Dysregulated TGF-β Signaling Research Articles

Impaired Tertiary Dentin Secretion after Shallow Injury in Tgfbr2-Deficient Dental Pulp Cells Is Rescued by Extended CGRP Signaling.

The transforming growth factor β (TGFβ) superfamily is a master regulator of development, adult homeostasis, and wound repair. Dysregulated TGFβ signaling can lead to cancer, fibrosis, and musculoskeletal malformations. We previously demonstrated that TGFβ receptor 2 (Tgfbr2) signaling regulates odontoblast differentiation, dentin mineralization, root elongation, and sensory innervation during tooth development. Sensory innervation also modulates the homeostasis and repair response in adult teeth. We hypothesized that Tgfbr2 regulates the neuro-pulpal responses to dentin injury. To test this, we performed a shallow dentin injury with a timed deletion of Tgfbr2 in the dental pulp mesenchyme of mice and analyzed the levels of tertiary dentin and calcitonin gene-related peptide (CGRP) axon sprouting. Microcomputed tomography imaging and histology indicated lower dentin volume in Tgfbr2cko M1s compared to WT M1s 21 days post-injury, but the volume was comparable by day 56. Immunofluorescent imaging of peptidergic afferents demonstrated that the duration of axon sprouting was longer in injured Tgfbr2cko compared to WT M1s. Thus, CGRP+ sensory afferents may provide Tgfbr2-deficient odontoblasts with compensatory signals for healing. Harnessing these neuro-pulpal signals has the potential to guide the development of treatments for enhanced dental healing and to help patients with TGFβ-related diseases.

Abstract 3388: Targeting liver specific βII-Spectrin to prevent the development of metabolic dysfunction associated steatohepatitis (MASH) through CEACAM1 axis

Abstract Background: Obesity and pro-inflammatory alteration of the gut microbiome are risk factors for gastrointestinal (GI) cancers, including liver cancer (HCC). Dysregulated TGF-β signaling and loss of CEACAM1 activity are implicated in fatty liver disease. Clinically, 40% of human liver and GI cancers have genetic alterations in the TGF-β pathway members. CEACAM1 expression is significantly decreased in the liver of patients with Metabolic dysfunction-associated steatohepatitis (MASH). In contrast, in hepatocellular carcinoma (HCC), high CEACAM1 is associated with invasion, metastasis and poor prognosis. We hypothesized that TGF-β signaling and βII-Spectrin modulate MASH and HCC through CEACAM1. Methods: Wild type and the liver-specific βII-Spectrin (Sptbn1) knockout (LSKO) mice fed a high-fat diet (HFD) or Western diet (WD) and analyzed for Ceacam1 expression, changes in immune cell population, liver inflammation, and cancer. We used Alphafold and molecular modeling to identify the CEACAM1 and SPTBN1 interaction sites. Results: Single cell sequencing analysis of MASH mice liver revealed that Ceacam1 expression is significantly decreased in hepatocytes. Interestingly, we found that CEACAM1 levels are restored to normal in tissues from liver-specific βII-Spectrin knockout (LSKO) mice. Transcriptomic and multiplex imaging analysis suggest that proinflammatory TGF-β signaling is activated and infiltration of CD11b+ cells is increased in MASH liver. These phenotypes are blocked in LSKO mice. Furthermore, siRNA-knockdown of βII-Spectrin blocks diet-induced obesity, fibrosis, lipid accumulation, tissue damage, and cancer susceptibility. We have also found that CEACAM1 interacts with the Smad3 adaptor, βII-Spectrin. Furthermore, structural analysis of CECAM1 and βII-Spectrin revealed critical residues involved in the interaction. Conclusion: These data suggest that βII-Spectrin regulates CEACAM1 expression in the liver and is a potential target for therapeutic intervention to treat MASH and prevent progression to HCC. Citation Format: Krishanu Bhowmick, Kazufumi Ohshiro, Xiyan Xiang, Sahara John, Xiaochun Yang, Nicole Beauchemin, Mohammad I. Hassan, Taj Mohammad, Lopa Mishra. Targeting liver specific βII-Spectrin to prevent the development of metabolic dysfunction associated steatohepatitis (MASH) through CEACAM1 axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3388.

Rhinovirus protease cleavage of nucleoporins: perspective on implications for airway remodeling.

