Explore the vast range of titles available.

Aristolochic acid nephropathy (AAN), a progressive renal interstitial fibrosis frequently associated with urothelial malignancies, was initially reported in a Belgian cohort of more than 100 patients after the intake of slimming pills containing a Chinese herb, Aristolochia fangchi. Although botanicals known or suspected to contain aristolochic acid (AA) were no longer permitted in many countries, several AAN cases were regularly observed all around the world. The incidence of AAN is probably much higher than initially thought, especially in Asia and the Balkans. In Asian countries, where traditional medicines are very popular, the complexity of the pharmacopoeia represents a high risk for AAN because of the frequent substitution of the botanical products by AA-containing herbs. In the Balkan regions, the exposure to AA found in flour obtained from wheat contaminated with seeds of Aristolochia clematitis could be responsible for the so-called Balkan-endemic nephropathy. Finally, despite the Food and Drug Administration's warnings concerning the safety of botanical remedies containing AA, these herbs are still sold via the Internet.

The term “aristolochic acid nephropathy” (AAN) is used to include any form of toxic interstitial nephropathy that is caused either by ingestion of plants containing aristolochic acids (AA) as part of traditional phytotherapies (formerly known as “Chinese herbs nephropathy”), or by the environmental contaminants in food (Balkan endemic nephropathy). It is frequently associated with urothelial malignancies. Although products containing AA have been banned in most of countries, AAN cases remain regularly reported all over the world. Moreover, AAN incidence is probably highly underestimated given the presence of AA in traditional herbal remedies worldwide and the weak awareness of the disease. During these two past decades, animal models for AAN have been developed to investigate underlying molecular and cellular mechanisms involved in AAN pathogenesis. Indeed, a more-in-depth understanding of these processes is essential to develop therapeutic strategies aimed to reduce the global and underestimated burden of this disease. In this regard, our purpose was to build a broad overview of what is currently known about AAN. To achieve this goal, we aimed to summarize the latest data available about underlying pathophysiological mechanisms leading to AAN development with a particular emphasis on the imbalance between vasoactive factors as well as a focus on the vascular events often not considered in AAN.

AMP-activated protein kinase (AMPK) is an important energy sensor that may be critical in regulating renal lipid accumulation. To evaluate the role of AMPK in mediating renal lipid accumulation, C57BL/6J mice were randomized to a standard diet, a high-fat diet, or a high-fat diet plus AICAR (an AMPK activator) for 14 weeks. Renal functional and structural studies along with electron microscopy were performed. Mice given the high-fat diet had proximal tubule injury with the presence of enlarged clear vacuoles, and multilaminar inclusions concurrent with an increase of tissue lipid and overloading of the lysosomal system. The margins of the clear vacuoles were positive for the endolysosomal marker, LAMP1, suggesting lysosome accumulation. Characterization of vesicles by special stains (Oil Red O, Nile Red, Luxol Fast Blue) and by electron microscopy showed they contained onion skin-like accumulations consistent with phospholipids. Moreover, cholesteryl esters and phosphatidylcholine-containing phospholipids were significantly increased in the kidneys of mice on a high-fat diet. AMPK activation with chronic AICAR treatment prevented the clinical and structural effects of high-fat diet. Thus, high-fat diet contributes to a dysfunction of the lysosomal system and altered lipid metabolism characterized by cholesterol and phospholipid accumulation in the kidney. AMPK activation normalizes the changes in renal lipid content despite chronic exposure to lipid challenge.

Introduction: Uremic toxins have been shown to cause adverse pulmonary effects by inducing endothelial and epithelial dysfunction, disrupting the alveolar-capillary barrier, and increasing inflammation and oxidative stress. This article reviews these effects with a specific focus on chronic kidney disease and the mechanisms by which uremic toxins affect lung tissue. Methods: A narrative review was conducted using keywords related to uremic toxins and lung injury to search the PubMed database. An advanced literature review was conducted in PubMed to identify studies explaining the mechanisms underlying lung pathophysiology in chronic kidney disease (CKD), with particular focus on CKD-induced pulmonary epithelial and endothelial dysfunction. Additionally, to highlight the pathological processes of lung congestion in CKD, studies on CKD-induced dysfunction of the alveolar-capillary barrier were retrieved. Studies published up to November 2025 were evaluated. Results: A total of 148 articles were reviewed in full text. Uremic toxins negatively impact lung tissue structure and function through multiple mechanisms, including oxidative stress, inflammation, and direct effects. Uremic toxins appear to share signaling pathways in endothelial cells, including those linked to Mitogen-activated protein kinases (MAPK), the Aryl Hydrocarbon Receptor (AhR), the receptor for advanced glycation end products (RAGE), and pro-inflammatory transcription factors such as nuclear factor κB (NF-κB). Additionally, oxidative stress acts as a pro-inflammatory signal shared by several uremic toxins. The mechanisms behind the harmful interactions between CKD and lung disease are mostly unknown, although more evidence exists for acute kidney injury (AKI). Conclusions: Chronic kidney disease, which leads to the buildup of uremic toxins, negatively affects the lungs. Overall, the accumulation of uremic toxins in CKD impairs endothelial and epithelial cells and the alveolar capillary barrier. Further research is needed to understand the specific mechanisms underlying these effects and to identify therapeutic options to protect the lungs in these patients.

