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. In this review, we describe 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. Finally, we discuss the perspectives and challenges of these booming new technologies.
Cholangiocarcinoma (CCA) and other liver cancer subtypes often develop in damaged organs. Physiological agents or extrinsic factors, like toxins, can induce cell death in such tissues, triggering compensatory proliferation and inflammation. Depending on extracellular and intracellular factors, different mechanisms, like apoptosis, necroptosis, ferroptosis, or autophagy, can be triggered. Each of them can lead to protumorigenic or anti-tumorigenic events within a cell or through regulation of the microenvironment. However, the exact role of each cell death mechanism in CCA onset, progression, and treatment is not well known. Here, we summarize current knowledge of different cell death mechanisms in patients with CCA and preclinical CCA research. We discuss cell death-related drugs with relevance to CCA treatment and how they could be used in the future to improve targeted CCA therapy.
Cholangiocarcinomas (CCAs) are a heterogeneous group of malignant tumors that originate from the biliary tract. They are usually diagnosed in advanced stages, leading to a dismal prognosis for affected patients. As CCA often arises as a sporadic cancer in individuals lacking specific risk factors or with heterogeneous backgrounds, and there are no defined high-risk groups, the implementation of effective surveillance programs for CCA is problematic. The identification and validation of new biomarkers useful for risk stratification, diagnosis, prognosis, and prediction of treatment response remains an unmet need for patients with CCA, even though numerous studies have been conducted lately to try to discover and validate CCA biomarkers. In this review, we overview the available information about the different types of biomarkers that have been investigated in recent years using minimally invasive biospecimens (blood, serum/plasma, bile, and urine) and their potential usefulness in diagnosis, prognosis, and risk stratification. It is widely accepted that early detection of CCA will impact patients' outcomes, by improving survival rates, quality of life, and the possibility of less invasive and/or curative treatments; however, challenges to its translation and clinical application for patients with CCA need to be resolved.
Chronic kidney disease (CKD) and its subset diabetic kidney disease are progressive conditions that affect >850 million people worldwide. Diabetes, hypertension, and glomerulonephritis are the most common causes of CKD, which is associated with significant patient morbidity and an increased risk of cardiovascular events, such as heart failure, ultimately leading to premature death. Despite newly approved drugs, increasing evidence shows that patients respond to treatment differently given the complexity of disease heterogeneity and complicated pathophysiology. This review article presents an integrative approach to understanding and addressing CKD through the lens of precision medicine and therapeutics. Leveraging advancements in single-cell omics technologies and artificial intelligence, we can explore the intricate cellular mechanisms underlying CKD and diabetic kidney disease pathogenesis. By dissecting the cellular heterogeneity and identifying rare cell populations using single-cell approaches, it will be possible to uncover novel therapeutic targets and biomarkers for personalized treatment strategies. Finally, we discuss the potential of artificial intelligence-driven analyses in predicting disease progression and treatment response, thereby paving the way for tailored interventions.
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 at work in kidney diseases and have allowed the recent creation of spatially anchored human kidney atlases in healthy and diseased kidney tissues. During ST data analysis, the obtained computationally annotated clusters are often superimposed on a histologic image without their initial identification being based on the morphologic and spatial analyses of the tissues and lesions. In this study, we conduct a histopathologic-based analysis of ST data on a human kidney sample corresponding as closely as possible to the reality of the interpretation of a kidney biopsy sample in a health care or research context. This study shows the feasibility of a morphology-based approach to interpreting ST data, helping to improve our understanding of the lesion phenomena at work in chronic kidney disease at both the cellular and the molecular level. Finally, we show that our newly identified pathology-based clusters can be accurately projected onto other slides from nephrectomy or needle biopsy samples. They thus serve as a reference for analyzing other kidney tissues, paving the way for the future of molecular microscopy and precision pathology.
