A Novel Hemostatic Peptide Solution for Common Acute Gastrointestinal Bleeding Diseases: First Case Series Study on the Treatment Results of Endoscopic Hemostasis by Nonexpert Endoscopists.

INTRODUCTION: We investigated the hemostatic effect and safety of a hemostatic peptide solution for the treatment of gastrointestinal bleeding requiring emergency endoscopy. METHODS: We retrospectively examined the patient backgrounds, hemostatic results, and procedural safety in patients who were treated with a hemostatic peptide solution for hemostasis during emergency endoscopies for gastrointestinal bleeding. All hemostatic procedures were performed by nonexpert physicians with less than 10 years of endoscopic experience. All of the cases were treated at a single institution over the months from January 2022 to January 2023. RESULTS: Twenty-six consecutive patients (17 males and 9 females) with a median age of 74 (45-95) years were included. Their conditions requiring emergency endoscopy were melena in 8 patients, hematochezia in 2, hematemesis in 8, anemia in 6, and bleeding during esophagogastroduodenoscopy in 2. The sites of bleeding were the esophagus in 3 patients, the stomach in 17, the duodenum in 3, the small intestine in 2, and the colon in 1. Hemostasis was obtained with another hemostasis device used in conjunction with the hemostatic peptide solution in 13 cases and with the hemostatic peptide solution alone in 13 cases. The hemostasis success rate was 100%, with no complications. Rebleeding occurred within 1 week in 4 cases. CONCLUSION: Hemostasis with the hemostatic peptide solution was safe and provided a temporary high hemostatic effect in emergency gastrointestinal endoscopy.

Timing of prescription of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers in patients hospitalized for acute heart failure with reduced/mildly reduced ejection fraction: a retrospective analysis.

Although angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) play critical roles in the treatment of heart failure with reduced or mildly reduced ejection fraction (HFrEF/HFmrEF; left-ventricular ejection fraction ≤ 50%), the ideal timing for initiation in patients with acute heart failure (AHF) is unclear. We sought to clarify the timing and safety of ACEi/ARB prescription relative to hemodynamic stabilization (pre or post) in patients hospitalized with acute HFrEF/HFmrEF. This was a retrospective, observational analysis of electronic data of patients hospitalized for AHF at 17 Japanese hospitals. Among 9107 patients hospitalized with AHF, 2648 had HFrEF/HFmrEF, and 83.0% met the hemodynamic stabilization criteria within 10 days of admission. During hospitalization, 63.5% of patients with HFrEF/HFmrEF were prescribed an ACEi/ARB, 79.4% of which were prescribed pre-stabilization. In a multivariable analysis, patients treated with an ACEi/ARB pre-stabilization were more likely to have comorbid hypertension, diabetes mellitus, or ischemic heart disease. ACEi/ARB prescription timing was not associated with adverse events, including hypotension and renal impairment, and early prescription was associated with a lower incidence of subsequent worsening of HF. In clinical practice, more hospitalized patients with AHF received an ACEi/ARB before compared with after hemodynamic stabilization, and no safety concerns were observed. Moreover, early prescription may be associated with a lower incidence of worsening HF.

Keratinocyte proline-rich protein modulates immune and epidermal response in imiquimod-induced psoriatic skin inflammation.

Psoriasis is a persistent inflammatory skin disease thought to arise as a result of the infiltration of inflammatory cells and activation of keratinocytes. Recent advances in basic research and clinical experience revealed that the interleukin (IL)-23/IL-17 axis has been identified as a major immune pathway in psoriasis. However, it remains unclear how keratinocyte factors contribute to the pathology of psoriasis. Keratinocyte proline-rich protein (KPRP) is a proline-rich insoluble protein, which is present in the epidermis and is likely to be involved in the skin barrier function. Here, to investigate the potential roles of KPRP in psoriatic skin inflammation, Kprp-modified mice were applied in the imiquimod (IMQ)-induced skin inflammation model, which develops psoriasis-like epidermal hyperplasia and cutaneous inflammation features. Then, heterozygous knockout (Kprp+/- ) but not homozygous knockout (Kprp-/- ) mice displayed attenuated skin erythema compared to control wild-type mice. In addition, RNA sequencing, quantitative PCR and/or histological analysis detected changes in the expression of several molecules related to psoriatic inflammation or keratinocyte differentiation in Kprp+/- mice, but not Kprp-/- mice. Further analysis exhibited reduced IL-17-producing γδlow T cells and amplified epidermal hyperplasia in Kprp+/- mice, which were implied to be related to decreased expression of ß-defensins and increased expression of LPAR1 (Lysophosphatidic acid receptor 1), respectively. Thus, our results imply that KPRP has the potential as a therapeutic target in psoriatic skin inflammation.

