Non-Smad signaling pathways

Exploring the molecular mechanisms and therapeutic potential of SMAD4 in colorectal cancer

Colorectal Cancer (CRC) is the third most common cancer worldwide, and the occurrence and development of CRC are influenced by the molecular biology characteristics of CRC, especially alterations in key signaling pathways. The transforming growth factor-β (TGF-β) plays a crucial role in cellular growth, differentiation, migration, and apoptosis, with SMAD4 protein serving as a key transcription factor in the TGF-β signaling pathway, thus playing a significant role in the onset and progression of CRC. CRC is one of the malignancies with a high mortality rate worldwide. Despite significant research progress in recent years, especially regarding the role of SMAD4, its dual role in the early and late stages of tumor progression has promoted further discussion on its complexity as a therapeutic target, highlighting the urgent need for a deeper analysis of its role in CRC. This review aims to explore the function of SMAD4 protein in CRC and its potential as a therapeutic target.

TGFβ in malignant canine mammary tumors: relation with angiogenesis, immunologic markers and prognostic role

Transforming growth factor-β (TGFβ) and FoxP3 regulatory T cells (Treg) are involved in human breast carcinogenesis. This topic is not well documented in canine mammary tumors (CMT). In this work, the tumoral TGFβ expression was assessed by immunohistochemistry in 67 malignant CMT and its correlation to previously determined FoxP3, VEGF, and CD31 markers and other clinicopathologic parameters was evaluated. The high levels of TGFβ were statistically significantly associated with skin ulceration, tumor necrosis, high histological grade of malignancy (HGM), presence of neoplastic intravascular emboli and presence of lymph node metastases. The observed levels of TGFβ were positively correlated with intratumoral FoxP3 (strong correlation), VEGF (weak correlation) and CD31 (moderate correlation). Tumors that presented a concurrent high expression of TGFβ/FoxP3, TGFβ/VEGF, and TGFβ/CD31 markers were statistically significantly associated with parameters of tumor malignancy (high HGM, presence of vascular emboli and nodal metastasis). Additionally, shorter overall survival (OS) time was statistically significantly associated with tumors with an abundant TGFβ expression and with concurrent high expression of TGFβ/FoxP3, TGFβ/VEGF, and TGFβ/CD31. The presence of lymph node metastasis increased 11 times the risk of disease-related death, arising as an independent predictor of poor prognosis in the multivariable analysis. In conclusion, TGFβ and Treg cells seem involved in tumor progression emerging as potential therapeutic targets for future immunotherapy studies.

Mapping and Analysis of Protein and Gene Profile Identification of the Important Role of Transforming Growth Factor Beta in Synovial Invasion in Patients With Pigmented Villonodular Synovitis

OBJECTIVE

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disease affecting the soft-tissue lining the synovial joints and tendons. Its etiology is poorly understood, largely limiting the availability of current therapeutic options. Here, we mapped the synovial gene and protein profiles of patients with PVNS, revealed a link between synovial inflammation and invasion, and elucidated the potential molecular mechanism involved.

METHODS

The expression of synovial genes from 6 control individuals, 7 patients with osteoarthritis (OA), and 19 patients with PVNS was analyzed via RNA sequencing. Protein profiles from 5 control individuals, 10 patients with OA, and 32 patients with PVNS were analyzed using label-free proteomics. Microarray and reverse transcription-polymerase chain reaction analyses and immunohistochemical staining were used to evaluate inflammatory cytokine and target gene expression levels in synovial tissue, epithelial cells, and synovial fibroblasts (FLSs) derived from tissue of patients with PVNS. Various signaling pathway inhibitors, small interfering RNAs, and Western blots were used for molecular mechanism studies. Transwell migration and invasion assays were subsequently performed.

RESULTS

In total, 522 differentially expressed proteins were identified in the tissues of patients with PVNS. By integrating RNA sequencing and microarray analyses, significant changes in the expression of epithelial-mesenchymal transition (EMT)-related genes, including transforming growth factor TGF-b induced, neural cadherin, epithelial cadherin, SNAIL, and TWIST, were confirmed in the tissue of patients with PVNS compared to the control tissue. In vitro, TGFβ induced EMT and increased epithelial cell migration and invasion. Moreover, TGFβ not only promoted interactions between epithelial cells and FLSs but also directly increased the migration and invasion abilities of FLSs by activating the classical Smad2/3 and nonclassical JNK/AKT signaling pathways.

CONCLUSION

This study provides overall protein and gene profiles of PVNS and identifies the crucial role of TGFβ in synovial invasion pathology. Exploring the related molecular mechanism may also reveal a new strategy or target for PVNS therapy.

The TβRI promotes migration and metastasis through thrombospondin 1 and ITGAV in prostate cancer cells

TGFβ potently modifies the extracellular matrix (ECM), which is thought to favor tumor cell invasion. However, the mechanism whereby the cancer cells employ the ECM proteins to facilitate their motility is largely unknown. In this study we used RNA-seq and proteomic analysis to examine the proteins secreted by castration-resistant prostate cancer (CRPC) cells upon TGFβ treatment and found that thrombospondin 1 (THBS1) was observed to be one of the predominant proteins. The CRISPR Cas9, or siRNA techniques was used to downregulate TGFβ type I receptor (TβRI) to interfere with TGFβ signaling in various cancer cells in vitro. The interaction of ECM proteins with the TβRI in the migratory prostate cancer cells in response to TGFβ1 was demonstrated by several different techniques to reveal that THBS1 mediates cell migration by interacting with integrin subunit alpha V (ITGAV) and TβRI. Deletion of TβRI or THBS1 in cancer cells prevented their migration and invasion. THBS1 belongs to a group of tumorigenic ECM proteins induced via TGFβ signaling in CRPC cells, and high expression of THBS1 in human prostate cancer tissues correlated with the degree of malignancy. TGFβ-induced production of THBS1 through TβRI facilitates the invasion and metastasis of CRPC cells as shown in vivo xenograft animal experiments.

The role of transforming growth factor β in cervical carcinogenesis

Human papillomavirus (HPV) is involved in virtually all cases of cervical cancer. However, HPV alone is not sufficient to cause malignant development. The effects of chronic inflammation and the interaction of immune components with the microenvironment infected with the high-risk HPV type (HR) may contribute to cancer development. Transforming growth factor β (TGFB) appears to play an important role in cervical carcinogenesis. Protein and mRNA levels of this cytokine gradually increase as normal tissue develops into malignant tissue and are closely related to the severity of HPV infection. At the onset of infection, TGFB can inhibit the proliferation of infected cells and viral amplification by inhibiting cell growth and downregulating the transcriptional activity of the long control region (LCR) of HPV, thereby reducing the expression of early genes. When infected cells progress to a malignant phenotype, the response to the cell growth inhibitory effect of TGFB1 is lost and the suppression of E6 and E7 expression decreases. Subsequently, TGFB1 expression is upregulated by high levels of E6 and E7 oncoproteins, leading to an increase in TGFB1 in the tumor microenvironment, where this molecule promotes epithelial-to-mesenchymal transition (EMT), cell motility, angiogenesis, and immunosuppression. This interaction between HPV oncoproteins and TGFB1 is an important mechanism promoting the development and progression of cervical cancer.

Binding with HSP90β, cimifugin ameliorates fibrotic cataracts in vitro and in vivo by inhibiting TGFβ signaling pathways

Fibrotic cataracts, the most frequent complications after phacoemulsification, cannot be cured by drugs in clinic. The primary mechanism underlying the disease is the epithelial-mesenchymal transition (EMT). Cimifugin is a natural monomer component of traditional Chinese medicines. Previous researches have demonstrated the effect of cimifugin inhibiting EMT in the lung. The purpose of this work is to evaluate the impact of cimifugin on EMT in the lens and elucidate its precise mechanism. The pathogenesis of fibrotic cataracts was simulated using TGFβ2-induced cell model of EMT and the injury-induced anterior subcapsular cataract animal model. Through H&E staining and immunofluorescence of mice eyeballs, we discovered that cimifugin can inhibit the expansion of fibrotic lesions in vivo. Furthermore, at mRNA and protein levels, we confirmed that cimifugin can allay EMT of lens epithelial cells (LECs) in vitro and in vivo. Additionally, the inhibition of cimifugin on the activation of TGFβ-related signaling pathways was certified by immunoblot. HSP90β, the target of cimifugin, was predicted by network pharmacology and verified by drug affinity responsive target stability, the cellular thermal shift assay, and microscale thermophoresis. Moreover, co-immunoprecipitation revealed the interaction between HSP90β and TGFβ receptor (TGFβR) II. Together, our findings showed that by weakening the binding of HSP90β and TGFβRII, cimifugin suppressed the TGFβ signaling pathways to alleviate fibrotic cataracts. Cimifugin is a promising medication for the treatment of fibrotic cataracts.

