Renal Interstitium Research Articles

Single Nucleus RNA Sequencing Reveals Cellular and Molecular Responses to Vanadium Exposure in Duck Kidneys

Vanadium (V) exposure is known to induce renal toxicity, yet its specific effects on renal cell types and molecular mechanisms remain incompletely understood. We used single nucleus RNA sequencing (snRNA-seq) to characterize the impact of V on duck kidney cells at a cellular resolution. Following a 44-day exposure, immunofluorescence analysis revealed a significant increase in α-SMC expression in the renal interstitium, indicative of fibrotic response. SnRNA-seq identified 12 major cell types organized into 19 clusters within the kidney. Significant changes in cell composition were observed, notably an increase in proximal tubule cells (PT2 subtype), glomerular endothelial cells, principal cells, and alterations in immune cell proportions, while collecting duct intercalated cells (CD-IC) and thick ascending limb showed decreased percentages. Differential gene expression analysis highlighted pathways implicated in V toxicity across different cell types. Changes in drug metabolism-cytochrome P450, butanoate metabolism, and actin cytoskeleton regulation were exhibited by PT cells. Alterations in collecting duct secretion, oxidative phosphorylation, and bicarbonate reclamation pathways were shown in CD-IC cells. Furthermore, immune cells displayed changes in T cell receptor and chemokine signaling pathways, indicative of altered immune responses. Taken together, these findings contribute to a better shedding light on the pathogenic mechanisms of V induced renal injury.

Novel TBC1D8B variant causes neonatal nephrotic syndrome combined with acute kidney injury

BackgroundNephrotic syndrome (NPHS), characterized by proteinuria, hypoalbuminemia, and edema, can be caused by genetic variations. TBC1D8B was recently discovered as a novel disease-causing gene for X-linked NPHS. With only a few reported cases, the clinical manifestations associated with variants of this gene need to be further examined.MethodsWe recruited a newborn with NPHS complicated by acute kidney injury (AKI) and his parents and tested the potential genetic cause of the disease through trio-whole exome sequencing and Sanger sequencing. Western blotting (WB) was performed using a mutant plasmid to evaluate mutant protein expression levels. Since the TBC1D8B protein interacts with RAB proteins to catalyze the GTPase hydrolysis process, immunofluorescence (IF) can be used to verify the interaction between the TBC1D8B mutant protein and RAB11A/RAB11B, and thus to confirm its effect on the endocytosis and vesicle recycling functions of RAB proteins within the cell.ResultsThe child, at 1 month, showed severe edema and proteinuria and unexplained coma with epilepsy. Ultrasound examination revealed multiple organ enlargement, and MRI showed nonspecific high diffusion-weighted imaging signal characteristics in the splenium of the corpus callosum. Hematoxylin and eosin staining showed diffuse inflammatory cell infiltration in the renal interstitium and multifocal renal tubule lumen expansion. Diffuse fusion of podocyte foot processes was observed under electron microscopy, indicating glomerular podocyte lesions. Genetic testing revealed a maternally inherited novel hemizygous variant, NM_017752: c.628 A > T, p.Lys210Ter, in TBC1D8B. In vitro functional experiments showed that this variant may lead to TBC1D8B protein degradation. IF results showed disrupted interaction with RAB11A/RAB11B, that then affects the biological function of RAB proteins in the process of cell intimal vesicle formation and intracellular transport.ConclusionThis study will enrich the mutational and phenotypic spectra of TBC1D8B and demonstrate the potential of this gene variants to cause early-onset NPHS leading to severe kidney disease.

Tubulointerstitial nephritis with IgM-positive plasma cells complicated by liver failure.