Ocular instillation of conditioned medium from mesenchymal stem cells is effective for dry eye syndrome by improving corneal barrier function.

Dry eye syndrome (DES) is a chronic ocular disease that induces epithelial damage to the cornea by decreasing tear production and quality. Adequate treatment options have not been established for severe DES such as Sjogren's syndrome due to complicated pathological conditions. To solve this problem, we focused on the conditioned medium of human adipose-derived mesenchymal stem cells (hAdMSC-CM), which have multiple therapeutic properties. Here, we showed that hAdMSC-CM suppressed Benzalkonium Chloride (BAC)-induced cytotoxicity and inflammation in human corneal epithelial cells (hCECs). In addition, hAdMSC-CM increased the expression level and regulated the localisation of barrier function-related components, and improved the BAC-induced barrier dysfunction in hCECs. RNA-seq analysis and pharmacological inhibition experiments revealed that the effects of hAdMSC-CM were associated with the TGFß and JAK-STAT signalling pathways. Moreover, in DES model rats with exorbital and intraorbital lacrimal gland excision, ocular instillation of hAdMSC-CM suppressed corneal epithelial damage by improving barrier dysfunction of the cornea. Thus, we demonstrated that hAdMSC-CM has multiple therapeutic properties associated with TGFß and JAK-STAT signalling pathways, and ocular instillation of hAdMSC-CM may serve as an innovative therapeutic agent for DES by improving corneal barrier function.

Vitamins and their derivatives synergistically promote hair shaft elongation ex vivo via PlGF/VEGFR-1 signalling activation.

BACKGROUND: Although vitamins or their derivatives (Vits), such as panthenyl ethyl ether, tocopherol acetate, and pyridoxine, have been widely used in topical hair care products, their efficacy and mode of action have been insufficiently studied. OBJECTIVE: To elucidate the biological influence of Vits on hair follicles and determine the underlying mechanisms. METHODS: A mouse vibrissa hair follicle organ culture model was utilized to evaluate the effects of Vits on hair shaft elongation. Gene and protein expression analyses and histological investigations were conducted to elucidate the responsible mechanisms. A human hair follicle cell culture was used to assess the clinical relevance. RESULTS: In organ culture models, the combination of panthenyl ethyl ether, tocopherol acetate, and pyridoxine (namely, PPT) supplementation significantly promoted hair shaft elongation. PPT treatment enhanced hair matrix cell proliferation by 1.9-fold compared to controls, as demonstrated by Ki67-positive immunoreactivity. PPT-treated mouse dermal papillae exhibited upregulated Placental growth factor (Plgf) by 1.6-fold compared to controls. Importantly, the addition of PlGF neutralizing antibodies to the ex vivo culture diminished the promotive effect on hair growth and increase in VEGFR-1 phosphorylation achieved by PPT. A VEGFR-1 inhibitor also inhibited the promotion of hair growth. Microarray analysis suggested synergistic summation of individual Vits' bioactivity, putatively explaining the effect of PPT. Moreover, PPT increased PlGF secretion in cultured human dermal papilla cells. CONCLUSION: Our findings suggested that PPT promoted hair shaft elongation by activating PlGF/VEGFR-1 signalling. The current study can shed light on the previously underrepresented advantage of utilizing Vits in hair care products.

Automatic Acne Object Detection and Acne Severity Grading Using Smartphone Images and Artificial Intelligence.