Aristolochic acid nephropathy (AAN) is a progressive tubulointerstitial nephritis caused by the intake of aristolochic acids (AA) contained in Chinese herbal remedies or contaminated food. AAN is characterized by tubular atrophy and interstitial fibrosis, characterizing advanced kidney disease. It is established that sustained or recurrent acute kidney injury (AKI) episodes contribute to the progression of CKD. Therefore, the study of underlying mechanisms of AA-induced nephrotoxicity could be useful in understanding the complex AKI-to-CKD transition. We developed a translational approach of AKI-to-CKD transition by reproducing human AAN in rodent models. Indeed, in such models, an early phase of acute tubular necrosis was rapidly followed by a massive interstitial recruitment of activated monocytes/macrophages followed by cytotoxic T lymphocytes, resulting in a transient AKI episode. A later chronic phase was then observed with progressive tubular atrophy related to dedifferentiation and necrosis of tubular epithelial cells. The accumulation of vimentin and αSMA-positive cells expressing TGFβ in interstitial areas suggested an increase in resident fibroblasts and their activation into myofibroblasts resulting in collagen deposition and CKD. In addition, we identified 4 major actors in the AKI-to-CKD transition: (1) the tubular epithelial cells, (2) the endothelial cells of the interstitial capillary network, (3) the inflammatory infiltrate, and (4) the myofibroblasts. This review provides the most comprehensive and informative data we were able to collect and examines the pending questions.

The platelet-derived growth factor receptor β (PDGFRβ)+ perivascular cell activation becomes increasingly recognized as a main source of scar-associated kidney myofibroblasts and recently emerged as a new cellular therapeutic target. In this regard, we first confirmed the presence of PDGFRβ+ perivascular cells in a human case of end-stage aristolochic acid nephropathy (AAN) and thereafter we focused on the early fibrosis events of transforming growth factor β (TGFβ) inhibition in a rat model of AAN. Neutralizing anti-TGFβ antibody (1D11) and its control isotype (13C4) were administered (5 mg/kg, i.p.) at Days -1, 0, 2 and 4; AA (15 mg/kg, sc) was injected daily. At Day 5, 1D11 significantly suppressed p-Smad2/3 signaling pathway improving renal function impairment, reduced the score of acute tubular necrosis, peritubular capillaritis, interstitial inflammation and neoangiogenesis. 1D11 markedly decreased interstitial edema, disruption of tubular basement membrane loss of brush border, cytoplasmic edema and organelle ultrastructure alterations (mitochondrial disruption and endoplasmic reticulum edema) in proximal tubular epithelial cells. Moreover, 1D11 significantly inhibited p-PERK activation and attenuated dysregulation of unfolded protein response (UPR) pathways, endoplasmic reticulum and mitochondrial proteostasis in vivo and in vitro. The early inhibition of p-Smad2/3 signaling pathway improved acute renal function impairment, partially prevented epithelial-endothelial axis activation by maintaining PTEC proteostasis and reduced early PDGFRβ+ pericytes-derived myofibroblasts accumulation.

Background: Olmesartan-induced enteropathy is a rare complication of a widely used angiotensin II receptor blocker. Patients usually present with chronic diarrhea and weight loss. Histologically, villous atrophy and intraepithelial lymphocyte infiltrates within the duodenum confirm the diagnosis. The prognosis is usually good after withdrawal of the offending drug. Case presentation: Here, we report the case of a 76-year-old woman who developed a severe form of Olmesartan-induced enteropathy complicated by acute kidney injury and acute recurrence after drug rechallenge. After definite cessation of the drug, the patient did not experience any gastrointestinal (GI) symptom recurrence after 6 months of follow-up. However, she experienced chronic kidney disease stage G3b. Histological analysis did not show any villous atrophy or intraepithelial lymphocyte infiltrates within the duodenum or the colon biopsy. Discussion and conclusion: This case highlights the broad spectrum of clinical manifestations and histological findings in Olmesartan-induced enteropathy. It also highlights the importance of rapid diagnosis in order to limit organ damage such as chronic kidney disease.

