Kidney Tissue Research Articles

Hypoxia activates FGF-23-ERK / MAPK signaling pathway in ischemia-reperfusion induced acute kidney injury.

Both hypoxia and fibroblast growth factor-23 (FGF-23) are key factors in ischemia-reperfusion (I/R)-induced acute kidney injury (AKI). This study aimed to explore the relationship between hypoxia and FGF-23 in AKI. An I/R-AKI animal model was established using male BALB/c mice. HK-2 cells, a part of the human proximal tubular epithelial cell line, were subjected to hypoxia/reoxygenation (H/R). qPCR was used to measure FGF-23 and HIF-1α, ELISA was used to measure inflammatory and oxidative stress cytokines. Western blotting used to measure the phosphorylation of ERK level. In I/R mice, the levels of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), malondialdehyde (MDA), and the phosphorylation of extracellular signal-regulated kinase (ERK) were increased, whereas the levels of interleukin-10 (IL-10), superoxide dismutase (SOD), glutathione peroxidase (GPx), and klotho were decreased, compared to the sham operated mice. Silencing the FGF-23 expression in I/R mice normalized the levels of IL-6, IL-10, TNF-α, MDA, SOD, Gpx, and ERK phosphorylation (p-ERK). In HK-2 cells, hypoxia-reperfusion (H/R) elevated the levels of IL-6, TNF-α, MDA, and ERK phosphorylation, but reduced IL-10, SOD, GPx, and klotho levels. Hypoxia induced apoptosis in HK-2 cells but silencing of FGF-23 expression blocked the effects of hypoxia on cell apoptosis, proinflammatory factors levels, oxidative stress response, and p-ERK levels. FGF-23 is a key molecule in AKI, and hypoxia plays a crucial role in AKI by inducing cell apoptosis; however, its role is regulated by FGF-23. FGF-23 affects oxidative stress and the inflammatory response of kidney tissues by activating the ERK/mitogen-activated protein kinase (MAPK) signaling pathway.

Nephroprotective and hepatoprotective effects of lemongrass essential oil and citral on diclofenac-induced toxicity in mice

The present study was carried out to evaluate and compare the protective potential of two well-known antioxidants of herbal origin in a mouse model of acute DIC-induced nephro- and hepatotoxicity. The tested antioxidants included lemongrass essential oil (LO) and its predominant bioactive constituent citral (CIT). A third herbal product, silymarin (SILY), was used as a reference hepato-renal protective agent. DIC administration led to elevated serum urea and creatinine levels, and prompted oxidative stress along with histopathological changes in the kidney tissue. In parallel, DIC administration increased serum liver enzyme activity, decreased total protein, albumin, and globulin levels, and caused oxidative stress with associated histopathological changes in the liver tissue. Pre-treatment with LO or CIT mitigated DIC-induced alterations in all serum biochemical markers of kidney and liver health (except albumin). High-dose LO, like SILY, within kidney and liver tissues, counteracted DIC-induced oxidative stress and histomorphological alterations. By contrast, CIT failed to mitigate DIC-induced oxidative stress in the kidneys and provided only partial control of DIC-induced oxidative stress in the liver, resulting in less efficient preservation of kidney function and liver structural integrity than LO. Besides confirming the efficacy of SILY at protecting kidneys and liver against the toxicity of DIC in a rodent species different from the one tested so far (rat), this study demonstrated the preventive properties of LO and, to a lesser extent, of CIT against DIC-induced hepato-renal toxicity in mice, supporting their developmental potential as therapeutics.

HOPE springs eternal: lack of HIV superinfection in HIV Organ Policy Equity Act kidney transplants.

Kidney transplantation from donors with HIV to recipients with HIV (HIV D+/R+) is an emerging practice that has shown substantial clinical benefit. Sustained HIV superinfection, whereby a transplant recipient acquires a new strain of HIV from their organ donor, is a theoretical risk, which might increase chances of viral failure. In this issue of the JCI, Travieso, Stadtler, and colleagues present phylogenetic analysis of HIV from kidney tissue, urine, plasma, and cells from 12 HIV D+/R+ kidney transplants out to five years of follow-up. Early after transplant, donor HIV was transiently detected in five of 12 recipients, primarily from donors with untreated HIV and high-level viremia, consistent with a viral inoculum. Long-term, donor HIV was not detected in any recipients, demonstrating no sustained HIV superinfection. These reassuring data support earlier findings from South Africa and the United States and further confirm the safety of HIV D+/R+ transplantation.

