Suppression of aldehyde dehydrogenase 2 in kidney proximal tubules contributes to kidney fibrosis through Transforming Growth Factor-ß signaling.

Chronic kidney disease (CKD) is an increasingly prevalent disorder that poses a significant global health and socioeconomic burden. East Asian countries such as China, Taiwan, Japan, and South Korea have a higher incidence and prevalence of kidney failure when compared to Western nations, and the reasons for this discrepancy remain unclear. Aldehyde dehydrogenase 2 (ALDH2) is an essential detoxifying enzyme for exogenous and endogenous aldehyde metabolism in mitochondria. Inactivating mutations at E504K and E487K are found in 35-45% of East Asian populations and has been linked to a higher risk of various disorders, including cardiovascular diseases and cancer. However, little is known about the role of ALDH2 in CKD. Here, we characterized the expression pattern of ALDH2 in normal and CKD human and mouse kidneys and demonstrated that ALDH2 expression was significantly reduced, and that the protein level was inversely correlated with the degree of CKD and fibrosis. Further, we treated ALDH2∗2 knock-in mice, a loss of ALDH2 function model, with aristolochic acid and found that these mice showed enhanced fibrosis. Moreover, ALDH2 deficiency was associated with kidney fibrosis involving epithelial cell differentiation process in vivo and in vitro. However, ALDH2 overexpression protected proximal tubule epithelial cells from transforming growth factor-ß-induced dedifferentiation or partial epithelial-mesenchymal transdifferentiation in vitro. Thus, our findings yield important clinical information regarding the development and progression of CKD involving ALDH2, especially among East Asian populations.

Analysis of banana plant health using machine learning techniques.

The Indian economy is greatly influenced by the Banana Industry, necessitating advancements in agricultural farming. Recent research emphasizes the imperative nature of addressing diseases that impact Banana Plants, with a particular focus on early detection to safeguard production. The urgency of early identification is underscored by the fact that diseases predominantly affect banana plant leaves. Automated systems that integrate machine learning and deep learning algorithms have proven to be effective in predicting diseases. This manuscript examines the prediction and detection of diseases in banana leaves, exploring various diseases, machine learning algorithms, and methodologies. The study makes a contribution by proposing two approaches for improved performance and suggesting future research directions. In summary, the objective is to advance understanding and stimulate progress in the prediction and detection of diseases in banana leaves. The need for enhanced disease identification processes is highlighted by the results of the survey. Existing models face a challenge due to their lack of rotation and scale invariance. While algorithms such as random forest and decision trees are less affected, initially convolutional neural networks (CNNs) is considered for disease prediction. Though the Convolutional Neural Network models demonstrated impressive accuracy in many research but it lacks in invariance to scale and rotation. Moreover, it is observed that due its inherent design it cannot be combined with feature extraction methods to identify the banana leaf diseases. Due to this reason two alternative models that combine ANN with scale-invariant Feature transform (SIFT) model or histogram of oriented gradients (HOG) combined with local binary patterns (LBP) model are suggested. The first model ANN with SIFT identify the disease by using the activation functions to process the features extracted by the SIFT by distinguishing the complex patterns. The second integrate the combined features of HOG and LBP to identify the disease thus by representing the local pattern and gradients in an image. This paves a way for the ANN to learn and identify the banana leaf disease. Moving forward, exploring datasets in video formats for disease detection in banana leaves through tailored machine learning algorithms presents a promising avenue for research.

Deletion of STAT3 from Foxd1 cell population protects mice from kidney fibrosis by inhibiting pericytes trans-differentiation and migration.

Signal transduction and activator of transcription 3 (STAT3) is a key transcription factor implicated in the pathogenesis of kidney fibrosis. Although Stat3 deletion in tubular epithelial cells is known to protect mice from fibrosis, vFoxd1 cells remains unclear. Using Foxd1-mediated Stat3 knockout mice, CRISPR, and inhibitors of STAT3, we investigate its function. STAT3 is phosphorylated in tubular epithelial cells in acute kidney injury, whereas it is expanded to interstitial cells in fibrosis in mice and humans. Foxd1-mediated deletion of Stat3 protects mice from folic-acid- and aristolochic-acid-induced kidney fibrosis. Mechanistically, STAT3 upregulates the inflammation and differentiates pericytes into myofibroblasts. STAT3 activation increases migration and profibrotic signaling in genome-edited, pericyte-like cells. Conversely, blocking Stat3 inhibits detachment, migration, and profibrotic signaling. Furthermore, STAT3 binds to the Collagen1a1 promoter in mouse kidneys and cells. Together, our study identifies a previously unknown function of STAT3 that promotes kidney fibrosis and has therapeutic value in fibrosis.

A novel antibody for the detection of alternatively spliced secreted KLOTHO isoform in human plasma.

αKlotho is primarily known to express as a transmembrane protein. Proteolytic cleavage results in shedding of the extracellular domain which enters systemic circulation. A truncated form of αKlotho resulting from alternative splicing of the αKLOTHO transcript exists and is believed to be secreted, thereby also entering systemic circulation. Existing ELISA methods fail to distinguish between the two circulating isoforms resulting in inconsistencies in assessing circulating αKlotho levels. We have exploited a unique 15aa peptide sequence present in the alternatively spliced secreted isoform to generate an antibody and show that it is able to specifically detect only the secreted Klotho isoform in human plasma. This finding will facilitate in distinguishing the levels of different circulating Klotho isoforms in health and disease and enhance their potential to serve as a biomarker for CKD and other conditions.

