miR-200 family promotes podocyte differentiation through repression of RSAD2

Profiling of five urinary exosomal miRNAs for the differential diagnosis of patients with diabetic kidney disease and focal segmental glomerulosclerosis

OBJECTIVE

The objective of this study is to investigate the diagnostic utility of microRNAs (miRNAs) for distinguishing between urine samples from patients with Diabetic Kidney Disease (DKD) and those with Focal Segmental Glomerulosclerosis (FSGS).

METHODS

In this multicentric, cross-sectional investigation, we enrolled patients diagnosed with DKD, individuals with primary biopsy-proven FSGS, and healthy controls. The top 5 miRNAs (hsa-mir-21, hsa-mir-30a, hsa-mir-193a, hsa-mir-196a, hsa-mir-200a) were selected to quantify miRNAs in urine samples. Isolation of targeted miRNAs was performed from urinary exosomes, and the quantitative profile of the isolated miRNAs was measured by RT-qPCR. The ΔΔCt method was implemented to calculate the fold differences between disease and control samples.

RESULTS

Thirteen DKD patients, 11 FSGS patients, and 14 healthy controls were included in this study. Hsa-mir-21 and hsa-mir-30a exhibited distinct regulation in both groups, with upregulation observed in FSGS and downregulation in DKD (hsa-mir-21 in DKD (0.668 ± 0.25, p < 0.0005) and FSGS (2.267 ± 1.138, p < 0.0077); hsa-mir-30a in DKD (0.874 ± 0.254, p = 0.079) and FSGS (1.378 ± 0.312, p < 0.0006)). Hsa-mir-193a exhibited significant dysregulation in DKD (1.017 ± 0.413, p < 0.029) but not in FSGS (4.18 ± 1.528, p = 0.058). Hsa-mir-196a and hsa-mir-200a showed upregulation in patient groups (hsa-mir-196a in DKD (1.278 ± 0.527, p = 0.074) and FSGS (2.47 ± 0.911, p < 0.0003); hsa-mir-200a in DKD (1.909 ± 0.825, p = 0.082) and FSGS (1.301 ± 0.358, p < 0.008)).

CONCLUSION

Specific miRNAs, particularly miR-21, miR-30a, miR-196a, and miR-200a, might play a role in the pathogenesis of kidney diseases and could potentially serve as biomarkers to distinguish between FSGS and DKD patients.

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

Transcriptome meta-analysis reveals the hair genetic rules in six animal breeds and genes associated with wool fineness

Wool plays an irreplaceable role in the lives of livestock and the textile industry. The variety of hair quality and shape leads to the diversity of its functions and applications, and the finer wool has a higher economic value. In this study, 10 coarse and 10 fine ordos fine wool sheep skin samples were collected for RNA-seq, and coarse and fine skin/hair follicle RNA-seq datasets of other five animal breeds were obtained from NCBI. Weighted gene co-expression network analysis showed that the common genes were clustered into eight modules. Similar gene expression patterns in sheep and rabbits with the same wool types, different gene expression patterns in animal species with different hair types, and brown modules were significantly correlated with species and breeds. GO and KEGG enrichment analyses showed that, most genes in the brown module associated with hair follicle development. Hence, gene expression patterns in skin tissues may determine hair morphology in animal. The analysis of differentially expressed genes revealed that 32 highly expressed candidate genes associated with the wool fineness of Ordos fine wool sheep. Among them, KAZALD1 (grey module), MYOC (brown module), C1QTNF6 (brown module), FOS (tan module), ITGAM, MX2, MX1, and IFI6 genes have been reported to be involved in the regulation of the hair follicle cycle or hair loss. Additionally, 12 genes, including KAZALD1, MYOC, C1QTNF6, and FOS, are differentially expressed across various animal breeds and species. The above results suggest that different sheep breeds share a similar molecular regulatory basis of wool fineness. Finally, the study provides a theoretical reference for molecular breeding of sheep breeds as well as for the investigation of the origin and evolution of animal hair.

Type I IFN in Glomerular Disease: Scarring beyond the STING

The field of nephrology has recently directed a considerable amount of attention towards the stimulator of interferon genes (STING) molecule since it appears to be a potent driver of chronic kidney disease (CKD). STING and its activator, the cyclic GMP-AMP synthase (cGAS), along with intracellular RIG-like receptors (RLRs) and toll-like receptors (TLRs), are potent inducers of type I interferon (IFN-I) expression. These cytokines have been long recognized as part of the mechanism used by the innate immune system to battle viral infections; however, their involvement in sterile inflammation remains unclear. Mounting evidence pointing to the involvement of the IFN-I pathway in sterile kidney inflammation provides potential insights into the complex interplay between the innate immune system and damage to the most sensitive segment of the nephron, the glomerulus. The STING pathway is often cited as one cause of renal disease not attributed to viral infections. Instead, this pathway can recognize and signal in response to host-derived nucleic acids, which are also recognized by RLRs and TLRs. It is still unclear, however, whether the development of renal diseases depends on subsequent IFN-I induction or other processes involved. This review aims to explore the main endogenous inducers of IFN-I in glomerular cells, to discuss what effects autocrine and paracrine signaling have on IFN-I induction, and to identify the pathways that are implicated in the development of glomerular damage.