Salt tolerance candidate genes identified by QTL mapping, RNA-seq, and functional analysis in tilapia

Salt tolerance in fish is crucial for aquaculture as it enhances survival and productivity in varying salinity conditions, thus expanding the range of viable farming environments and improving economic sustainability. Through QTL mapping and GWAS in a hybrid F2 family of Mozambique and Nile tilapia, two large-effect QTL on chromosomes 11 and 18 were identified respectively. These two QTL explained a total of 39.9 % of the phenotypic variance. The identification of a QTL on LG11 suggests the presence of a previously unrecognized genetic factor contributing to salt tolerance. Comparative transcriptomic analysis of gill and kidney tissues between susceptible and tolerant tilapias highlights the importance of osmotic balance in regulation of salt tolerance in tilapia. Integration of QTL and RNA-seq data identified two candidate genes: acyl-coenzyme A thioesterase 5 (acot5) and sodium- and chloride-dependent taurine transporter (slc6a6) likely playing critical roles in such process. Functional analysis showed that over-expressing acot5 or slc6a6 in grouper kidney cells increased viability under salt stress by 4.46 % and 17.53 %, respectively. Subcellular localization revealed nuclear presence of ACOT5 and stress-induced nuclear translocation of SLC6A6. These findings highlight acot5 and slc6a6 as candidates for genetic manipulation and selection to enhance salt tolerance in tilapia, guiding genetic improvement efforts and promoting sustainable practices.

Enhanced Antidiabetic Effects of Gymnema sylvestre and Probiotics in Alloxan-Induced Diabetic Rats

Abstract Introduction/Objective Introduction: Gymnema sylvestre is a well-known herbal remedy for diabetes, with its anti-diabetic properties attributed to gymnemic acids isolated from its leaves. Probiotics, such as Lactobacillus acidophilus and Lactobacillus casei, have also shown potential in managing diabetes. This study aims to evaluate the combined antidiabetic effects of G. sylvestre and probiotics in alloxan-induced diabetic rats. Methods/Case Report Methods: Experimental rats were divided into seven groups: negative control, untreated diabetic control, L. acidophilus-treated, L. casei-treated, G. sylvestre-treated, a combination of L. casei and G. sylvestre-treated, and a combination of L. acidophilus and G. sylvestre-treated. Blood glucose levels, lipid profiles, and reduced glutathione levels were measured, and histopathological examination of pancreas and kidney tissues was performed. Results (if a Case Study enter NA) Results: In the third week of the experiment, the combined administration of G. sylvestre and probiotics showed the most significant reductions in glucose levels (250 mg/dL), alkaline phosphatase (ALP) (613.3 U/L), urea (31 U/L), serum creatinine (0.77 U/L), and superoxide dismutase (SOD) (854.7 UMOL). G. sylvestre alone exhibited the lowest levels of glutamate pyruvate transaminase (GPT) (30 U/L), cholesterol (41 mg/dL), triglycerides (101.3 mg/dL), very-low-density lipoprotein (VLDL) (22.9 mg/dL), and malondialdehyde (MDA) (119.3 U MOL/SEC). Probiotic treatment alone resulted in the lowest levels of uric acid (UA) (4.4 U/L) and low-density lipoprotein (LDL) (95.06 mg/dL). G. sylvestre demonstrated the highest level of high-density lipoprotein (HDL) (44 mg/dL), while probiotics exhibited the highest catalase (CAT) activity (92 UMOL/SEC). Histopathological examination revealed the preservation of normal pancreatic and renal tissue morphology with G. sylvestre treatment. Conclusion Conclusion: The combination of G. sylvestre and probiotics enhances the antidiabetic activity compared to G. sylvestre alone in alloxan-induced diabetic rats. These findings suggest a potential synergistic effect of combining herbal and probiotic therapy for diabetes management.

