Evaluation of the novel ALK5 inhibitor EW-7197 on therapeutic efficacy in renal fibrosis using a three-dimensional chip model.

Background: EW-7197, a potent oral ALK5 inhibitor, was assessed for its impact on transforming growth factor beta 1 (TGF-ß1)-induced fibrosis in a three-dimensional (3D) renal fibrosis-on-a-chip and a mouse model. The evaluation included tubular epithelial-mesenchymal transition, angiogenesis, and inflammatory cytokine expression. Methods: In a 3D renal fibrosis-on-a-chip model, three cell types (kidney fibroblasts, human proximal tubular cell line, and human umbilical vein endothelial cells) were cultured and treated with TGF-ß1 and EW-7197. Expression of alpha smooth muscle actin (α-SMA) and keratin 8 (KRT-8) was assessed, angiogenesis was observed via confocal microscopy, and cytokine levels were measured using real-time polymerase chain reaction, immunoassay, and enzyme-linked immunosorbent assay. In a cisplatin-induced renal fibrosis mouse model, blood urea nitrogen levels, TGF-ß, and Smad 2/3 were determined, and renal fibrosis was assessed with Masson's trichrome stain. Results: The α-SMA expression was significantly lower in the EW-7197 group than in the TGF-ß fibrosis group. TGF-ß decreased the expression of the epithelial marker KRT-8, an effect that was reversed by EW-7197 and SB431542. In the TGF-ß-induced fibrosis model, the length of the thick vessels was reduced, and the diameter of both thick and thin vessels was decreased, but EW-7197 reversed these effects. EW-7197 significantly reduced the messenger RNA expression of TGF-ß and increased the levels of vascular endothelial growth factor receptor 2, interleukin (IL)-10, and IL-6. EW-7197 reduced the levels of secretory cytokines TGF-ß1, TGF-ß3, IL-1ß. In the cisplatin-induced renal fibrosis mouse model, EW-7197 reduced renal fibrosis by down-regulating TGF-ß signaling. Conclusion: EW-7197 attenuated the TGF-ß1-induced fibrotic cellular response in the 3D chip model and animal model. These findings indicate the potential effect of EW-7197 in attenuating renal fibrosis.

Synthesis and biological evaluation of sulfonamide derivatives containing imidazole moiety as ALK5 inhibitors.

Four series of sulfonamide derivatives (13a-b, 14a-d, 15a-b, and 16a-d) were synthesized and evaluated for their activin receptor-like kinase 5 (ALK5) inhibitory activities. Of these, compounds 13b (IC50 = 0.130 µM) and 15a (IC50 = 0.130 µM) showed the highest inhibitory activities against ALK5 kinase, with activities similar to the positive control LY-2157299. Notably, we discovered that introduction of sulfonamide group at the 2-position of the central imidazole ring significantly increased ALK5 inhibitory activity. Compounds 13b and 15a did not show toxicity in A549 cells up to the maximum concentration of 50 µM, and effectively inhibited TGF-ß1-induced Smad-signaling and cell motility in A549 cells. The results indicate that compounds 13b and 15a are worth of further development as anticancer agents.

Synthesis of amide derivatives containing the imidazole moiety and evaluation of their anti-cardiac fibrosis activity.

Three series of N-{[4-([1,2,4]triazolo[1,5-α]pyridin-6-yl)-5-(6-methylpyridin-2-yl)-1H-imidazol-2-yl]methyl}acetamides (14a-d, 15a-n, and 16a-f) were synthesized and evaluated for activin receptor-like kinase 5 (ALK5) inhibitory activities in an enzymatic assay. The target compounds showed high ALK5 inhibitory activity and selectivity. The half maximal inhibitory concentration (IC50) for phosphorylation of ALK5 of 16f (9.1 nM), the most potent compound, was 2.7 times that of the clinical candidate EW-7197 (vactosertib) and 14 times that of the clinical candidate LY-2157299. The selectivity index of 16f against p38α mitogen-activated protein kinase was >109, which was much higher than that of positive controls (EW-7197: >41, and LY-2157299: 4). Furthermore, a molecular docking study provided the interaction modes between the target compounds and ALK5. Compounds 14c, 14d, and 16f effectively inhibited the protein expression of α-smooth muscle actin (α-SMA), collagen I, and tissue inhibitor of metalloproteinase 1 (TIMP-1)/matrix metalloproteinase 13 (MMP-13) in transforming growth factor-ß-induced human umbilical vein endothelial cells. Compounds 14c and 16f showed especially high activity at low concentrations, which suggests that these compounds could inhibit myocardial cell fibrosis. Compounds 14c, 14d, and 16f are potential preclinical candidates for the treatment of cardiac fibrosis.