Human Rhinoviruses (RV) are a major cause of common colds and infections in early childhood and can lead to subsequent development of asthma via an as yet unknown mechanism. Asthma is a chronic inflammatory pulmonary disease characterized by significant airway remodeling. A key component of airway remodeling is the transdifferentiation of airway epithelial and fibroblast cells into cells with a more contractile phenotype. Interestingly, transforming growth factor-beta (TGF-β), a well characterized inducer of transdifferentiation, is significantly higher in airways of asthmatics compared to non-asthmatics. RV infection induces TGF-β signaling, at the same time nucleoporins (Nups), including Nup153, are cleaved by RV proteases disrupting nucleocytoplasmic transport. As Nup153 regulates nuclear export of SMAD2, a key intermediate in the TGF-β transdifferentiation pathway, its loss of function would result in nuclear retention of SMAD2 and dysregulated TGF-β signaling. We hypothesize that RV infection leads to increased nuclear SMAD2, resulting in sustained TGF-β induced gene expression, priming the airway for subsequent development of asthma. Our hypothesis brings together disparate studies on RV, asthma and Nup153 with the aim to prompt new research into the role of RV infection in development of asthma.

A longitudinal molecular and cellular lung atlas of lethal SARS-CoV-2 infection in K18-hACE2 transgenic mice

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to approximately 500 million cases and 6 million deaths worldwide. Previous investigations into the pathophysiology of SARS-CoV-2 primarily focused on peripheral blood mononuclear cells from patients, lacking detailed mechanistic insights into the virus's impact on inflamed tissue. Existing animal models, such as hamster and ferret, do not faithfully replicate the severe SARS-CoV-2 infection seen in patients, underscoring the need for more relevant animal system-based research. In this study, we employed single-cell RNA sequencing (scRNA-seq) with lung tissues from K18-hACE2 transgenic (TG) mice during SARS-CoV-2 infection. This approach allowed for a comprehensive examination of the molecular and cellular responses to the virus in lung tissue. Upon SARS-CoV-2 infection, K18-hACE2 TG mice exhibited severe lung pathologies, including acute pneumonia, alveolar collapse, and immune cell infiltration. Through scRNA-seq, we identified 36 different types of cells dynamically orchestrating SARS-CoV-2-induced pathologies. Notably, SPP1+ macrophages in the myeloid compartment emerged as key drivers of severe lung inflammation and fibrosis in K18-hACE2 TG mice. Dynamic receptor-ligand interactions, involving various cell types such as immunological and bronchial cells, defined an enhanced TGFβ signaling pathway linked to delayed tissue regeneration, severe lung injury, and fibrotic processes. Our study provides a comprehensive understanding of SARS-CoV-2 pathogenesis in lung tissue, surpassing previous limitations in investigating inflamed tissues. The identified SPP1+ macrophages and the dysregulated TGFβ signaling pathway offer potential targets for therapeutic intervention. Insights from this research may contribute to the development of innovative diagnostics and therapies for COVID-19. This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2020M3A9I2109027, 2021R1A2C2004501).

MED1 Regulates BMP/TGF-β in Endothelium: Implication for Pulmonary Hypertension.

Dysregulated BMP (bone morphogenetic protein) or TGF-β (transforming growth factor beta) signaling pathways are imperative in idiopathic and familial pulmonary arterial hypertension (PAH) as well as experimental pulmonary hypertension (PH) in rodent models. MED1 (mediator complex subunit 1) is a key transcriptional co-activator and KLF4 (Krüppel-like factor 4) is a master transcription factor in endothelium. However, MED1 and KLF4 epigenetic and transcriptional regulations of the BMP/TGF-β axes in pulmonary endothelium and their dysregulations leading to PAH remain elusive. We investigate the MED1/KLF4 co-regulation of the BMP/TGF-β axes in endothelium by studying the epigenetic regulation of BMPR2 (BMP receptor type II), ETS-related gene (ERG), and TGFBR2 (TGF-β receptor 2) and their involvement in the PH. High-throughput screening involving data from RNA-seq, MED1 ChIP-seq, H3K27ac ChIP-seq, ATAC-seq, and high-throughput chromosome conformation capture together with in silico computations were used to explore the epigenetic and transcriptional regulation of BMPR2, ERG, and TGFBR2 by MED1 and KLF4. In vitro experiments with cultured pulmonary arterial endothelial cells (ECs) and bulk assays were used to validate results from these in silico analyses. Lung tissue from patients with idiopathic PAH, animals with experimental PH, and mice with endothelial ablation of MED1 (EC-MED1-/-) were used to study the PH-protective effect of MED1. Levels of MED1 were decreased in lung tissue or pulmonary arterial endothelial cells from idiopathic PAH patients and rodent PH models. Mechanistically, MED1 acted synergistically with KLF4 to transactivate BMPR2, ERG, and TGFBR2 via chromatin remodeling and enhancer-promoter interactions. EC-MED1-/- mice showed PH susceptibility. In contrast, MED1 overexpression mitigated the PH phenotype in rodents. A homeostatic regulation of BMPR2, ERG, and TGFBR2 in ECs by MED1 synergistic with KLF4 is essential for the normal function of the pulmonary endothelium. Dysregulation of MED1 and the resulting impairment of the BMP/TGF-β signaling is implicated in the disease progression of PAH in humans and PH in rodent models.