Skin image analysis using artificial intelligence (AI) has recently attracted significant research interest, particularly for analyzing skin images captured by mobile devices. Acne is one of the most common skin conditions with profound effects in severe cases. In this study, we developed an AI system called AcneDet for automatic acne object detection and acne severity grading using facial images captured by smartphones. AcneDet includes two models for two tasks: (1) a Faster R-CNN-based deep learning model for the detection of acne lesion objects of four types, including blackheads/whiteheads, papules/pustules, nodules/cysts, and acne scars; and (2) a LightGBM machine learning model for grading acne severity using the Investigator's Global Assessment (IGA) scale. The output of the Faster R-CNN model, i.e., the counts of each acne type, were used as input for the LightGBM model for acne severity grading. A dataset consisting of 1572 labeled facial images captured by both iOS and Android smartphones was used for training. The results show that the Faster R-CNN model achieves a mAP of 0.54 for acne object detection. The mean accuracy of acne severity grading by the LightGBM model is 0.85. With this study, we hope to contribute to the development of artificial intelligent systems to help acne patients better understand their conditions and support doctors in acne diagnosis.

Design and synthesis of aryl-piperidine derivatives as potent and selective PET tracers for cholesterol 24-hydroxylase (CH24H).

Cholesterol 24-hydroxylase (CH24H, CYP46A1) is a cytochrome P450 family enzyme that maintains the homeostasis of brain cholesterol. Soticlestat, a potent and selective CH24H inhibitor, is in development as a therapeutic agent for Dravet syndrome and Lennox-Gastaut syndrome. Herein, we report the discovery of aryl-piperidine derivatives as potent and selective CH24H positron emission tomography (PET) tracers which can be used for dose guidance of a clinical CH24H inhibitor and as a diagnostic tool for CH24H-related pathology. Starting from compound 1 (IC50 = 16 nM, logD = 1.7), which was reported as a CH24H inhibitor with lower lipophilicity, a18F-labeling site (3-fluoroazetidine) was incorporated by structure-based drug design (SBDD) utilizing the co-crystal structure of a compound 1 analog. Subsequent optimization to adjust key parameters for PET tracers, such as potency, lipophilicity, brain penetration, and unbound plasma protein binding, enabled compounds 3f (IC50 = 8.8 nM) and 3g (IC50 = 8.7 nM) as PET imaging candidates. Selectivity of these compounds for CH24H was validated by a brain distribution study using CH24H-WT and KO mice. In non-human primate PET imaging, [18F]3f and [18F]3g showed similar regional uptake in the brain, indicating that these tracers were specific to the CH24H-expressed regions and validated the expression of CH24H in the living brain by different tracers.

Anti-inflammatory effects of differential molecular weight Hyaluronic acids on UVB-induced calprotectin-mediated keratinocyte inflammation.

BACKGROUND: The biological functions of Hyaluronic acid are related to its molecular weight and binding to its receptor, Toll-like receptor4 (TLR4) or CD44. Recent studies have shown that low-molecular-weight Hyaluronic acid (LMW-HA) exhibits proinflammatory effects, while high-molecular-weight Hyaluronic acid (HMW-HA) functions as an anti-inflammatory factor. UVB-induced epidermal inflammation is mainly mediated by endogenous molecules, such as damage-associated molecular patterns (DAMPs), that cause severe skin damage by activating TLR signaling pathways. OBJECTIVE: Since both LMW- and HMW-HA have inhibitory functions on TLR-mediated macrophage inflammation, HA is assumed to suppress UVB-induced DAMP-mediated inflammation in the skin. In this study, both Ultra- low-molecular-weight Hyaluronic acid (uLMW-HA) and HMW-HA were found to inhibit UVB-induced keratinocyte inflammation. METHODS: HaCaT cells were treated with medium containing Hyaluronic acid at the appropriate concentration after 15 mJ/cm2 irradiation. Secreted protein levels were determined with ELISA kits. Expression levels of proteins downstream of TLR4 were detected by Simple Western system. RESULTS: By competitively binding to TLR4, uLMW-HA downregulated Calprotectin-induced TRAF6 expression, which might be the direct process by which uLMW-HA decreased UVB-induced IL-6 secretion. Reduced　CD44 variant (CD44v) expression in keratinocytes attenuated the inhibitory effect of both uLMW-HA and HMW-HA on UVB-induced inflammation, which indicated the involvement of CD44v in HA-regulated anti-inflammatory activity. CONCLUSION: Overall, this research indicates that Hyaluronic acid is more than a moisturizer; it is also a biologically effective material that can prevent the excessive skin inflammation caused in daily life, especially in the late stages after sunburn.

