modulates the Differential Effects of Fructose and High-Fat Diet on Renal Damage, Inflammation, Fibrosis, and Lipid Metabolism.

Dyslipidemia and obesity hypercaloric diet-induced lead to kidney damage. We investigated the effect of curcumin on the expression of proteins related to inflammation, fibrosis, fatty acids metabolism, kidney damage, and morphological changes in the kidneys of mice hypercaloric diets-fed. Groups of 5-week-old C57BL/6 mice (n=6) were formed: Control (C), High-fructose diet (F), Highfructose diet and curcumin (F+Cur), High-fat diet (HFD), High-fat diet and curcumin (HFD+Cur), High-fat diet and fructose (HFD+F), High-fat diet, fructose and curcumin (HFD+F+Cur), treated for 16 weeks with 30% (w/v) fructose, 60% (w/w) fat and 0.75% (w/w) curcumin. Kidneys were obtained for histomorphological and Western Blot analysis. Curcumin prevented TNF-α overexpression in the F and HFD+F groups. VLCAD expression was higher in the F, HFD, and HFD+F groups. PPARγ expression was lower in the F+Cur, HFD+Cur, and HFD+F+Cur groups. Curcumin prevented overexpression of CPT1 and KIM1 in the HFD+F and HFD groups. Curcumin prevented morphological lesions, fibrosis, and lipid deposition that were hypercaloric diet-induced. Chronic consumption of hypercaloric diets causes inflammation, fibrosis, and lipid deposition in the kidney. It is suggested that curcumin prevents renal structural damage, limits tissue lipid deposition, and differentially modulates renal injury depending on diet composition in mice fed high-fat and/or high-fructose diets.

The effect of toluene sulfonic acid remimazolam on postoperative delirium in elderly patients undergoing painless bronchoscopy

Toluene sulfonic acid remimazolam is a novel benzodiazepine that differs from traditional benzodiazepines (BZDs) due to its rapid onset, swift metabolism, and lack of hepatic or renal metabolism, as well as its reduced effects on cardiac and cerebral functions. Despite its potential advantages, clinical experience with this agent remains limited. This study investigated the effect of remizolam on postoperative delirium in elderly patients undergoing painless bronchoscopy. Among elderly patients undergoing routine painless bronchoscopy examinations, 50 cases were included in the remimazolam group, while the other 50 cases were selected as the propofol group. The primary outcome measured was the incidence of delirium on the first, second, third, fifth, and seventh postoperative days. The secondary outcome was the occurrence of adverse events, including hypotension, hypoxia, physical activity, agitation during recovery, dizziness, and nausea/vomiting during the procedure.This study confirmed that no cases of delirium in the remimazolam group, which also demonstrated a significantly lower incidence of adverse events compared to the propofol group (20% vs. 50%, P < 0.05). The results indicated remimazolam provides effective sedation with minimal adverse reactions and is associated with a lack of complications such as postoperative delirium in elderly patients undergoing painless bronchoscopy.

Efficacy of Hypoxia-Inducible Factor Prolyl-Hydroxylase Inhibitors in Renal Anemia: Enhancing Erythropoiesis and Long-Term Outcomes in Patients with Chronic Kidney Disease.

Renal anemia is one of the major complications associated with chronic kidney disease (CKD). Erythropoietin-stimulating agents (ESAs) are commonly used; however, some patients exhibit resistance. Hypoxia-inducible factor prolyl-hydroxylase inhibitors (HIF-PHIs) have emerged as a novel treatment for renal anemia, enhancing erythropoiesis and iron metabolism. We retrospectively analyzed laboratory data related to erythropoiesis from 105 patients with CKD before and after treatment with HIF-PHI or ESA. The dialysis initiation and mortality rates were also assessed over a median follow-up of 614 days. HIF-PHI and ESA significantly increased the hemoglobin levels within 6 months of treatment (9.5 ± 1.0 to 10.7 ± 1.1, p < 0.01, and 9.9 ± 1.5 to 10.7 ± 1.2 g/dL, p < 0.01, respectively). The HIF-PHI group demonstrated a significant decrease in red cell distribution width (14.5 ± 1.9% to 13.8 ± 1.4%, p < 0.01), suggesting improved erythropoiesis, and exhibited a lower cumulative incidence of outcomes. The aged-adjusted multivariate analysis confirmed the independent association between HIF-PHI treatment and reduced risk of cumulative outcome (p = 0.042). HIF-PHIs can serve as an alternative to ESA for managing renal anemia in CKD, improving both hematological parameters and long-term outcomes.