Slow Interstitial Fluid Flow Activates TGF-ß 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-ß 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-ß 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.

Synthesis of and anti-fibrotic effect of pyrazole derivative J-1048: Inhibition of ALK5 as a novel approach to liver fibrosis targeting inflammation.

Liver fibrosis is a worldwide challenge of health issue. Developing effective new drugs for treating liver fibrosis is of great importance. In recent years, chemically synthesized drugs have significant advantages in treating liver fibrosis. Small molecule pyrazole derivatives as activin receptor-like kinase 5 (ALK5) inhibitors have also shown anti-fibrotic and tumor growth inhibitory effects. To develop the candidate with anti-fibrotic effect, we synthesized a novel pyrazole derivative, J-1048. The inhibitory effect of J-1048 on ALK5 and p38α mitogen-activated protein (MAP) kinase activity was assessed by enzymatic assays. We established an in vivo liver fibrosis model by injecting thioacetamide (TAA) into mice and in vitro model of TGF-ß stimulated hepatic stellated cells to explore the inhibition mechanisms and therapeutic potential of J-1048 as an ALK5 inhibitor in liver fibrosis. Our data showed that J-1048 inhibited TAA-induced liver fibrosis in mice by explicitly blocking the TGF-ß/Smad signaling pathway. Additionally, J-1048 inhibited the production of inflammatory cytokine Interleukin-1ß (IL-1ß) by inhibiting the purinergic ligand-gated ion channel 7 receptor (P2X7r) -Nucleotide-binding domain-(NOD-)like receptor protein 3 (NLRP3) axis, thereby alleviating liver fibrosis. Our findings demonstrated that a novel small molecule ALK5 inhibitor, J-1048, exhibited strong potential as a clinical therapeutic candidate for liver fibrosis.

Beneficial Effects of a Curcumin Derivative and Transforming Growth Factor-ß Receptor I Inhibitor Combination on Nonalcoholic Steatohepatitis.

BACKGRUOUND: Curcumin 2005-8 (Cur5-8), a derivative of curcumin, improves fatty liver disease via AMP-activated protein kinase activation and autophagy regulation. EW-7197 (vactosertib) is a small molecule inhibitor of transforming growth factor ß (TGF-ß) receptor I and may scavenge reactive oxygen species and ameliorate fibrosis through the SMAD2/3 canonical pathway. This study aimed to determine whether co-administering these two drugs having different mechanisms is beneficial. METHODS: Hepatocellular fibrosis was induced in mouse hepatocytes (alpha mouse liver 12 [AML12]) and human hepatic stellate cells (LX-2) using TGF-ß (2 ng/mL). The cells were then treated with Cur5-8 (1 µM), EW-7197 (0.5 µM), or both. In animal experiments were also conducted during which, methionine-choline deficient diet, Cur5-8 (100 mg/kg), and EW-7197 (20 mg/kg) were administered orally to 8-week-old C57BL/6J mice for 6 weeks. RESULTS: TGF-ß-induced cell morphological changes were improved by EW-7197, and lipid accumulation was restored on the administration of EW-7197 in combination with Cur5-8. In a nonalcoholic steatohepatitis (NASH)-induced mouse model, 6 weeks of EW-7197 and Cur5-8 co-administration alleviated liver fibrosis and improved the nonalcoholic fatty liver disease (NAFLD) activity score. CONCLUSION: Co-administering Cur5-8 and EW-7197 to NASH-induced mice and fibrotic hepatocytes reduced liver fibrosis and steatohepatitis while maintaining the advantages of both drugs. This is the first study to show the effect of the drug combination against NASH and NAFLD. Similar effects in other animal models will confirm its potential as a new therapeutic agent.

Synthesis and biological evaluation of N-(3-fluorobenzyl)-4-(1-(methyl-d3)-1H-indazol-5-yl)-5-(6-methylpyridin-2-yl)-1H-imidazol-2-amine as a novel, potent ALK5 receptor inhibitor.

