Multimodal spatial transcriptomic characterization of mouse kidney injury and repair.

The transition from acute kidney injury to chronic kidney disease is characterized by significant changes in the cellular composition and molecular interactions within the kidney. Utilizing high-resolution Xenium and whole transcriptome Visium spatial transcriptomics platforms, we analyze over a million cells on 12 male mouse kidneys across six stages of renal injury and repair. We define and validate 20 major kidney cell populations and delineate distinct cellular neighborhoods through this multimodal spatial analysis.

Podocyte-specific YAP activation triggers crescentic glomerulonephritis through cross-talk with parietal epithelial cells.

Crescentic glomerulonephritis (cGN) is a severe kidney pathology characterized by the aberrant proliferation of epithelial cells, leading to crescent formation within the Bowman's space. The molecular pathways involved in crescent formation remain poorly understood despite its clinical relevance. Given the mechanical stress experienced by podocytes, likely exacerbated in cGN, we hypothesized that activation of the mechanosensor yes-associated protein 1 (YAP), an effector of the Hippo pathway, may contribute to the development of cGN.

A Snake Toxin Derivative for Treatment of Hyponatremia and Polycystic Kidney Diseases.

Key Points: MQ232, a disulfide-bond reticulated peptide derived from a natural snake toxin, was optimized as a new aquaretic drug candidate. MQ232 showed very low acute and chronic toxicity in rat and a biodistribution in mice strongly in favor of the kidney organs. MQ232 induced a sole aquaretic effect and demonstrated high activities on hyponatremia and polycystic kidney disease models.

Successful prevention of BK-polyomavirus nephropathy using extracorporeal photopheresis for immunosuppression minimisation following severe BK polyomavirus replication after kidney transplantation in a double lung transplant recipient, a case report.

Background: BK-polyomavirus (BKpyV) nephropathy (BKVN) is associated with end-stage kidney disease in kidney and non-kidney solid organ transplantation, with no curative treatment.

Case Presentation: A 45-year-old woman with a past medical history of double lung transplantation subsequently developed end-stage kidney disease, of undetermined origin. One month after receiving a kidney transplant, a diagnosis of early BKVN was suspected, and in retrospect was a reasonable cause for the loss of her native kidneys.

Spatial Transcriptomics: Integrating Morphology and Molecular Mechanisms of Kidney Diseases.

The recent arrival of high-resolution spatial transcriptomics (ST) technologies is generating a veritable revolution in life sciences, enabling biomolecules to be measured in their native spatial context. By integrating morphology and molecular biology, ST technologies offer the potential of improving the understanding of tissue biology and disease and may also provide meaningful clinical insights. This review describes the main ST technologies currently available and the computational analysis for data interpretation and visualization, and illustrate their scientific and potential medical interest in the context of kidney disease.

Histopathologic Analysis of Human Kidney Spatial Transcriptomics Data: Toward Precision Pathology.

The application of spatial transcriptomics (ST) technologies is booming and has already yielded important insights across many different tissues and disease models. In nephrology, ST technologies have helped to decipher the cellular and molecular mechanisms in kidney diseases and have allowed the recent creation of spatially anchored human kidney atlases of healthy and diseased kidney tissues. During ST data analysis, the computationally annotated clusters are often superimposed on a histologic image without their initial identification being based on the morphologic and/or spatial analyses of the tissues and lesions.

PIK3CA inhibition in models of proliferative glomerulonephritis and lupus nephritis.

Proliferative glomerulonephritis is a severe condition that often leads to kidney failure. There is a significant lack of effective treatment for these disorders. Here, following the identification of a somatic PIK3CA gain-of-function mutation in podocytes of a patient, we demonstrate using multiple genetically engineered mouse models, single-cell RNA sequencing, and spatial transcriptomics the crucial role played by this pathway for proliferative glomerulonephritis development by promoting podocyte proliferation, dedifferentiation, and inflammation.

Effects of Hemorrhagic Shock and Rhabdomyolysis on Renal Microcirculation, Oxygenation, and Function in a Female Swine Model.