Protective Effects of Dioscin and Diosgenin on Plateau Hyperuricemia by Attenuating Renal Inflammation via EPHX2.

Plateau hyperuricemia is a common disease in the plateau area, and the incidence is much higher than that in the plain area. Dioscin (DIO) and its active metabolite Diosgenin (DG) exert therapeutic effects on hyperuricemia through oxidative stress and inflammation. In this study, DIO and its active metabolite DG were taken as the research objects to explore their therapeutic effects on high-altitude hyperuricemia in rats. To evaluate the therapeutic effect of DIO on the rat model of high-altitude hyperuricemia, the evaluation indexes include blood biochemical indexes, renal histopathology, oil red O staining of the kidney, rat kidney index, and rat renal inflammatory factors. Transcriptomics was used to analyze the control group, model group, and drug-administered group to preliminarily explore the protective mechanism of DIO in rats with high-altitude hyperuricemia. An HK-2 high-altitude hyperuricemia cell injury model was established to verify the therapeutic mechanism of DIO in rats with high-altitude hyperuricemia. Western blot was used to detect the expression of related proteins in renal tissues and cell models. The results showed that DIO and its active metabolite DG regulate renal lipid metabolism through the EPHX2 gene, attenuate renal inflammatory reaction, and then promote the excretion of uric acid and reduce its reabsorption, which ultimately achieves the effect of treating plateau hyperuricemia.

Five-Year Incidence of Age-Related Macular Degeneration and Its Risk Factors in Adult Chinese Population: The Tongren Health Care Study.

To examine the 5-year incidence of age-related macular degeneration (AMD) and its associated factors in an adult Chinese population. The Tongren Health Care Study included individuals attending regular health care check-up examinations in the Beijing Tongren Hospital. Baseline examinations were performed from 2014 to 2015, with 5-year follow-up examinations conducted between 2019 and 2020. Fundus photographs were graded according to the Beckman Initiative guidelines. A total of 5658 participants with gradable photographs at both examinations were included in the study, comprising 58.0% women, with a mean age of 54.9 ± 11.0years. The 5-year incidence of any, early, intermediate, and late AMD were 6.1% (95% confidence interval [CI], 5.5%-6.8%), 5.0% (95% CI, 4.4%-5.6%), 3.4% (95% CI, 2.9%-3.9%), and 0.3% (95% CI, 0.2%-0.4%), respectively. In multivariate analysis, incident early AMD was associated with older age (P < 0.001; odds ratio [OR], 1.04; 95% CI, 1.02-1.06), female sex (P = 0.011; OR, 1.42; 95% CI, 1.08-1.86), and a higher estimated glomerular filtration rate (P = 0.020; OR, 1.15; 95% CI, 1.02-1.30), whereas having diabetes was a protective factor (P = 0.019; OR, 0.61; 95% CI, 0.41-0.92). Incident intermediate AMD was associated with older age (P < 0.001; OR, 1.05; 95% CI, 1.04-1.07), a higher high-density lipoprotein cholesterol level (P < 0.001; OR, 1.97; 95% CI, 1.38-2.83) and a lower triglyceride level (P = 0.008; OR, 0.77; 95% CI, 0.64-0.93). A higher estimated glomerular filtration rate level was a risk factor for incident early AMD. A higher high-density lipoprotein cholesterol level and lower triglyceride level were risk factors for incident intermediate AMD. This finding may point to the role of renal circulation and lipid metabolism in incident AMD. This community-based longitudinal study may provide a valuable understanding of AMD and its associated factors for targeted prevention and management strategies.