AMIGO2 enhances the invasive potential of colorectal cancer by inducing EMT

In our previous studies, we identified amphoterin-inducible gene and open reading frame 2 (AMIGO2) as a driver gene for liver metastasis and found that AMIGO2 expression in cancer cells worsens the prognosis of patients with colorectal cancer (CRC). Epithelial-mesenchymal transition (EMT) is a trigger for CRC to acquire a malignant phenotype, such as invasive potential, leading to metastasis. However, the role of AMIGO2 expression in the invasive potential of CRC cells remains unclear. Thus, this study aimed to examine AMIGO2 expression and elucidate the mechanisms by which it induces EMT and promotes CRC invasion. Activation of the TGFβ/Smad signaling pathway was found involved in AMIGO2-induced EMT, and treatment with the TGFβ receptor inhibitor LY2109761 suppressed AMIGO2-induced EMT. Studies using CRC samples showed that AMIGO2 expression was highly upregulated in the invasive front, where AMIGO2 expression was localized to the nucleus and associated with EMT marker expression. These results suggest that the nuclear translocation of AMIGO2 induces EMT to promote CRC invasion by activating the TGFβ/Smad signaling pathway. Thus, AMIGO2 is an attractive therapeutic target for inhibiting EMT and metastatic CRC progression.

Possible mechanisms of SARS-CoV-2-associated myocardial fibrosis: reflections in the post-pandemic era

Since December 2019, coronavirus disease 2019 (COVID-19) has been spreading worldwide with devastating immediate or long-term effects on people's health. Although the lungs are the primary organ affected by COVID-19, individuals infected with SARS-CoV-2 also develop systemic lesions involving multiple organs throughout the body, such as the cardiovascular system. Emerging evidence reveals that COVID-19 could generate myocardial fibrosis, termed "COVID-19-associated myocardial fibrosis." It can result from the activation of fibroblasts via the renin-angiotensin-aldosterone system (RAAS), transforming growth factor-β1 (TGF-β1), microRNAs, and other pathways, and can also occur in other cellular interactions with SARS-CoV-2, such as immunocytes, endothelial cells. Nonetheless, to gain a more profound insight into the natural progression of COVID-19-related myocardial fibrosis, additional investigations are necessary. This review delves into the underlying mechanisms contributing to COVID-19-associated myocardial fibrosis while also examining the antifibrotic potential of current COVID-19 treatments, thereby offering guidance for future clinical trials of these medications. Ultimately, we propose future research directions for COVID-19-associated myocardial fibrosis in the post-COVID-19 era, such as artificial intelligence (AI) telemedicine. We also recommend that relevant tests be added to the follow-up of COVID-19 patients to detect myocardial fibrosis promptly.

Anti-fibrogenic effect of umbilical cord-derived mesenchymal stem cell-conditioned media in human esophageal fibroblasts

Esophageal fibrosis can develop due to caustic or radiation injuries. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are known to mitigate fibrosis in various organs. However, the potential effects of UC-MSCs on human esophageal fibrosis remain underexplored. This study investigated the anti-fibrogenic properties and mechanisms of UC-MSC-derived conditioned media (UC-MSC-CM) on human esophageal fibroblasts (HEFs). HEFs were treated with TGF-β1 and then cultured with UC-MSC-CM, and the expression levels of extracellular matrix (ECM) components, RhoA, myocardin related transcription factor A (MRTF-A), serum response factor (SRF), Yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) were measured. UC-MSC-CM suppressed TGF-β1-induced fibrogenic activation in HEFs, as evidenced by the downregulation of ECM. UC-MSC-CM diminished the expression of RhoA, MRTF-A, and SRF triggered by TGF-β1. In TGF-β1-stimulated HEFs, UC-MSC-CM decreased the nuclear localization of MRTF-A and YAP. Additionally, UC-MSC-CM diminished the TGF-β1-induced nuclear expressions of YAP and TAZ, while concurrently enhancing the cytoplasmic presence of phosphorylated YAP. Furthermore, UC-MSC-CM reduced TGF-β1-induced phosphorylation of Smad2. These findings suggest that UC-MSC-CM may inhibit TGF-β1-induced fibrogenic activation in HEFs by targeting the Rho-mediated MRTF/SRF and YAP/TAZ pathways, as well as the Smad2 pathway. This indicates its potential as a stem cell therapy for esophageal fibrosis.

Exploring the role of the immune microenvironment in hepatocellular carcinoma: Implications for immunotherapy and drug resistance

Hepatocellular carcinoma (HCC), the most common type of liver tumor, is a leading cause of cancer-related deaths, and the incidence of liver cancer is still increasing worldwide. Curative hepatectomy or liver transplantation is only indicated for a small population of patients with early-stage HCC. However, most patients with HCC are not candidates for radical resection due to disease progression, leading to the choice of the conventional tyrosine kinase inhibitor drug sorafenib as first-line treatment. In the past few years, immunotherapy, mainly immune checkpoint inhibitors (ICIs), has revolutionized the clinical strategy for HCC. Combination therapy with ICIs has proven more effective than sorafenib, and clinical trials have been conducted to apply these therapies to patients. Despite significant progress in immunotherapy, the molecular mechanisms behind it remain unclear, and immune resistance is often challenging to overcome. Several studies have pointed out that the complex intercellular communication network in the immune microenvironment of HCC regulates tumor escape and drug resistance to immune response. This underscores the urgent need to analyze the immune microenvironment of HCC. This review describes the immunosuppressive cell populations in the immune microenvironment of HCC, as well as the related clinical trials, aiming to provide insights for the next generation of precision immunotherapy.

Investigating the impact of SMAD2 and SMAD4 downregulation in colorectal cancer and their correlation with immune markers, prognosis, and drug resistance and sensitivity

BACKGROUND

While many genes linked to colorectal cancer (CRC) contribute to cancer development, a thorough investigation is needed to explore crucial hub genes yet to be fully studied. A pivotal pathway in CRC is transforming growth factor-beta (TGF-β). This study aimed to assess SMAD2 and SMAD4 gene expression from this pathway.

METHODS AND RESULTS

Counted data from the Cancer Genome Atlas (TCGA) were examined, comparing 483 tumor and 41 normal samples. Using clinical data, genes impacting overall survival (OS) were evaluated. GSE39582 was employed to confirmed the levels of genes in CRC compared to the normal samples. Additionally, employing unhealthy samples and the RT-qPCR means our outcomes was validated. Finally, PharmacoGx information were utilized to connect the levels of potential genes to drug tolerance and susceptibility. Our findings showed SMAD2 and SMAD4 levels in TGF-β signaling were more significant than other pathway genes. Our findings indicated that the protein levels of these genes were lower in malignant tissues than in healthy tissues. Results revealed a significant correlation between low levels of SMAD2 and unfavorable OS in CRC individuals. RT-qPCR results demonstrated decreased expressions of both SMAD2 and SMAD4 in cancer tissues compared to elevated levels in adjacent normal samples. Our results showed significant association between selected genes and immune cell infiltration markers such as CD8+, and B-cells. Our results indicated a potential association among the levels of SMAD2 and SMAD4 genes and tolerance and susceptibility to Nilotinib and Panobinostat drugs.

CONCLUSION

Reduced expression of SMAD2 and SMAD4 may be pivotal in CRC progression, impacting downstream genes unrelated to patient OS. These findings suggest a potential role for SMAD2 and SMAD4 as predictive markers for drug response in CRC patients.

Pirfenidone Prevents Heart Fibrosis during Chronic Chagas Disease Cardiomyopathy

Cardiac fibrosis is a severe outcome of Chagas disease (CD), caused by the protozoan Trypanosoma cruzi. Clinical evidence revealed a correlation between fibrosis levels with impaired cardiac performance in CD patients. Therefore, we sought to analyze the effect of inhibitors of TGF-β (pirfenidone), p38-MAPK (losmapimod) and c-Jun (SP600125) on the modulation of collagen deposition in cardiac fibroblasts (CF) and in vivo models of T. cruzi chronic infection. Sirius Red/Fast Green dye was used to quantify both collagen expression and total protein amount, assessing cytotoxicity. The compounds were also used to treat C57/Bl6 mice chronically infected with T. cruzi, Brazil strain. We identified an anti-fibrotic effect in vitro for pirfenidone (TGF-β inhibitor, IC50 114.3 μM), losmapimod (p38 inhibitor, IC50 17.6 μM) and SP600125 (c-Jun inhibitor, IC50 3.9 μM). This effect was independent of CF proliferation since these compounds do not affect T. cruzi-induced host cell multiplication as measured by BrdU incorporation. Assays of chronic infection of mice with T. cruzi have shown a reduction in heart collagen by pirfenidone. These results propose a novel approach to fibrosis therapy in CD, with the prospect of repurposing pirfenidone to prevent the onset of ECM accumulation in the hearts of the patients.

The role of TGF-β signaling in muscle atrophy, sarcopenia and cancer cachexia

Skeletal muscle, comprising a significant proportion (40 to 50 percent) of total body weight in humans, plays a critical role in maintaining normal physiological conditions. Muscle atrophy occurs when the rate of protein degradation exceeds protein synthesis. Sarcopenia refers to age-related muscle atrophy, while cachexia represents a more complex form of muscle wasting associated with various diseases such as cancer, heart failure, and AIDS. Recent research has highlighted the involvement of signaling pathways, including IGF1-Akt-mTOR, MuRF1-MAFbx, and FOXO, in regulating the delicate balance between muscle protein synthesis and breakdown. Myostatin, a member of the TGF-β superfamily, negatively regulates muscle growth and promotes muscle atrophy by activating Smad2 and Smad3. It also interacts with other signaling pathways in cachexia and sarcopenia. Inhibition of myostatin has emerged as a promising therapeutic approach for sarcopenia and cachexia. Additionally, other TGF-β family members, such as TGF-β1, activin A, and GDF11, have been implicated in the regulation of skeletal muscle mass. Furthermore, myostatin cooperates with these family members to impair muscle differentiation and contribute to muscle loss. This review provides an overview of the significance of myostatin and other TGF-β signaling pathway members in muscular dystrophy, sarcopenia, and cachexia. It also discusses potential novel therapeutic strategies targeting myostatin and TGF-β signaling for the treatment of muscle atrophy.

