Dae-Kee Kim

Severe wounds often lead to delayed healing and fibrotic scar formation, primarily driven by dysregulated transforming growth factor beta (TGF-β) signaling, which causes excessive collagen accumulation. Current treatments face limitations, including poor drug delivery, systemic side effects, and patient compliance issues. To address these challenges, we developed a detachable microneedle (d-MN) patch made of biodegradable poly(lactic-co-glycolic acid) for the localized, sustained delivery of the selective TGF-β inhibitor EW-7197 directly into skin wounds. The patch features detachable drug-loaded tips that remain embedded in the tissue shortly after application, allowing for prolonged drug release without continuous attachment. Drug dosage was controlled by adjusting the tip size, and rapid detachment was confirmed within 1 min using ex vivo models. In vitro tests showed sustained EW-7197 release for up to 14 days. In vivo studies using a rat excisional wound model demonstrated that the d-MN patch reduced wound size by approximately 50% and suppressed fibrotic scar formation compared to the controls. This minimally invasive, patient-friendly approach effectively regulates TGF-β signaling to suppress fibrosis during the wound-healing process. Our findings indicate that EW-7197-loaded d-MN patches are a promising therapeutic strategy for improving healing outcomes and reducing fibrotic scar formation.

A series of fexaramine analogs were synthesized and evaluated to develop an intestine-selective/specific FXR partial agonist. Introduction of both a CN substituent at the C-2 in the biphenyl ring and a fluorine at the C-5 in the aniline ring in fexaramine markedly increased FXR agonistic activity. 27c showed 53 +/- 3% maximum efficacy relative to GW4064 in an FXR agonist assay. A substantial amount of 27c was absorbed in the intestine after oral administration in rats, and then it was rapidly metabolized to inactive carboxylic acid 44 by serum esterases. In CDAHFD-fed mice, oral administration of 27c strongly induced multiple intestinal FXR target genes, FGF15, SHP, IBABP, and OST-alpha, but failed to activate SHP in the liver. 27c significantly reduced the liver fibrogenesis area, hepatic fibrosis markers, and serum level of AST. Rational optimization of fexaramine has led to the identification of an intestine-specific FXR partial agonist 27c.

A series of 2,4-disubstituted-5-(6-alkylpyridin-2-yl)-1H-imidazoles, 7a–c, 11a–h, and 16a–h has been synthesised and evaluated for their ALK5 inhibitory activity in an enzyme assay and in a cell-based luciferase reporter assay. Incorporation of a quinoxalin-6-yl moiety and a methylene linker at the 4- and 2-position of the imidazole ring, respectively, and a m-CONH₂ substituent in the phenyl ring generated a highly potent and selective ALK5 inhibitor 11e. Docking model of ALK5 in complex with 11e showed that it fitted well in the ATP-binding pocket with favourable interactions.

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‐β 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.

Transforming growth factor-β (TGF-β) and interleukin-6 (IL-6) are the pivotal cytokines to induce IL-17-producing CD4⁺ T helper cells (T_H17); yet their signalling network remains largely unknown. Here we show that the highly homologous TGF-β receptor-regulated Smads (R-Smads): Smad2 and Smad3 oppositely modify STAT3-induced transcription of IL-17A and retinoic acid receptor-related orphan nuclear receptor, RORγt encoded by Rorc, by acting as a co-activator and co-repressor of STAT3, respectively. Smad2 linker phosphorylated by extracellular signal-regulated kinase (ERK) at the serine 255 residue interacts with STAT3 and p300 to transactivate, whereas carboxy-terminal unphosphorylated Smad3 interacts with STAT3 and protein inhibitor of activated STAT3 (PIAS3) to repress the Rorc and Il17a genes. Our work uncovers carboxy-terminal phosphorylation-independent noncanonical R-Smad–STAT3 signalling network in T_H17 differentiation.

A series of 2-substituted-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)-5-(6-methylpyridin-2-yl)imidazoles was synthesized and evaluated to optimize a prototype inhibitor of TGF-β type I receptor kinase (ALK5), 6. Combination of replacement of a quinoxalin-6-yl moiety of 6 with a [1,2,4]triazolo[1,5-a]pyridin-6-yl moiety, insertion of a methyleneamino linker, and a o-F substituent in the phenyl ring markedly increased ALK5 inhibitory activity, kinase selectivity, and oral bioavailability. The 12b (EW-7197) inhibited ALK5 with IC₅₀ value of 0.013 μM in a kinase assay and with IC₅₀ values of 0.0165 and 0.0121 μM in HaCaT (3TP-luc) stable cells and 4T1 (3TP-luc) stable cells, respectively, in a luciferase assay. Selectivity profiling of 12b using a panel of 320 protein kinases revealed that it is a highly selective ALK5/ALK4 inhibitor. Pharmacokinetic study with 12b·HCl in rats showed an oral bioavailability of 51% with high systemic exposure (AUC) of 1426 ng × h/mL and maximum plasma concentration (C_max) of 1620 ng/mL. Rational optimization of 6 has led to the identification of a highly potent, selective, and orally bioavailable ALK5 inhibitor 12b.

Histone deacetylases (HDACs) are enzymes involved in the remodelling of chromatin, and have a key role in the epigenetic regulation of gene expression. Histone deacetylase (HDAC) inhibitors are emerging as an exciting new class of potential anti-cancer agents. In recent years, a number of structurally diverse HDAC inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. However, the underlying molecular mechanisms remain unclear. This study aimed at investigating the anti-tumor activity of various HDAC inhibitors, IN-2001, using T47D human breast cancer cells. Moreover, the possible mechanism by which HDAC inhibitors exhibit anti-tumor activity was also explored. In estrogen receptor positive T47D cells, IN-2001, HDAC inhibitor showed anti-proliferative effects in dose-and time-dependent manner. In T47D human breast cancer cells showed anti-tumor activity of IN-2001 and the growth inhibitory effects of IN-2001 were related to the cell cycle arrest and induction of apoptosis. Flow cytometry studies revealed that IN-2001 showed accumulation of cells at G2/M phase. At the same time, IN-2001 treatment time-dependently increased sub-G1 population, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with induction of cdk inhibitor expression. In T47D cells, IN-2001 as well as other HDAC inhibitors treatment significantly increased p21(WAF1) and p27(KIP1) expression. In addition, thymidylate synthase, an essential enzyme for DNA replication and repair, was down-regulated by IN-2001 and other HDAC inhibitors in the T47D human breast cancer cells. In summary, IN-2001 with a higher potency than other HDAC inhibitors induced growth inhibition, cell cycle arrest, and eventual apoptosis in human breast cancer possibly through modulation of cell cycle and apoptosis regulatory proteins, such as cdk inhibitors, cyclins, and thymidylate synthase.