Abstract 1463: Impaired reciprocal regulation between SIRT6 and TGF-β signaling as a potential mechanism for development and progression of fatty liver

Abstract Background: Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of fibrotic liver disease and hepatocellular carcinoma (HCC). Dysregulated TGF-β signaling and loss of SIRT6 activity are implicated in fatty liver disease. SIRT6 limits fibrosis by inhibiting SMAD3 activity and limits de novo lipogenesis by inhibiting SREBP1 and SREBP2 activity. We hypothesized that altered reciprocal regulation between TGF-β signaling and SIRT6 contributes to NAFLD and its progression. The goal of this study was to identify regulatory crosstalk between SIRT6 and SMAD3 and SPTBN1, a regulator of SMAD3 activity. Methods: We used bioinformatics and chromatin immunoprecipitation (ChIP) with HepG2 cells to examine the binding of SMAD3 or CTCF to the SIRT6 gene in the presence or absence of TGF-β. Using cultured cells, we examined the effect of altering SPTBN1 or SMAD3 on SIRT6 abundance, and of altering SIRT6 on SPTBN1 and SMAD3 abundance. We examined liver phenotypes of SPTBN1+/- mice fed either a normal chow diet or a high-fat diet (HFD) and monitored body weight and serum total cholesterol and triglyceride concentrations, as well as analyzed liver tissue for SIRT6 abundance. Results: We identified two consensus SMAD-binding elements and two consensus CTCF binding sites in the SIRT6 promoter and showed by ChIP that TGF-β stimulated SMAD3 and CTCF binding to the promoter region of SIRT6. We found that deficiency in SMAD3 or SPTBN1 reduced SIRT6 mRNA and protein abundance. Overexpression of SIRT6 reduced expression of selected TGF-β-induced genes. Knockdown of SIRT6 increased SPTBN1 but not SMAD3 abundance and overexpression of SIRT6 reduced only SPTBN1 abundance. We found that fatty liver and associated metabolic changes induced by HFD is worse in SPTBN1+/- mice than in control mice. Furthermore, this condition was associated with reduced SIRT6 protein abundance in the liver. Conclusions: We found a reciprocal regulatory mechanism involving SPTBN1 through which SIRT6 can influence TGF-β signaling and identified SIRT6 as a target of TGF-β-SMAD3 signaling. The development of liver steatosis with reduced SIRT6 in SPTBN1+/- mice suggested that impaired induction of SIRT6 contributes to the severe liver phenotype, which resembles nonalcoholic steatohepatitis (NASH). Future investigation may yield opportunities to intervene and prevent NAFLD from progressing to NASH and thus reduce the risk of HCC. Citation Format: Kazufumi Ohshiro, Xiyan Xiang, David Bernstein, James M. Crawford, Bibhuti Mishra, Patricia S. Latham, Nancy R. Gough, Shuyun Rao, Lopa Mishra. Impaired reciprocal regulation between SIRT6 and TGF-β signaling as a potential mechanism for development and progression of fatty liver [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1463.

Megakaryocytes Are Regulators of the Tumor Microenvironment and Malignant Hematopoietic Progenitor Cells in Myelofibrosis.

