Epidermal growth factor receptor activation is essential for kidney fibrosis development

Therapeutic opportunities in polycystic kidney and liver disease through extracellular matrix dynamics

Autosomal Dominant and Autosomal Recessive Polycystic Kidney Disease (ADPKD and ARPKD) are, respectively, common and rare forms of polycystic disorders, characterized by the formation and progressive growth of cysts from tubules in the kidneys and bile ducts in the liver. Alterations in the extracellular matrix (ECM) and in the activity of matrix metalloproteases (MMPs), both associated with fibrosis, have been shown to be important factors in cystic growth and progression of these diseases. We used tandem mass spectrometry (LC-MS/MS) to identify the most enriched proteins and pathways in an orthologous rapidly progressive mouse model of ADPKD: Pkd1flox/floxTamCre. This information was used to discover and validate novel therapeutic targets in orthologous models of ADPKD (Pkd1flox/floxTamCre) and ARPKD (Pkdh1del3-4/del3-4). ECM related pathways and expression levels of MMPs were among the most dysregulated cellular processes in polycystic kidney and liver. Selective inhibition of MMPs by marimastat (MTT) altered the ECM response and resulted in inhibition of collecting duct-derived cyst growth, delay of global kidney cyst progression and rescue of liver phenotype by normalized MMPs expression and significant reduction in fibrosis. This phenotypic improvement was further enhanced by treatment of MTT and tolvaptan, indicating an additive benefit to targeting the fibrotic and growth pathways in cysts. As conclusion, targeting of MMPs are important in ECM dysregulation and offers a new potential therapeutic strategy for both kidney and bile duct derived fibrocystic disease in ADPKD and ARPKD. Such approaches can have additive benefits with other treatment approaches, such as tolvaptan.

Procyanidin C1 ameliorates aging-related skin fibrosis through targeting EGFR to inhibit TGFβ/SMAD pathway

BACKGROUND

Aging-related skin fibrosis (SF) is a complex condition with limited treatment options. Procyanidin C1 (PCC1), a natural polyphenolic compound with demonstrated senolytic activity, has emerged as a potential therapeutic agent for fibrotic disorders through its selective elimination of senescent cells. However, its therapeutic efficacy and mechanisms in aging-related SF remain unclear.

PURPOSE

This study aimed to investigate the mechanisms of PCC1 in aging-related SF.

RESULTS

In D-galactose-induced L929 cells, PCC1 treatment significantly attenuated the expression of both senescence-associated markers (IL-1β, P16, P21 and LMNB1) and fibrosis-related markers (α-SMA, LOXL2 and COL1). Network pharmacology and experimental validation (molecular docking, DARTS, CETSA, MST) identified EGFR as a primary target, with PCC1 directly binding to and inhibiting EGFR phosphorylation. Furthermore, PCC1 treatment effectively down-regulated TGFβ1 expression and suppressed SMAD2/3 phosphorylation in D-galactose-induced L929 cells. Notably, PCC1 blocked NSC228155-induced EGFR phosphorylation and inhibited ERK/MAPK, AKT/mTOR and TGFβ/SMAD pathway activation. In bleomycin-induced SF mice, PCC1 significantly attenuated epidermal hyperplasia, improved collagen structure, restored the collagen I/III ratio, and reduced EGFR phosphorylation along with TGFβ1 expression and SMAD2/3 phosphorylation.

CONCLUSION

This study elucidates that PCC1 exerts its anti-fibrotic effects through dual mechanisms: resistance to cellular senescence and modulation of fibroblast heterogeneity. By directly binding to EGFR and inhibiting its phosphorylation, PCC1 subsequently suppresses multiple downstream signaling cascades, ultimately ameliorating TGFβ/SMAD-mediated SF. These findings establish PCC1 as a promising therapeutic candidate for aging-related skin fibrosis, offering a novel approach through targeted EGFR inhibition and comprehensive pathway modulation.

Targeting STING and protecting mitochondrial function with Nephropathy Ⅱ decoction to alleviate renal fibrosis

BACKGROUND

Nephrology II Decoction (NED), a compound from traditional Chinese medicine, has been used in the clinical treatment of chronic kidney disease (CKD) for a long time. However, the specific active ingredients and the mechanisms by which they operate are not yet fully understood.