MicroRNA193a: An Emerging Mediator of Glomerular Diseases

MicroRNAs (miRNAs) are noncoding small RNAs that regulate the protein expression of coding messenger RNAs. They are used as biomarkers to aid in diagnosing, prognosticating, and surveillance of diseases, especially solid cancers. MiR-193a was shown to be directly pathogenic in an experimental mouse model of focal segmental glomerulosclerosis (FSGS) during the last decade. Its specific binding and downregulation of Wilm's tumor-1 (WT-1), a transcription factor regulating podocyte phenotype, is documented. Also, miR-193a is a regulator switch causing the transdifferentiation of glomerular parietal epithelial cells to a podocyte phenotype in in vitro study. Interaction between miR-193a and apolipoprotein 1 (APOL1) mRNA in glomeruli (filtration units of kidneys) is potentially involved in the pathogenesis of common glomerular diseases. Since the last decade, there has been an increasing interest in the role of miR-193a in glomerular diseases, including diabetic nephropathy and membranous nephropathy, besides FSGS. Considering the lack of biomarkers to manage FSGS and diabetic nephropathy clinically, it is worthwhile to invest in evaluating miR-193a in the pathogenesis of these diseases. What causes the upregulation of miR-193a in FSGS and how the mechanism is different in different glomerular disorders still need to be elucidated. This narrative review highlights the pathogenic mechanisms of miR-193a elevation in various glomerular diseases and its potential use in clinical management.

The diverse roles of miRNAs in HIV pathogenesis: Current understanding and future perspectives

Despite noteworthy progress made in the management and treatment of HIV/AIDS-related disease, including the introduction of the now almost ubiquitous HAART, there remains much to understand with respect to HIV infection. Although some roles that miRNAs play in some diseases have become more obvious of late, the roles of miRNAs in the context of HIV pathogenesis have not, as yet, been elucidated, and require further investigations. miRNAs can either be beneficial or harmful to the host, depending upon the genes they target. Some miRNAs target the 3' UTR of viral mRNAs to accomplish restriction of viral infection. However, upon HIV-1 infection, there are several dysregulated host miRNAs which target their respective host factors to either facilitate or abrogate viral infection. In this review, we discuss the miRNAs which play roles in various aspects of viral pathogenesis. We describe in detail the various mechanisms thereby miRNAs either directly or indirectly regulate HIV-1 infection. Moreover, the predictive roles of miRNAs in various aspects of the HIV viral life cycle are also discussed. Contemporary antiretroviral therapeutic drugs have received much attention recently, due to their success in the treatment of HIV/AIDS; therefore, miRNA involvement in various aspects of antiretroviral therapeutics are also elaborated upon herein. The therapeutic potential of miRNAs are discussed, and we also propose herein that the therapeutic potential of one specific miRNA, miR-34a, warrants further exploration, as this miRNA is known to target three host proteins to promote HIV-1 pathogenesis. Finally, future perspectives and some controversy around the expression of miRNAs by HIV-1 are also discussed.

The Effect of miRNA Gene Regulation on HIV Disease

Over many years, research on HIV/AIDS has advanced with the introduction of HAART. Despite these advancements, significant gaps remain with respect to aspects in HIV life cycle, with specific attention to virus-host interactions. Investigating virus-host interactions may lead to the implementation of novel therapeutic strategies against HIV/AIDS. Notably, host gene silencing can be facilitated by cellular small non-coding RNAs such as microRNAs paving the way for epigenetic anti-viral therapies. Numerous studies have elucidated the importance of microRNAs in HIV pathogenesis. Some microRNAs can either promote viral infection, while others can be detrimental to viral replication. This is accomplished by targeting the HIV-proviral genome or by regulating host genes required for viral replication and immune responses. In this review, we report on 1) the direct association of microRNAs with HIV infection; 2) the indirect association of known human genetic factors with HIV infection; 3) the regulation of human genes by microRNAs in other diseases that can be explored experimentally to determine their effect on HIV-1 infection; and 4) therapeutic interactions of microRNA against HIV infection.

Chromatin Remodelers Interact with Eya1 and Six2 to Target Enhancers to Control Nephron Progenitor Cell Maintenance

BACKGROUND

Eya1 is a critical regulator of nephron progenitor cell specification and interacts with Six2 to promote NPC self-renewal. Haploinsufficiency of these genes causes kidney hypoplasia. However, how the Eya1-centered network operates remains unknown.