Megakaryocytes (MKs) are multifunctional hematopoietic cells that produce platelets, serve as components of bone marrow (BM) niches that support the development of hematopoietic stem and progenitor cell (HSPC) and provide inflammatory signals. MKs can dynamically change their activities during homeostasis and following stress, thereby regulating hematopoietic stem cell (HSC) function. Myelofibrosis (MF) is a progressive chronic myeloproliferative neoplasm (MPN) characterized by hyperactivation of JAK/STAT signaling and MK hyperplasia, which is associated with an aberrant inflammatory signature. Since JAK1/2 inhibitor alone is incapable of depleting the malignant HSC clones or reversing BM fibrosis, the identification of mechanisms that cooperate with MF JAK/STAT signaling to promote disease progression might help in developing combination therapies to modify disease outcomes. Chronic inflammation and MK hyperplasia result in an abnormal release of TGFβ1, which plays a critical role in the pathobiology of MF by contributing to the development of BM fibrosis. Dysregulated TGFβ signaling can also alter the hematopoietic microenvironment supporting the predominance of MF-HSCs and enhance the quiescence of the reservoir of wild-type HSCs. Upregulation of TGFβ1 levels is a relatively late event in MF, while during the early pre-fibrotic stage of MF the alarmin S100A8/S100A9 heterocomplex promotes pro-inflammatory responses and sustains the progression of MF-HSCs. In this review, we will discuss the recent advances in our understanding of the roles of abnormal megakaryopoiesis, and the altered microenvironment in MF progression and the development of novel combined targeted therapies to disrupt the aberrant interplay between MKs, the BM microenvironment and malignant HSCs which would potentially limit the expansion of MF-HSC clones.

Targeted IL-4Rα blockade ameliorates refractory allergic eosinophilic inflammation in a patient with dysregulated TGF-β signaling due to ERBIN deficiency

Transforming growth factor-beta (TGF-β) is a multifunctional cytokine that possesses immune stimulatory and inhibitory functions, influences T-lymphocyte differentiation, and promotes cell proliferation and wound healing.1 This TGF-β signaling activates the transcription factor SMAD3, which increases interleukin-4 (IL-4) receptor expression associated with type 2–skewed immune responses (Figure 1). Dysregulated TGF-β signaling has been implicated in human syndromes with coexistent connective tissue abnormalities and atopy (eg, Ehlers-Danlos syndrome, Loeys-Dietz syndrome).

Dual inhibition of TGF-β and PD-L1: a novel approach to cancer treatment.

Transforming growth factor‐β (TGF‐β) and programmed death ligand 1 (PD‐L1) initiate signaling pathways with complementary, nonredundant immunosuppressive functions in the tumor microenvironment (TME). In the TME, dysregulated TGF‐β signaling suppresses antitumor immunity and promotes cancer fibrosis, epithelial‐to‐mesenchymal transition, and angiogenesis. Meanwhile, PD‐L1 expression inactivates cytotoxic T cells and restricts immunosurveillance in the TME. Anti‐PD‐L1 therapies have been approved for the treatment of various cancers, but TGF‐β signaling in the TME is associated with resistance to these therapies. In this review, we discuss the importance of the TGF‐β and PD‐L1 pathways in cancer, as well as clinical strategies using combination therapies that block these pathways separately or approaches with dual‐targeting agents (bispecific and bifunctional immunotherapies) that may block them simultaneously. Currently, the furthest developed dual‐targeting agent is bintrafusp alfa. This drug is a first‐in‐class bifunctional fusion protein that consists of the extracellular domain of the TGF‐βRII receptor (a TGF‐β ‘trap’) fused to a human immunoglobulin G1 (IgG1) monoclonal antibody blocking PD‐L1. Given the immunosuppressive effects of the TGF‐β and PD‐L1 pathways within the TME, colocalized and simultaneous inhibition of these pathways may potentially improve clinical activity and reduce toxicity.

Combination Therapy of Bispecific Protein of Anti-PD-L1 Fused with TGF- β Receptor in Cancer

Transforming growth factor β (TGF-β) and programmed death-ligand 1 (PD-L1) initiate signaling pathways with complementary, nonredundant immunosuppressive functions in the tumor microenvironment (TME). In the TME, dysregulated TGF-β signaling suppresses antitumor immunity and promotes cancer fibrosis, epithelial-mesenchymal transition, and angiogenesis. Meanwhile, PD-L1 expression inactivates cytotoxic T cell function and restricts immunosurveillance in the TME. Anti-PD-L1 therapies have been approved for the treatment of various cancers, while TGF-β signaling in the TME is associated with resistance to anti-PD-L1 therapies. Here, we have reviewed the rationale of the TGF-β and PD-L1 pathways in cancer and discussed current strategies using combination therapies that block these pathways separately or approaches with dualtargeting agents that may block the pathways simultaneously. Importantly, according to current clinical results, we propose the developing strategy of combination treatment with two or more agents.