OBJECTIVE

The study aims to explore how NED eases CKD, with an emphasis on its influence on stimulator of interferon genes (STING)-mediated mitochondrial balance within kidney cells.

METHODS

Various CKD mouse models, including folic acid nephropathy (FAN), unilateral ureteral obstruction (UUO), and bilateral renal ischemia-reperfusion injury (bIRI), were administered with NED via oral gavage for three weeks. This study evaluated kidney function, pathological alterations, and fibrosis markers (fibronectin, collagen I, TGF-β, α-SMA) were assessed. Bulk RNA-sequencing of kidney tissues identified key targets, with molecular docking, dynamics simulations, and microscale thermophoresis were used to predict active components and pathways. These components and pathways were confirmed in renal tissues from CKD mice and renal tubular cells induced by folic acid. Additionally, oxidative stress induced by Tert‑butyl hydroperoxide (t-BHP) in HK2 cells was used to replicate CKD-induced renal fibrosis in vitro.

RESULTS

NED significantly improved renal function, reduced pathological damage, and decreased fibrosis in mice with CKD. Bulk RNA-seq identified STING as a pivotal target, and molecular docking demonstrated a strong binding affinity between NED's active components and murine STING. NED inhibited the cGAS/STING/TBK1/IRF3/IFN-β pathway, thereby alleviating renal fibrosis. It also corrected defects in mitochondrial oxidative phosphorylation, diminished inflammatory responses, and reduced apoptosis in fibrotic kidneys. In vitro, NED prevented mitochondrial DNA leakage induced by t-BHP, preserved mitochondrial function, and suppressed STING activation. STING inhibitor C176 effectively reduced fibrosis in both FAN mice and folic acid -induced cells, whereas the STING agonist DMXAA intensified fibrosis. There were potential interactions observed when DMXAA was combined with NED.

CONCLUSIONS

This study clarified the anti-fibrotic mechanisms of NED through the cGAS/STING pathway, highlighting STING as a primary target and the involvement of mitochondrial phosphorylation. NED appears to be a promising candidate for the treatment of CKD and reductions of renal fibrosis.

CD133+CD24+ Renal Tubular Progenitor Cells Drive Hypoxic Injury Recovery via Hypoxia-Inducible Factor-1A and Epidermal Growth Factor Receptor Expression

CD133+CD24+ renal tubular progenitor cells play a crucial role in the repair and regeneration of renal tubules after acute kidney injury. The aim of this study is to investigate the responses of the human renal tubular precursor TERT (HRTPT) CD133+CD24+ cells and human renal epithelial cell 24 TERT (HREC24T) CD133-CD24+ cells to hypoxic stress, as well as their gene expression profiles. Whole transcriptome sequencing and functional network analysis identified distinct molecular characteristics of HRTPT cells as they were enriched with hypoxia-inducible factor-1A (HIF1A), epidermal growth factor (EGF), and endothelin-1 (EDN1). Our in vitro experiments demonstrated that, under hypoxia (2.5% oxygen), HRTPT cells showed minimal cell death and a 100-fold increase in HIF1A protein levels. In contrast, HREC24T cells exhibited significant cell death and only a two-fold increase in HIF1A protein level. These results indicate that CD133+CD24+ renal tubular progenitor cells have enhanced survival mechanisms under hypoxic stress, enabling them to survive and proliferate to replace damaged tubular cells. This study provides novel insights into the protective role of CD133+CD24+ renal tubular progenitor cells in hypoxic renal injury and identifies their potential survival mechanisms.

The roles of the ubiquitin-proteasome system in renal disease

The ubiquitin-proteasome system (UPS) is a major pathway of specific intracellular protein degradation through proteasome degradation of ubiquitin-labeled substrates. Numerous biological processes, including the cell cycle, transcription, translation, apoptosis, receptor activity, and intracellular signaling, are regulated by UPS. Alterations of the UPS, which render them more or less susceptible to degradation, are responsible for disorders of renal diseases. This review aims to summarize the mechanism of UPS in renal diseases. Besides, this review explores the relationship among UPS, autophagy, and deubiquitination in the development of renal disease. The specific molecular linkages among these systems and pathogenesis, on the other hand, are unknown and controversial. In addition, we briefly describe some anti-renal disease agents targeting UPS components. This review emphasizes UPS as a promising therapeutic modality for the treatment of kidney disease. Our work, though still basic and limited, could provide options to future potential therapeutic targets for renal diseases with a UPS underlying basis.