FUNCTIONAL STATE OF RENAL PARENCHYMA IN CHILDREN WITH DYSMETABOLIC NEPHROPATHY

Abstract. Metabolic nephropathy in children is a relevant issue in our time, as the prevalence of this disease is increasing. Negative consequences of metabolic nephropathy include a gradual deterioration of kidney function. A significant aspect is the fact that metabolic nephropathy can lead to the development of chronic kidney disease in children. Chronicity requires continuous medical monitoring and treatment to support kidney function and prevent further complications, such as renal insufficiency and other metabolic disorders. There is no doubt that one of the leading pathogenetic factors in kidney dysfunction is hypoxia. It can be caused by both hemodynamic disturbances associated with renal pathology and tissue respiration disorders in congenital dysplasia of the kidney's connective tissue, which arises in the embryo under the influence of epigenetic factors in utero and is further exacerbated by various epigenetic factors in postnatal life. Purpose of the work to investigate the functional state of kidney parenchyma in children with dysmetabolic nephropathy. Materials and methods. Two groups of children were examined: those with a complicated course of dysmetabolic nephropathy, a history of inflammatory episodes of the urinary system organs (Group I - UN, 52 children), and dysmetabolic nephropathy with persistent crystalluria (Group II - DN, 56 children). A control group consisted of 65 healthy children. Tubular reabsorption, as a partial function of the proximal segment of the nephrons, was assessed based on urinolysis test data, specifically the levels of excretion of inorganic phosphates, proteinuria, amino acids, reduced sugars (maltose, sucrose, fructose by Benedict's test), glucose (by Gaines's test), and calcium (by Sulcovitch's test). The level of creatinine and glycosaminoglycan (GAG) excretion in daily urine in children with dysmetabolic nephropathy was determined and compared with data from healthy children in the control group. Research results. In children from both observation groups, a significantly high frequency of hyperphosphaturia (94.23% and 96.42%), calciuria (94.23% and 89.28%), glucosuria (78.85% and 73.21%), increased excretion of amino acids in the urine (40.38% and 37.5%), microproteinuria (32.69% and 28.57%), and increased excretion of reduced sugars (28.85% and 26.79%) were observed. The daily excretion of creatinine, glycosaminoglycans, and oxypyrrolidine in the urine of children with dysmetabolic nephropathy indicates a significantly reduced level of creatinine in the daily urine in the majority of children in Group I (0.56±0.19 g/L, 80.77% of those examined) and more than half of the children in Group II (0.83±0.08 g/L, 57.14% of those examined), compared to the data from healthy children in the control group (1.25±0.75 g/L, 0.0%). Conclusions. The analysis of the functional state of the kidney tissue in oxalate dysmetabolic nephropathy in children allows us to testify to the presence of tubular and glomerular partial renal tissue failure. Significant decreases in creatinine excretion and increased excretion of glycosoaminoglycans in the urine and significantly higher levels of oxyproline in the urine indicate the presence of glomerular type partial renal failure in oxalate dysmetabolic nephropathy in children and the presence of undifferentiated dysplasia of the renal connective tissue with the onset of its sclerosis with subsequent transition to interstitial nephritis. The presence of these changes in the vast majority of children with complicated course of oxalate dysmetabolic nephropathy in the period of clinical and laboratory remission of the inflammatory process indicates the priority of renal connective tissue dysplasia and paucity of renal failure in the pathogenesis of dysmetabolic nephropathy and its severity in children. Indicators of oxyproline creatinine, glycosoaminoglycans and oxyproline excretion can be used as epigenetic markers of susceptibility to dysmetabolic nephropathy in general and its more severe course in particular. Keywords: dysmetabolic nephropathy, functional state, kidney parenchyma, nephron.

Renoprotective effect of liraglutide on diabetic nephropathy by modulation of Krüppel-like transcription factor 5 expression in rats.

Diabetic nephropathy (DN) is a serious consequence of diabetes that can develop through the lysophosphatidic acid axis. The purpose of this study was to determine whether the antidiabetic drug liraglutide can slow the development of diabetic kidney damage by altering the lysophosphatidic acid axis via KLF5. Wistar albino rats were divided into nondiabetic and diabetic rats (resulting from an intraperitoneal streptozotocin dose of 30mg/kg and a high-fat diet). These rats were further divided into four groups: nondiabetic control, liraglutide-treated nondiabetic, diabetic control, and liraglutide-treated diabetic. The nondiabetic and diabetic control groups received normal saline for 42 days, while the liraglutide-treated nondiabetic and diabetic groups received normal saline for 21 days, followed by a subcutaneous dose of liraglutide (200 μg/kg/day) for 21 days. Subsequently, serum levels of DN biomarkers were evaluated, and kidney tissues were histologically examined. The protein expression of PCNA, autotaxin, and KLF5 was detected. Liraglutide treatment in diabetic rats decreased DN biomarkers, histological abnormalities in kidney tissues, and the protein expression of PCNA, autotaxin, and KLF5. Liraglutide can slow the progression of DN by modulating KLF5-related lysophosphatidic acid axis. Thus, liraglutide may be an effective treatment for preventing or mitigating diabetes-related kidney damage.