Lack of CFTR alters the ferret pancreatic ductal epithelial secretome and cellular proteome: Implications for exocrine/endocrine signaling

BackgroundCystic fibrosis (CF) related diabetes is the most common comorbidity for CF patients and associated with islet dysfunction. Exocrine pancreas remodeling in CF alters the microenvironment in which islets reside. Since CFTR is mainly expressed in pancreatic ductal epithelium, we hypothesized altered CF ductal secretions could impact islet function through paracrine signals. MethodWe evaluated the secretome and cellular proteome of polarized WT and CF ferret ductal epithelia using quantitative ratiometric mass spectrometry. Differentially secreted proteins (DSPs) or expressed cellular proteins were used to mine pathways, upstream regulators and the CFTR interactome to map candidate CF-associated alterations in ductal signaling and phenotype. Candidate DSPs were evaluated for their in vivo pancreatic expression patterns and their functional impact on islet hormone secretion. ResultsThe secretome and cellular proteome of CF ductal epithelia was significantly altered relative to WT and implicated dysregulated TGFβ, WNT, and BMP signaling pathways. Cognate receptors of DSPs from CF epithelia were equally distributed among endocrine, exocrine, and stromal pancreatic cell types. IGFBP7 was a downregulated DSP in CF ductal epithelia in vitro and exhibited reduced CF ductal expression in vivo. IGFBP7 also altered WT islet insulin secretion in response to glucose. Many CFTR-associated proteins, including SLC9A3R1, were differentially expressed in the CF cellular proteome. Upstream regulators of the differential CF ductal proteome included TGFβ, PDX1, AKT/PTEN, and INSR signaling. Data is available via ProteomeXchange with identifier PXD025126. ConclusionThese findings provide a proteomic roadmap for elucidating disturbances in autocrine and paracrine signals from CF pancreatic ducts and how they may alter islet function and maintenance.

Dysregulated TGF-β Signaling Leads to Cell-Intrinsic Changes in T cell Development that Promote Allergic Inflammation

Abstract Variants in genes in the Transforming Growth Factor Beta (TGFβ) signaling pathway are associated with allergic diseases suggesting that this cytokine may be a central player in the allergic diathesis. The role of TGFβ in preserving T cell mediated self-tolerance is well appreciated but how disruption in this pathway promotes allergic inflammation is unclear. We previously demonstrated that patients with Loeys-Dietz Syndrome (LDS), an autosomal dominant disorder caused by mutations in TGFBR1 and TGFBR2, are highly predisposed to allergic disease. LDS patients and mice harboring a knock in allele (Tgfbr1mut) of an LDS mutation known to cause severe disease in humans exhibit higher levels of total and food specific IgE. These serologic changes were associated with higher frequencies of T follicular helper (Tfh) cells and lower T follicular regulatory (Tfr) cells. Using a mixed bone marrow and fetal liver chimera model, we showed that these alterations in T cell development are cell intrinsic. Chimera models also demonstrated that the TGFβ mutation drives higher IgE production despite the presence of wildtype Tregs. Furthermore OVA specific Tgfbr1mutOTII cells were more likely to accumulate in the peyers patch and differentiate into Tfh cells in response to orally ingested OVA. These findings correlated with increased AKT/pS6 signaling downstream of TCR in Tgfbr1mut T cells, and mTOR inhibition decreased Tgfbr1mut OTII Tfh cells in response to fed ova. Additionally, RNA sequence analysis of murine Tgfbr1mut Tfh cells revealed enhanced PI3K/AKT pathway activity. These findings suggest that TGFβ signaling plays an important role in T cell development and function via the PI3K/AKT pathway that when disrupted promotes allergic inflammation.