Tubulointerstitial nephritis (TIN) is characterized by inflammation of the renal interstitium with the infiltration of immune cells, mainly consisting of T cells. Recently, patients with TIN with the predominant infiltration of immunoglobulin M (IgM)-positive plasma cells were reported, coined IgMPC-TIN. Here we report the case of a 70-year-old woman diagnosed with Fanconi syndrome and renal tubular acidosis. Renal biopsy revealed IgMPC-TIN. Her renal dysfunction and clinical findings improved after corticosteroid therapy. However, the patient died of progressive liver failure and spontaneous bacterial peritonitis. In laboratory tests, viral hepatitis was excluded, and autoantibodies associated with liver diseases were negative. Generally, IgMPC-TIN is often complicated by primary biliary cholangitis (PBC), whereas her autopsy revealed the local infiltration of IgM-positive plasma cells, obliterative portal venopathy, and nodular regenerative hyperplasia in liver. This case is the first demonstration that IgMPC-TIN is also seen in liver disease with nodular regenerative hyperplasia, although IgMPC-TIN is more common in anti-M2 antibody-positive disease.

Empagliflozin attenuating renal interstitial fibrosis in diabetic kidney disease by inhibiting lymphangiogenesis and lymphatic endothelial-to-mesenchymal transition via the VEGF-C/VEGFR3 pathway

Renal interstitial fibrosis (RIF) is a significant pathological change in diabetic kidney disease (DKD) that can be induced by endothelial-to-mesenchymal transition (EndMT). Lymphangiogenesis, mediated by the vascular endothelial growth factor-C (VEGF-C)/vascular endothelial growth factor receptor-3 (VEGFR-3) pathway, plays a crucial role in the development of RIF in DKD. Although numerous studies have demonstrated the efficacy of empagliflozin in treating renal injury, its effects on lymphangiogenesis in DKD-related RIF and the underlying mechanisms remain unclear. In the present study, significant lymphangiogenesis was assessed in the renal interstitium of patients with DKD. We subsequently explored the relationship between DKD-related RIF and lymphangiogenesis in mouse models, high-glucose (HG)-stimulated renal HK-2 cell lines, and human lymphatic endothelial cells (hLECs). Additionally, we evaluated the effects of empagliflozin on these processes. The results revealed that HG induces lymphangiogenesis, which exacerbates RIF by promoting inflammatory responses. Furthermore, hLECs directly contributed to the progression of DKD-related RIF through EndMT. Further analysis revealed that tubular epithelial cells (TECs) act as effector cells for VEGF-C, with the epithelial-to-mesenchymal transition (EMT) of TECs occurring concurrently with the EndMT of lymphatic vessels. Empagliflozin inhibited RIF in DKD by suppressing the VEGF-C/VEGFR3 pathway and reducing lymphangiogenesis. In conclusion, this study elucidates the interplay between lymphangiogenesis, EndMT, and RIF in DKD and provides new insights into the mechanism by which empagliflozin treats DKD.

Trim21 mediates metabolic reprogramming in renal tubular cells via PFKP ubiquitination to alleviate renal fibrosis

AbstractChronic kidney disease (CKD), stemming from varied nephric impairments, manifests a steadily escalating global incidence. As a progressive pathological condition, CKD is typified by an intensification in the gravity of renal interstitium fibrotic transformations. Nonetheless, the intrinsic mechanisms underpinning nephric fibrosis remain elusive. In this context, we elucidated a marked augmentation in aerobic glycolysis within proximal tubular epithelial cells (TECs) of CKD patients, alongside unilateral ureteral obstruction (UUO) and ischemia‐reperfusion injury (IRI) murine models, concomitant with deficiency of Trim21. Experimental investigations, both in vivo and in vitro, revealed that Trim21 deficiency aggravates the aberrantly heightened aerobic glycolysis, thereby exacerbating fibrotic reaction progression. Concomitantly, enhancive glycolytic flux paralleled an elevation in ATP genesis and reconstitution of cytoskeletal architecture. Mechanistically, we uncovered that Trim21 modulates aerobic glycolysis in TECs via ubiquitin‐facilitated degradation of phosphofructokinase platelet (PFKP), thus attenuating nephric fibrosis. Collectively, our insights posit Trim21 as a prospective therapeutic target in the amelioration of renal fibrosis.