Sex-specific proximal tubular cell differentiation pathways identified by single-nucleus RNA sequencing

Postnatal kidney growth is substantial and involves expansion in kidney tubules without growth of new nephrons, which are the functional units of the kidney. Proliferation and differentiation pathways underpinning nephron elongation are not well defined. To address this, we performed sequential characterization of mouse kidney transcriptomics at the single cell level. Single nuclear RNA sequencing (snRNA-seq) was performed on kidney tissue from male and female mice at 1, 2, 4 and 12 weeks of age using the 10x Chromium platform. Unbiased clustering was performed on 68,775 nuclei from 16 animals. 31 discrete cellular clusters were seen, which were identified through comparison of their gene expression profiles to canonical markers of kidney cell populations. High levels of proliferation were evident at early time points in some cell types, especially tubular cells, but not in other cell types, for example podocytes. Proliferation was especially evident in Proximal Tubular Cells (PTCs) which are the most abundant cell type in the adult kidney. Uniquely when compared to other kidney cell types, PTCs demonstrated sex-specific expression profiles at late, but not early, time points. Mapping of PTC differentiation pathways using techniques including trajectory and RNA Velocity analyses delineated increasing PTC specialization and sex-specific phenotype specification. Our single-cell transcriptomics data characterise cellular states observed during kidney growth. We have identified PTC differentiation pathways that lead to sex-specific tubular cell phenotypes. Tubular proliferative responses are of central importance in postnatal kidney growth and have also been linked to kidney recovery versus fibrosis following injury. Our unbiased and comprehensive dataset of tubular cell development can be used to identify candidate pathways for therapeutic targeting.

The Streptococcus agalactiae LytSR two-component regulatory system promotes vaginal colonization and virulence in vivo.

Streptococcus agalactiae (or group B Streptococcus, GBS) is a leading cause of neonatal sepsis and meningitis globally. To sense and respond to variations in its environment, GBS possesses multiple two-component regulatory systems (TCSs), such as LytSR. Here, we aimed to investigate the role of LytSR in GBS pathogenicity. We generated an isogenic lytS knockout mutant in a clinical GBS isolate and used a combination of phenotypic in vitro assays and in vivo murine models to investigate the contribution of lytS to the colonization and invasive properties of GBS. Deletion of the lytS gene in the GBS chromosome resulted in significantly higher survival rates in mice during sepsis, accompanied by reduced bacterial loads in blood, lung, spleen, kidney, and brain tissues compared to infection with the wild-type strain. In a mouse model of GBS vaginal colonization, we also observed that the lytS knockout mutant was cleared more readily from the vaginal tract compared to its wild-type counterpart. Interestingly, lower levels of proinflammatory cytokines were found in the serum of mice infected with the lytS mutant. Our results demonstrate that the LytSR TCS plays a key role in GBS tissue invasion and pathogenesis, and persistence of mucosal colonization.IMPORTANCEStreptococcus agalactiae (group B Streptococcus, or GBS) is a common commensal of the female urogenital tract and one of WHO's priority pathogens. The bacterium has evolved mechanisms to adapt and survive in its host, many of which are regulated via two-component signal transduction systems (TCSs); however, the exact contributions of TCSs toward GBS pathogenicity remain largely obscure. We have constructed a TCS lytS-deficient mutant in a CC-17 hypervirulent GBS clinical isolate. Using murine models, we showed that LytSR regulatory system is essential for vaginal colonization via promoting biofilm production. We also observed that lytS deficiency led to significantly attenuated virulence properties and lower levels of proinflammatory cytokines in blood. Our findings are of significant importance in that they unveil a previously unreported role for LytSR in GBS and pave the way toward a better understanding of its ability to transition from an innocuous commensal to a deadly pathogen.

β-Mangostin Alleviates Renal Tubulointerstitial Fibrosis via the TGF-β1/JNK Signaling Pathway.

The epithelial-to-mesenchymal transition (EMT) plays a key role in the pathogenesis of kidney fibrosis, and kidney fibrosis is associated with an adverse renal prognosis. Beta-mangostin (β-Mag) is a xanthone derivative obtained from mangosteens that is involved in the generation of antifibrotic and anti-oxidation effects. The purpose of this study was to examine the effects of β-Mag on renal tubulointerstitial fibrosis both in vivo and in vitro and the corresponding mechanisms involved. As shown through an in vivo study conducted on a unilateral ureteral obstruction mouse model, oral β-Mag administration, in a dose-dependent manner, caused a lesser degree of tubulointerstitial damage, diminished collagen I fiber deposition, and the depressed expression of fibrotic markers (collagen I, α-SMA) and EMT markers (N-cadherin, Vimentin, Snail, and Slug) in the UUO kidney tissues. The in vitro part of this research revealed that β-Mag, when co-treated with transforming growth factor-β1 (TGF-β1), decreased cell motility and downregulated the EMT (in relation to Vimentin, Snail, and N-cadherin) and phosphoryl-JNK1/2/Smad2/Smad3 expression. Furthermore, β-Mag co-treated with SB (Smad2/3 kinase inhibitor) or SP600125 (JNK kinase inhibitor) significantly inhibited the TGF-β1-associated downstream phosphorylation and activation of JNK1/2-mediated Smad2 targeting the Snail/Vimentin axis. To conclude, β-Mag protects against EMT and kidney fibrotic processes by mediating the TGF-β1/JNK/Smad2 targeting Snail-mediated Vimentin expression and may have therapeutic implications for renal tubulointerstitial fibrosis.