Specific inhibition of ALK5 provides a novel method for controlling the development of cancers and fibrotic diseases. In this work, a novel series of N-(3-fluorobenzyl)-4-(1-(methyl-d3)-1H-indazol-5-yl)-5-(6-methylpyridin-2-yl)-1H-imidazol-2-amine (11), a potential clinical candidate, was synthesized by strategic incorporation of deuterium at potential metabolic soft spots and identified as ALK5 inhibitors. This compound has a low potential for CYP-mediated drug-drug interactions as a CYP450 inhibitor (IC50 = >10 µM) and showed potent inhibitory effects in cellular assay (IC50 = 3.5 ± 0.4 nM). The pharmacokinetic evaluation of 11 in mice demonstrated moderate clearance (29.0 mL/min/kg) and also revealed high oral bioavailability in mice (F = 67.6%).

ALK-5 Inhibitors for Efficient Derivation of Mesenchymal Stem Cells from Human Embryonic Stem Cells.

Objectives: Successful tissue regeneration requires a clinically viable source of mesenchymal stem cells (MSCs). We explored activin receptor-like kinase (ALK)-5 inhibitors to rapidly derive an MSC-like phenotype with high cartilage forming capacity from a xeno-free human embryonic cell line. Methods: Embryonic stem cell (ESC) lines (H9 and HADC100) were treated with the ALK-5 inhibitor SB431542; HADC100 cells were additionally treated with ALK-5 inhibitors SB525334 or GW788388. Cells were then seeded upon human fibronectin in the presence of fibroblast growth factor 2 (FGF2) in a serum-free medium. Flow cytometry was used to assess MSC markers (positive for CD73, CD90, and CD105; negative for CD34 and CD45). Differentiation status was assessed through quantitative polymerase chain reaction. Cartilage forming capacity was determined in high-density pellet cultures, in fibrin gels containing extracellular matrix (fibrin-ECM), and after implantation in ex vivo human osteoarthritic cartilage. Gene expression, histology, and immunostaining were used to assess cartilage phenotype, tissue regeneration, and integration. Results: Exposure to all three ALK-5 inhibitors lead to expression of mesodermal gene markers and differentiation into MSC-like cells (embryonic stem cell-derived mesenchymal stem cells [ES-MSCs]) based on surface marker expression. ES-MSC in pellet cultures or in fibrin-ECM gels expressed high levels of chondrogenic genes: COL2A1, ACAN, and COMP; and low levels of COL1A1 and RUNX2. Cell pellets or fibrin constructs implanted into ex vivo human osteoarthritic cartilage defects produced GAG-rich (safranin O positive) and collagen type II-positive neocartilage tissues that integrated well with native diseased tissue. Conclusions: We developed a protocol for rapid differentiation of xeno-free ESC into MSC-like cells with high cartilage forming capacity with potential for clinical applications. Impact statement Osteoarthritis (OA) is a common disease resulting in significant disability and no approved disease modifying treatment (other than total joint replacement). Embryonic stem cell-derived cell therapy has the potential to benefit patients with cartilage lesions leading to OA and may prevent or delay the need for total joint replacement.

Cpd-0225 attenuates renal fibrosis via inhibiting ALK5.

Chronic kidney disease (CKD) is an increasing public health concern, characterized by a reduced glomerular filtration rate and increased urinary albumin excretion. Renal fibrosis is an important pathological condition in patients with CKD. In this study, we evaluated the anti-fibrotic effect of Cpd-0225, a novel transforming growth factor-ß (TGF-ß) type I receptor (also known as ALK5) inhibitor, in vitro and in vivo, by comparing its effect with that of SB431542, a classic ALK5 inhibitor, which has not entered the clinical trial stage owing to multiple side effects. Our data showed that Cpd-0225 attenuated fibrotic response in TGF-ß1-stimulated human kidney tubular epithelial cells and repeated hypoxia/reoxygenation-treated mouse tubular epithelial cells. We further confirmed that Cpd-0225 improved renal tubular injury and ameliorated collagen deposition in unilateral ureteral obstruction-, ischemia/reperfusion-, and aristolochic acid-induced mouse models of renal fibrosis. In addition, molecular docking and site-directed mutagenesis showed that Cpd-0225 exerted a higher reno-protective effect than SB431542, by physically binding to the key amino acid residues, Lys232 and Lys335 of ALK5, thereby suppressing the phosphorylation of Smad3 and ERK1/2. Taken together, these findings suggest that Cpd-0225 administration attenuates renal fibrosis via ALK5-dependent mechanisms and displays a more effective therapeutic effect than SB431542. Thus, Cpd-0225 may serve as a potential therapeutic agent for the treatment of CKD.