Maternal malnutrition associated with postnatal sugar consumption increases inflammatory response and prostate disorders in rat offspring

Maternal malnutrition can alter developmental biology, programming health and disease in offspring. The increase in sugar consumption during the peripubertal period, a worldwide concern, also affects health through adulthood. Studies have shown that maternal exposure to a low protein diet (LPD) is associated with an increase in prostate disease with aging. However, the combined effects of maternal LPD and early postnatal sugar consumption on offspring prostate disorders were not investigated. The effects on aging were evaluated using a maternal gestational model with lactational LPD (6% protein) and sugar consumption (10%) from postnatal day (PND) 21-90, associating the consequences on ventral prostate (VP) rats morphophysiology on PND540. An increase was shown in mast cells and in the VP of the CTR + SUG and Gestational and Lactational Low Protein (GLLP) groups. In GLLP + SUG, a significant increase was shown in TGF-β1 expression in both the systemic and intra-prostatic forms, and SMAD2/3p had increased. The study identified maternal LPD and sugar consumption as risk factors for prostatic homeostasis in senility, activating the TGFβ1-SMAD2/3 pathway, a signaling pathway with potential markers for prostatic disorders.

Potential therapeutic effects of peroxisome proliferator-activated receptors on corneal diseases

The cornea is an avascular tissue in the eye that has multiple functions in the eye to maintain clear vision which can significantly impair one's vision when subjected to damage. Peroxisome proliferator-activated receptors (PPARs), a family of nuclear receptor proteins comprising three different peroxisome proliferator-activated receptor (PPAR) isoforms, namely, PPAR alpha (α), PPAR gamma (γ), and PPAR delta (δ), have emerged as potential therapeutic targets for treating corneal diseases. In this review, we summarised the current literature on the therapeutic effects of PPAR agents on corneal diseases. We discussed the role of PPARs in the modulation of corneal wound healing, suppression of corneal inflammation, neovascularisation, fibrosis, stimulation of corneal nerve regeneration, and amelioration of dry eye by inhibiting oxidative stress within the cornea. We also discussed the underlying mechanisms of these therapeutic effects. Future clinical trials are warranted to further attest to the clinical therapeutic efficacy.

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

Cholangiocarcinoma Malignant Traits Are Promoted by Schwann Cells through TGFβ Signaling in a Model of Perineural Invasion

The term cholangiocarcinoma (CCA) defines a class of epithelial malignancies originating from bile ducts. Although it has been demonstrated that CCA patients with perineural invasion (PNI) have a worse prognosis, the biological features of this phenomenon are yet unclear. Our data show that in human intrahepatic CCA specimens with documented PNI, nerve-infiltrating CCA cells display positivity of the epithelial marker cytokeratin 7, lower with respect to the rest of the tumor mass. In an in vitro 3D model, CCA cells move towards a peripheral nerve explant allowing contact with Schwann cells (SCs) emerging from the nerve. Here, we show that SCs produce soluble factors that favor the migration, invasion, survival and proliferation of CCA cells in vitro. This effect is accompanied by a cadherin switch, suggestive of an epithelial-mesenchymal transition. The influence of SCs in promoting the ability of CCA cells to migrate and invade the extracellular matrix is hampered by a specific TGFβ receptor 1 (TGFBR1) antagonist. Differential proteomic data indicate that the exposure of CCA cells to SC secreted factors induces the upregulation of key oncogenes and the concomitant downregulation of some tumor suppressors. Taken together, these data concur in identifying SCs as possible promoters of a more aggressive CCA phenotype, ascribing a central role to TGFβ signaling in regulating this process.

miR-539-5p targets BMP2 to regulate Treg activation in B-cell acute lymphoblastic leukemia through TGF-β/Smads/MAPK

MicroRNAs (mRNAs) were believed to play an important role in cancers, and this study aimed to explore the mechanism of miRNA regulating Treg in B-cell acute lymphoblastic leukemia (B-ALL). Firstly, the differentially expressed miRNAs and target genes significantly associated with Tregs were screened out by high-throughput sequencing, and their enrichment pathways were analyzed. The binding relationship between miRNA and target genes was further verified, and the effects of miRNA on the proliferation and apoptosis of B-ALL Nalm-6 cells and Treg activation were analyzed. Results showed that differentially expressed miR-539-5p was significantly under-expressed, and its target gene BMP2 was significantly over-expressed in B-ALL, and significantly enriched in the TGF-β1 pathway. In addition, both miR-539-5p and BMP2 were significantly correlated with Treg activity in B-ALL. In vitro experiments further confirmed that miR-539-5p could directly target BMP2. The low expression of miR-539-5p in B-ALL significantly promoted BMP2 expression to promote the proliferation and inhibit apoptosis of Nalm-6 cells. Furthermore, the high expression of BMP2 in B-ALL could cooperate with TGF-β1 to promote the activation of human CD4+CD25-T cells to Treg, and significantly activate the TGF-β/Smads/MAPK pathway. In vivo experiments also confirmed that overexpression of miR-539-5p significantly inhibited BMP2 to suppress Treg activation and Smad1 and Smad2 phosphorylation, and finally inhibit the B-ALL process. In conclusion, miR-539-5p was significantly under-expressed in B-ALL and could target BMP2 to promote its expression, and the overexpressed BMP2 further promoted Treg activation in B-ALL by regulating TGF-β/Smads/MAPK pathway.

The role of stromal cells in epithelial-mesenchymal plasticity and its therapeutic potential

The epithelial-mesenchymal transition (EMT) is a critical tumor invasion and metastasis process. EMT enables tumor cells to migrate, detach from their original location, enter the circulation, circulate within it, and eventually exit from blood arteries to colonize in foreign sites, leading to the development of overt metastases, ultimately resulting in death. EMT is intimately tied to stromal cells around the tumor and is controlled by a range of cytokines secreted by stromal cells. This review summarizes recent research on stromal cell-mediated EMT in tumor invasion and metastasis. We also discuss the effects of various stromal cells on EMT induction and focus on the molecular mechanisms by which several significant stromal cells convert from foes to friends of cancer cells to fuel EMT processes via their secretions in the tumor microenvironment (TME). As a result, a better knowledge of the role of stromal cells in cancer cells' EMT may pave the path to cancer eradication.

Serum-Induced Proliferation of Human Cardiac Stem Cells Is Modulated via TGFβRI/II and SMAD2/3

The ageing phenotype is strongly driven by the exhaustion of adult stem cells (ASCs) and the accumulation of senescent cells. Cardiovascular diseases (CVDs) and heart failure (HF) are strongly linked to the ageing phenotype and are the leading cause of death. As the human heart is considered as an organ with low regenerative capacity, treatments targeting the rejuvenation of human cardiac stem cells (hCSCs) are of great interest. In this study, the beneficial effects of human blood serum on proliferation and senescence of hCSCs have been investigated at the molecular level. We show the induction of a proliferation-related gene expression response by human blood serum at the mRNA level. The concurrent differential expression of the TGFβ target and inhibitor genes indicates the participation of TGFβ signalling in this context. Surprisingly, the application of TGFβ1 as well as the inhibition of TGFβ type I and type II receptor (TGFβRI/II) signalling strongly increased the proliferation of hCSCs. Likewise, both human blood serum and TGFβ1 reduced the senescence in hCSCs. The protective effect of serum on senescence in hCSCs was enhanced by simultaneous TGFβRI/II inhibition. These results strongly indicate a dual role of TGFβ signalling in terms of the serum-mediated effects on hCSCs. Further analysis via RNA sequencing (RNA-Seq) revealed the participation of Ras-inactivating genes wherefore a prevention of hyperproliferation upon serum-treatment in hCSCs via TGFβ signalling and Ras-induced senescence is suggested. These insights may improve treatments of heart failure in the future.

Antistricture Ureteral Stents with a Braided Composite Structure and Surface Modification with Antistenosis Drugs

The present work describes the development of a drug-loaded ureteral stent with antistricture function based on a trilayer design in which the middle layer was braided from biodegradable poly(p-dioxanone) (PDO) monofilament. Antistenosis drugs rapamycin and paclitaxel were loaded into a silk fibroin (SF) solution and coated on the inner and outer layers of the braided PDO stent. The cumulative release of rapamycin and paclitaxel was sustained over 30 days, with a total release above 80%. The drug-loaded ureteral stents inhibited the proliferation of fibroblasts and smooth muscle cells in vitro. Subcutaneous implantation in rats showed that the drug-loaded ureteral stents were biocompatible with durable mechanical properties in vivo, revealing the inhibition of an excessive growth of fibroblasts and excessive deposition of collagen fibers. In conclusion, the dual-drug-loaded biodegradable ureteral stents show the possibility for treatment of ureteral strictures and avoid the occurrence of complications such as inflammation and restricture.