Exposure to aristolochic acid (AA) is associated with human nephropathy and urothelial cancer. The tumour suppressor TP53 is a critical gene in carcinogenesis and frequently mutated in AA-induced urothelial tumours. We investigated the impact of p53 on AAI-induced nephrotoxicity and DNA damage in vivo by treating Trp53(+/+), Trp53(+/−) and Trp53(−/−) mice with 3.5 mg/kg body weight (bw) AAI daily for 2 or 6 days. Renal histopathology showed a gradient of intensity in proximal tubular injury from Trp53(+/+) to Trp53(−/−) mice, especially after 6 days. The observed renal injury was supported by nuclear magnetic resonance (NMR)-based metabonomic measurements, where a consistent Trp53 genotype-dependent trend was observed for urinary metabolites that indicate aminoaciduria (i.e. alanine), lactic aciduria (i.e. lactate) and glycosuria (i.e. glucose). However, Trp53 genotype had no impact on AAI-DNA adduct levels, as measured by 32P-postlabelling, in either target (kidney and bladder) or non-target (liver) tissues, indicating that the underlying mechanisms of p53-related AAI-induced nephrotoxicity cannot be explained by differences in AAI genotoxicity. Performing gas chromatography–mass spectrometry (GC–MS) on kidney tissues showed metabolic pathways affected by AAI treatment, but again Trp53 status did not clearly impact on such metabolic profiles. We also cultured primary mouse embryonic fibroblasts (MEFs) derived from Trp53(+/+), Trp53(+/−) and Trp53(−/−) mice and exposed them to AAI in vitro (50 µM for up to 48 h). We found that Trp53 genotype impacted on the expression of NAD(P)H:quinone oxidoreductase (Nqo1), a key enzyme involved in AAI bioactivation. Nqo1 induction was highest in Trp53(+/+) MEFs and lowest in Trp53(−/−) MEFs; and it correlated with AAI-DNA adduct formation, with lowest adduct levels being observed in AAI-exposed Trp53(−/−) MEFs. Overall, our results clearly demonstrate that p53 status impacts on AAI-induced renal injury, but the underlying mechanism(s) involved remain to be further explored. Despite the impact of p53 on AAI bioactivation and DNA damage in vitro, such effects were not observed in vivo.

Pro-inflammatory and pro-thrombotic stimuli can activate endothelial cells (ECs) and predispose them to thrombotic microangiopathies (TMAs). Drug-induced TMA (DITMA) may occur in clinical practice during treatment with interferon-β1a (IFN-β1a), ciclosporin A (CsA), and gemcitabine (GEM). DITMA may also trigger the complement system and induce membrane attack complex (MAC, C5b-9) deposition in vivo , although their role and the benefit of inhibition remain unclear. In an experimental in vitro model of microvascular ECs exposed to these three drugs, we searched for MAC deposits and drug-specific pro-inflammatory and pro-thrombotic traits to gain insights into the mechanisms potentially involved in DITMA. Human microvascular endothelial cells line-1 (HMEC-1) was treated with 10% normal human serum, CsA, GEM, and IFN-β1a. Cell viability for each drug was measured using the resazurin assay. Cell component expression of the following markers involved in endothelial pathogenic activation was measured via immunofluorescence and flow cytometry: C5b-9, interleukin (IL)-1α, IL-6, E-selectin, platelet EC adhesion molecule-1 (PECAM-1), intercellular adhesion molecule-1 (ICAM-1), and von Willebrand factor (vWF). Levels of plasminogen activator inhibitor-1 (PAI-1) and urokinase plasminogen activator (uPA) were measured in the supernatants using the enzyme-linked immunosorbent assay (ELISA). Significantly increased C5b-9 deposits were found with each drug, and increased drug-specific activation marker expressions appeared in HMEC-1s when exposed to CsA (IL-1α, IL-6, ICAM-1, E-selectin, vWF, and uPA), GEM (IL-1α, IL-6, PECAM-1, ICAM-1, E-selectin, and vWF), and IFN-β1a (PECAM-1, ICAM-1, PAI-1, and uPA). Each drug induces MAC deposits on HMEC-1s and singular endothelial activation profiles, potentially leading to thrombogenesis observed in DITMA.