Revealing the Mechanisms of Shikonin Against Diabetic Wounds: A Combined Network Pharmacology and In Vitro Investigation

Background: Shikonin (SHK) possesses extensive pharmacological effects including antimicrobial and anti-inflammatory properties for diabetic wound (DW), while its molecular mechanism remains to be clarified. In this study, we investigated the potential mechanisms of SHK in treating DW by combining network pharmacology and in vitro experiments. Methods: We obtained potential targets for SHK and DW from the publicly available database. Based on the interaction network and conducting GO and KEGG pathway enrichment analysis, we constructed a target pathway network to explore the relationship between SHK and DW. To validate the mechanism of SHK, we established an in vitro experimental model. Results: Sixty intersecting targets between SHK and DW were obtained, and the top 10 targets of the protein-protein interaction (PPI) network included AKT1, SRC, EGFR, CASP3, MMP9, PPARG, ESR1, ANXA5, MMP2, and JAK2. Based on target-pathway networks, the PI3K-AKT signaling pathway was found to be a signaling pathway with low p value in enrichment analysis. In vitro experiments revealed that SHK significantly promoted angiogenesis. Meanwhile, SHK could inhibit the high glucose-induced human umbilical vein endothelial cell dysfunction through regulating the PI3K-AKT pathway. Conclusion: This study initially revealed the molecular mechanism of SHK in DW by multitarget and multipathway. The PI3K-AKT signaling pathway, MAPK signaling pathway, and AGE-RAGE signaling pathways may be the main pathways of SHK in treating DW.

Genetic and molecular drivers of scleroderma pathogenesis

Scleroderma is a heterogeneous disease with various clinical findings involving immune dysregulation, vasculopathy, and fibrosis. Biological and genetic studies over recent decades have elucidated molecular mechanisms of scleroderma pathogenesis. Genetic association studies have identified interferon and other immune regulatory genes as strongly linked to scleroderma risk, highlighting the immune system as a fundamental determinant of disease. Human and murine biological studies have identified growth factor signaling as a central feature linking tissue damage to the clinical phenotype. Growth factors activated in vascular endothelial cells overlap with those of other diseases having vascular abnormalities, such as hereditary hemorrhagic telangiectasia. Activated growth factor receptors in fibroblasts drive excessive collagen expression in the skin and lungs. Because growth factor signaling is overactivated in multiple malignancies, biological insights and therapeutic approaches may be translated from oncology to understand scleroderma better. Enhanced understanding of the molecular drivers of scleroderma pathogenesis has given greater insight into patient phenotypes and new therapeutic approaches, including those that target immune and growth factor signaling.

Early prediction of preeclampsia using the first trimester vaginal microbiome

Preeclampsia is a severe obstetrical syndrome which contributes to 10-15% of all maternal deaths. Although the mechanisms underlying systemic damage in preeclampsia-such as impaired placentation, endothelial dysfunction, and immune dysregulation-are well studied, the initial triggers of the condition remain largely unknown. Furthermore, although the pathogenesis of preeclampsia begins early in pregnancy, there are no early diagnostics for this life-threatening syndrome, which is typically diagnosed much later, after systemic damage has already manifested. Here, we performed deep metagenomic sequencing and multiplex immunoassays of vaginal samples collected during the first trimester from 124 pregnant individuals, including 62 who developed preeclampsia with severe features. We identified multiple significant associations between vaginal immune factors, microbes, clinical factors, and the early pathogenesis of preeclampsia. These associations vary with BMI, and stratification revealed strong associations between preeclampsia and Bifidobacterium spp., Prevotella timonensis, and Sneathia vaginalis. Finally, we developed machine learning models that predict the development of preeclampsia using this first trimester data, collected ~5.7 months prior to clinical diagnosis, with an auROC of 0.78. We validated our models using data from an independent cohort (MOMS-PI), achieving an auROC of 0.80. Our findings highlight robust associations among the vaginal microbiome, local host immunity, and early pathogenic processes of preeclampsia, paving the way for early detection, prevention and intervention for this devastating condition.