Acute lymphoblastic leukemia with nephrogenic diabetes insipidus as the first symptom: a case report

BackgroundAcute lymphoblastic leukemia is the most common pediatric malignancy, characterized by fever, anemia, hemorrhage, and symptoms brought on by blasts infiltrating organs.Case presentationThis is a case report of a 9-year-old Asian patient with acute lymphoblastic leukemia who presented with polyuria alone as a presenting feature without any other clinical manifestation; primary renal disease or inherited metabolic disease was highly suspected. However, the water deprivation test and water deprivation pressurization test suggested nephrogenic diabetes insipidus, and the renal biopsy displayed diffuse lymphocytic infiltration in the renal interstitium. Bone marrow aspiration was performed immediately, and a comprehensive diagnosis of B-lymphoblastic leukemia was finally made.ConclusionsRenal infiltration with leukemic blasts mostly remains asymptomatic, but our case suggests that it can present with nephrogenic diabetes insipidus. This case fully demonstrates that the presentation of extramedullary infiltration in acute lymphoblastic leukemia is varied. When the patient has renal diabetes insipidus as the first symptom, the possibility of hematological tumor infiltration should be considered when finding the cause, and timely bone marrow cytology should be performed.

Osteogenic-Like Microenvironment of Renal Interstitium Induced by Osteomodulin Contributes to Randall's Plaque Formation.

Calcium oxalate (CaOx) kidney stones are common and recurrent, lacking pharmacological prevention. Randall's plaques (RPs), calcium deposits in renal papillae, serve as niduses for some CaOx stones. This study exploresthe role of osteogenic-like cells in RP formation resembling ossification. CaP crystals deposit around renal tubules, interstitium, and blood vessels in RP tissues. Human renal interstitial fibroblasts (hRIFs) exhibit the highest osteogenic-like differentiation potential compared to chloride voltage-gated channel Ka positive tubular epithelial cells, aquaporin 2 positive collecting duct cells, and vascular endothelial cells, echoing the upregulated osteogenic markers primarily in hRIFs within RP tissues. Utilizing RNA-seq, osteomodulin (OMD) is found to be upregulated in hRIFs within RP tissues and hRIFs following osteogenic induction. Furthermore, OMD colocalizes with CaP crystals and calcium vesicles within RP tissues. OMD can enhance osteogenic-like differentiation of hRIFs in vitro and in vivo. Additionally, crystal deposits are attenuated in mice with Omd deletion in renal interstitial fibroblasts following CaOx nephrocalcinosis induction. Mechanically, a positive feedback loop of OMD/BMP2/BMPR1A/RUNX2/OMD drives hRIFs to adopt osteogenic-like fates, by which OMD induces osteogenic-like microenvironment of renal interstitium to participate in RP formation. Weidentify OMD upregulation as a pathological feature of RP, paving the way for preventing CaOx stones.

A high-calcium environment induced ectopic calcification ofrenal interstitial fibroblasts via TFPI-2-DCHS1-ALP/ENPP1 axis to participate inRandall's plaque formation.

Randall's plaques (RP) serve as anchoring sites for calcium oxalate (CaOx) stones, but the underlying mechanism remains unclear. Renal interstitium with a high-calcium environment is identified as pathogenesis of RP formation where the role of human renal interstitial fibroblasts (hRIFs) was highlighted. Our study aims to elucidate the potential mechanism by which a high-calcium environment drives ectopic calcification of hRIFs to participate in RP formation. Alizarin Red staining demonstrated calcium nodules in hRIFs treated with high-calcium medium. Utilizing transcriptome sequencing, tissue factor pathway inhibitor-2 (TFPI-2) was found to be upregulated in high-calcium-induced hRIFs and RP tissues, and TFPI-2 promoted high-calcium-induced calcification of hRIFs. Subsequently, the downstream regulator of TFPI2 was screened by transcriptome sequencing analysis of hRIFs with TFPI-2 knockdown or overexpressed. Dachsous Cadherin Related 1 (DCHS1) knockdown was identified to suppress the calcification of hRIFs enhanced by TFPI-2. Further investigation revealed that TFPI-2/DCHS1 axis promoted high-calcium-induced calcification of hRIFs via disturbing the balance of ENPP1/ALP activities, but without effect on the canonical osteogenic markers, such as osteopontin (OPN), osteogenic factors runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2). In summary, our study mimicked the high-calcium environment observed in CaOx stone patients with hypercalciuria, and discovered that the high-calcium drove ectopic calcification of hRIFs via a novel TFPI-2-DCHS1-ALP/ENPP1 pathway rather than adaption of osteogenic phenotypes to participate in RP formation.