High glucose-induced senescence contributes to tubular epithelial cell damage in diabetic nephropathy

Dysfunctional renal tubular epithelial cells, induced by high glucose, are commonly observed in the kidney tissues of diabetic nephropathy (DN) patients. The epithelial-mesenchymal transition (EMT) of these cells often leads to renal interstitial fibrosis and kidney damage in DN. High glucose also triggers mitochondrial damage and apoptosis, contributing further to the dysfunction of renal tubular epithelial cells. Cellular senescence, a recognized characteristic of DN, is primarily caused by high glucose. However, it remains unclear whether high glucose-induced cellular senescence in DN exacerbates the functional impairment of tubular epithelial cells. In this study, we examined the relationship between EMT and cellular senescence in kidney tissues from streptozotocin (STZ)-induced DN and HK-2 cells treated with high glucose (HG). We also investigated the impact of HG concentrations on tubular epithelial cells, specifically mitochondrial dysfunction, cellular senescence and apoptosis. These damages were primarily associated with the secretion of cytokines (such as IL-6, and TNF-α), production of reactive oxygen species (ROS), and an increase of intracellular Ca2+. Notably, resveratrol, an anti-aging agent, could effectively attenuate the occurrence of EMT, mitochondrial dysfunction, and apoptosis induced by HG. Mechanistically, anti-aging treatment leads to a reduction in cytokine secretion, ROS production, and intracellular Ca2+ levels.

Hydrogel-Based Vascularized Organ Tissue Engineering: A Systematized Review on Abdominal Organs.

Biomedical engineering, especially tissue engineering, is trying to provide an alternative solution to generate functional organs/tissues for use in various applications. These include beyond the final goal of transplantation, disease modeling and drug discovery as well. The aim of this study is to comprehensively review the existing literature on hydrogel-based vascularized organ (i.e., liver, pancreas, kidneys, intestine, stomach and spleen) tissue engineering of the abdominal organs. A comprehensive literature search was conducted on the Scopus database (latest search 1 September 2024). The research studies including hydrogel-based vascularized organ tissue engineering in the organs examined here were eligible for the review. Herein, 18 studies were included. Specifically, 10 studies included the liver or hepatic tissue, 5 studies included the pancreas or pancreatic islet tissue, 3 studies included the kidney or renal tissue, 1 study included the intestine or intestinal or bowel tissue, 1 study included the stomach or gastric tissue, and 0 studies included spleen tissue. Hydrogels are biocompatible materials with ideal characteristics for use as scaffolds. Even though organ tissue engineering is a rapidly growing field, there are still many obstacles to overcome to create a fully functional and long-lasting organ.

Single-Shot 3D Imaging Meta-Microscope.

Three-dimensional (3D) imaging enables high-precision and high-resolution axial positioning, which is crucial for biological imaging, semiconductor defect monitoring, and other applications. Conventional implementations rely on bulky optical elements or scanning mechanisms, resulting in low speed and complicated setups. Here, we generate the double-helix (DH) point spread function with an all-dielectric metasurface and thus innovate the 3D imaging microscope (hence dubbed meta-microscope), both in 4f and 2f imaging systems. The 4f-meta-microscope with a numerical aperture of 0.7 achieves an axial localization accuracy below 0.12 μm within a 15.47 μm detection range, while the 2f-DH meta-microscope with a numerical aperture of 0.3 shows a 1.12 μm accuracy within a 227.33 μm range. We also demonstrate single-shot and accurate 3D biological imaging of the mouse kidney tissue and peach anther, providing a comprehensive and efficient approach for 3D bioimaging and other applications through a single-shot 3D meta-microscope.

Long non-coding RNA MALAT1 triggers ferroptosis via interaction with FUS to enhance ACSF2 mRNA stabilization in septic acute kidney injury.