The Genomic Landscape of Actinic Keratosis

Actinic keratoses (AKs) are lesions of epidermal keratinocyte dysplasia and are precursors for invasive cutaneous squamous cell carcinoma (cSCC). Identifying the specific genomic alterations driving the progression from normal skin to skin with AK to skin with invasive cSCC is challenging because of the massive UVR-induced mutational burden characteristic at all stages of this progression. In this study, we report the largest AK whole-exome sequencing study to date and perform a mutational signature and candidate driver gene analysis on these lesions. We demonstrate in 37 AKs from both immunosuppressed and immunocompetent patients that there are significant similarities between AKs and cSCC in terms of mutational burden, copy number alterations, mutational signatures, and patterns of driver gene mutations. We identify 44 significantly mutated AK driver genes and confirm that these genes are similarly altered in cSCC. We identify azathioprine mutational signature in all AKs from patients exposed to the drug, providing further evidence for its role in keratinocyte carcinogenesis. cSCCs differ from AKs in having higher levels of intrasample heterogeneity. Alterations in signaling pathways also differ, with immune-related signaling and TGFβ signaling significantly more mutated in cSCC. Integrating our findings with independent gene expression datasets confirms that dysregulated TGFβ signaling may represent an important event in AK‒cSCC progression.

Modeling Uremic Vasculopathy With Induced Pluripotent Stem Cell-Derived Endothelial Cells as a Drug Screening System.

Background: Cardiovascular complications are the leading cause of mortality in patients with chronic kidney disease (CKD). Uremic vasculopathy plays a crucial role in facilitating the progression of cardiovascular complications in advanced CKD. However, the improvement of conventional research methods could provide further insights into CKD.Objectives: In this study, we aimed to develop a novel model of uremic vasculopathy as a potential drug screening system.Methods and Results: The effects of uremic serum and different combinations of uremic toxins on induced pluripotent stem cell (iPSC)-derived endothelial cells (ECs) of a normal control and a CKD patient were investigated using several functional assays. We found that a mixture of uremic toxins composed of high urea, creatinine, uric acid, and indoxyl sulfate exerted deleterious effects on normal control iPSC-ECs that were comparable to uremic serum by increasing reactive oxygen species and apoptosis, as well as suppression of tube formation. Additional characterization revealed a potential involvement of dysregulated TGF-β signaling as treatment with either losartan or TGF-β inhibitors led to the attenuation of adverse effects induced by uremic toxins. Importantly, impaired wound healing potential seen in CKD patient-specific iPSC-ECs was rescued by treatment with losartan and TGF-β inhibitors.Conclusion: Our study demonstrated that simplified uremic toxin mixtures can simulate the uremic micromilieu reproducibly and CKD patient-specific iPSC-ECs can potentially recapitulate susceptibility to uremic vasculopathy. This novel model of uremic vasculopathy may provide a new research tool as a drug screening system.

Diversity of Mechanisms Underlying Latent TGF-β Activation in Recessive Dystrophic Epidermolysis Bullosa

Injury- and inflammation-driven progressive dermal fibrosis is a severe manifestation of recessive dystrophic epidermolysis bullosa-a genetic skin blistering disease caused by mutations in COL7A1. TGF-β activation plays a prominent part in progressing dermal fibrosis. However, the underlying mechanisms are not fully elucidated. TGF-β is secreted in a latent form, which has to be activated for its biological functions. In this study, we determined that recessive dystrophic epidermolysis bullosa fibroblasts have an enhanced capacity to activate the latent form. Mechanistic and functional assessment demonstrated that this process depends on multiple latent TGF-β activators, including TSP-1, RGD-binding integrins, matrix metalloproteinases, and ROS, which act in concert, in a self-perpetuating feedback loop to progress fibrosis. Importantly, our study also disclosed keratinocytes as prominent facilitators of fibrosis in recessive dystrophic epidermolysis bullosa. They stimulate microenvironmental latent TGF-β activation through enhanced production of the above mediators. Collectively, our study provides data on the molecular mechanism behind dysregulated TGF-β signaling in recessive dystrophic epidermolysis bullosa, which are much needed for the development of evidence-based fibrosis-delaying treatments.

The Roles of TGF-β Signaling in Cerebrovascular Diseases.

Cerebrovascular diseases are one of the leading causes of death worldwide, however, little progress has been made in preventing or treating these diseases to date. The transforming growth factor-β (TGF-β) signaling pathway plays crucial and highly complicated roles in cerebrovascular development and homeostasis, and dysregulated TGF-β signaling contributes to cerebrovascular diseases. In this review, we provide an updated overview of the functional role of TGF-β signaling in the cerebrovascular system under physiological and pathological conditions. We discuss the current understanding of TGF-β signaling in cerebral angiogenesis and the maintenance of brain vessel homeostasis. We also review the mechanisms by which disruption of TGF-β signaling triggers or promotes the progression of cerebrovascular diseases. Finally, we briefly discuss the potential of targeting TGF-β signaling to treat cerebrovascular diseases.