Cancer-associated fibroblasts in neoadjuvant setting for solid cancers

Therapeutic approaches for cancer have become increasingly diverse in recent times. A comprehensive understanding of the tumor microenvironment (TME) holds great potential for enhancing the precision of tumor therapies. Neoadjuvant therapy offers the possibility of alleviating patient symptoms and improving overall quality of life. Additionally, it may facilitate the reduction of inoperable tumors and prevent potential preoperative micrometastases. Within the TME, cancer-associated fibroblasts (CAFs) play a prominent role as they generate various elements that contribute to tumor progression. Particularly, extracellular matrix (ECM) produced by CAFs prevents immune cell infiltration into the TME, hampers drug penetration, and diminishes therapeutic efficacy. Therefore, this review provides a summary of the heterogeneity and interactions of CAFs within the TME, with a specific focus on the influence of neoadjuvant therapy on the microenvironment, particularly CAFs. Finally, we propose several potential and promising therapeutic strategies targeting CAFs, which may efficiently eliminate CAFs to decrease stroma density and impair their functions.

CAP2 promotes gastric cancer metastasis by mediating the interaction between tumor cells and tumor-associated macrophages

The metastasis of cancer cells is the main cause of death in patients with gastric cancer (GC). Mounting evidence has demonstrated the vital importance of tumor-associated macrophages in promoting tumor invasion and metastasis; however, the interaction between tumor cells and macrophages in GC is largely unknown. In this study, we demonstrated that cyclase-associated protein 2 (CAP2) was upregulated in GC, especially in cases with lymph node metastasis, and was correlated with a poorer prognosis. The transcription factor JUN directly bound to the promoter region of CAP2 and activated CAP2 transcription. The N-terminal domain of CAP2 bound to the WD5 to WD7 domains of receptor for activated C kinase 1 (RACK1) and induced M2 macrophage polarization by activating the SRC/focal adhesion kinase (FAK)/ERK signaling pathway, which resulted in IL-4 and IL-10 secretion. Polarized M2 macrophages induced premetastatic niche formation and promoted GC metastasis by secreting TGFB1, which created a TGFB1/JUN/CAP2 positive-feedback loop to activate CAP2 expression continuously. Furthermore, we identified salvianolic acid B as an inhibitor of CAP2, which effectively inhibited GC cell invasion capabilities by suppressing the SRC/FAK/ERK signaling pathway. Our data suggest that CAP2, a key molecule mediating the interaction between GC cells and tumor-associated macrophages, may be a promising therapeutic target for suppressing tumor metastasis in GC.

Transforming growth factor beta-3 localization in the corneal response to epithelial-stromal injury and effects on corneal fibroblast transition to myofibroblasts

The purpose of this study was to evaluate the localization of TGF beta-3 in situ in unwounded rabbit corneas and corneas that had epithelial-stromal injuries produced by photorefractive keratectomy (PRK) in rabbits and to evaluate the in vitro effects of TGF beta-3 compared to TGF beta-1 on alpha-smooth muscle actin (α-SMA) protein expression and myofibroblast development in corneal fibroblasts. Forty-eight New Zealand white rabbits underwent either -3 diopter (D) or -9D PRK and were studied from one to eight weeks (four corneas in each group at each time point) after surgery with immunohistochemistry for TGF beta-3, laminin alpha-5, and alpha-smooth muscle actin (α-SMA). Rabbit corneal fibroblasts were treated with activated TGF beta-1 and/or TGF beta-3 at different concentrations and duration of exposure and studied with immunocytochemistry for myofibroblast development and the expression of α-SMA using Jess automated Western blotting. TGF beta-3 was detected at high levels in the stroma of unwounded corneas and corneas at one to eight weeks after -3D or -9D PRK, as well as in the epithelium and epithelial basement membrane (EBM). No difference was noted between corneas that healed with and without myofibroblast-mediated fibrosis, although TGF beta-3 was commonly associated with myofibroblasts. TGF beta-3 effects on corneal fibroblasts in vitro were similar to TGF beta-1 in stimulating transition to α-SMA-positive myofibroblasts and promoting α-SMA protein expression. The corneal stromal localization pattern of TGF beta-3 protein in unwounded corneas and corneas after epithelial-stromal injury was found to be higher and different from TGF beta-1 and TGF beta-2 reported in previous studies. TGF beta-3 had similar effects to TGF beta-1 in driving myofibroblast development and α-SMA expression in corneal fibroblasts cultured in medium with 1% fetal bovine serum.

Rehmannioside A Inhibits TRAF6/MAPK Pathway and Improves Psoriasis by Interfering with the Interaction of HaCaT Cells with IL-17A

Objective

As a common chronic inflammatory skin disease, psoriasis seriously affects the physical health and psychological well-being of patients. Various clinical treatments for psoriasis have their own drawbacks, so it is important to find effective and safe drugs. Rehmannioside A (ReA) has anti-inflammatory properties and is the main active ingredient in Fuzhengzhiyanghefuzhiyang decoction (FZHFZY), an herbal compound for the treatment of psoriasis. But no studies have been conducted to determine whether ReA alone can treat psoriasis. Therefore, this study was designed to investigate the effect of ReA in the treatment of psoriasis and its potential mechanism of action.

Methods

HaCaT cells were treated with ReA and IL-17A alone for 24 h and 48 h, and the most effective concentrations of ReA and interleukin (IL)-17A were found at 25 μg/mL and 100 ng/mL, respectively. A psoriasis cell model was constructed by stimulating HaCaT cells with IL-17A, followed by intervention with ReA. Cell viability and cell cycle distribution were measured by MTT assay and flow cytometry. The expression levels of keratin family members and chemokines were detected by real-time quantitative PCR (RT-qPCR), the levels of pro-inflammatory cytokines by enzyme-linked immunosorbent assay (ELISA), and key proteins of TRAF6/MAPK signaling pathway by Western blot.

Results

ReA weaken cell viability, down-regulate the expression of keratin family members (KRT6 and KRT17), restore cell cycle distribution to normal distribution, inhibit the release of pro-inflammatory cytokines (IL-6, IL-8 and IL-1β) and lower the expression of chemokines (S100A7, S100A9 and CXCL2) by interfering with the interaction between HaCaT cells and IL-17A. Thus, it exerts an anti-psoriatic effect by reducing the inflammatory response and inhibiting abnormal proliferation of HaCaT cells. Mechanistically, ReA inhibited the TRAF6/MAPK signaling pathway activated by IL-17A stimulation in HaCaT cells.

Conclusion

ReA has in vitro anti-psoriatic effects and may be a new therapeutic agent for psoriasis.

Slow Interstitial Fluid Flow Activates TGF-β Signaling and Drives Fibrotic Responses in Human Tenon Fibroblasts

BACKGROUND

Fibrosis limits the success of filtering glaucoma surgery. We employed 2D and 3D in vitro models to assess the effects of fluid flow on human tenon fibroblasts (HTF).

METHODS

HTF were exposed to continuous or pulsatile fluid flow for 48 or 72 h, at rates expected at the transscleral outflow site after filtering surgery. In the 2D model, the F-actin cytoskeleton and fibronectin 1 (FN1) were visualized by confocal immunofluorescence microscopy. In the 3D model, mRNA and whole cell lysates were extracted to analyze the expression of fibrosis-associated genes by qPCR and Western blot. The effects of a small-molecule inhibitor of the TGF-β receptor ALK5 were studied.

RESULTS

Slow, continuous fluid flow induced fibrotic responses in the 2D and 3D models. It elicited changes in cell shape, the F-actin cytoskeleton, the deposition of FN1 and activated the intracellular TGF-β signaling pathway to induce expression of fibrosis-related genes, such as CTGF, FN1 and COL1A1. ALK5-inhibition reduced this effect. Intermittent fluid flow also induced fibrotic changes, which decreased with increasing pause duration.

CONCLUSIONS

Slow interstitial fluid flow is sufficient to induce fibrosis, could underlie the intractable nature of fibrosis following filtering glaucoma surgery and might be a target for antifibrotic therapy.

Connective tissue growth factor: Role in trabecular meshwork remodeling and intraocular pressure lowering

Connective tissue growth factor (CTGF) is a distinct signaling molecule modulating many physiological and pathophysiological processes. This protein is upregulated in numerous fibrotic diseases that involve extracellular matrix (ECM) remodeling. It mediates the downstream effects of transforming growth factor beta (TGF-β) and is regulated via TGF-β SMAD-dependent and SMAD-independent signaling routes. Targeting CTGF instead of its upstream regulator TGF-β avoids the consequences of interfering with the pleotropic effects of TGF-β. Both CTGF and its upstream mediator, TGF-β, have been linked with the pathophysiology of glaucomatous optic neuropathy due to their involvement in the regulation of ECM homeostasis. The excessive expression of these growth factors is associated with glaucoma pathogenesis via elevation of the intraocular pressure (IOP), the most important risk factor for glaucoma. The raised in the IOP is due to dysregulation of ECM turnover resulting in excessive ECM deposition at the site of aqueous humor outflow. It is therefore believed that CTGF could be a potential therapeutic target in glaucoma therapy. This review highlights the CTGF biology and structure, its regulation and signaling, its association with the pathophysiology of glaucoma, and its potential role as a therapeutic target in glaucoma management.