Septic acute kidney injury (AKI) is a fatal disease in the intensive care unit, with ferroptosis playing a crucial role in its pathogenesis. Long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been implicated in septic-induced AKI inflammation and apoptosis. However, its regulatory role in ferroptosis and underlying mechanisms remain unclear. In vivo and in vitro models of septic AKI were established using cecal ligation and puncture (CLP) and lipopolysaccharide (LPS) challenge, respectively. Serum levels of creatinine (Cr), blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), neutrophil gelatinase-associated lipocalin (NGAL), and inflammatory cytokine in kidney tissues were determined by ELISA kits. Histopathological alterations and apoptosis were evaluated by HE staining and TUNEL. Ferroptosis was accessed by measuring MDA, GSH, Fe2+, total and lipid ROS levels, and mitochondrial ultrastructure changes. Target molecular levels were determined using RT-qPCR, Western blotting, and immunofluorescence. Interactions among MALAT1, acyl-CoA synthetase family member 2 (ACSF2) and FUS RNA binding protein (FUS) were validated by RIP and RNA-pull down. MALAT1 level was significantly elevated in both in vivo and in vitro septic AKI models, of which knockdown impeded ferroptosis to alleviate septic AKI. Mechanistically, high MALAT1 expression increased ACSF2 mRNA stability via interaction with FUS. Rescue experiments showed that ACSF2 overexpression partially reversed the ferroptosis inhibition mediated by MALAT1 silencing. MALAT1 induces ferroptosis and exacerbates septic AKI by stabilizing ACSF2 mRNA with the assistance of FUS. These findings provide theoretical evidence for MALAT1 as a potential therapeutic target for septic AKI.

Impairment of Renal Function in Hermansky-Pudlak Syndrome.

Introduction Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder characterized by defective biogenesis of lysosome-related organelles. The genetic types of HPS are associated with a spectrum of multisystemic clinical manifestations. Phenotypic features of HPS type 1 (HPS-1) or HPS-4, which are associated with defects in biogenesis of lysosome-related organelles complex-3 (BLOC-3), are generally more severe than those of HPS-3, HPS-5, or HPS-6, which are associated with defects in BLOC-2. A paucity of information is available about renal impairment in HPS. The objective of this study is to expand the understanding of kidney disease in HPS. Methods Medical records and clinical data of patients with HPS evaluated at the National Institutes of Health Clinical Center from 1995 to 2020 were retrospectively reviewed. For patients with more than one visit, the most recent renal function and urinalysis tests were analyzed. Estimated glomerular filtration rate (eGFR) was calculated using standard equations (i.e., Chronic Kidney Disease Epidemiology Collaboration, Modification of Diet in Renal Disease). Kidney tissue sections from five patients with HPS-1 and one patient with HPS-6 were examined. Results Records from 205 adults and 52 children with HPS were reviewed. Calculated eGFR of adult patients with different HPS types differed significantly, and calculated eGFR of pediatric and adult patients with BLOC-3 disorders was significantly lower than that of patients with BLOC-2 disorders. Linear regression analysis showed that renal function progressively decreases with age in patients with BLOC-3 or BLOC-2 disorders, but the rate of decline was more rapid in patients with BLOC-3 disorders compared to patients with BLOC-2 disorders. In adult patients with HPS-1, glucosuria was found in 4%, proteinuria in 12%, hematuria in 15%, high levels of urinary β2MG in 24%, and elevated urinary albumin to creatinine ratios in 9%. Histological examination of kidney tissue in showed accumulation of intracellular deposits of ceroid lipofuscin in proximal renal tubular epithelial cells in patients with HPS-1. There was no evidence of fibrosis, and glomeruli, distal renal tubular epithelial cells, and interstitial regions appeared histologically normal. Conclusion Mild impairment of renal function is a feature of HPS. Kidneys of patients with HPS-1 contain Proximal renal tubular intracellular deposits and no histologic evidence of fibrosis. Consistent with other manifestations of HPS, the phenotype of renal impairment is relatively more pronounced in patients with BLOC-3 disorders than in patients with BLOC-2 disorders. Strategies to avoid nephrotoxicity or renal tubular injury and to protect renal function should be considered for patients with HPS irrespective of age.