Background: Hemorrhagic shock (HS) and rhabdomyolysis (RM) are two important risk factors for acute kidney injury after severe trauma; however, the effects of the combination of RM and HS on kidney function are unknown. The purpose of this study was to determine the impact of RM and HS on renal function, oxygenation, perfusion, and morphology in a pig model.

Methods: Forty-seven female pigs were divided into five groups: sham, RM, HS, HS and moderate RM (RM4/HS), and HS and severe RM (RM8/HS).

Comparative histological analysis of spleens in pediatric patients with hemolytic anemias: Insights into the pathophysiological mechanisms of spleen destruction in sickle cell anemia.

While sickle cell anemia (SCA) and hereditary spherocytosis (HS) share common features of increased spleen erythrophagocytosis due to increased red blood cell (RBC) turnover, SCA is specifically characterized by susceptibility to infections. In this study, histological lesions in the spleens of pediatric patients with SCA were analyzed, in close correlation with past clinical history and comparatively to HS, healthy and transfused β-thalassemia patients (TDT). An evaluation of red pulp elementary lesions (red pulp fibrosis, iron deposition, number of Gandy-Gamna, and RBC trapping) combined into a severity score was established, as well as B-cell follicles analysis.

The AMPK-Sirtuin 1-YAP axis is regulated by fluid flow intensity and controls autophagy flux in kidney epithelial cells.

Shear stress generated by urinary fluid flow is an important regulator of renal function. Its dysregulation is observed in various chronic and acute kidney diseases. Previously, we demonstrated that primary cilium-dependent autophagy allows kidney epithelial cells to adapt their metabolism in response to fluid flow.

Combined germline and somatic human FADD mutations cause autoimmune lymphoproliferative syndrome.

Background: The autoimmune lymphoproliferative syndrome (ALPS) is a noninfectious and nonmalignant lymphoproliferative disease frequently associated with autoimmune cytopenia resulting from defective FAS signaling. We previously described germline monoallelic FAS (TNFRSF6) haploinsufficient mutations associated with somatic events, such as loss of heterozygosity on the second allele of FAS, as a cause of ALPS-FAS. These somatic events were identified by sequencing FAS in DNA from double-negative (DN) T cells, the pathognomonic T-cell subset in ALPS, in which the somatic events accumulated.

The spectrum of glomerular and vascular kidney pathology associated with myeloproliferative neoplasms.

A high prevalence of chronic kidney disease (CKD) occurs in patients with myeloproliferative neoplasms (MPN). However, MPN-related glomerulopathy (MPN-RG) may not account for the entirety of CKD risk in this population. The systemic vasculopathy encountered in these patients raises the hypothesis that vascular nephrosclerosis may be a common pattern of injury in patients with MPN and with CKD.

Mycobacterium canettii Tuberculosis Lymphadenopathy in a 3-Year-old Child.

A 3-year-old male originating from Djibouti presented with a cervical mass evolving for 2 months. Tuberculous lymphadenopathy was suspected based on biopsy results, and he improved quickly on standard antituberculous quadritherapy. Subsequently some features of the mycobacterium that grew in culture were unusual.

[Immunopathology of the small intestine].

The gastrointestinal tract is the site of exciting immunological interactions between the epithelium and the mucosa-associated lymphoid tissue, leading to the immune response to food and microbial antigens in the digestive lumen. The objective of this review is to present the main dysimmune pathologies of the digestive tract leading to an enteropathy. As examples, we describe celiac and non-celiac enteropathies to clarify a florid diagnostic framework, by identifying a spectrum of elementary lesions, which must be confronted with the clinico biological context of the patient to orient the diagnosis.

[Towards understanding chronic kidney disease].

Chronic kidney disease (CKD) is a global health problem affecting almost 15% of the population worldwide. After renal injury, there is a nephron loss and remaining nephrons ensure the glomerular filtration rate (GFR) with compensatory hyperplasia and hypertrophy: This is called the nephron reduction. After nephron reduction, renal function will gradually decline and lead to chronic end-stage renal failure.