METHODS

We engineered a 2×HA-3×Flag-Eya1 knock-in mouse line and performed coimmunoprecipitation with anti-HA or -Flag to precipitate the multitagged-Eya1 and its associated proteins. Loss-of-function, transcriptome profiling, and genome-wide binding analyses for Eya1's interacting chromatin-remodeling ATPase Brg1 were carried out. We assayed the activity of the cis-regulatory elements co-occupied by Brg1/Six2 in vivo.

RESULTS

Eya1 and Six2 interact with the Brg1-based SWI/SNF complex during kidney development. Knockout of Brg1 results in failure of metanephric mesenchyme formation and depletion of nephron progenitors, which has been linked to loss of Eya1 expression. Transcriptional profiling shows conspicuous downregulation of important regulators for nephrogenesis in Brg1-deficient cells, including Lin28, Pbx1, and Dchs1-Fat4 signaling, but upregulation of podocyte lineage, oncogenic, and cell death-inducing genes, many of which Brg1 targets. Genome-wide binding analysis identifies Brg1 occupancy to a distal enhancer of Eya1 that drives nephron progenitor-specific expression. We demonstrate that Brg1 enrichment to two distal intronic enhancers of Pbx1 and a proximal promoter region of Mycn requires Six2 activity and that these Brg1/Six2-bound enhancers govern nephron progenitor-specific expression in response to Six2 activity.

CONCLUSIONS

Our results reveal an essential role for Brg1, its downstream pathways, and its interaction with Eya1-Six2 in mediating the fine balance among the self-renewal, differentiation, and survival of nephron progenitors.

MicroRNA-26a: An Emerging Regulator of Renal Biology and Disease

MicroRNAs (miRNAs) are short, single-stranded, noncoding RNAs that modulate many key biological processes by simultaneously suppressing multiple target genes. Among them, miR-26a, a conserved miRNA among vertebrates, is highly expressed in various tissues. Accumulating evidence demonstrates that miR-26a plays pivotal roles in cellular differentiation, cell growth, apoptosis, and metastasis, thereby participating in the initiation and development of various human diseases, such as metabolic disease and cancer. More recently, miR-26a was found as a versatile regulator of renal biology and disease. miR-26a is intensively involved in the maintenance of podocyte homeostasis and the actin cytoskeleton. It is also able to modulate the homeostasis and function of mesangial cells. In addition, miR-26a affects the expansion of regulatory T cells in the context of ischemia-reperfusion injury and autoimmune diabetes and thus protects the renal system from immune attack. These available data strongly suggest that renal miR-26a possesses critical pathological functions and represents a potential target for renal disease therapies. This review summarizes current knowledge of miR-26a in renal biology and disease, laying the foundation for exploring its previously unknown functions and mechanisms in the renal system.

Engineering renal epithelial cells: programming and directed differentiation towards glomerular podocyte's progenitor and mature podocyte

Current knowledge of normal developmental physiology and identification of specific cell types of the kidney at molecular levels enables us to generate various cells of the kidney. The generation of renal specialized cells in vitro with its correct molecular and functional implications is the urgent need for cellular therapy in chronic kidney diseases and for organ formation. Glomerular podocytes are one of the major renal cells lose its functionality to maintain glomerular blood filtration function. In vitro, many inductions or reprogramming methods have been established for podocytes development. In these methods transcription factors, small molecules, and growth factors play the major role to remodel stem cells into podocyte progenitors and towards mature podocytes. Micro ribonucleic acids (miRNAs) have been utilizing as another strategy to generate podocyte. In this review, current protocols for in vitro glomerular podocyte differentiation have summarized emphasizing programming methods, signaling modulation, and cytoskeletal changes. Novel ideas are also pointed out, which are required for efficient optimal glomerular podocyte generation and their functional characterization in vitro with nanoarchitecture impression of the glomerular basement membrane.

The antiviral protein viperin regulates chondrogenic differentiation via CXCL10 protein secretion