Renal leukocyte chemokine type 2 amyloidosis: a clinicopathological analysis of fifteen cases

Objective: To investigate the clinicopathological features of renal leukocyte chemokine type 2 amyloidosis (ALECT2). Methods: The prevalence, clinical characteristics, renal histopathological features, and renal outcome of 15 patients with ALECT2 by kidney biopsy were collected in the Department of Kidney Pathology, Shanxi Medical University Second Hospital, Taiyuan, China from January 1993 to December 2023. Immunohistochemistry and mass spectrometry for amyloid proteins were carried out. Results: Fifteen patients with ALECT2 were included in the study, representing 12.93% (15/116) of the renal biopsy-proven amyloidosis cases. There were 5 males and 10 females. The median age at diagnosis was 61 years. All patients had various degrees of proteinuria; 7 patients had nephrotic syndrome; 3 patients had renal insufficiency; 7 patients had microscopic hematuria. Renal biopsy showed that strongly orangophilic amyloid proteins distributed mainly in the renal cortical interstitium, vascular walls, the glomerular mesangium and/or glomerular basement membrane. Eight cases were diagnosed with ALECT2 alone and 7 cases combined with other renal diseases, including 4 cases with membranous nephropathy, 2 cases with IgA nephropathy, and 1 case with subacute tubular interstitial nephropathy. ALECT2 patients with concurrent renal disease showed a higher proteinuria level than those without (3.48 g/24 h versus 4.58 g/24 h). All patients were corroborated by immunohistochemistry to exhibit the specific location of LECT2 in the amyloid fibrils. Mass spectrometry analysis revealed LECT2 polypeptide in 9 patients. Except two patients with worsening renal function, the others showed stable renal function during the mean follow-up period of 12.5 months. Conclusions: ALECT2 is the second common type of renal amyloidosis in our center. The majority of ALECT2 patients show concurrent renal diseases, with a high rate of membranous nephropathy. Amyloid deposits distribute mainly in the cortical interstitium of the kidney, the glomerular mesangium and vascular walls. Mass spectrometry is the most sensitive and specific method for detecting LECT2 amyloidosis.

Low-dose quercetin at 25 mg/kg ameliorates dolutegravir-lamivudine-tenofovirdisoproxilfumarate-inducedcardio-hepato-renal toxicities in Wistar rats

Combination antiretroviral therapies (cARTs) are linked with multiple-organ system (MOS) toxicities in laboratory animals, and in humans undertaking treatment for HIV/AIDS. The ameliorative potential of low-dose quercetin following cART-associated MOS-toxicities in cardio-hepato-renal organs was evaluated in in vivo model. Oral administration of cART (Dolutegravir 50 mg, Lamivudine 300 mg and Tenofovir disoproxil fumarate 300 mg [DLT]) at 9.29 mg/kg, was challenged against low-dose quercetin 25 mg/kg body weight (bw) in Wistar rats. Group 1, the normal control (NC) received distilled water (5 mL), while groups 2 to 4 received quercetin (25 mg), DLT (9.29 mg), and DLT + quercetin (9.29 mg + 25 mg respectively), per kg bw. All administrations lasted for 14 days, and thereafter animals were humanely sacrificed after intraperitoneal anesthesia injection with 100 mg ketamine /5 mg xylazine per kg bw followed by cervical dislocation. Blood and organs were harvested for analyses using standard protocols. The serum concentrations of lipid parameters [total cholesterol, triglycerides, LDL-cholesterol, and VLDL-cholesterol], liver biomarkers (total-bilirubin, direct-bilirubin, and transaminases], and kidney biomarkers [urea and creatinine] were significantly increased (p < 0.05) while electrolytes (Na+, K+, Cl− and HCO3−) were significantly decreased (p < 0.05) in DLT group but improved in DLT + Q group. Histopathology demonstrated distorted myocytes, hepatocytes and renal tubules, fatty liver with vacuolization, dystrophied glomeruli and distorted renal interstitium in DLT group, compared with normal appearing histoarchitectural features in NC and DLT + Q groups. In conclusion, oral administration of low-dose quercetin (25 mg/kg) ameliorated cART-associated cardio-hepato-renal toxicities in rats, improving their biomarkers and histoarchitecture.