Adoptive cellular therapy using chimeric antigen receptors (CARs) has transformed immunotherapy by engineering T cells to target specific antigens on tumor cells. As the field continues to advance, pathology laboratories will play increasingly essential roles in the complicated multi-step process of CAR T-cell therapy. These include detection of targetable tumor antigens by flow cytometry or immunohistochemistry at the time of disease diagnosis and the isolation and infusion of CAR T cells. Additional roles include: i) detecting antigen loss or heterogeneity that renders resistance to CAR T cells as well as identifying alternative targetable antigens on tumor cells, ii) monitoring the phenotype, persistence, and tumor infiltration properties of CAR T cells and the tumor microenvironment for factors that predict CAR T-cell therapy success, and iii) evaluating side effects and biomarkers of CAR T-cell cytotoxicity such as cytokine release syndrome. This review highlights existing technologies that are applicable to monitoring CAR T-cell persistence, target antigen identification, and loss. Also discussed are emerging technologies that address new challenges such as how to put a brake on CAR T cells. Although pathology laboratories have already provided companion diagnostic tests important in immunotherapy (eg, programmed death-ligand 1, microsatellite instability, and human epidermal growth factor receptor 2 testing), it draws attention to the exciting new translational research opportunities in adoptive cellular therapy.
Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by pulmonary fibroblast overactivation, resulting in the accumulation of abnormal extracellular matrix and lung parenchymal damage. Although the pathogenesis of IPF remains unclear, aging was proposed as the most prominent nongenetic risk factor. Propionate metabolism undergoes reprogramming in the aging population, leading to the accumulation of the by-product methylmalonic acid (MMA). This study aimed to explore alterations in propionate metabolism in IPF and the impact of the by-product MMA on pulmonary fibrosis. It revealed alterations in the expression of enzymes involved in propionate metabolism within IPF lung tissues, characterized by an increase in propionyl-CoA carboxylase and methylmalonyl-CoA epimerase expression, and a decrease in methylmalonyl-CoA mutase expression. Knockdown of methylmalonyl-CoA mutase, the key enzyme in propionate metabolism, induced a profibrotic phenotype and activated co-cultured fibroblasts in A549 cells. MMA exacerbated bleomycin-induced mouse lung fibrosis and induced a profibrotic phenotype in both epithelial cells and fibroblasts through activation of the canonical transforming growth factor-β/Smad pathway. Overall, these findings unveil an alteration of propionate metabolism in IPF, leading to MMA accumulation, thus exacerbating lung fibrosis through promoting profibrotic phenotypic transitions via the canonical transforming growth factor-β/Smad signaling pathway.
Pulmonary arterial hypertension (PAH) is a sex-biased disease with female sex as a significant risk factor. Increased expression of the long noncoding RNA X-inactive–specific transcript (Xist), as induced by an intersectin-1s protein fragment with proliferative potential (EHITSN), may explain the sexual dimorphism of female pulmonary artery endothelial cells (ECs) and at least in part, the imbalance sex/ratio of PAH. Xist is essential for X-chromosome inactivation and dosage compensation of X-linked genes. Herein, increased Xist expression was detected in a subset of ECs and lung tissue samples of male patients with PAH. The role of different Xist expression levels in ECs of male patients with PAH (ECPAH) was studied in several lines of male ECPAH in conjunction with molecular, biochemical, morphologic, and functional approaches. Male ECPAH showed on average 10.3-fold increase in high Xist versus low Xist, a significant association between Xist levels and their proliferative potential, and a heterogeneous methylation of the Xist/XIST antisense RNA (Tsix) locus. Interestingly, Xist up-regulation in male ECPAH decreased the expression of Krueppel-like factor 2 (Klf2), via EHITSN interaction with enhancer of zeste polycomb repressive complex 2 subunit (EZH2), the catalytic subunit of the polycomb repressive complex 2. Moreover, the studies demonstrate that EHITSN-triggered p38/ETS domain-containing protein Elk1/AP-1 transcription factor subunit (c-Fos) signaling is a pathologic mechanism central to ECPAH proliferation and the dynamic crosstalk with cell cycle regulatory proteins cyclin A1/cyclin D2 and Xist-EZH2-Klf2 interaction participate directly and differentially in establishing the proliferative profile of male ECPAH.