Viperin (also known as radical SAM domain–containing 2 (RSAD2)) is an interferon-inducible and evolutionary conserved protein that participates in the cell's innate immune response against a number of viruses. Viperin mRNA is a substrate for endoribonucleolytic cleavage by RNase mitochondrial RNA processing (MRP) and mutations in the RNase MRP small nucleolar RNA (snoRNA) subunit of the RNase MRP complex cause cartilage-hair hypoplasia (CHH), a human developmental condition characterized by metaphyseal chondrodysplasia and severe dwarfism. It is unknown how CHH-pathogenic mutations in RNase MRP snoRNA interfere with skeletal development, and aberrant processing of RNase MRP substrate RNAs is thought to be involved. We hypothesized that viperin plays a role in chondrogenic differentiation. Using immunohistochemistry, real-time quantitative PCR, immunoblotting, ELISA, siRNA-mediated gene silencing, plasmid-mediated gene overexpression, label-free MS proteomics, and promoter reporter bioluminescence assays, we discovered here that viperin is expressed in differentiating chondrocytic cells and regulates their protein secretion and the outcome of chondrogenic differentiation by influencing transforming growth factor β (TGF-β)/SMAD family 2/3 (SMAD2/3) activity via C-X-C motif chemokine ligand 10 (CXCL10). Of note, we observed disturbances in this viperin–CXCL10–TGF-β/SMAD2/3 axis in CHH chondrocytic cells. Our results indicate that the antiviral protein viperin controls chondrogenic differentiation by influencing secretion of soluble proteins and identify a molecular route that may explain impaired chondrogenic differentiation of cells from individuals with CHH.

Probing the changes in gene expression due to α-crystallin mutations in mouse models of hereditary human cataract

The mammalian eye lens expresses a high concentration of crystallins (α, β and γ-crystallins) to maintain the refractive index essential for lens transparency. Crystallins are long-lived proteins that do not turnover throughout life. The structural destabilization of crystallins by UV exposure, glycation, oxidative stress and mutations in crystallin genes leads to protein aggregation and development of cataracts. Several destabilizing mutations in crystallin genes are linked with human autosomal dominant hereditary cataracts. To investigate the mechanism by which the α-crystallin mutations Cryaa-R49C and Cryab-R120G lead to cataract formation, we determined whether these mutations cause an altered expression of specific transcripts in the lens at an early postnatal age by RNA-seq analysis. Using knock-in mouse models previously generated in our laboratory, in the present work, we identified genes that exhibited altered abundance in the mutant lenses, including decreased transcripts for Clic5, an intracellular water channel in Cryaa-R49C heterozygous mutant lenses, and increased transcripts for Eno1b in Cryab-R120G heterozygous mutant lenses. In addition, RNA-seq analysis revealed increased histones H2B, H2A, and H4 gene expression in Cryaa-R49C mutant lenses, suggesting that the αA-crystallin mutation regulates histone expression via a transcriptional mechanism. Additionally, these studies confirmed the increased expression of histones H2B, H2A, and H4 by proteomic analysis of Cryaa-R49C knock-in and Cryaa;Cryab gene knockout lenses reported previously. Taken together, these findings offer additional insight into the early transcriptional changes caused by Cryaa and Cryab mutations associated with autosomal dominant human cataracts, and indicate that the transcript levels of certain genes are affected by the expression of mutant α-crystallin in vivo.

Autophagy is involved in mouse kidney development and podocyte differentiation regulated by Notch signalling

Podocyte dysfunction results in glomerular diseases accounted for 90% of end-stage kidney disease. The evolutionarily conserved Notch signalling makes a crucial contribution in podocyte development and function. However, the underlying mechanism of Notch pathway modulating podocyte differentiation remains less obvious. Autophagy, reported to be related with Notch signalling pathways in different animal models, is regarded as a possible participant during podocyte differentiation. Here, we found the dynamic changes of Notch1 were coincided with autophagy: they both increased during kidney development and podocyte differentiation. Intriguingly, when Notch signalling was down-regulated by DAPT, autophagy was greatly diminished, and differentiation was also impaired. Further, to better understand the relationship between Notch signalling and autophagy in podocyte differentiation, rapamycin was added to enhance autophagy levels in DAPT-treated cells, and as a result, nephrin was recovered and DAPT-induced injury was ameliorated. Therefore, we put forward that autophagy is involved in kidney development and podocyte differentiation regulated by Notch signalling.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.

The Functions of MicroRNA-200 Family in Ovarian Cancer: Beyond Epithelial-Mesenchymal Transition

The majority of studies on microRNA-200 family members (miR-200s) in human cancers are based on the premise that miR-200s maintain epithelial cell integrity by suppressing epithelial-mesenchymal transition (EMT) through direct inhibition of mesenchymal transcription factors zinc finger E-box-binding homeobox 1/2 (ZEB1/ZEB2) and transforming growth factor-β (TGF-β), a potent inducer of EMT. Hence, downregulation of miR-200 in cancer cells promotes EMT and cancer metastasis. Yet, miR-200s are highly expressed in ovarian cancer, and ovarian cancer metastasizes primarily by dissemination within the pelvic cavity. In this review, we will refocus the epithelial property of ovarian cancer cells and the role of miR-200s in safeguarding this property, as well as the diverse roles of miR-200s in inclusion cyst formation, cancer cell growth, collective movement, angiogenesis, exosome-mediated cell communication, and chemoresponse. Taken together, miR-200s play a significant role in the initiation, progression and metastasis of ovarian cancer and may serve as diagnostic biomarkers and a target in therapeutic development.