Role of CD99 in regulating homeostasis and differentiation in normal human epidermal keratinocytes.

CD99 is a glycoprotein primarily expressed in immune cells. Physiologically, it is involved in the adhesion, migration, and development of immune cells. The presence of CD99 in the skin was first reported in 2016 and its function is yet to be determined. In this study, we aimed to understand the role of CD99 in the skin using normal human epidermal keratinocytes (NHEK). CD99 expression increased with the confluency of NHEK, while the CD99-high expressing NHEK lost their stem cell properties and played a role in barrier function. We characterized CD99-expressing NHEK as cells committed to early differentiation because they expressed early differentiation markers. However, the deficiency of CD99 in NHEK disrupted homeostasis and caused aberrant differentiation, as evidenced by larger cells with lesser Ki67 staining and higher expression of terminal differentiation markers. Hence, we propose that CD99 is involved in maintaining homeostasis and initiating early differentiation in the skin.

Discovery of Novel 3-Piperidinyl Pyridine Derivatives as Highly Potent and Selective Cholesterol 24-Hydroxylase (CH24H) Inhibitors.

Cholesterol 24-hydroxylase (CH24H or CYP46A1) is a brain-specific cytochrome P450 enzyme that metabolizes cholesterol into 24S-hydroxycholesterol (24HC) for regulating brain cholesterol homeostasis. For the development of a novel and potent CH24H inhibitor, we designed and synthesized 3,4-disubstituted pyridine derivatives using a structure-based drug design approach starting from compounds 1 (soticlestat) and 2 (thioperamide). Optimization of this series by focusing on ligand-lipophilicity efficiency value resulted in the discovery of 4-(4-methyl-1-pyrazolyl)pyridine derivative 17 (IC50 = 8.5 nM) as a potent and highly selective CH24H inhibitor. The X-ray crystal structure of CH24H in complex with compound 17 revealed a unique binding mode. Both blood-brain barrier penetration and reduction of 24HC levels (26% reduction) in the mouse brain were confirmed by oral administration of 17 at 30 mg/kg, indicating that 17 is a promising tool for the novel and selective inhibition of CH24H.

Effects of the dipeptide L-glutamic acid-L-tryptophan on dermatitis in mice and human keratinocytes.

Allergic contact dermatitis (ACD) and atopic dermatitis (AD) are inflammatory eczematous skin diseases caused by various factors. Here, we report that topical application of the dipeptide, L-glutamic acid-L-tryptophan (L-Glu-L-Trp), improved symptoms in both ACD and AD in mice. Using a mouse model of ACD induced by repeated application of 2,4-dinitorofluorbenzene (DNFB), we demonstrated that L-Glu-L-Trp attenuated DNFB-induced skin thickening. In addition, quantification of cytokines in serum revealed that L-Glu-L-Trp suppressed the DNFB-induced increase in the interleukin (IL)-22 level. Moreover, L-Glu-L-Trp attenuated mite antigen extract-induced AD model symptoms such as the increase of skin thickening and elevation of serum IL-22. We also confirmed that the dipeptide structure rather than the individual amino acid components was important for the therapeutic effects of L-Glu-L-Trp. Furthermore, we showed that IL-22 decreased the expression level of filaggrin mRNA in human epidermal keratinocytes, and L-Glu-L-Trp attenuated that effect. These results suggested that the topical application of the dipeptide, L-Glu-L-Trp, to the skin may be useful for treating ACD and AD.

Transcriptome analysis to identify the downstream genes of androgen receptor in dermal papilla cells.