EFFICACY OF CHROMOLAENA ODORATA SUPPLEMENTATION ON METHOTREXATE -INDUCED NEPHROPATHY AND OXIDATIVE STRESS

We carried out this research to investigate nephro-protective efficacy of Chromolaena odorata aqueous leaf extract on kidney toxicity in Methotrexate (MTX)-induced albino male rats. Thirty (30) wistar male rats spread into five study groups were used. Group I: orally administered normal saline daily and was the normal control. Group II: received C. odorata extract (250 mg/kg B.W.) orally once daily for ten days. Group III: received MTX (7mg/kg B.W.) intraperitoneally from 8th day for three days consecutively. Group IV: received C. odorata extract (250 mg/kg B.W.) orally once daily for ten days and then administered MTX (7 mg/kg B.W.) intraperitoneally from 8th day for three days consecutively. Group V: received Vitamin C (100 mg/kg B.W.) orally once daily for ten days and then administered MTX (7 mg/kg BW) intraperitoneally from 8th day for three days consecutively. 24hours after last treatment and administration, all rats were sacrificed and blood collected in EDTA bottles for hematology or in plain tubes for biochemical analysis. Creatinine and Urea were analyzed in serum. Superoxide Dismutase (SOD), Catalase, Malondialdehyde (MDA) and histopathological analysis was assessed using the kidney tissues. The obtained results revealed that three days of consecutive Methotrexate administration caused a significant rise in kidney function activity as well as severe oxidative damage and oxidative stress shown by a significant rise in Creatinine and Urea, increased level of MDA and a significant drop in SOD and CAT. However, C. odorata attenuated Methotrexate-induced biochemical alterations and oxidative stress in kidney. Also, C. odorata alone or in combination with Methotrexate showed an increase in Packed Cell Volume (PCV), Red Blood Cells (RBC), Haemoglobin (HB), White Blood Cells (WBC) and Platelets level compared to the group administered Methotrexate alone which showed degenerative levels in the analyzed hematological parameters. Showing corroboration, histopathological analysis showed deterioration and collapse of the kidney tubules in rats administered Methotrexate alone whereas C. odorata groups showed considerable nephro-protection and restoration towards normalcy. The results from this study revealed that the C. odorata have a nephro-protective efficacy against Methotrexate-induced kidney toxicity and damage via scavenging of free radicals and stabilization/enhancement of endogenous antioxidant status

S100A2 activation promotes interstitial fibrosis in kidneys by FoxO1-mediated epithelial-mesenchymal transition

BackgroundRenal interstitial fibrosis (RIF) is a common feature of chronic kidney diseases (CKD), with epithelial-mesenchymal transition (EMT) being one of its important mechanisms. S100A2 is a protein associated with cell proliferation and differentiation, but its specific functions and molecular mechanisms in RIF remain to be determined.MethodsS100A2 levels were evaluated in three mouse models, including unilateral ureteral obstruction (UUO), ischemia-reperfusion injury (IRI), and aristolochic acid nephropathy (AAN), as well as in TGF-β1- treated HK-2 cells and in kidney tissue samples. Furthermore, the role of S100A2 and its interaction with FoxO1 was investigated using RT-qPCR, immunoblotting, immunofluorescence staining, co-immunoprecipitation (Co-IP), transcriptome sequencing, and gain- or loss-of-function approaches in vitro.ResultsElevated expression levels of S100A2 were observed in three mouse models and TGF-β1-treated HK2 cells, as well as in kidney tissue samples. Following siRNA silencing of S100A2, exposure to TGF-β1 in cultured HK-2 cells suppressed EMT process and extracellular matrix (ECM) accumulation. Conversely, Overexpression of S100A2 induced EMT and ECM deposition. Notably, we identified that S100A2-mediated EMT depends on FoxO1. Immunofluorescence staining indicated that S100A2 and FoxO1 colocalized in the nucleus and cytoplasm, and their interaction was verified in Co-IP assay. S100A2 knockdown decreased TGF-β1-induced phosphorylation of FoxO1 and increased its protein expression, whereas S100A2 overexpression hampered FoxO1 activation. Furthermore, pharmacological blockade of FoxO1 rescued the induction of TGF-β1 on EMT and ECM deposition in S100A2 siRNA-treated cells.ConclusionS100A2 activation exacerbates interstitial fibrosis in kidneys by facilitating FoxO1-mediated EMT.Graphical abstractA schematic diagram of the underlying mechanisms by which S100A2 regulates EMT and renal fibrosis. Following injury, the cytoplasmic expression of S100A2 in renal tubular epithelial cells is markedly elevated. This increase promotes the phosphorylation of FoxO1, preventing its translocation into the nucleus and enhances EMT and extracellular matrix ECM deposition, thereby exacerbating renal interstitial fibrosis.

ACE2 and TMPRSS2 in human kidney tissue and urine extracellular vesicles with age, sex, and COVID-19.