Potential pathways for traditional Chinese medicine intervention in diabetic kidney disease: macrophage polarization

Diabetic kidney disease(DKD) is a prevalent and severe microvascular complication of type 2 diabetes mellitus(T2DM). Chronic microinflammation is an important factor exacerbating renal tissue damage in DKD individuals. Macrophages play a crucial role in immune-inflammatory responses, and they can transiently and reversibly polarize into the pro-inflammatory M1 phenotype and anti-inflammatory M2 phenotype based on microenvironmental differences. The imbalance in M1/M2 macrophage polarization can exacerbate DKD progression by fostering inflammatory cytokine aggregation in the glomeruli and renal interstitium. Therefore, restoring the balance of macrophage is a pivotal avenue to ameliorate the chronic microinflammation state in DKD. Macrophage polarization is a complex and dynamic process. Various information molecules and cytokines involved in the polarization process play important roles in regulating phenotypes during the progression of DKD. They are closely related to various mechanisms such as metabolism, inflammation, fibrosis, and mitochondrial autophagy in DKD. By coordinating the inflammatory responses through polarization, they play a key role in regulating inflammation in metabolic-related diseases. The complex network of pathways involved in macrophage polarization corresponds well with the multi-pathway, multi-target treatment model of traditional Chinese medicine(TCM). Active ingredients and formulas of TCM can intervene in DKD by regulating macrophage polarization. Studies on relieving renal inflammation, repairing renal tissues, and promoting renal function recovery through macrophage polarization modulation are not uncommon. Therefore, based on exis-ting evidence, this study reviews TCM in targeting M1/M2 macrophage polarization balance to improve DKD, aiming to explore the potential of macrophage polarization in regulating DKD, which is expected to provide evidence support for the clinical diagnosis and treatment of DKD with TCM as well as the exploration of its biological mechanisms.

Profiling dendritic cells subsets in renal tissue of patients with crescentic glomerulonephritis.

Dendritic cells (DCs) have been speculated to be involved in the pathogenesis of glomerular diseases. However, the numbers and distribution of DC subsets in the kidneys of patients with crescentic glomerulonephritis (CrGN) have not been clearly elucidated. A total of 26 patients with biopsy-proven CrGN were enrolled. Indirect immunofluorescence staining was used to quantify DC subsets in renal specimens. Double staining of HLA with CD11C, BDCA2 and CD209 respectively was performed to detect DC subsets. The correlation between DC subsets infiltrated in the kidney and clinical and pathological parameters was investigated. DC subsets were predominantly present in the kidney interstitium, particularly in the peri-glomerular area. The numbers of CD11C+DCs, BDCA2+DCs and CD209+DCs increased in the patients with CrGN and varied among different types of CrGN. Though significant correlation between DC subsets and the percentage of crescents had not been identified, a notable increase in the number of CD11C+DCs were observed with the chronic development of crescents. Furthermore, patients with severe tubulointerstitial injury exhibited significantly more infiltrations of CD11C+DCs, BDCA2+DCs and CD209+DCs. Moreover, the numbers of CD11C+DCs and BDCA2+DCs were found to correlate with the level of serum C3. Patients with CrGN showed increased kidney infiltration of DC subsets, primarily localized in the renal interstitium and peri-glomerular region. The correlation between DC subsets and fibrosis of crescent and severe tubulointerstitial injury implied a potential involvement of DCs in the development of CrGN.

Endoplasmic Reticulum Stress-Mediated Cell Death in Renal Fibrosis.