BACKGROUND: Testosterone signaling mediates various diseases, such as androgenetic alopecia and prostate cancer. Testosterone signaling is mediated by the androgen receptor (AR). In this study, we fortuitously found that primary and immortalized dermal papilla cells suppressed AR expression, although dermal papilla cells express AR in vivo. To analyze the AR signaling pathway, we exogenously introduced the AR gene via a retrovirus into immortalized dermal papilla cells and comprehensively compared their expression profiles with and without AR expression. RESULTS: Whole-transcriptome profiling revealed that the focal adhesion pathway was mainly affected by the activation of AR signaling. In particular, we found that caveolin-1 gene expression was downregulated in AR-expressing cells, suggesting that caveolin-1 is controlled by AR. CONCLUSION: Our whole transcriptome data is critical resources for discovery of new therapeutic targets for testosterone-related diseases.

Once-daily, single-inhaler indacaterol/mometasone versus twice-daily salmeterol/fluticasone in Asian patients with inadequately controlled asthma: post hoc pooled analysis from PALLADIUM and IRIDIUM studies.

OBJECTIVE: PALLADIUM and IRIDIUM studies demonstrated efficacy and safety of indacaterol/mometasone (IND/MF) versus salmeterol/fluticasone (SAL/FLU). This post hoc analysis of pooled data from PALLADIUM and IRIDIUM studies evaluated efficacy and safety of IND/MF versus SAL/FLU in Asian patients with inadequately controlled asthma. METHODS: Both studies were Phase III, 52-week, randomized, double-blind, active-controlled that included patients with predicted pre-bronchodilator FEV1 (PALLADIUM, ≥50%-<85%; IRIDIUM, <80%), ACQ-7 score ≥1.5. Patients treated with IND/MF high- (150/320 µg) or medium-dose (150/160 µg) or SAL/FLU high-dose (50/500 µg) were included. Lung function, asthma control, and asthma exacerbations were evaluated. RESULTS: In total, 323 patients (IND/MF high-dose, n = 107; IND/MF medium-dose, n = 106, SAL/FLU high-dose, n = 110) were included. IND/MF high-dose showed improvement in trough FEV1 versus SAL/FLU high-dose at Weeks 26 (Δ, 42 mL; 95% CI, -35 to 120 mL), and 52 (Δ, 41 mL; 95% CI, -37 to 120 mL). IND/MF high-dose exhibited numerically greater improvement in ACQ-7 score versus SAL/FLU high-dose at Weeks 26 (Δ, -0.215; 95% CI, -0.385 to -0.044) and 52 (Δ, -0.176; 95% CI, -0.348 to -0.005). Improvements in trough FEV1 and ACQ-7 score were comparable between IND/MF medium-dose and SAL/FLU high-dose. IND/MF high- and medium-dose showed reductions in moderate or severe (45%; 30%), severe (39%; 41%), and all (9%; 25%) exacerbations, respectively, versus SAL/FLU high-dose over 52 weeks. All treatments were well tolerated. CONCLUSIONS: Once-daily, single-inhaler IND/MF high-dose improved lung function with better asthma control, reduced asthma exacerbations with comparable safety versus twice-daily SAL/FLU high-dose. IND/MF medium-dose showed comparable outcomes to SAL/FLU high-dose at a reduced steroid dose.

Discovery of Soticlestat, a Potent and Selective Inhibitor for Cholesterol 24-Hydroxylase (CH24H).

Cholesterol 24-hydroxylase (CH24H, CYP46A1), a brain-specific cytochrome P450 (CYP) family enzyme, plays a role in the homeostasis of brain cholesterol by converting cholesterol to 24S-hydroxycholesterol (24HC). Despite a wide range of potential of CH24H as a drug target, no potent and selective inhibitors have been identified. Here, we report on the structure-based drug design (SBDD) of novel 4-arylpyridine derivatives based on the X-ray co-crystal structure of hit derivative 1b. Optimization of 4-arylpyridine derivatives led us to identify 3v ((4-benzyl-4-hydroxypiperidin-1-yl)(2,4'-bipyridin-3-yl)methanone, IC50 = 7.4 nM) as a highly potent, selective, and brain-penetrant CH24H inhibitor. Following oral administration to mice, 3v resulted in a dose-dependent reduction of 24HC levels in the brain (1, 3, and 10 mg/kg). Compound 3v (soticlestat, also known as TAK-935) is currently under clinical investigation for the treatment of Dravet syndrome and Lennox-Gastaut syndrome as a novel drug class for epilepsies.

