Bone marrow-derived cells contribute to podocyte regeneration and amelioration of renal disease in a mouse model of Alport syndrome.

In a model of autosomally recessive Alport syndrome, mice that lack the alpha3 chain of collagen IV (Col4alpha3(-/-)) develop progressive glomerular damage leading to renal failure. The proposed mechanism is that podocytes fail to synthesize normal glomerular basement membrane, so the collagen IV network is unstable and easily degraded. We used this model to study whether bone marrow (BM) transplantation can rectify this podocyte defect by correcting the deficiency in Col4alpha3. Female C57BL/6 Col4alpha3(-/-) (-/-) mice were transplanted with whole BM from male wild-type (+/+) mice. Control female -/- mice received BM from male -/- littermates. Serum urea and creatinine levels were significantly lower in recipients of +/+ BM compared with those of -/- BM 20 weeks post-transplant. Glomerular scarring and interstitial fibrosis were also significantly decreased. Donor-derived cells were detected by in situ hybridization (ISH) for the Y chromosome, and fluorescence and confocal microscopy indicated that some showed an apparent podocyte phenotype in mice transplanted with +/+ BM. Glomeruli of these mice showed small foci of staining for alpha3(IV) protein by immunofluorescence. alpha3(IV) mRNA was detectable by reverse transcription-polymerase chain reaction and ISH in some mice transplanted with +/+ BM but not -/- BM. However, a single injection of mesenchymal stem cells from +/+ mice to irradiated -/- recipients did not improve renal disease. Our data show that improved renal function in Col4alpha3(-/-) mice results from BM transplantation from wild-type donors, and the mechanism by which this occurs may in part involve generation of podocytes without the gene defect

Bone marrow-derived cells do not contribute significantly to collagen I synthesis in a murine model of renal fibrosis.

Interstitial fibroblasts play a central role in kidney fibrosis. Their origin is debated, with recent data indicating a contribution of bone marrow (BM)-derived cells to the expanded population of interstitial cells after kidney damage in animals and humans. This study investigated whether these BM-derived cells would respond appropriately to a fibrotic drive by producing collagen. A transgenic mouse that expresses both luciferase and beta-galactosidase reporter molecules under the control of a 17-kb promoter and enhancer element of the gene encoding the alpha2 chain of the collagen I was used. Male transgenic BM was transplanted into female wild-type C57BL/6 mice (n=14), and unilateral ureteric obstruction was performed later to induce renal fibrosis. In the obstructed kidney of the BM-chimeric female mice, a mean of 8.6% of smooth muscle actin-positive interstitial cells were Y chromosome positive. Increased collagen I mRNA in the obstructed kidney was detected by in situ hybridization. No luciferase activity was detected by enzyme assays in tissue homogenates of BM recipients, and very few luciferase mRNA transcripts were seen, mainly in tubular cells. beta-Galactosidase activity was not a useful reporter molecule because it could not be distinguished from enhanced endogenous beta-galactosidase activity in the obstructed kidney. These results indicate that BM-derived interstitial cells do not make a significant contribution to collagen I synthesis in the context of renal injury

A 3-miRNA Signature Enables Risk Stratification in Glioblastoma Multiforme Patients with Different Clinical Outcomes

Malignant gliomas constitute a complex disease phenotype that demands optimum decision-making as they are highly heterogeneous. Such inter-individual variability also renders optimum patient stratification extremely difficult. microRNA (hsa-miR-20a, hsa-miR-21, hsa-miR-21) expression levels were determined by RT-qPCR, upon FFPE tissue sample collection of glioblastoma multiforme patients (n = 37). In silico validation was then performed through discriminant analysis. Immunohistochemistry images from biopsy material were utilized by a hybrid deep learning system to further cross validate the distinctive capability of patient risk groups. Our standard-of-care treated patient cohort demonstrates no age- or sex- dependence. The expression values of the 3-miRNA signature between the low- (OS > 12 months) and high-risk (OS < 12 months) groups yield a p-value of <0.0001, enabling risk stratification. Risk stratification is validated by a. our random forest model that efficiently classifies (AUC = 97%) patients into two risk groups (low- vs. high-risk) by learning their 3-miRNA expression values, and b. our deep learning scheme, which recognizes those patterns that differentiate the images in question. Molecular-clinical correlations were drawn to classify low- (OS > 12 months) vs. high-risk (OS < 12 months) glioblastoma multiforme patients. Our 3-microRNA signature (hsa-miR-20a, hsa-miR-21, hsa-miR-10a) may further empower glioblastoma multiforme prognostic evaluation in clinical practice and enrich drug repurposing pipelines