The endoplasmic reticulum (ER) is indispensable for maintaining normal life activities. Dysregulation of the ER function results in the accumulation of harmful proteins and lipids and the disruption of intracellular signaling pathways, leading to cellular dysfunction and eventual death. Protein misfolding within the ER disrupts its delicate balance, resulting in the accumulation of misfolded or unfolded proteins, a condition known as endoplasmic reticulum stress (ERS). Renal fibrosis, characterized by the aberrant proliferation of fibrotic tissue in the renal interstitium, stands as a grave consequence of numerous kidney disorders, precipitating a gradual decline in renal function. Renal fibrosis is a serious complication of many kidney conditions and is characterized by the overgrowth of fibrotic tissue in the glomerular and tubular interstitium, leading to the progressive failure of renal function. Studies have shown that, during the onset and progression of kidney disease, ERS causes various problems in the kidneys, a process that can lead to kidney fibrosis. This article elucidates the underlying intracellular signaling pathways modulated by ERS, delineating its role in triggering diverse forms of cell death. Additionally, it comprehensively explores a spectrum of potential pharmacological agents and molecular interventions aimed at mitigating ERS, thereby charting novel research avenues and therapeutic advancements in the management of renal fibrosis.

Jian-Pi-Yi-Shen formula ameliorates renal fibrosis-induced anemia in rats with chronic kidney disease

Ethnopharmacological relevanceJian-Pi-Yi-Shen (JPYS) formula is an effective herbal therapy against renal injury, and JPYS has been clinically applied to ameliorate chronic kidney disease (CKD) and CKD-associated anemia. Increasing evidence supports the link between renal fibrosis and anemia in CKD. JPYS possessed anti-fibrosis effects in experimental CKD. Nevertheless, research on the mechanisms of JPYS in ameliorating renal anemia (RA) through suppressing renal fibrosis remains to be clarified. Aim of the studyOur study here was carried out to investigate the mechanisms of JPYS in protecting against RA. Materials and methodsAn adenine-induced anemia model in rats with CKD at three different time points was established, and bio-samples taken from each group were analyzed. Biochemical analysis was employed to detect kidney function and hematological parameters. Masson staining was used to evaluate renal fibrosis of rats. Western blot and immunohistochemistry were utilized to evaluate the expressions of fibrotic markers, erythropoietin (EPO) and hypoxia inducible factor-2α (HIF-2α) in the kidneys of rats. Subsequently, transcriptomic analysis was conducted to disclose the possible mechanisms of JPYS in treating RA. Finally, the expression levels of key targets were analyzed and validated by using Western blot and enzyme-linked immunosorbent assay (ELISA). ResultsJPYS treatment improved kidney function, suppressed renal fibrosis and enhanced hematological parameters in CKD rats. Moreover, JPYS treatment restored the increased expression levels of fibrotic markers and the declined EPO with time dependence. In parallel, data indicated JPYS treatment stimulated the translocation of HIF-2α into nucleus in the renal interstitium and thus promoted the expression of EPO. Transcriptomic profiling disclosed that activations of both nuclear factor kappa B (NF-κB) and transforming growth factor-β (TGF-β)/Smad pathways were closely associated with RA. Ultimately, experimental validation results presented that the increased expressions of target proteins from the above-mentioned two pathways in the kidneys were decreased significantly after JPYS treatment. ConclusionOur findings suggest that JPYS may improve RA by alleviating renal fibrosis, and the mechanisms of which involve in inhibiting the NF-κB and TGF-β/Smad pathways.

Urinary hyaluronidase activity is closely related to vasopressinergic system following an oral water load in men: a potential role in blood pressure regulation and early stages of hypertension development.

