MicroRNA deregulation is a consistent feature of glioblastoma, yet the biological effect of each single gene is generally modest, and therapeutically negligible. Here we describe a module of microRNAs, constituted by miR-124, miR-128 and miR-137, which are co-expressed during neuronal differentiation and simultaneously lost in gliomagenesis. Each one of these miRs targets several transcriptional regulators, including the oncogenic chromatin repressors EZH2, BMI1 and LSD1, which are functionally interdependent and involved in glioblastoma recurrence after therapeutic chemoradiation. Synchronizing the expression of these three microRNAs in a gene therapy approach displays significant anticancer synergism, abrogates this epigenetic-mediated, multi-protein tumor survival mechanism and results in a 5-fold increase in survival when combined with chemotherapy in murine glioblastoma models. These transgenic microRNA clusters display intercellular propagation in vivo, via extracellular vesicles, extending their biological effect throughout the whole tumor. Our results support the rationale and feasibility of combinatorial microRNA strategies for anticancer therapies.
Crescentic glomerulonephritis is characterized by vascular necrosis and parietal epithelial cell hyperplasia in the space surrounding the glomerulus, resulting in the formation of crescents. Little is known about the molecular mechanisms driving this process. Inducing crescentic glomerulonephritis in two Pax2Cre reporter mouse models revealed that crescents derive from clonal expansion of single immature parietal epithelial cells. Preemptive and delayed histone deacetylase inhibition with panobinostat, a drug used to treat hematopoietic stem cell disorders, attenuated crescentic glomerulonephritis with recovery of kidney function in the two mouse models. Three-dimensional confocal microscopy and stimulated emission depletion superresolution imaging of mouse glomeruli showed that, in addition to exerting an anti-inflammatory and immunosuppressive effect, panobinostat induced differentiation of an immature hyperplastic parietal epithelial cell subset into podocytes, thereby restoring the glomerular filtration barrier. Single-cell RNA sequencing of human renal progenitor cells in vitro identified an immature stratifin-positive cell subset and revealed that expansion of this stratifin-expressing progenitor cell subset was associated with a poor outcome in human crescentic glomerulonephritis. Treatment of human parietal epithelial cells in vitro with panobinostat attenuated stratifin expression in renal progenitor cells, reduced their proliferation, and promoted their differentiation into podocytes. These results offer mechanistic insights into the formation of glomerular crescents and demonstrate that selective targeting of renal progenitor cells can attenuate crescent formation and the deterioration of kidney function in crescentic glomerulonephritis in mice.
12 November 2021 in Nephrology Dialysis Transplantation
Acute kidney injury (AKI) is a life-threatening condition characterized by a rapid and transient decrease in kidney function. AKI is part of an array of conditions collectively defined as acute kidney diseases (AKD). In AKD, persistent kidney damage and dysfunction lead to chronic kidney disease (CKD) over time. A variety of insults can trigger AKI; however, chemotherapy-associated nephrotoxicity is increasingly recognized as a significant side effect of chemotherapy. New biomarkers are urgently needed to identify patients at high risk of developing chemotherapy-associated nephrotoxicity and subsequent AKI. However, a lack of understanding of cellular mechanisms that trigger chemotherapy-related nephrotoxicity has hindered the identification of effective biomarkers to date. In this review, we aim to (1) describe the known and potential mechanisms related to chemotherapy-induced AKI; (2) summarize the available biomarkers for early AKI detection, and (3) raise awareness of chemotherapy-induced AKI.
Primary Sjögren’s disease is primarily driven by B-cell activation and is associated with a high risk of developing non-Hodgkin’s lymphoma (NHL). Over the last few decades, microRNA-155 (miR-155) has arisen as a key regulator of B-cells. Nevertheless, its role in primary Sjögren’s disease remains elusive. Thus, the purpose of this study was (i) to explore miR-155, B-cell activating factor (BAFF)-receptor (BAFF-R), and Interleukin 6 receptor (IL-6R) expression in the labial salivary glands (LSG) of patients with primary Sjögren’s disease, aiming to identify potential B-cell activation biomarkers related to NHL development. Twenty-four patients with primary Sjögren’s disease, and with available tissue blocks from a LSG biopsy performed at diagnosis, were enrolled. Among them, five patients developed B-cell NHL during follow-up (7.3 ± 3.1 years). A comparison group of 20 individuals with sicca disease was included. Clinical and laboratory parameters were recorded and the LSG biopsies were evaluated to assess local inflammation in terms of miR-155/BAFF-R and IL-6R expression. Stratifying the primary Sjögren’s disease cohort according to lymphomagenesis, miR-155 was upregulated in primary Sjögren’s disease patients who experienced NHL, more so than those who did not experience NHL. Moreover, miR-155 expression correlated with the focus score (FS), as well as BAFF-R and IL-6R expression, which were increased in primary Sjögren’s disease patients and in turn related to neoplastic evolution. In conclusion, epigenetic modulation may play a crucial role in the aberrant activation of B-cells in primary Sjögren’s disease, profoundly impacting the risk of NHL development.