Renal Iron Metabolism and Its Role in the Kidney

Renal Iron Metabolism and Its Role in the Kidney

NAD + activates renal metabolism and protects from chronic kidney disease in a model of Alport syndrome.

Chronic kidney disease (CKD) is associated with renal metabolic disturbances, including impaired fatty acid oxidation (FAO). Nicotinamide adenine dinucleotide (NAD + ) is a small molecule that participates in hundreds of metabolism-related reactions. NAD + levels are decreased in CKD, and NAD + supplementation is protective. However, both the mechanism of how NAD + supplementation protects from CKD, as well as the cell types involved, are poorly understood. Using a mouse model of Alport syndrome, we show that nicotinamide riboside (NR), an NAD + precursor, stimulates renal peroxisome proliferator-activated receptor alpha signaling and restores FAO in the proximal tubules, thereby protecting from CKD in both sexes. Bulk RNA-sequencing shows that renal metabolic pathways are impaired in Alport mice and activated by NR in both sexes. These transcriptional changes are confirmed by orthogonal imaging techniques and biochemical assays. Single nuclei RNA-sequencing and spatial transcriptomics, both the first of their kind from Alport mice, show that NAD + supplementation restores FAO in proximal tubule cells. Finally, we also report, for the first time, sex differences at the transcriptional level in this Alport model. In summary, we identify a nephroprotective mechanism of NAD + supplementation in CKD, and we demonstrate that the proximal tubule cells substantially contribute to this benefit.

Normothermic Machine Perfusion Reconstitutes Porcine Kidney Tissue Metabolism But Induces an Inflammatory Response, Which Is Reduced by Complement C5 Inhibition.

Normothermic machine perfusion (NMP) is a clinical strategy to reduce renal ischemia-reperfusion injury (IRI). Optimal NMP should restore metabolism and minimize IRI induced inflammatory responses. Microdialysis was used to evaluate renal metabolism. This study aimed to assess the effect of complement inhibition on NMP induced inflammatory responses. Twenty-two pig kidneys underwent 18h of static cold storage (SCS) followed by 4h of NMP using a closed-circuit system. Kidneys were randomized to receive a C5-inhibitor or placebo during SCS and NMP. Perfusion resulted in rapidly stabilized renal flow, low renal resistance, and urine production. During SCS, tissue microdialysate levels of glucose and pyruvate decreased significantly, whereas glycerol increased (p < 0.001). In the first hour of NMP, glucose and pyruvate increased while glycerol decreased (p < 0.001). After 4h, all metabolites had returned to baseline. Inflammatory markers C3a, soluble C5b-9, TNF, IL-6, IL-1β, IL-8, and IL-10 increased significantly during NMP in perfusate and kidney tissue. C5-inhibition significantly decreased perfusate and urine soluble C5b-9 (p < 0.001; p = 0.002, respectively), and tissue IL-1β (p = 0.049), but did not alter other inflammatory markers. Microdialysis can accurately monitor the effect of NMP on renal metabolism. Closed-circuit NMP induces inflammation, which appeared partly complement-mediated. Targeting additional immune inhibitors should be the next step.

CD3D silencing alleviates diabetic nephropathy via inhibition of JAK/STAT pathway.