Antihypertensive agent losartan promotes tongue squamous cell carcinoma cell proliferation via EGFR/ERK1/2/cyclin D1 signaling axis

OBJECTIVE

To study the effects of losartan, an angiotensin II receptor blocker, in the SCC4 and SCC25 human tongue squamous cell carcinoma cell lines.

METHODS

Cell proliferation was measured by MTS/PMS activity and trypan blue exclusion assays. The levels of the cell proliferation marker, cyclin D1, were analyzed by western blotting. Apoptosis was assessed by caspase-3 activation and Annexin V-FITC/propidium iodide double staining. Activation of epidermal growth factor receptor (EGFR) and ERK1/2 was validated by western blotting.

RESULTS

Moderate concentrations of losartan enhanced the proliferation of SCC4 and SCC25 cells. However, high losartan concentrations induced apoptosis in SCC4 cells. Losartan activated the EGFR/ERK1/2/cyclin D1 signaling axis, which in turn promoted cell proliferation. Afatinib (EGFR inhibitor) and U0126 (ERK1/2 inhibitor) abolished losartan-induced cell proliferation. In contrast, UC2288 (p21 inhibitor) enhanced it.

CONCLUSIONS

Losartan exhibited dual effects on tongue squamous cell carcinoma cells. Moderate losartan concentrations facilitated cell proliferation, whereas high concentrations induced cytotoxicity in tongue carcinoma cells.

Chlorogenic acid attenuates idiopathic pulmonary fibrosis: An integrated analysis of network pharmacology, molecular docking, and experimental validation

AIMS

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung condition, the cause of which remains unknown and for which no effective therapeutic treatment is currently available. Chlorogenic acid (CGA), a natural polyphenolic compound found in different plants and foods, has emerged as a promising agent due to its anti-inflammatory, antioxidant, and antifibrotic properties. However, the molecular mechanisms underlying the therapeutic effect of CGA in IPF remain unclear. The purpose of this study was to analyze the pharmacological impact and underlying mechanisms of CGA in IPF.

MAIN METHODS

Using network pharmacology analysis, genes associated with IPF and potential molecular targets of CGA were identified through specialized databases, and a protein-protein interaction (PPI) network was constructed. Molecular docking was performed to accurately select potential therapeutic targets. To investigate the effects of CGA on lung histology and key gene expression, a murine model of bleomycin-induced lung fibrosis was used.

KEY FINDINGS

Network pharmacology analysis identified 384 were overlapped between CGA and IPF. Key targets including AKT1, TP53, JUN, CASP3, BCL2, MMP9, NFKB1, EGFR, HIF1A, and IL1B were identified. Pathway analysis suggested the involvement of cancer, atherosclerosis, and inflammatory processes. Molecular docking confirmed the stable binding between CGA and targets. CGA regulated the expression mRNA of EGFR, MMP9, AKT1, BCL2 and IL1B and attenuated pulmonary fibrosis in the mouse model.

SIGNIFICANCE

CGA is a promising multi-target therapeutic agent for IPF, which is supported by its efficacy in reducing fibrosis through the modulation of key pathways. This evidence provides a basis to further investigate CGA as an IPF potential treatment.

Renal Fibrosis: SIRT1 Still of Value

Chronic kidney disease (CKD) is a major global health concern. Renal fibrosis, a prevalent outcome regardless of the initial cause, ultimately leads to end-stage renal disease. Glomerulosclerosis and renal interstitial fibrosis are the primary pathological features. Preventing and slowing renal fibrosis are considered effective strategies for delaying CKD progression. However, effective treatments are lacking. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to class III histone deacetylases, is implicated in the physiological regulation and protection of the kidney and is susceptible to a diverse array of pathological influences, as demonstrated in previous studies. Interestingly, controversial conclusions have emerged as research has progressed. This review provides a comprehensive summary of the current understanding and advancements in the field; specifically, the biological roles and mechanisms of SIRT1 in regulating renal fibrosis progression. These include aspects such as lipid metabolism, epithelial-mesenchymal transition, oxidative stress, aging, inflammation, and autophagy. This manuscript explores the potential of SIRT1 as a therapeutic target for renal fibrosis and offers new perspectives on treatment approaches and prognostic assessments.