Copper chelation suppresses epithelial-mesenchymal transition by inhibition of canonical and non-canonical TGF-β signaling pathways in cancer

BACKGROUND

Metastatic cancer cells exploit Epithelial-mesenchymal-transition (EMT) to enhance their migration, invasion, and resistance to treatments. Recent studies highlight that elevated levels of copper are implicated in cancer progression and metastasis. Clinical trials using copper chelators are associated with improved patient survival; however, the molecular mechanisms by which copper depletion inhibits tumor progression and metastasis are poorly understood. This remains a major hurdle to the clinical translation of copper chelators. Here, we propose that copper chelation inhibits metastasis by reducing TGF-β levels and EMT signaling. Given that many drugs targeting TGF-β have failed in clinical trials, partly because of severe side effects arising in patients, we hypothesized that copper chelation therapy might be a less toxic alternative to target the TGF-β/EMT axis.

RESULTS

Our cytokine array and RNA-seq data suggested a link between copper homeostasis, TGF-β and EMT process. To validate this hypothesis, we performed single-cell imaging, protein assays, and in vivo studies. Here, we used the copper chelating agent TEPA to block copper trafficking. Our in vivo study showed a reduction of TGF-β levels and metastasis to the lung in the TNBC mouse model. Mechanistically, TEPA significantly downregulated canonical (TGF-β/SMAD2&3) and non-canonical (TGF-β/PI3K/AKT, TGF-β/RAS/RAF/MEK/ERK, and TGF-β/WNT/β-catenin) TGF-β signaling pathways. Additionally, EMT markers of MMP-9, MMP-14, Vimentin, β-catenin, ZEB1, and p-SMAD2 were downregulated, and EMT transcription factors of SNAI1, ZEB1, and p-SMAD2 accumulated in the cytoplasm after treatment.

CONCLUSIONS

Our study suggests that copper chelation therapy represents a potentially effective therapeutic approach for targeting TGF-β and inhibiting EMT in a diverse range of cancers.

Tenascins and osteopontin in biological response in cornea

The structural composition, integrity and regular curvature of the cornea contribute to the maintenance of its transparency and vision. Disruption of its integrity caused by injury results in scarring, inflammation and neovascularization followed by losses in transparency. These sight compromising effects is caused by dysfunctional corneal resident cell responses induced by the wound healing process. Upregulation of growth factors/cytokines and neuropeptides affect development of aberrant behavior. These factors trigger keratocytes to first transform into activated fibroblasts and then to myofibroblasts. Myofibroblasts express extracellular matrix components for tissue repair and contract the tissue to facilitate wound closure. Proper remodeling following primary repair is critical for restoration of transparency and visual function. Extracellular matrix components contributing to the healing process are divided into two groups; a group of classical tissue structural components and matrix macromolecules that modulate cell behaviors/activities besides being integrated into the matrix structure. The latter components are designated as matricellular proteins. Their functionality is elicited through mechanisms which modulate the scaffold integrity, cell behaviors, activation/inactivation of either growth factors or cytoplasmic signaling regulation. We discuss here the functional roles of matricellular proteins in mediating injury-induced corneal tissue repair. The roles are described of major matricellular proteins, which include tenascin C, tenascin X and osteopontin. Focus is directed towards dealing with their roles in modulating individual activities of wound healing-related growth factors, e. g., transforming growth factor β (TGF β). Modulation of matricellular protein functions could encompass a potential novel strategy to improve the outcome of injury-induced corneal wound healing.

TGF-β as Predictive Marker and Pharmacological Target in Lung Cancer Approach

Lung cancer (LC) represents the leading cause of cancer incidence and mortality worldwide. LC onset is strongly related to genetic mutations and environmental interactions, such as tobacco smoking, or pathological conditions, such as chronic inflammation. Despite advancement in knowledge of the molecular mechanisms involved in LC, this tumor is still characterized by an unfavorable prognosis, and the current therapeutic options are unsatisfactory. TGF-β is a cytokine that regulates different biological processes, particularly at the pulmonary level, and its alteration has been demonstrated to be associated with LC progression. Moreover, TGF-β is involved in promoting invasiveness and metastasis, via epithelial to mesenchymal transition (EMT) induction, where TGF-β is the major driver. Thus, a TGF-β-EMT signature may be considered a potential predictive marker in LC prognosis, and TGF-β-EMT inhibition has been demonstrated to prevent metastasis in various animal models. Concerning a LC therapeutic approach, some TGF-β and TGF-β-EMT inhibitors could be used in combination with chemo- and immunotherapy without major side effects, thereby improving cancer therapy. Overall, targeting TGF-β may be a valid possibility to fight LC, both in improving LC prognosis and cancer therapy, via a novel approach that could open up new effective strategies against this aggressive cancer.

Inflammatory Networks in Renal Cell Carcinoma

Cancer-associated inflammation has been established as a hallmark feature of almost all solid cancers. Tumor-extrinsic and intrinsic signaling pathways regulate the process of cancer-associated inflammation. Tumor-extrinsic inflammation is triggered by many factors, including infection, obesity, autoimmune disorders, and exposure to toxic and radioactive substances. Intrinsic inflammation can be induced by genomic mutation, genome instability and epigenetic remodeling in cancer cells that promote immunosuppressive traits, inducing the recruitment and activation of inflammatory immune cells. In RCC, many cancer cell-intrinsic alterations are assembled, upregulating inflammatory pathways, which enhance chemokine release and neoantigen expression. Furthermore, immune cells activate the endothelium and induce metabolic shifts, thereby amplifying both the paracrine and autocrine inflammatory loops to promote RCC tumor growth and progression. Together with tumor-extrinsic inflammatory factors, tumor-intrinsic signaling pathways trigger a Janus-faced tumor microenvironment, thereby simultaneously promoting or inhibiting tumor growth. For therapeutic success, it is important to understand the pathomechanisms of cancer-associated inflammation, which promote cancer progression. In this review, we describe the molecular mechanisms of cancer-associated inflammation that influence cancer and immune cell functions, thereby increasing tumor malignancy and anti-cancer resistance. We also discuss the potential of anti-inflammatory treatments, which may provide clinical benefits in RCCs and possible avenues for therapy and future research.

Activin and BMP Signalling in Human Testicular Cancer Cell Lines, and a Role for the Nucleocytoplasmic Transport Protein Importin-5 in their Crosstalk

Testicular germ cell tumours (TGCTs) are the most common malignancy in young men. Originating from foetal testicular germ cells that fail to differentiate correctly, TGCTs appear after puberty as germ cell neoplasia in situ cells that transform through unknown mechanisms into distinct seminoma and non-seminoma tumour types. A balance between activin and BMP signalling may influence TGCT emergence and progression, and we investigated this using human cell line models of seminoma (TCam-2) and non-seminoma (NT2/D1). Activin A- and BMP4-regulated transcripts measured at 6 h post-treatment by RNA-sequencing revealed fewer altered transcripts in TCam-2 cells but a greater responsiveness to activin A, while BMP4 altered more transcripts in NT2/D1 cells. Activin significantly elevated transcripts linked to pluripotency, cancer, TGF-β, Notch, p53, and Hippo signalling in both lines, whereas BMP4 altered TGF-β, pluripotency, Hippo and Wnt signalling components. Dose-dependent antagonism of BMP4 signalling by activin A in TCam-2 cells demonstrated signalling crosstalk between these two TGF-β superfamily arms. Levels of the nuclear transport protein, IPO5, implicated in BMP4 and WNT signalling, are highly regulated in the foetal mouse germline. IPO5 knockdown in TCam-2 cells using siRNA blunted BMP4-induced transcript changes, indicating that IPO5 levels could determine TGF-β signalling pathway outcomes in TGCTs.

MiR-146b-5p/SEMA3G regulates epithelial-mesenchymal transition in clear cell renal cell carcinoma

OBJECTIVE

The primary purpose was to unveil how the miR-146b-5p/SEMA3G axis works in clear cell renal cell carcinoma (ccRCC).

METHODS

ccRCC dataset was acquired from TCGA database, and target miRNA to be studied was further analyzed using survival analysis. We performed miRNA target gene prediction through the database, and those predicted miRNAs were intersected with differential mRNAs. After calculating the correlation between miRNAs and mRNAs, we completed the GSEA pathway enrichment analysis on mRNAs. MiRNA and mRNA expression was examined by qRT-PCR. Western blot was introduced to detect SEMA3G, MMP2, MMP9 expression, epithelial-mesenchymal transition (EMT) marker proteins, and Notch/TGF-β signaling pathway-related proteins. Targeted relationship between miRNA and mRNA was validated using a dual-luciferase test. Transwell assay was employed to assess cell migration and invasion. Wound healing assay was adopted for evaluation of migration ability. The effect of different treatments on cell morphology was observed by a microscope.

RESULTS

In ccRCC cells, miR-146b-5p was remarkably overexpressed, yet SEMA3G was markedly less expressed. MiR-146b-5p was capable of stimulating ccRCC cell invasion, migration and EMT, and promoting the transformation of ccRCC cell morphology to mesenchymal state. SEMA3G was targeted and inhibited via miR-146b-5p. MiR-146b-5p facilitated ccRCC cell migration, invasion, morphology transforming to mesenchymal state and EMT process by targeting SEMA3G and regulating Notch and TGF-β signaling pathways.

CONCLUSION

MiR-146b-5p regulated Notch and TGF-β signaling pathway by suppressing SEMA3G expression, thus promoting the growth of ccRCC cells, which provides a possible target for ccRCC therapy and prognosis prediction.