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes that poses a significant burden to global health. This investigation aims to illustrate the functional role of CD3D and its relevant mechanisms in DN progression. The pivotal genes between the GSE47183 and GSE30528 datasets were identified using bioinformatics methods. The effects of CD3D silencing on renal damage, inflammatory response, and lipid metabolism were validated in DN mice. Furthermore, the impacts of CD3D knockdown on cell viability, apoptotic rate, inflammation, and lipid levels were investigated in HK-2 cells under high glucose (HG) conditions. Additionally, RO8191 was employed to investigate the role of CD3D in the JAK/STAT pathway in HG-treated cells. A total of 5 focal genes were identified through bioinformatics and were found to be upregulated in renal tissues from DN mice. CD3D silencing mitigated pathological damage to kidneys, reduced inflammatory response, and decreased lipid accumulation in DN mice. HG stimulation restrained viability, increased apoptosis, promoted the release of inflammatory cytokines, and affected expressions of hallmarks related to lipid metabolism in HG-treated cells; these changes were partially abolished by CD3D knockdown. Mechanistically, CD3D downregulation ameliorated HG-induced injury in HK-2 cells by blocking the JAK/STAT pathway. This study underscores that CD3D silencing has significant potential as a promising candidate in the treatment of DN.

Leech granules inhibit ferroptosis and alleviate renal injury in mice with diabetic kidney disease

Ethnopharmacological relevanceThe underlying mechanisms of diabetic kidney disease (DKD) and effective treatment strategies remain unclear. DKD progression is closely associated with abnormal iron metabolism and ferroptosis in vivo. Leeches, used in traditional Chinese medicine for promoting blood circulation and resolving blood stasis, are utilized to treat diabetes and its associated complications. Leeches effectively antagonize oxidative stress injury and exert protective effects on renal function. However, whether leeches can inhibit ferroptosis by modulating oxidative stress and iron metabolism remains unclear. Aim of the studyTo investigate the therapeutic potential of leech granules in DKD and, specifically, their effects on ferroptosis. Materials and methodsWe used a mouse model of DKD. The mice were treated with leech granules via gavage. Component identification and analysis of leech granules were performed using UPLC-MS, and efficacy was assessed by histopathology and analysis of blood glucose, lipids, and renal function. Additionally, the pharmacological mechanisms of leech granules were explored via proteomics, immunohistochemical staining, western blotting, and cell culture. ResultsProteomic analysis showed that iron metabolism was dysregulated and ferroptosis increased in DKD mice. Leech granules significantly reduced iron accumulation and renal pathological damage, decreased ROS levels, upregulated GSH levels, and inhibited ferroptosis in the kidneys of DKD mice. Furthermore, in vitro cellular experiments demonstrated that leech granules could inhibit erastin-induced ferroptosis and protect renal cells. ConclusionsThe regulation of renal iron metabolism and inhibition of ferroptosis mediates the therapeutic effect of leech granules on DKD. Leech granules represent a promising approach for DKD treatment.

Nephroprotective Effects of Cilastatin in People at Risk of Acute Kidney Injury: A Systematic Review and Meta-analysis

Cilastatin is an inhibitor of drug metabolism in the proximal tubule that demonstrates nephroprotective effects in animals. It has been used in humans in combination with the antibiotic imipenem to block imipenem's renal metabolism. This systematic review and meta-analysis evaluated the nephroprotective effects of cilastatin in humans. Systematic review and meta-analysis of observational (comparative effectiveness) studies or randomized clinical trials (RCTs). People of any age at risk of acute kidney injury (AKI). We systematically searched MEDLINE, Embase, Web of Science, and the Cochrane Controlled Trials registry from database inception to November 2023 for observational studies or RCTs that compared kidney outcomes among groups treated with cilastatin, either alone or as combination imipenem-cilastatin, versus an inactive or active control group not treated with cilastatin. Two reviewers independently evaluated studies for inclusion and risk of bias. Treatment effects were estimated using random-effects models, and heterogeneity was quantified using the I 2 statistic. We identified 10 studies (5 RCTs, n=531patients; 5 observational studies, n=6,321 participants) that met the inclusion criteria, including 4 studies with comparisons to inactive controls and 6 studies with comparisons to alternate antibiotics. Based on pooled results from 7 studies, the risk of AKI was lower with imipenem-cilastatin (risk ratio [RR], 0.52; 95% confidence intervals [CI], 0.40-0.67; I 2=26.5%), with consistent results observed in RCTs (3 RCTs, RR, 0.26; 95% CI, 0.09-0.77; I 2=44.4%) and observational studies (4 studies, RR, 0.54; 95% CI, 0.41-0.72; I 2=44.4%). Based on results from 6 studies, serum creatinine concentration was lower following treatment with imipenem-cilastatin than comparators (weighted mean difference in serum creatinine-0.14 mg/dL (95% CI,-0.21 to-0.07; I 2=0%). The overall certainty of the evidence was low due to heterogeneity of the results, high risk of bias, and indirectness among the identified studies. Clinical and statistical heterogeneity could not be fully explained due to a limited number of studies. Patients treated with imipenem-cilastatin developed AKI less frequently and had lower serum creatinine concentration following treatment than control groups or those who had received comparator antibiotics. Larger clinical trials with less risk of detection bias due to lack of allocation concealment and blinding are needed to establish the efficacy of cilastatin for AKI prevention.