Blood pressure (BP) regulation is a complex process involving several factors, among which water-sodium balance holds a prominent place. Arginin-vasopressin (AVP), a key player in water metabolism, has been evoked in hypertension development since the 1980s, but, to date, the matter is still controversial. Hyaluronic acid metabolism has been reported to be involved in renal water management, and AVP appears to increase hyaluronidase activity resulting in decreased high-molecular-weight hyaluronan content in the renal interstitium, facilitating water reabsorption in collecting ducts. Hence, our aim was to evaluate urinary hyaluronidase activity in response to an oral water load in hypertensive patients (HT, n=21) compared to normotensive subjects with (NT+, n=36) and without (NT-, n=29) a family history of hypertension, and to study its association with BP and AVP system activation, expressed by serum copeptin levels and urine Aquaporin 2 (AQP2)/creatinine ratio. Eighty-six Caucasian men were studied. Water load test consisted in oral administration of 15-20 ml of water/kg body weight over 40-45 min. BP, heart rate, serum copeptin, urine hyaluronidase activity and AQP2 were monitored for 4 hours. In response to water drinking, BP raised in all groups with a peak at 20-40 min. Baseline levels of serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio were similar among groups and all decreased after water load, reaching their nadir at 120min and then gradually recovering to baseline values. Significantly, a blunted reduction in serum copeptin, urinary hyaluronidase activity and AQP2/creatinine ratio was observed in NT+ compared to NT- subjects. A strong positive correlation was also found between urinary hyaluronidase activity and AQP2/creatinine ratio, and, although limited to the NT- group, both parameters were positively associated with systolic BP. Our results demonstrate for the first time the existence in men of a close association between urinary hyaluronidase activity and vasopressinergic system and suggest that NT+ subjects have a reduced ability to respond to water loading possibly contributing to the blood volume expansion involved in early-stage hypertension. Considering these data, AVP could play a central role in BP regulation by affecting water metabolism through both hyaluronidase activity and AQP2 channel expression.

Hydroxycitric acid inhibits ectopic calcification of renal interstitial fibroblasts by suppressing cell apoptosis

Ectopic calcification of the renal interstitium as an important cause of renal stone formation. Hydroxycitric acid (HCA), a derivative of citric acid, has antioxidant properties and inhibits the crystallisation of calcium salts.The study found that HCA has an inhibitory effect on calcification and calcium salt deposition in fibroblasts. Additionally, HCA was found to reduce calcification-induced oxidative damage and apoptosis.Animal experiments also showed that HCA reduced calcium salt deposition and expression of calcification-related proteins. Cellular transcriptomic analysis demonstrated that HCA can regulate the changes in cellular transcriptome caused by calcification in culture. HCA can effectively inhibit the calcification of renal interstitial fibroblasts, reducing the risk of stone formation by inhibiting calcification culture-induced apoptosis and calcium salt deposition. Therefore, HCA is a promising alternative drug for inhibiting renal stone formation.

Rosehip tea as a possible cause of acute interstitial nephritis

BackgroundAcute interstitial nephritis (AIN) is characterized by an inflammatory infiltrate in the renal interstitium. The etiology of AIN is broad with the most common cause being medications. Treatment includes removal of the offending agent, glucocorticoid therapy, and immunosuppression. Rosehips are a fruit produced from wild roses that are often used in teas and herbal supplements. They are reported to have anti-inflammatory effects and sought after for this purported benefit.Case presentationWe present a case of a 67-year-old woman who presented with acute kidney injury after two months of excessive rosehip tea consumption. She was dialyzed for 1 month and treated with oral steroids. Her initial renal biopsy revealed AIN, a thin glomerular basement membrane, and five nodular sclerosed glomeruli. Her work-up was negative for known causes of AIN and the etiology was determined to be rosehip tea. Two months after initial presentation she continued to have clinical and pathologic signs of AIN. She was started on mycophenolate mofetil (MMF) with clinical improvement.ConclusionRosehip tea is known to have diuretic properties and, when consumed, may lead to a self-perpetuating cycle of intake. Excessive consumption may lead to increased concentrations of arachidonic acid and its metabolites. These metabolites have been shown to perpetuate an inflammatory response capable of causing AIN. Providers should be aware when counseling patients that excessive intake of rosehip tea may lead to AIN.