TGF-β signaling pathway: Therapeutic targeting and potential for anti-cancer immunity

Transforming growth factor-β (TGFβ) is a pleiotropic secretory cytokine exhibiting both cancer-inhibitory and promoting properties. It transmits its signals via Suppressor of Mother against Decapentaplegic (SMAD) and non-SMAD pathways and regulates cell proliferation, differentiation, invasion, migration, and apoptosis. In non-cancer and early-stage cancer cells, TGFβ signaling suppresses cancer progression via inducing apoptosis, cell cycle arrest, or anti-proliferation, and promoting cell differentiation. On the other hand, TGFβ may also act as an oncogene in advanced stages of tumors, wherein it develops immune-suppressive tumor microenvironments and induces the proliferation of cancer cells, invasion, angiogenesis, tumorigenesis, and metastasis. Higher TGFβ expression leads to the instigation and development of cancer. Therefore, suppressing TGFβ signals may present a potential treatment option for inhibiting tumorigenesis and metastasis. Different inhibitory molecules, including ligand traps, anti-sense oligo-nucleotides, small molecule receptor-kinase inhibitors, small molecule inhibitors, and vaccines, have been developed and clinically trialed for blocking the TGFβ signaling pathway. These molecules are not pro-oncogenic response-specific but block all signaling effects induced by TGFβ. Nonetheless, targeting the activation of TGFβ signaling with maximized specificity and minimized toxicity can enhance the efficacy of therapeutic approaches against this signaling pathway. The molecules that are used to target TGFβ are non-cytotoxic to cancer cells but designed to curtail the over-activation of invasion and metastasis driving TGFβ signaling in stromal and cancer cells. Here, we discussed the critical role of TGFβ in tumorigenesis, and metastasis, as well as the outcome and the promising achievement of TGFβ inhibitory molecules in the treatment of cancer.

Comparative proteomics analysis of transforming growth factor-beta1-overexpressed human dental pulp stem cell-derived secretome on CD44-mediated fibroblast activation via canonical smad signal pathway

PURPOSE

The aim of this study investigates whether the secretome collected from human dental pulp stem cells (hDPSCs) transfected with transforming growth factor-beta1 (TGF-β1) is related to CD44 expression of fibroblasts and canonical smad signaling pathway via proteomic analyzes.

MATERIALS AND METHODS

In order to obtain secretome, hDPSCs were conditioned with serum-free alpha-MEM in an incubator containing 37°C, 5% CO₂, and humidity for 18-24 h. Proteins in control and TGF-β1 secretome were analyzed by tandem mass spectrometry-based shotgun proteomic method. Bioinformatic evaluations were completed via Ingenuity Pathway Analysis (IPA, QIAGEN) software. CD44 expressions in fibroblasts were evaluated by real time-PCR, western blot, and immunofluorescent staining. The relationship of canonical smad pathway and CD44 was analyzed by western blot and LC-MS/MS. Cell cycle, proliferation and wound healing tests were performed in the secretome groups.

RESULTS

Venn diagram was showed 174 common proteins were identified from each group. In the control secretome 140 unique proteins were identified and 66 entries were exclusive for TGF-β1 secretome. CD44 gene and protein expressions were increased in fibroblasts treated with TGF-β1 secretome. Relationship between targeted protein data showed that activation of the canonical TGF-β1/Smad pathway was up-regulated CD44 expression in fibroblasts. The canonical smad pathway-mediated upregulation of CD44 may increase the mitotic activity, proliferation, and wound healing potential in fibroblasts.

CONCLUSION

While TGF-β1-transfected hDPSC secretome may be a potential therapeutic candidate in regenerative connective tissue therapies as it induces fibroblast activation, anti-TGF-β1-based therapies would be considered in histopathological conditions such as pulmonary fibrosis or hepatic fibrosis.

Mutual regulation between glycosylation and transforming growth factor-β isoforms signaling pathway

Transforming growth factor-beta (TGF-β) superfamily members orchestrate a wide breadth of biological processes. Through Sma and Mad (Smad)-related dependent or noncanonical pathways, TGF-β members involve in the occurrence and development of many diseases such as cancers, fibrosis, autoimmune diseases, cardiovascular diseases and brain diseases. Glycosylation is one kind of the most common posttranslational modifications on proteins or lipids. Abnormal protein glycosylation can lead to protein malfunction and biological process disorder, thereby causing serious diseases. Previously, researchers commonly make comprehensive systematic overviews on the roles of TGF-β signaling in a specific disease or biological process. In recent years, more and more evidences associate glycosylation modification with TGF-β signaling pathway, and we can no longer disengage and ignore the roles of glycosylation from TGF-β signaling to make investigation. In this review, we provide an overview of current findings involved in glycosylation within TGF-βs and theirs receptors, and the interaction effects between glycosylation and TGF-β subfamily signaling, concluding that there is an intricate mutual regulation between glycosylation and TGF-β signaling, hoping to present the glycosylation regulatory patterns that concealed in TGF-βs signaling pathways.

Extracellular matrix stiffness-The central cue for skin fibrosis

Skin fibrosis is a physiopathological process featuring the excessive deposition of extracellular matrix (ECM), which is the main architecture that provides structural support and constitutes the microenvironment for various cellular behaviors. Recently, increasing interest has been drawn to the relationship between the mechanical properties of the ECM and the initiation and modulation of skin fibrosis, with the engagement of a complex network of signaling pathways, the activation of mechanosensitive proteins, and changes in immunoregulation and metabolism. Simultaneous with the progression of skin fibrosis, the stiffness of ECM increases, which in turn perturbs mechanical and humoral homeostasis to drive cell fate toward an outcome that maintains and enhances the fibrosis process, thus forming a pro-fibrotic "positive feedback loop". In this review, we highlighted the central role of the ECM and its dynamic changes at both the molecular and cellular levels in skin fibrosis. We paid special attention to signaling pathways regulated by mechanical cues in ECM remodeling. We also systematically summarized antifibrotic interventions targeting the ECM, hopefully enlightening new strategies for fibrotic diseases.

Transforming Growth Factor-β1 in Cancer Immunology: Opportunities for Immunotherapy

Transforming growth factor-beta1 (TGF-β) regulates a plethora of cell-intrinsic processes that modulate tumor progression in a context-dependent manner. Thus, although TGF-β acts as a tumor suppressor in the early stages of tumorigenesis, in late stages, this factor promotes tumor progression and metastasis. In addition, TGF-β also impinges on the tumor microenvironment by modulating the immune system. In this aspect, TGF-β exhibits a potent immunosuppressive effect, which allows both cancer cells to escape from immune surveillance and confers resistance to immunotherapy. While TGF-β inhibits the activation and antitumoral functions of T-cell lymphocytes, dendritic cells, and natural killer cells, it promotes the generation of T-regulatory cells and myeloid-derived suppressor cells, which hinder antitumoral T-cell activities. Moreover, TGF-β promotes tumor-associated macrophages and neutrophils polarization from M1 into M2 and N1 to N2, respectively. Altogether, these effects contribute to the generation of an immunosuppressive tumor microenvironment and support tumor promotion. This review aims to analyze the relevant evidence on the complex role of TGF-β in cancer immunology, the current outcomes of combined immunotherapies, and the anti-TGF-β therapies that may improve the success of current and new oncotherapies.

Epithelial-Mesenchymal Transition Induced in Cancer Cells by Adhesion to Type I Collagen

The epithelial-mesenchymal transition (EMT) is an important biological process that is physiologically observed during development, wound healing, and cancer invasion. During EMT induction, cancer cells lose their epithelial properties owing to various tumor microenvironmental factors and begin to exhibit mesenchymal properties, such as loss of apical-basal polarity, weakened intercellular adhesion, and promotion of single cell migration. Several factors, including growth factor stimulation and adhesion to type I collagen (Col-I), induce EMT in cancer cells. Cells adhere to Col-I via specific receptors and induce EMT by activating outside-in signals. In vivo, Col-I molecules often form fibrils, which then assemble into supramolecular structures (gel form). Col-I also self-assembles in vitro under physiological conditions. Notably, Col-I can be used as a culture substrate in both gel and non-gel forms, and the gel formation state of Col-I affects cell fate. Although EMT can be induced in both forms of Col-I, the effects of gel formation on EMT induction remain unclear and somewhat inconsistent. Therefore, this study reviews the relationship between Col-I gel-forming states and EMT induction in cancer cells.

The roles of TGF-β and VEGF pathways in the suppression of antitumor immunity in melanoma and other solid tumors

Immune checkpoint blockade (ICB) has become well-known in cancer therapy, strengthening the body's antitumor immune response rather than directly targeting cancer cells. Therapies targeting immune inhibitory checkpoints, such as PD-1, PD-L1, and CTLA-4, have resulted in impressive clinical responses across different types of solid tumors. However, as with other types of cancer treatments, ICB-based immunotherapy is hampered by both innate and acquired drug resistance. We previously reported the enrichment of gene signatures associated with wound healing, epithelial-to-mesenchymal, and angiogenesis processes in the tumors of patients with innate resistance to PD-1 checkpoint antibody therapy; we termed these the Innate Anti-PD-1 Resistance Signatures (IPRES). The TGF-β and VEGFA pathways emerge as the dominant drivers of IPRES-associated processes. Here, we review these pathways' functions, their roles in immunosuppression, and the currently available therapies that target them. We also discuss recent developments in the targeting of TGF-β using a specific antibody class termed trap antibody. The application of trap antibodies opens the promise of localized targeting of the TGF-β and VEGFA pathways within the tumor microenvironment. Such specificity may offer an enhanced therapeutic window that enables suppression of the IPRES processes in the tumor microenvironment while sparing the normal homeostatic functions of TGF-β and VEGFA in healthy tissues.