HNF1B Transcription Factor: Key Regulator in Renal Physiology and Pathogenesis.

The HNF1B gene, located on chromosome 17q12, encodes a transcription factor essential for the development of several organs. It regulates the expression of multiple genes in renal, pancreatic, hepatic, neurological, and genitourinary tissues during prenatal and postnatal development, influencing processes such as nephrogenesis, cellular polarity, tight junction formation, cilia development, ion transport in the renal tubule, and renal metabolism. Mutations that alter the function of Hnf1b deregulate those processes, leading to various pathologies characterized by both renal and extrarenal manifestations. The main renal diseases that develop are polycystic kidney disease, hypoplastic or dysplastic kidneys, structural abnormalities, Congenital Anomalies of the Kidney and Urinary Tract (CAKUT), and electrolyte imbalances such as hyperuricemia and hypomagnesemia. Extrarenal manifestations include Maturity-Onset Diabetes of the Young (MODY), hypertransaminasemia, genital and urinary tract malformations, Autism Spectrum Disorder (ASD), and other neurodevelopmental disorders. Patients with HNF1B alterations typically carry either punctual mutations or a monoallelic microdeletion in the 17q12 region. Future research on the molecular mechanisms and genotype-phenotype correlations in HNF1B-related conditions will enhance our understanding, leading to improved clinical management, genetic counseling, monitoring, and patient care.

Associations between Renin-Angiotensin System and Abnormal Renal Energy Metabolism in a Mouse Model of Diabetic Kidney Disease

Associations between Renin-Angiotensin System and Abnormal Renal Energy Metabolism in a Mouse Model of Diabetic Kidney Disease

Lack of Role of NHE4 in Renal Ammonia Metabolism

Lack of Role of NHE4 in Renal Ammonia Metabolism

Effects of Laser Acupuncture on Metabolic Functions of Sedentary People: A Double-Blind Randomized Clinical Trial.

Background: Laser acupuncture regulates energy flow and restores body fluid metabolism. Objective: To evaluate the effects of the laser acupuncture protocol (LAP) on hepatic and renal metabolism in sedentary people. Methods: Longitudinal, double-blind, and randomized clinical trial with 29 participants, adults, both sexes, sedentary, without pre-existing metabolic diseases, subdivided into control and laser groups. Based on the STandards for Reporting Interventions in Clinical Trials of Acupuncture 2010 guidelines, 10 laser applications (660 nm ±10 nm wavelength, 100 mW power. The irradiation tip has a diameter of 5 mm, which corresponds to an area of 0.19 cm2, totaling a power density of 0.52 W/cm2 and considering the irradiation time of 90 s, the energy density applied was 47.3 J/cm2) were performed on the acupoints of metabolic functions (LR3, SP6, ST36, and LI4) and blood samples were collected for fasting glycemia, lipid profile (HDL, LDL, total cholesterol, and triglycerides), liver function (AST/GOT and ALT/GPT), and renal function (serum creatinine and urea). A repeated measures analysis of variance (ANOVA) with Bonferroni corrected post hoc comparisons was applied to compare statistical differences between groups and times, adopting p < 0.05 as the null hypothesis. Results: The laser stimulated changes in serum lipid profile values and renal and hepatic functions. There was a significant (p = 0.014) reduction in LDL ("bad" cholesterol) from 105.75 ± 32.83 pre- to 84.32 ± 18.38 mg/dL postintervention, associated with cardioprotective function. Positive significant (p = 0.035) impacts were also observed in the reduction of creatinine (0.86 ± 0.12 mg/dL to 0.75 ± 0.12 mg/dL) and the enzyme AST/GOT (33.73 ± 12.95 U/L to 20.80 ± 4.99 U/L, p = 0.002). Conclusion: LAP applied to basal metabolism acupoints promoted positive metabolic changes in the lipid profile (LDL), and in main markers of the liver (AST/GOT) and kidney (creatinine) functions, contributing to risk control of cardiovascular diseases.