Targeting the epidermal growth factor receptor (EGFR/ErbB) for the potential treatment of renal pathologies

Epidermal growth factor receptor (EGFR), which is referred to as ErbB1/HER1, is the prototype of the EGFR family of receptor tyrosine kinases which also comprises ErbB2 (Neu, HER2), ErbB3 (HER3), and ErbB4 (HER4). EGFR, along with other ErbBs, is expressed in the kidney tubules and is physiologically involved in nephrogenesis and tissue repair, mainly following acute kidney injury. However, its sustained activation is linked to several kidney pathologies, including diabetic nephropathy, hypertensive nephropathy, glomerulonephritis, chronic kidney disease, and renal fibrosis. This review aims to provide a summary of the recent findings regarding the consequences of EGFR activation in several key renal pathologies. We also discuss the potential interplay between EGFR and the reno-protective angiotensin-(1-7) (Ang-(1-7), a heptapeptide member of the renin-angiotensin-aldosterone system that counter-regulates the actions of angiotensin II. Ang-(1-7)-mediated inhibition of EGFR transactivation might represent a potential mechanism of action for its renoprotection. Our review suggests that there is a significant body of evidence supporting the potential inhibition of EGFR/ErbB, and/or administration of Ang-(1-7), as potential novel therapeutic strategies in the treatment of renal pathologies. Thus, EGFR inhibitors such as Gefitinib and Erlinotib that have an acceptable safety profile and have been clinically used in cancer chemotherapy since their FDA approval in the early 2000s, might be considered for repurposing in the treatment of renal pathologies.

Exploring the role of granzyme B in subretinal fibrosis of age-related macular degeneration

Age-related macular degeneration (AMD), a prevalent and progressive degenerative disease of the macula, is the leading cause of blindness in elderly individuals in developed countries. The advanced stages include neovascular AMD (nAMD), characterized by choroidal neovascularization (CNV), leading to subretinal fibrosis and permanent vision loss. Despite the efficacy of anti-vascular endothelial growth factor (VEGF) therapy in stabilizing or improving vision in nAMD, the development of subretinal fibrosis following CNV remains a significant concern. In this review, we explore multifaceted aspects of subretinal fibrosis in nAMD, focusing on its clinical manifestations, risk factors, and underlying pathophysiology. We also outline the potential sources of myofibroblast precursors and inflammatory mechanisms underlying their recruitment and transdifferentiation. Special attention is given to the potential role of mast cells in CNV and subretinal fibrosis, with a focus on putative mast cell mediators, tryptase and granzyme B. We summarize our findings on the role of GzmB in CNV and speculate how GzmB may be involved in the pathological transition from CNV to subretinal fibrosis in nAMD. Finally, we discuss the advantages and drawbacks of animal models of subretinal fibrosis and pinpoint potential therapeutic targets for subretinal fibrosis.

Single cell multi-omics of fibrotic kidney reveal epigenetic regulation of antioxidation and apoptosis within proximal tubule

BACKGROUND

Until now, there has been no particularly effective treatment for chronic kidney disease (CKD). Fibrosis is a common pathological change that exist in CKD.

METHODS

To better understand the transcriptional dynamics in fibrotic kidney, we make use of single-nucleus assay for transposase-accessible chromatin sequencing (snATAC-seq) and single-cell RNA sequencing (scRNA-seq) from GEO datasets and perform scRNA-seq of human biopsy to seek possible transcription factors (TFs) regulating target genes in the progress of kidney fibrosis across mouse and human kidneys.

RESULTS

Our analysis has displayed chromatin accessibility, gene expression pattern and cell-cell communications at single-cell level in kidneys suffering from unilateral ureteral obstruction (UUO) or chronic interstitial nephritis (CIN). Using multimodal data, there exists epigenetic regulation producing less Sod1 and Sod2 mRNA within the proximal tubule which is hard to withstand oxidative stress during fibrosis. Meanwhile, a transcription factor Nfix promoting the apoptosis-related gene Ifi27 expression found by multimodal data was validated by an in vitro study. And the gene Ifi27 upregulated by in situ AAV injection within the kidney cortex aggravates kidney fibrosis.

CONCLUSIONS

In conclusion, as we know oxidation and apoptosis are traumatic factors during fibrosis, thus enhancing antioxidation and inhibiting the Nfix-Ifi27 pathway to inhibit apoptosis could be a potential treatment for kidney fibrosis.