Efficacy of one time per day, single-inhaler indacaterol/glycopyrronium/mometasone in patients with inadequately controlled asthma: post hoc analysis of IRIDIUM study in Asian population.

BACKGROUND AND OBJECTIVE: The 52-week IRIDIUM study demonstrated the efficacy of indacaterol acetate/glycopyrronium bromide/mometasone furoate (IND/GLY/MF) versus IND/MF and salmeterol xinafoate/fluticasone propionate (SAL/FLU) in patients with symptomatic asthma, despite long-acting ß2-agonist/inhaled corticosteroids (LABA/ICS) medium-dose or high-dose, predicted forced expiratory volume in 1 s (FEV1) <80% and at least one exacerbation in the previous year. Here, we present data from a post hoc analysis of the IRIDIUM study in the Asian subpopulation. METHODS: This post hoc analysis evaluated improvements in lung function, asthma control and reduction in asthma exacerbations with IND/GLY/MF medium- (150/50/80 µg) and high-dose (150/50/160 µg) versus IND/MF medium- (150/160 µg) and high-dose (150/320 µg), all one time per day and SAL/FLU high-dose (50/500 µg) two times per day, in Asian patients from the IRIDIUM study. RESULTS: In total, 258 patients (IND/GLY/MF medium-dose, 52; IND/GLY/MF high-dose, 52; IND/MF medium-dose, 51; IND/MF high-dose, 51; SAL/FLU high-dose, 52) were included. IND/GLY/MF medium- and high-dose showed greater improvement in trough FEV1 at week 26 versus respective doses of IND/MF (Δ, 100 mL and 101 mL; both p<0.05, respectively), and SAL/FLU high-dose (Δ, 125 mL; p=0.0189, and 136 mL; p=0.0118, respectively), which were maintained over 52 weeks. Both doses of IND/GLY/MF showed greater improvement in morning and evening peak expiratory flow versus respective doses of IND/MF and SAL/FLU high-dose at week 52. The changes in Asthma Control Questionnaire-7 scores from baseline were comparable in all treatment groups. IND/GLY/MF medium- and high-dose showed greater reductions in severe (34%, 69%), moderate or severe (18%, 54%) and all exacerbations (21%, 34%) compared with SAL/FLU high-dose over 52 weeks. CONCLUSION: One time per day, single-inhaler IND/GLY/MF improved lung function, reduced asthma exacerbations and provided comparable asthma control versus IND/MF and SAL/FLU in Asian patients with inadequately controlled asthma despite LABA/ICS. The results of this analysis were consistent with the overall population in the IRIDIUM study.

Combinatorial expression of cell cycle regulators is more suitable for immortalization than oncogenic methods in dermal papilla cells.

The immortalized cell is an essential research tool that uses robust growth properties for the functional investigation of gene products. Immortalized mammalian cells have mainly been established using three methods: expression of simian vacuolating virus 40 T antigen (the SV40 method); human papilloma virus-derived oncoprotein E6/E7 (the E6/E7 method); or combinatorial expression of R24C mutant cyclin-dependent kinase 4, cyclin D1, and telomerase reverse transcriptase (the K4DT method). However, it is unclear as to which method is optimal for an in vitro model. Here, we compared the biological characteristics and genome-wide expression profiles of immortalized human dermal papilla cells generated by the SV40, E6/E7, or K4DT method. To our knowledge, this is the first study to comprehensively compare expression profiles to determine the optimal immortalization method for maintaining the original nature of the wild-type cells. These data would be valuable to scientists aiming to establish new immortalized cell lines.

Discovery of Novel and Highly Selective Cyclopropane ALK Inhibitors through a Fragment-Assisted, Structure-Based Drug Design.