Synthesis and biological evaluation of 4-(pyridine-4-oxy)-3-(tetrahydro-2H-pyran-4-yl)-pyrazole derivatives as novel, potent of ALK5 receptor inhibitors.

The transforming growth factor type ß receptor I (TGF-ß R1, also known as activin-like kinase 5 or ALK5) plays a significant role in the pathogenesis of multiple diseases such as malignant tumors and tissue fibrosis. Specific inhibition of ALK5 provides a novel method for controlling the development of cancers and fibrotic diseases. Herein, a novel series of 4-(pyridine-4-oxy)-3-(tetrahydro-2H-pyran-4-yl)-pyrazole derivatives was synthesized and identified as ALK5 inhibitors. Among them, compound 8h inhibited ALK5 autophosphorylation and NIH3T3 cell activity with IC50 values of 25 nM and 74.6 nM, respectively. Compound 8h also showed favorable pharmacokinetic profile and ameliorated hERG inhibition. More importantly, 30 mg/kg oral administration of 8h could significantly induce tumour growth inhibition in CT26 xenograft model without obvious toxicity.

Transcriptome analysis reveals key genes modulated by ALK5 inhibition in a bleomycin model of systemic sclerosis.

OBJECTIVE: SSc is a rheumatic autoimmune disease affecting roughly 20 000 people worldwide and characterized by excessive collagen accumulation in the skin and internal organs. Despite the high morbidity and mortality associated with SSc, there are no approved disease-modifying agents. Our objective in this study was to explore transcriptomic and model-based drug discovery approaches for SSc. METHODS: In this study, we explored the molecular basis for SSc pathogenesis in a well-studied mouse model of scleroderma. We profiled the skin and lung transcriptomes of mice at multiple timepoints, analysing the differential gene expression that underscores the development and resolution of bleomycin-induced fibrosis. RESULTS: We observed shared expression signatures of upregulation and downregulation in fibrotic skin and lung tissue, and observed significant upregulation of key pro-fibrotic genes including GDF15, Saa3, Cxcl10, Spp1 and Timp1. To identify changes in gene expression in responses to anti-fibrotic therapy, we assessed the effect of TGF-ß pathway inhibition via oral ALK5 (TGF-ß receptor I) inhibitor SB525334 and observed a time-lagged response in the lung relative to skin. We also implemented a machine learning algorithm that showed promise at predicting lung function using transcriptome data from both skin and lung biopsies. CONCLUSION: This study provides the most comprehensive look at the gene expression dynamics of an animal model of SSc to date, provides a rich dataset for future comparative fibrotic disease research, and helps refine our understanding of pathways at work during SSc pathogenesis and intervention.

Targeting the TGF-ß signaling pathway for resolution of pulmonary arterial hypertension.

Aberrant transforming growth factor-ß (TGF-ß) signaling activation is linked to pulmonary arterial hypertension (PAH). BMPR2 mutations perturb the balance between bone morphogenetic protein (BMP) and TGF-ß pathways, leading to vascular remodeling, narrowing of the lumen of pulmonary vasculature, and clinical symptoms. This forum highlights the association of the TGF-ß pathway with pathogenesis and therapeutic approaches.

Human Liver Spheroids as a Model to Study Aetiology and Treatment of Hepatic Fibrosis.

Non-alcoholic fatty liver disease affects approximately one billion adults worldwide. Non-alcoholic steatohepatitis (NASH) is a progressive disease and underlies the advancement to liver fibrosis, cirrhosis, and hepatocellular carcinoma, for which there are no FDA-approved drug therapies. We developed a hetero-cellular spheroid system comprised of primary human hepatocytes (PHH) co-cultured with crude fractions of primary human liver non-parenchymal cells (NPC) from several matched or non-matched donors, to identify phenotypes with utility in investigating NASH pathogenesis and drug screening. Co-culture spheroids displayed stable expression of hepatocyte markers (albumin, CYP3A4) with the integration of stellate (vimentin, PDGFRß), endothelial (vWF, PECAM1), and CD68-positive cells. Several co-culture spheroids developed a fibrotic phenotype either spontaneously, primarily observed in PNPLA3 mutant donors, or after challenge with free fatty acids (FFA), as determined by COL1A1 and αSMA expression. This phenotype, as well as TGFß1 expression, was attenuated with an ALK5 inhibitor. Furthermore, CYP2E1, which has a strong pro-oxidant effect, was induced by NPCs and FFA. This system was used to evaluate the effects of anti-NASH drug candidates, which inhibited fibrillary deposition following 7 days of exposure. In conclusion, we suggest that this system is suitable for the evaluation of NASH pathogenesis and screening of anti-NASH drug candidates.