SARS-CoV-2 virus infects cells by engaging with ACE2 requiring protease TMPRSS2. ACE2 is highly expressed in kidneys. Predictors for severe disease are high age and male sex. We hypothesized that ACE2 and TMPRSS2 proteins are more abundant (1) in males and with increasing age in kidney and (2) in urine and extracellular vesicles (EVs) from male patients with COVID-19 and (3) SARS-CoV-2 is present in urine and EVs during infection. Kidney cortex samples from patients subjected to cancer nephrectomy (male/female; < 50years/˃75years, n = 24; ˃80years, n = 15) were analyzed for ACE2 and TMPRSS2 protein levels. Urine from patients hospitalized with SARS-CoV-2 infection was analyzed for ACE2 and TMPRSS2. uEVs were used for immunoblotting and SARS-CoV-2 mRNA and antigen detection. Tissue ACE2 and TMPRSS2 protein levels did not change with age. ACE2 was not more abundant in male kidneys in any age group. ACE2 protein was associated with proximal tubule apical membranes in cortex. TMPRSS2 was observed predominantly in the medulla. ACE2 was elevated significantly in uEVs and urine from patients with COVID-19 with no sex difference compared with urine from controls w/wo albuminuria. TMPRSS2 was elevated in uEVs from males compared to female. ACE2 and TMPRSS2 did not co-localize in uEVs/apical membranes. SARS-CoV-2 nucleoprotein and mRNA were not detected in urine. Higher kidney ACE2 protein abundance is unlikely to explain higher susceptibility to SARS-CoV-2 infection in males. Kidney tubular cells appear not highly susceptible to SARS-CoV-2 infection. Loss of ACE2 into urine in COVID could impact susceptibility and angiotensin metabolism.

SMYD2 Promotes Calcium Oxalate-Induced Glycolysis in Renal Tubular Epithelial Cells via PTEN Methylation.

Background/Objectives: Damage to renal tubular cells (RTCs) represents a critical pathological manifestation in calcium oxalate (CaOx) stone disease, but the underlying mechanism remains elusive. Energy metabolism reprogramming is a vital influencer of RTC survival, and SMYD2 is a histone methylation transferase that has been extensively implicated in various metabolic disorders. Hence, this research aimed to identify whether SMYD2 induces the reprogramming of energy metabolism in RTCs exposed to CaOx nephrolithiasis. Methods: Kidney samples were obtained from patients who underwent laparoscopic nephrectomy for non-functioning kidneys caused by nephrolithiasis. The glyoxylate-induced CaOx stone mice model was established and treated with AZ505. The SMYD2-knockout HK-2 cell line was constructed. Histological changes were evaluated by HE, VK, Tunel, Masson stainings. The molecular mechanism was explored through co-immunoprecipitation and western blotting. Results: The results found that SMYD2 upregulation led to energy reprogramming to glycolysis in human kidney tissue samples and in mice with CaOx nephrolithiasis. We also identified the substantial involvement of glycolysis in the induction of apoptosis, inflammation, and epithelial-mesenchymal transition (EMT) in HK-2 cells caused by calcium oxalate monohydrate (COM). In vivo and in vitro results demonstrated that SMYD2 inhibition reduces glycolysis, kidney injury, and fibrosis. Mechanistically, SMYD2 was found to promote metabolic reprogramming of RTCs toward glycolysis by activating the AKT/mTOR pathway via methylated PTEN, which mediates CaOx-induced renal injury and fibrosis. Conclusions: Our findings reveal an epigenetic regulatory role of SMYD2 in metabolic reprogramming in CaOx nephrolithiasis and associated kidney injury, suggesting that targeting SMYD2 and glycolysis may represent a potential therapeutic strategy for CaOx-induced kidney injury and fibrosis.

The effect of aqueous extracts and isolation proteinous compound from clove buds on serumglucose, triglyceride , glutathione and malnodialdehyde levels in alloxan induced diabetic mice

This study was included preparing acold aqueous extract of clove buds The study also comprised the isolation and studying the proteinous compound,which was seperated using gel filtration technique and determined approximately molecular weight of this isolated compound(6799) dalton . The aim of the study demonstrate effects of the crude aqueous, non proteinous extract, proteinous precipitate and proteinous compound on serum glucose, total cholesterol, triglyceride and high density lipoprotein-cholesterol levels, also glutathione and malondialdehyde levels in liver and kidney tissues in diabetic mice-induced alloxan.Extracts were administerated interaperitioneally. The results were indicated that the crude aqueous, non proteinous extract, proteinous precipitate and proteinous compound which were caused asignificant decrease in serum glucose, total cholesterol, triglyceride levels and malondialdehyde level in liver and kidney tissues, while aproteinous precipitate don’t show asignificant decrease in serum cholesterol level but all extracts don’t show asignificant changes in serum high density lipoprotein-cholesterol level in alloxan induced diabetic mice, on other wise all extracts showed asignificant increase in glutathione level in liver and kidney tissues except non proteinous extract and proteinous precipitate which were caused asignificant increase in glutathione level in liver tissue only.