The type II TGF-β receptor phosphorylates Tyr 182 in the type I receptor to activate downstream Src signaling

Transforming growth factor–β (TGF-β) signaling has important roles during embryonic development and in tissue homeostasis. TGF-β ligands exert cellular effects by binding to type I (TβRI) and type II (TβRII) receptors and inducing both SMAD-dependent and SMAD-independent intracellular signaling pathways, the latter of which includes the activation of the tyrosine kinase Src. We investigated the mechanism by which TGF-β stimulation activates Src in human and mouse cells. Before TGF-β stimulation, inactive Src was complexed with TβRII. Upon TGF-β1 stimulation, TβRII associated with and phosphorylated TβRI at Tyr 182 . Binding of Src to TβRI involved the interaction of the Src SH2 domain with phosphorylated Tyr 182 and the interaction of the Src SH3 domain with a proline-rich region in TβRI and led to the activation of Src kinase activity and Src autophosphorylation. TGF-β1–induced Src activation required the kinase activities of TβRII and Src but not that of TβRI. Activated Src also phosphorylated TβRI on several tyrosine residues, which may stabilize the binding of Src to the receptor. Src activation was required for the ability of TGF-β to induce fibronectin production and migration in human breast carcinoma cells and to induce α–smooth muscle actin and actin reorganization in mouse fibroblasts. Thus, TGF-β induces Src activation by stimulating a direct interaction with TβRI that depends on tyrosine phosphorylation of TβRI by TβRII.

Transforming growth factor-β in tumour development

Transforming growth factor-β (TGFβ) is a ubiquitous cytokine essential for embryonic development and postnatal tissue homeostasis. TGFβ signalling regulates several biological processes including cell growth, proliferation, apoptosis, immune function, and tissue repair following injury. Aberrant TGFβ signalling has been implicated in tumour progression and metastasis. Tumour cells, in conjunction with their microenvironment, may augment tumourigenesis using TGFβ to induce epithelial-mesenchymal transition, angiogenesis, lymphangiogenesis, immune suppression, and autophagy. Therapies that target TGFβ synthesis, TGFβ-TGFβ receptor complexes or TGFβ receptor kinase activity have proven successful in tissue culture and in animal models, yet, due to limited understanding of TGFβ biology, the outcomes of clinical trials are poor. Here, we review TGFβ signalling pathways, the biology of TGFβ during tumourigenesis, and how protein quality control pathways contribute to the tumour-promoting outcomes of TGFβ signalling.

Browning of the white adipose tissue regulation: new insights into nutritional and metabolic relevance in health and diseases

Adipose tissues are dynamic tissues that play crucial physiological roles in maintaining health and homeostasis. Although white adipose tissue and brown adipose tissue are currently considered key endocrine organs, they differ functionally and morphologically. The existence of the beige or brite adipocytes, cells displaying intermediary characteristics between white and brown adipocytes, illustrates the plastic nature of the adipose tissue. These cells are generated through white adipose tissue browning, a process associated with augmented non-shivering thermogenesis and metabolic capacity. This process involves the upregulation of the uncoupling protein 1, a molecule that uncouples the respiratory chain from Adenosine triphosphate synthesis, producing heat. β-3 adrenergic receptor system is one important mediator of white adipose tissue browning, during cold exposure. Surprisingly, hyperthermia may also induce beige activation and white adipose tissue beiging. Physical exercising copes with increased levels of specific molecules, including Beta-Aminoisobutyric acid, irisin, and Fibroblast growth factor 21 (FGF21), which induce adipose tissue browning. FGF21 is a stress-responsive hormone that interacts with beta-klotho. The central roles played by hormones in the browning process highlight the relevance of the individual lifestyle, including circadian rhythm and diet. Circadian rhythm involves the sleep-wake cycle and is regulated by melatonin, a hormone associated with UCP1 level upregulation. In contrast to the pro-inflammatory and adipose tissue disrupting effects of the western diet, specific food items, including capsaicin and n-3 polyunsaturated fatty acids, and dietary interventions such as calorie restriction and intermittent fasting, favor white adipose tissue browning and metabolic efficiency. The intestinal microbiome has also been pictured as a key factor in regulating white tissue browning, as it modulates bile acid levels, important molecules for the thermogenic program activation. During embryogenesis, in which adipose tissue formation is affected by Bone morphogenetic proteins that regulate gene expression, the stimuli herein discussed influence an orchestra of gene expression regulators, including a plethora of transcription factors, and chromatin remodeling enzymes, and non-coding RNAs. Considering the detrimental effects of adipose tissue browning and the disparities between adipose tissue characteristics in mice and humans, further efforts will benefit a better understanding of adipose tissue plasticity biology and its applicability to managing the overwhelming burden of several chronic diseases.

Therapeutic Potential of the Combination of Pentoxifylline and Vitamin-E in Inflammatory Bowel Disease: Inhibition of Intestinal Fibrosis

Background: Although intestinal fibrosis is a consequence of recurrent inflammation in Inflammatory bowel disease (IBD), alleviating inflammation alone does not prevent the progression of fibrosis, suggesting that the development of direct anti-fibrotic agents is necessary. This study aimed to evaluate the anti-fibrotic properties of combination treatment with pentoxifylline (PTX) and vitamin E (Vit-E) on human primary intestinal myofibroblasts (HIMFs) and the therapeutic potential of the combination therapy in murine models of IBD. Methods: HIMFs were pretreated with PTX, Vit-E, or both, and incubated with TGF-β1. We performed Western blot, qPCR, collagen staining, and immunofluorescence to estimate the anti-fibrotic effects of PTX and Vit-E. The cytotoxicity of these was investigated through MTT assay. To induce murine models of IBD for in vivo study, C57BL/6 mice were treated with repeated cycles of dextran sulfate sodium (DSS), developing chronic colitis. We examined whether the combined PTX and Vit-E treatment would effectively ameliorate colonic fibrosis in vivo. Results: We found that the co-treatment with PTX and Vit-E suppressed TGF-β1-induced expression of fibrogenic markers, with decreased expression of pERK, pSmad2, and pJNK, more than either treatment alone in HIMFs. Neither PTX nor Vit-E showed any significant cytotoxicity in given concentrations. Consistently with the in vitro results, the co-administration with PTX and Vit-E effectively attenuated colonic fibrosis with recovery from thickening and shortening of colon in murine models of IBD. Conclusions: These findings demonstrated that the combination of PTX and Vit-E exhibits significant anti-fibrotic effects in both HIMFs and in vivo IBD models, providing a promising therapy for IBD.

GLUT3 Promotes Epithelial–Mesenchymal Transition via TGF-β/JNK/ATF2 Signaling Pathway in Colorectal Cancer Cells

Glucose transporter (GLUT) 3, a member of the GLUTs family, is involved in cellular glucose utilization and the first step in glycolysis. GLUT3 is highly expressed in colorectal cancer (CRC) and it leads to poor prognosis to CRC patient outcome. However, the molecular mechanisms of GLUT3 on the epithelial–mesenchymal transition (EMT) process in metastatic CRC is not yet clear. Here, we identified that activation of the c-Jun N-terminal kinase (JNK)/activating transcription factor-2 (ATF2) signaling pathway by transforming growth factor-β (TGF-β) promotes GLUT3-induced EMT in CRC cells. The regulation of GLUT3 expression was significantly associated with EMT-related markers such as E-cadherin, α- smooth muscle actin (α-SMA), plasminogen activator inhibitor-1 (PAI-1), vimentin and zinc finger E-box binding homeobox 1 (ZEB1). We also found that GLUT3 accelerated the invasive ability of CRC cells. Mechanistically, TGF-β induced the expression of GLUT3 through the phosphorylation of JNK/ATF2, one of the SMAD-independent pathways. TGF-β induced the expression of GLUT3 by increasing the phosphorylation of JNK, the nuclear translocation of the ATF2 transcription factor, and the binding of ATF2 to the promoter region of GLUT3, which increased EMT in CRC cells. Collectively, our results provide a new comprehensive mechanism that GLUT3 promotes EMT process through the TGF-β/JNK/ATF2 signaling pathway, which could be a potential target for the treatment of metastatic CRC.

The In-Vitro Antitumor Effects of AST-3424 Monotherapy and Combination Therapy With Oxaliplatin or 5-Fluorouracil in Primary Liver Cancer

Background

Primary liver cancer (PLC) is a common and highly lethal malignancy in the world. Approximately 85% of PLC is hepatocellular carcinoma (HCC), and this study mainly focuses on HCC. The onset of liver cancer is insidious and often complicated with basic liver disease. Meanwhile, its clinical symptoms are atypical, and the degree of malignancy is high. What is worse is that its treatment is difficult, and the prognosis is poor. All these factors make its mortality close to its incidence. AST-3424 is a prodrug of a potent nitrogen mustard, which targets the tumor by its specific and selective mode of activation and results in the concentration of the drug in the tumor and plays a higher intensity of antitumor effect with reduced side effects. The purpose of this study was to explore the in-vitro antitumor activity and mechanism of AST-3424 monotherapy and combination therapy with oxaliplatin (OXA) or 5-fluorouracil (5-Fu). Moreover, it can provide an experimental basis for further studies.