Synthesis and evaluation of the HIF-1α inhibitory activity of 3(5)-substituted-4-(quinolin-4-yl)- and 4-(2-phenylpyridin-4-yl)pyrazoles as inhibitors of ALK5.

The transcription factor hypoxia-inducible factor-1α (HIF-1α) plays an important role in apoptosis, metastasis, and proliferation and is recognized as an important potential therapeutic target for cancer. Six series of 3(5)-(6-methylpyridin-2-yl)-4-(quinolin-4-yl)pyrazoles (11a-d, 12a-d, and 18a-d) and 3(5)-(6-methylpyridin-2-yl)-4-(2-phenyl-pyridin-4-yl)pyrazoles (19a-d, 20a-d, and 21a-d) were synthesized and evaluated for activin receptor-like kinase 5 (ALK5) and HIF-1α inhibitory activity at the enzyme and cell levels. The effect of the lead compound 20d (J-1012) on HIF-1α activation in HCT116 cells was investigated. J-1012 markedly decreased the hypoxia-induced or TNF-induced accumulation of HIF-1α protein dose-dependently. Analysis revealed that J-1012 inhibited HIF-1α protein synthesis, without affecting the degradation of HIF-1α protein. Furthermore, by inhibiting the activation of HIF-1α, J-1012 suppressed the metastasis and proliferation and promoted apoptosis of HCT116 cells. These results suggest that J-1012 may be a potential therapeutic agent against human colon cancer.

Pharmacokinetic characteristics of vactosertib, a new activin receptor-like kinase 5 inhibitor, in patients with advanced solid tumors in a first-in-human phase 1 study.

Purposes Vactosertib is a new investigational inhibitor of activin receptor-like kinase 5. The objective of this study was to characterize vactosertib pharmacokinetics that are to be applied for subsequent clinical studies. Methods Vactosertib plasma concentration-time data were obtained from a multicenter, dose-escalation, first-in-human phase 1 study conducted in patients with advanced solid tumors. Each patient orally received a fixed dose of vactosertib with the range of 30 mg to 340 mg once daily under fasted condition. Pharmacokinetic analysis was performed using a non-compartmental method. Results Pharmacokinetic data were evaluable in 29 patients. Vactosertib was rapidly absorbed after the first dose with a median time to maximum concentration (tmax) of 1.2 h (interquartile range, 0.8-1.8 h) and quickly eliminated with a median terminal half-life (t1/2) of 3.2 h (2.2-4.2 h) over the dose range studied. Such trend was also observed after repeated doses for five days (median tmax, 1.5 h; median t1/2, 3.0 h). The area under the concentration-time curve within a dosing interval increased in proportion to dose. The median values of apparent clearance and volume of distribution were 29 L/h (21-44 L/h) and 133 L (77-222 L), respectively. The median accumulation ratio after repeated once-daily doses for five days was 0.87 (0.69-1.07). Conclusions Vactosertib pharmacokinetics were dose-proportional within tested dose range with negligible accumulation when administered once daily for five days. Considering the short half-life, it seems necessary to administer vactosertib twice- or thrice-daily to maintain its concentrations above minimum effective level over a dosing interval.

Synthesis and Evaluation of 3-Substituted-4-(quinoxalin-6-yl) Pyrazoles as TGF-ß Type I Receptor Kinase Inhibitors.

The transforming growth factor-ß (TGF-ß), in which overexpression has been associated with various diseases, has become an attractive molecular target for the treatment of cancers. Thirty-two quinoxaline-derivatives of 3-substituted-4-(quinoxalin-6-yl) pyrazoles 14a⁻d, 15a⁻d, 16a⁻d, 17a⁻d, 18a⁻d, 19a⁻d, 25a, 25b, 25d, 26a, 26b, 26d, 27b, and 27d were synthesized and evaluated for their activin TGF-ß type I receptor kinase and p38α mitogen activated protein (MAP) kinase inhibitory activity in enzymatic assays. Among these compounds, the most active compound 19b inhibited TGF-ß type I receptor kinase phosphorylation with an IC50 value of 0.28 µM, with 98% inhibition at 10 µM. Compound 19b also had good selectivity index of >35 against p38α MAP kinase, with 9.0-fold more selective than clinical candidate, compound 3 (LY-2157299). A molecular docking study was performed to identify the mechanism of action of the synthesized compounds and their good binding interactions were observed. ADMET prediction of good active compounds showed that these ones possess good pharmacokinetics and drug-likeness behavior.