Dysregulated TGF-β Signaling Leads to Cell-Intrinsic Changes in T cell Development that Promote Allergic Inflammation

Abstract Variants in genes in the Transforming Growth Factor Beta (TGFb) signaling pathway are associated with allergic diseases suggesting that this cytokine may be a central player in allergic disease. The role of TGFb in preserving T cell mediated self-tolerance is well-appreciated but how disruption in this pathway promotes allergic inflammation is not clear. TGFb signals through its receptor TGFβRI and II, leading to phosphorylation and nuclear translocation of Smad proteins 2 and 3. We previously demonstrated that patients with Loeys-Dietz Syndrome (LDS), an autosomal dominant disorder caused by mutations in TGFBR1 and TGFBR2 are highly predisposed to developing allergic disease. Both LDS patients and mice harboring a knock-in allele (Tgfbr1mut) of an LDS mutation known to cause severe disease in humans exhibit increased levels of total and food-specific IgE, consistent with their allergic tendencies. These serologic changes were associated with increased numbers of T follicular helper (Tfh) cells which promote memory B cell and plasma cell formation, and decreased T follicular regulatory (Tfr) cells, which suppress humoral immune responses, in LDS patients and mice. Using a mixed bone marrow chimera model we demonstrated that these alterations in T cell development are cell-intrinsic. Furthermore, OVA specific OTII cells harboring the Tgfbr1mut were more likely to accumulate in the peyer’s patch, differentiate into Tfh cells, and less likely to upregulate Foxp3 in response to orally ingested OVA. Tgfbr1mut OTII cells also produced more IL-4 and less IL-10 in response to OVA. These findings suggest that TGF-β signaling plays an important role in T cell development and function that, when disrupted, promotes allergic inflammation.

Proteomic Profiling of Fibroblasts Isolated from Chronic Wounds Identifies Disease-Relevant Signaling Pathways

Chronic skin wounds accompany many prevalent age-related diseases and are a major cause of morbidity and mortality. Both keratinocytes and fibroblasts contribute to the pathomechanisms in chronic skin wounds. Dysregulated pathways in the epidermis have been extensively studied, but little is known of the influence of dermal fibroblasts on chronic wounding. We isolated fibroblasts from chronic wounds, propagated them invitro, and analyzed them using proteomic profiling in combination with functional characterization of the proteomic changes. Chronic wound-associated fibroblasts exhibit a unique proteome profile characteristic of lysosomal dysfunction and dysregulated TGFβ signaling. They display a decreased propensity for cell proliferation and migration, combined with an enhanced ability to contract the extracellular matrix. With these properties, chronic wound-associated fibroblasts actively contribute to pathological inabilities to close wounds and represent potential targets for pharmacological interference for changing cellular phenotypes.

The role of transforming growth factor-beta in immune suppression and chronic inflammation of squamous cell carcinomas.

Despite a decline in the incidence of squamous cell carcinomas (SCCs) over the past 20 years, their survival rate has remained nearly the same, indicating that treatment options have not improved relative to other cancer types. Immunotherapies have a high potential for a sustained effect in SCC patients, but their response rate is low. Here, we review the suppressive role of transforming growth factor-beta (TGFβ) on the antitumor immune response in SCC and present its potential as a therapeutic target in combination with the current range of immunotherapies available for SCC patients. We conclude that SCCs are an optimal cancer type to study the effectiveness of TGFβ inhibition due to the prevalence of dysregulated TGFβ signaling in them.

OA-related inflammation inhibits protective transforming growth factor-β signaling via post-translational modification of the SMAD2/3 linker region

Purpose: Osteoarthritis (OA) is a degenerative joint disease characterized by inflammation and irreversible cartilage damage. The development of OA is associated with dysregulated TGF-β signaling. Via intracellular activation of the transcription factors SMAD2 and SMAD3 this growth factor inhibits chondrocyte hypertrophy and expression of cartilage degrading enzymes. Recently, it has been shown that post-translational modification of these SMAD proteins in their linker protein domain can dysregulate TGF-β signaling.