Fabrication of losartan-loaded chitosan-cloaked dopamine nanoparticles for improving diabetic nephropathy via regulation of oxidative stress and blood glucose

Diabetic nephropathy (DN) is a significant problem for people with diabetes, and its progression is strongly associated with oxidative stress induced by high blood sugar levels (hyperglycemia). This study presents a novel type of losartan-loaded chitosan-cloaked dopamine nanoparticles (CSDLNPs). It can specifically aggregate in damaged kidneys, lower blood glucose levels, and ameliorate the damage caused by oxidative stress. CSDLNPs exhibit excellent dispersion physiological stability and sensitive release under an acidic pH milieu. Additionally, they have potent scavenging capabilities against a wide range of reactive nitrogen and oxygen radicals. Furthermore, in vitro, investigations validate that CSDLNPs exhibit superior biocompatibility, facilitate specific absorption in the HK-2 proximal tubule epithelial cell line, and effectively mitigate oxidative stress generated by high hyperglycemia. Following CSDLNPs treatment, DN exhibits a reduction in fasting blood glucose (FBG) levels and a restoration of urine and blood indices to levels close to normal. The H&E pathological staining results demonstrate that CSDLNPs effectively suppress collagen deposition, glycogen accumulation, and renal interstitium enlargement, indicating remarkable therapeutic efficacy. Furthermore, dopamine is a drug carrier and antioxidant without needing an external carrier, demonstrating superior biosafety and potential for translation to diabetic nephropathy.

Controversias en la fisiopatología de la hipertensión arterial.

Introduction: Purinergic receptors actively participate in the renal alterations in high blood pressure. The elevation of ATP in the renal interstitium activates purinergic receptors, constituting a fundamental pathway in the generation and persistence of arterial hypertension. Objective of the review: This article is a narrative review that aims to show the importance of new concepts in the pathophysiology of arterial hypertension. Essential points of the review: Purinergic receptors are ATP receptors; the more significant the ATP, the greater the purinergic receptors. Elevated ATP concentrations alter fundamental mechanisms related to blood pressure control, such as the pressure natriuresis mechanism and renal sodium excretion, the regulation of glomerular filtration, and the tubuloglomerular feedback mechanism. The alteration of these mechanisms decreases urinary sodium excretion. Whether influenced by genetic alterations or induced by vasoconstrictor peptides, a decrease in renal function and tubulointerstitial injury occur before the glomerulus is injured. The interaction between angiotensin II and purinergic receptors favors the progression of kidney damage. Conclusion: Kidney damage in high blood pressure is critical, so efforts should be made to control hypertension to prevent the progression of kidney damage that leads to kidney failure. To obtain better blood pressure control, developing purinergic receptor antagonists for clinical use is possible.

#2062 Protein interactome and trafficking of uromodulin in HEK and MDCK cell model

Abstract Background and Aims Uromodulin (UMOD) is a kidney-specific glycoprotein and the most abundant urinary protein in healthy individuals. Genome-wide association studies have shown an association between UMOD variants, kidney diseases, and hypertension. UMOD exhibits bidirectional secretion as it releases into the renal interstitium and circulation. However, the molecular trafficking of UMOD and its interaction remains poorly defined. We aimed to establish a stable Human Embryonic Kidney (HEK293) cell line expressing human UMOD to identify the potential regulators of UMOD expression or secretion. This study will provide significant implications for conditions such as hypertension, chronic kidney diseases, acute kidney injury, or UMOD-autosomal dominant tubulointerstitial kidney disease (UMOD-ADTKD). Method A HEK-UMOD-expressing cell line was generated by introducing human UMOD transcript 1 expression and using a tetracycline-inducible expression vector (pcDNA™FRT⁄TO vector) with yellow fluorescent protein tag at the C-terminal and previously established MDCK-UMOD cell line was also used. An untargeted proteomic approach was used to identify proteins, using GFP trap co-immunoprecipitation assay followed by mass spectrometry analysis. Results We identified 1367 and 1140 UMOD interacting proteins in HEK and MDCK cell models respectively. There were 620 proteins common to both these models. Through gene ontology, we unravel the molecular mechanisms involved in the biosynthesis, folding, and transport of UMOD. We observed several proteins associated with clathrin-mediated transporting. To study the role of clathrin in UMOD transport, we treated the polarised MDCK-UMOD cells with pitstop 2. There was significantly more secretion of UMOD with pitstop 2 treatment in the apical compartment compared to untreated cells however there was no significant difference in UMOD secretion in the basolateral compartment. Conclusion These results suggested that clathrin-coated vesicles are involved in transporting and sorting UMOD. Further studies need to investigate the functional importance of these proteins in UMOD trafficking and their implications in different physiological processes.