Application of a deep-learning marker for morbidity and mortality prediction derived from retinal photographs: a cohort development and validation study

Biological ageing markers are useful to risk stratify morbidity and mortality more precisely than chronological age. In this study, we aimed to develop a novel deep-learning-based biological ageing marker (referred to as RetiPhenoAge hereafter) using retinal images and PhenoAge, a composite biomarker of phenotypic age. We used retinal photographs from the UK Biobank dataset to train a deep-learning algorithm to predict the composite score of PhenoAge. We used a deep convolutional neural network architecture with multiple layers to develop our deep-learning-based biological ageing marker, as RetiPhenoAge, with the aim of identifying patterns and features in the retina associated with variations of blood biomarkers related to renal, immune, liver functions, inflammation, and energy metabolism, and chronological age. We determined the performance of this biological ageing marker for the prediction of morbidity (cardiovascular disease and cancer events) and mortality (all-cause, cardiovascular disease, and cancer) in three independent cohorts (UK Biobank, the Singapore Epidemiology of Eye Diseases [SEED], and the Age-Related Eye Disease Study [AREDS] from the USA). We also compared the performance of RetiPhenoAge with two other known ageing biomarkers (hand grip strength and adjusted leukocyte telomere length) and one lifestyle factor (physical activity) for risk stratification of mortality and morbidity. We explored the underlying biology of RetiPhenoAge by assessing its associations with different systemic characteristics (eg, diabetes or hypertension) and blood metabolite levels. We also did a genome-wide association study to identify genetic variants associated with RetiPhenoAge, followed by expression quantitative trait loci mapping, a gene-based analysis, and a gene-set analysis. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and corresponding 95% CIs for the associations between RetiPhenoAge and the different morbidity and mortality outcomes. Retinal photographs for 34 061UK Biobank participants were used to train the model, and data for 9429participants from the SEED cohort and for 3986participants from the AREDS cohort were included in the study. RetiPhenoAge was associated with all-cause mortality (HR 1·92 [95% CI 1·42-2·61]), cardiovascular disease mortality (1·97 [1·02-3·82]), cancer mortality (2·07 [1·29-3·33]), and cardiovascular disease events (1·70[1·17-2·47]), independent of PhenoAge and other possible confounders. Similar findings were found in the two independent cohorts (HR 1·67 [1·21-2·31] for cardiovascular disease mortality in SEED and 2·07 [1·10-3·92] in AREDS). RetiPhenoAge had stronger associations with mortality and morbidity than did hand grip strength, telomere length, and physical activity. We identified two genetic variants that were significantly associated with RetiPhenoAge (single nucleotide polymorphisms rs3791224 and rs8001273), and were linked to expression quantitative trait locis in various tissues, including the heart, kidneys, and the brain. Our new deep-learning-derived biological ageing marker is a robust predictor of mortality and morbidity outcomes and could be used as a novel non-invasive method to measure ageing. Singapore National Medical Research Council and Agency for Science, Technology and Research, Singapore.