Novel oral transforming growth factor-ß signaling inhibitor EW-7197 eradicates CML-initiating cells.

Recent strategies for treating CML patients have focused on investigating new combinations of tyrosine kinase inhibitors (TKIs) as well as identifying novel translational research agents that can eradicate CML leukemia-initiating cells (CML-LICs). However, little is known about the therapeutic benefits such CML-LIC targeting therapies might bring to CML patients. In this study, we investigated the therapeutic potential of EW-7197, an orally bioavailable transforming growth factor-ß signaling inhibitor which has recently been approved as an Investigational New Drug (NIH, USA), to suppress CML-LICs in vivo. Compared to TKI treatment alone, administration of TKI plus EW-7197 to CML-affected mice significantly delayed disease relapse and prolonged survival. Notably, combined treatment with EW-7197 plus TKI was effective in eliminating CML-LICs even if they expressed the TKI-resistant T315I mutant BCR-ABL1 oncogene. Collectively, these results indicate that EW-7197 may be a promising candidate for a new therapeutic that can greatly benefit CML patients by working in combination with TKIs to eradicate CML-LICs.

Synthesis and biological evaluation of 5-(fluoro-substituted-6-methylpyridin-2-yl)-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)imidazoles as inhibitors of transforming growth factor-ß type I receptor kinase.

To further optimize a clinical candidate 5 (EW-7197), a series of 5-(3-, 4-, or 5-fluoro-substituted-6-methylpyridin-2-yl)-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)imidazoles 19a-l have been synthesized and evaluated for their TGF-ß type I receptor kinase (ALK5) and p38α MAP kinase inhibitory activity in an enzyme assay. The 5-(5-fluoro-substituted-6-methylpyridin-2-yl)-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)imidazoles 19h-l displayed the similar level of potency to that of 5 against both ALK5 (IC50=7.68-13.70 nM) and p38α MAP kinase (IC50=1240-3370 nM). Among them, 19j inhibited ALK5 with IC50 value of 7.68 nM in a kinase assay and displayed 82% inhibition at 100 nM in a luciferase reporter assay.

Topical application of ALK5 inhibitor A-83-01 reduces burn wound contraction in rats by suppressing myofibroblast population.

Burn scar contracture that follows the healing of deep dermal burns causes severe deformation and functional impairment. However, its current therapeutic interventions are limited with unsatisfactory outcomes. When we treated deep second-degree burns in rat skin with activin-like kinase 5 (ALK5) inhibitor A-83-01, it reduced wound contraction and enhanced the area of re-epithelialization so that the overall time for wound closing was not altered. In addition, it reduced myofibroblast population in the dermis of burn scar with a diminished deposition of its biomarker proteins such as α-SMA and collagen. Treatment of rat dermal fibroblast with A-83-01 inhibited transforming growth factor-ß1 (TGF-ß1)-dependent induction of α-SMA and collagen type I. Taken together, these results suggest that topical application of ALK5 inhibitor A-83-01 could be effective in preventing the contraction of burn wound without delaying the wound closure by virtue of its inhibitory activity against the TGF-ß-induced increase of myofibroblast population.

Reversal of ß cell de-differentiation by a small molecule inhibitor of the TGFß pathway.

Dysfunction or death of pancreatic ß cells underlies both types of diabetes. This functional decline begins with ß cell stress and de-differentiation. Current drugs for type 2 diabetes (T2D) lower blood glucose levels but they do not directly alleviate ß cell stress nor prevent, let alone reverse, ß cell de-differentiation. We show here that Urocortin 3 (Ucn3), a marker for mature ß cells, is down-regulated in the early stages of T2D in mice and when ß cells are stressed in vitro. Using an insulin expression-coupled lineage tracer, with Ucn3 as a reporter for the mature ß cell state, we screen for factors that reverse ß cell de-differentiation. We find that a small molecule inhibitor of TGFß receptor I (Alk5) protects cells from the loss of key ß cell transcription factors and restores a mature ß cell identity even after exposure to prolonged and severe diabetes.