Methods

Tumor growth of HCC cells was examined by using the Cell Counting Kit-8 (CCK-8), flow cytometry, and clone formation assays. Tumor migration of HCC cells was examined by using the Transwell assay. The in-vitro antitumor activity of AST-3424 monotherapy and combination therapy with OXA and 5-Fu was quantified by growth and metastasis inhibition rate. The underlying molecular mechanism was investigated by using Western blotting.

Results

The inhibiting effects of AST-3424 were significant in both HepG2 cells and PLC/PRF/5 cells. Moreover, HepG2 cells showed higher sensitivity to AST-3424. With increasing AST-3424 concentration, AKR1C3 protein expression level was downregulated significantly. The inhibition of AST-3424 was significantly higher than OXA, 5-Fu, Sor (sorafenib), and Apa (apatinib) in both HCC cells. AST-3424 monotherapy and combination therapy with OXA or 5-Fu all strongly inhibited the proliferation of HCC cells, blocked HCC cells in the S phase, promoted apoptosis induction, and suppressed the migration of HCC cells. Among them, the antitumor effect of AST-3424 in combination with OXA was obviously enhanced. Western blotting analysis demonstrated the regulation of P21, Bax, Caspase3, PARP, MMP-2, MMP-9, and p-Smad proteins in the presence of AST-3424 monotherapy and combination therapy with OXA or 5-Fu, indicating that its antitumor mechanisms may be associated with the regulation of the TGF-β signaling cascade.

Conclusion

The in-vitro studies revealed that AST-3424 in combination with both OXA and 5-Fu showed an increased antitumor effect, and the combination with OXA resulted in a synergistic effect. Together with the in-vitro results, additional in-vitro and in-vivo studies are warranted to further certify its antitumor effects and explore more potential antitumor mechanisms.

Increased TGFβ1 and SMAD3 Contribute to Age-Related Aortic Valve Calcification

Aims

Calcific aortic valve disease (CAVD) is a progressive heart disease that is particularly prevalent in elderly patients. The current treatment of CAVD is surgical valve replacement, but this is not a permanent solution, and it is very challenging for elderly patients. Thus, a pharmacological intervention for CAVD may be beneficial. In this study, we intended to rescue aortic valve (AV) calcification through inhibition of TGFβ1 and SMAD3 signaling pathways.

Methods and Results

The klotho gene, which was discovered as an aging-suppressor gene, has been observed to play a crucial role in AV calcification. The klotho knockout (Kl^–/–) mice have shorter life span (8–12 weeks) and develop severe AV calcification. Here, we showed that increased TGFβ1 and TGFβ-dependent SMAD3 signaling were associated with AV calcification in Kl^–/– mice. Next, we generated Tgfb1- and Smad3-haploinsufficient Kl^–/– mice to determine the contribution of TGFβ1 and SMAD3 to the AV calcification in Kl^–/– mice. The histological and morphometric evaluation suggested a significant reduction of AV calcification in Kl^–/–; Tgfb1^± mice compared to Kl^–/– mice. Smad3 heterozygous deletion was observed to be more potent in reducing AV calcification in Kl^–/– mice compared to the Kl^–/–; Tgfb1^± mice. We observed significant inhibition of Tgfb1, Pai1, Bmp2, Alk2, Spp1, and Runx2 mRNA expression in Kl^–/–; Tgfb1^± and Kl^–/–; Smad3^± mice compared to Kl^–/– mice. Western blot analysis confirmed that the inhibition of TGFβ canonical and non-canonical signaling pathways were associated with the rescue of AV calcification of both Kl^–/–; Tgfb1^± and Kl^–/–; Smad3^± mice.

Conclusion

Overall, inhibition of the TGFβ1-dependent SMAD3 signaling pathway significantly blocks the development of AV calcification in Kl^–/– mice. This information is useful in understanding the signaling mechanisms involved in CAVD.

Transforming growth factor β1-enriched secretome up-regulate osteogenic differentiation of dental pulp stem cells, and a potential therapeutic for gingival wound healing: A comparative proteomics study

OBJECTIVES

Current study aimed at comparing the human dental pulp-derived stem cell (hDPSC) secretome (Control secretome) and transforming growth factor beta1 (TGF-β1)-transfected hDPSC secretome (TGF-β1 Secretome), which have the potential to be therapeutic in terms of regenerative dentistry, in terms of osteogenesis, adipogenesis and gingival wound healing with proteomic analyses.

MATERIALS AND METHODS

pCMV-TGF-β1 plasmid was transfected into hDPSCs by electroporation. hDPSC and TGF-β1 transfected hDPSC secretomes were collected for LC-MS/MS. Protein contents in control secretome and TGF-β1 secretome were analyzed by tandem mass spectrometry-based shotgun proteomic method. Bioinformatic evaluations for canonical pathways, upstream regulators and networks were completed via Ingenuity Pathway Analysis (IPA, QIAGEN) software. Surface marker expressions between groups, treated secretome were measured by flow cytometry. To support the proteomic data morphologically, we performed osteogenic-adipogenic differentiation in hDPSCs treated with control secretome and TGF-β1 secretome, and scratch wound healing assay in gingival fibroblasts. Statistical analyses were performed by GraphPad Prism 8.02.

RESULTS

Venn diagram classification showed us 174 common proteins were identified from each group. In the control secretome 140 unique proteins were identified and 66 entries were exclusive for TGF-β1 secretome. TGF-β1 secretome was found to have therapeutic effect on MSC-specific immunophenotypes. TGF-β1 secretome was determined to up-regulate osteogenesis-related molecules and pathways while down-regulating adipogenesis-related pathways. Analysis of canonical pathways showed that TGF-β1 secretome is associated with the wound healing pathway.

CONCLUSION

Our study provided the first evidence that proteins identified in TGF-β1-transfected hDPSC secretomes are potential regulators of osteogenic/adipogenic differentiation and fibroblast wound healing.

CLINICAL SIGNIFICANCE

Based on these results, TGF-β1 secretome may have a therapeutic effect in repairing osteoporosis-related bone injuries, wound healing of oral mucosa and gingival tissue. TGF-β1 secretome may be a potential cell-free therapeutic in orthopedics and regenerative dentistry.

USP8 promotes cancer progression and extracellular vesicle-mediated CD8+ T cell exhaustion by deubiquitinating the TGF-β receptor TβRII

TGF-β signaling is a key player in tumor progression and immune evasion, and is associated with poor response to cancer immunotherapies. Here, we identified ubiquitin-specific peptidase 8 (USP8) as a metastasis enhancer and a highly active deubiquitinase in aggressive breast tumors. USP8 acts both as a cancer stemness-promoting factor and an activator of the TGF-β/SMAD signaling pathway. USP8 directly deubiquitinates and stabilizes the type II TGF-β receptor TβRII, leading to its increased expression in the plasma membrane and in tumor-derived extracellular vesicles (TEVs). Increased USP8 activity was observed in patients resistant to neoadjuvant chemotherapies. USP8 promotes TGF-β/SMAD-induced epithelial-mesenchymal transition (EMT), invasion, and metastasis in tumor cells. USP8 expression also enables TβRII+ circulating extracellular vesicles (crEVs) to induce T cell exhaustion and chemoimmunotherapy resistance. Pharmacological inhibition of USP8 antagonizes TGF-β/SMAD signaling, and reduces TβRII stability and the number of TβRII+ crEVs to prevent CD8+ T cell exhaustion and to reactivate anti-tumor immunity. Our findings not only reveal a novel mechanism whereby USP8 regulates the cancer microenvironment but also demonstrate the therapeutic advantages of engineering USP8 inhibitors to simultaneously suppress metastasis and improve the efficacy of cancer immunotherapy.

Targeted inhibition of TGF-β type I receptor by AZ12601011 protects against kidney fibrosis

Renal fibrosis, a common feature of chronic kidney disease, causes the progressive loss of renal function, in which TGF-β₁ plays a critical role. In this study, we found that expression levels of TGF-β₁ and its receptor 1 (TGF-βR1) were both significantly increased in obstructive fibrosis kidneys. AZ12601011 is a small molecular inhibitor of TGF-βR1; however, its therapeutic potential for renal fibrosis remains unclear. During the experiments, AZ12601011 was applied to various models of renal fibrosis followed by unilateral ureteral obstruction (UUO) and ischemia/reperfusion (I/R) in vivo, in addition to renal tubular epithelial cells (TECs) challenged by hypoxia/reoxygenation (H/R) and TGF-β₁in vitro. Our results revealed that AZ12601011 ameliorated renal injuries and fibrosis shown by PAS, HE, and Masson staining, which was consistent with the decrease in Col-1 and α-SMA expression in the kidneys from UUO and I/R mice. Similarly, in vitro data showed that AZ12601011 inhibited the induction of Col-1 and α-SMA in both TECs treated with TGF-β₁ and H/R. In addition, the results of cellular thermal shift assay (CETSA), molecular docking, and western bolt indicated that AZ12601011 could directly bind to TGF-βR1 and block activation of the downstream Smad3. Taken together, our findings suggest that AZ12601011 can attenuate renal fibrosis by blocking the TGF-β/Smad3 signaling pathway and it might serve as a promising clinical candidate in the fight against fibrotic kidney diseases.