Fragment screening is frequently used for hit identification. However, there was no report starting from a small fragment for the development of an anaplastic lymphoma kinase (ALK) inhibitor, despite the number of ALK inhibitors reported. We began our research with the fragment hit F-1 and our subsequent linker design, and its docking analysis yielded novel cis-1,2,2-trisubstituted cyclopropane 1. The fragment information was integrated with a structure-based approach to improve upon the selectivity over tropomyosin receptor kinase A, leading to the potent and highly selective ALK inhibitor, 4-trifluoromethylphenoxy-cis-1,2,2-trisubstituted cyclopropane 12. This work shows that fragments become a powerful tool for both lead generation and optimization, such as the improvement of selectivity, by combining them with a structure-based drug design approach, resulting in the fast and efficient development of a novel, potent, and highly selective compound.

Identification of Novel, Potent, and Orally Available GCN2 Inhibitors with Type I Half Binding Mode.

General control nonderepressible 2 (GCN2) is a master regulator kinase of amino acid homeostasis and important for cancer survival in the tumor microenvironment under amino acid depletion. We initiated studies aiming at the discovery of novel GCN2 inhibitors as first-in-class antitumor agents and conducted modification of the substructure of sulfonamide derivatives with expected type I half binding on GCN2. Our synthetic strategy mainly corresponding to the αC-helix allosteric pocket of GCN2 led to significant enhancement in potency and a good pharmacokinetic profile in mice. In addition, compound 6d, which showed slow dissociation in binding on GCN2, demonstrated antiproliferative activity in combination with the asparagine-depleting agent asparaginase in an acute lymphoblastic leukemia (ALL) cell line, and it also displayed suppression of GCN2 pathway activation with asparaginase treatment in the ALL cell line and mouse xenograft model.

Discovery of Potent, Selective, and Brain-Penetrant 1 H-Pyrazol-5-yl-1 H-pyrrolo[2,3- b]pyridines as Anaplastic Lymphoma Kinase (ALK) Inhibitors.

Anaplastic lymphoma kinase (ALK), a member of the receptor tyrosine kinase family, is predominantly expressed in the brain and implicated in neuronal development and cognition. However, the detailed function of ALK in the central nervous system (CNS) is still unclear. To elucidate the role of ALK in the CNS, it was necessary to discover a potent, selective, and brain-penetrant ALK inhibitor. Scaffold hopping and lead optimization of N-(2,4-difluorobenzyl)-3-(1 H-pyrazol-5-yl)imidazo[1,2- b]pyridazin-6-amine 1 guided by a cocrystal structure of compound 1 bound to ALK resulted in the identification of (6-(1-(5-fluoropyridin-2-yl)ethoxy)-1-(5-methyl-1 H-pyrazol-3-yl)-1 H-pyrrolo[2,3- b]pyridin-3-yl)((2 S)-2-methylmorpholin-4-yl)methanone 13 as a highly potent, selective, and brain-penetrable compound. Intraperitoneal administration of compound 13 significantly decreased the phosphorylated-ALK (p-ALK) levels in the hippocampus and prefrontal cortex in the mouse brain. These results suggest that compound 13 could serve as a useful chemical probe to elucidate the mechanism of ALK-mediated brain functions and the therapeutic potential of ALK inhibition.

Keratinocyte Proline-Rich Protein Deficiency in Atopic Dermatitis Leads to Barrier Disruption.

Atopic dermatitis is a common inflammatory skin disease caused by the interaction of genetic and environmental factors. By allelic copy number analysis at missense single-nucleotide polymorphisms on 26 genes with copy number variation, we identified a significant association between atopic dermatitis and human KPRP. Human KPRP expression, which was localized to the upper granular layer of epidermis, was significantly decreased in atopic dermatitis compared with normal skin. KPRP was histologically colocalized with loricrin and was mainly detected in cytoskeleton fractions of human keratinocytes. To further investigate the role of KPRP in skin, Kprp-knockout mice were generated. Heterozygous knockout (Kprp+/-) mice exhibited reduced KPRP expression to level a similar to that of human AD lesional skin. Kprp+/- mice showed abnormal desmosome structure and detachment of lower layers of the stratum corneum. Percutaneous inflammation by topical application of croton oil or oxazolone was enhanced, and epicutaneous immunization with ovalbumin induced a high level of IgE in Kprp+/- mice. Our study, started from allelic copy number analysis in human AD, identified the importance of KPRP, the decrease of which leads to barrier dysfunction.