The axis of local cardiac endogenous Klotho-TGF-ß1-Wnt signaling mediates cardiac fibrosis in human.

BACKGROUND: Cardiovascular fibrosis is a major contributor to cardiovascular disease, the primary cause of death in patients with chronic kidney disease (CKD). We previously reported expression of endogenous Klotho in human arteries, and that CKD is a state of Klotho deficiency, resulting in vascular calcification, but myocardial expression of Klotho is poorly understood. This study aimed to further clarify endogenous Klotho's functional roles in cardiac fibrosis in patients with underlying CKD. METHODS AND RESULTS: Human atrial appendage specimens were collected during cardiac surgery from individuals with or without CKD. Cardiac fibrosis was quantified using trichrome staining. For endogenous Klotho functional studies, primary human cardiomyocytes (HCMs) were treated with uremic serum from CKD patients or recombinant human TGF-ß1. The effects of endogenous Klotho in HCMs were studied using Klotho-siRNA and Klotho-plasmid transfection. Both gene and protein expression of endogenous Klotho are found in human heart, but decreased Klotho expression is clearly associated with the degree of cardiac fibrosis in CKD patients. Moreover, we show that endogenous Klotho is expressed by HCMs and cardiac fibroblasts (HCFs) but that HCM expression is suppressed by uremic serum or TGF-ß1. Klotho knockdown or overexpression aggravates or mitigates TGF-ß1-induced fibrosis and canonical Wnt signaling in HCMs, respectively. Furthermore, co-culture of HCMs with HCFs increases TGF-ß1-induced fibrogenic proteins in HCFs, but overexpression of endogenous Klotho in HCMs mitigates this effect, suggesting functional crosstalk between HCMs and HCFs. CONCLUSIONS: Our data from analysis of human hearts as well as functional in vitro studies strongly suggests that the loss of cardiac endogenous Klotho in CKD patients, specifically in cardiomyocytes, facilitates intensified TGF-ß1 signaling which enables more vigorous cardiac fibrosis through upregulated Wnt signaling. Upregulation of endogenous Klotho inhibits pathogenic Wnt/ß-catenin signaling and may offer a novel strategy for prevention and treatment of cardiac fibrosis in CKD patients.

RNA-binding Protein Musashi Homologue 1 Regulates Kidney Fibrosis by Translational Inhibition of p21 and Numb mRNA.

RNA-binding proteins (RBPs) are recognized as key posttranscriptional regulators that not only modulate the spatiotemporal expression of genes during organism development but also regulate disease pathogenesis. Very limited information exists on the potential role of RBPs in modulating kidney fibrosis, which is a major hallmark of chronic kidney disease. Here, we report a novel mechanism in kidney fibrosis involving a RBP, Musashi homologue 1 (Msi1), which is expressed in tubular epithelial cells. Using two mechanistically distinct mouse models of kidney fibrosis, we show that Msi1 protein levels are significantly down-regulated in the kidneys following fibrosis. We found that Msi1 functions by negatively regulating the translation of its target mRNAs, p21 and Numb, whose protein levels are markedly increased in kidney fibrosis. Also, Msi1 overexpression and knockdown in kidney epithelial cells cause p21- and Numb-mediated cell cycle arrest. Furthermore, we observed that Numb looses its characteristic membrane localization in fibrotic kidneys and therefore is likely unable to inhibit Notch resulting in tubular cell death. Oleic acid is a known inhibitor of Msi1 and injecting oleic acid followed by unilateral ureteral obstruction surgery in mice resulted in enhanced fibrosis compared with the control group, indicating that inhibiting Msi1 activity renders the mice more susceptible to fibrosis. Given that deregulated fatty acid metabolism plays a key role in kidney fibrosis, these results demonstrate a novel connection between fatty acid and Msi1, an RNA-binding protein, in kidney fibrosis.

Multiple maternal proteins coordinate to restrict the translation of C. elegans nanos-2 to primordial germ cells.

Although germ cell formation has been relatively well understood in worms and insects, how germ cell-specific developmental programs are initiated is not clear. In Caenorhabditis elegans, translational activation of maternal nos-2 mRNA is the earliest known molecular event specific to the germline founder cell P(4). Cis-elements in nos-2 3'UTR have been shown to mediate translational control; however, the trans-acting proteins are not known. Here, we provide evidence that four maternal RNA-binding proteins, OMA-1, OMA-2, MEX-3 and SPN-4, bind nos-2 3'UTR to suppress its translation, and POS-1, another maternal RNA-binding protein, relieves this suppression in P(4). The POS-1: SPN-4 ratio in P(4) increases significantly over its precursor, P(3); and POS-1 competes with SPN-4 for binding to nos-2 RNA in vitro. We propose temporal changes in the relative concentrations of POS-1 and SPN-4, through their effect on the translational status of maternal mRNAs such as nos-2, initiate germ cell-specific developmental programs in C. elegans.