Detection of a Prethrombotic State in Patients with Hepatocellular Carcinoma, Using a Clot Waveform Analysis.

Background: Although hepatocellular carcinoma (HCC) is frequently associated with thrombosis, it is also associated with liver cirrhosis (LC) which causes hemostatic abnormalities. Therefore, hemostatic abnormalities in patients with HCC were examined using a clot waveform analysis (CWA). Methods: Hemostatic abnormalities in 88 samples from HCC patients, 48 samples from LC patients and 153 samples from patients with chronic liver diseases (CH) were examined using a CWA-activated partial thromboplastin time (APTT) and small amount of tissue factor induced FIX activation (sTF/FIXa) assay. Results: There were no significant differences in the peak time on CWA-APTT among HCC, LC, and CH, and the peak heights of CWA-APTT were significantly higher in HCC and CH than in HVs and LC. The peak heights of the CWA-sTF/FIXa were significantly higher in HCC than in LC. The peak times of the CWA-APTT were significantly longer in stages B, C, and D than in stage A or cases of response. In the receiver operating characteristic (ROC) curve, the fibrin formation height (FFH) of the CWA-APTT and CWA-sTF/FIXa showed the highest diagnostic ability for HCC and LC, respectively. Thrombosis was observed in 13 HCC patients, and arterial thrombosis and portal vein thrombosis were frequently associated with HCC without LC and HCC with LC, respectively. In ROC, the peak time×peak height of the first derivative on the CWA-sTF/FIXa showed the highest diagnostic ability for thrombosis. Conclusion: The CWA-APTT and CWA-sTF/FIXa can increase the evaluability of HCC including the association with LC and thrombotic complications.

Efficacy of Endoscopic Resection for Rectal Neuroendocrine Tumors Smaller than 15 mm.

BACKGROUND: Local resection, including endoscopic resection, is recommended for rectal neuroendocrine tumors (NETs) < 15 mm in patients without risk factors for metastasis, though the short- and long-term outcomes are unclear. AIMS: This study investigates the efficacy of endoscopic resection for rectal NETs < 15 mm. METHODS: The short- and long-term outcomes of patients with rectal NETs < 15 mm who underwent endoscopic resection and the outcomes of each endoscopic technique were analyzed. The tumors were stratified as < 10 mm (small-size group, SSG) and 10-14 mm (intermediate-size group, IMG). RESULTS: Overall, 139 lesions (SSG, n = 118; IMG, n = 21) were analyzed. All tumors were classified as G1 (n = 135) or G2 (n = 4) according to the 2019 World Health Organization grading criteria. The complete resection rate was not different between the groups (P = 0.151). Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection with a ligation device (ESMR-L) achieved complete resection rates > 90% in the SSG. The ESMR-L procedure time (P < 0.001) and hospitalized period (P < 0.001) were significantly shorter than those of ESD. ESD achieved a complete resection rate of 80.0% in the IMG. The tumor size did not affect the overall survival or rate of lymph node/distant metastases. CONCLUSIONS: Endoscopic resection is a feasible and effective treatment for patients with rectal NETs < 15 mm without the risk factors of metastasis. ESMR-L and ESD are optimal techniques for resecting tumors smaller than 10 mm and 10-14 mm, respectively.

The gut microbiota composition in patients with right- and left-sided colorectal cancer and after curative colectomy, as analyzed by 16S rRNA gene amplicon sequencing.

BACKGROUND: Gut pathological microbial imbalance or dysbiosis is closely associated with colorectal cancer. Although there are observable differences in molecular and clinical characteristics between patients with right- and left-sided colon cancer, differences in their gut microbiomes have not been thoroughly investigated. Furthermore, subsequent changes in microbiota status after partial colectomy remain unknown. We examined the human gut microbiota composition to determine its relationship with colon cancer and partial colon resection according to location. METHODS: Stool samples from forty-one subjects (10 in the control group, 10 in the right-sided colon cancer [RCC] group, 6 in the sigmoid colon cancer [SCC] group, 9 in the right colon resection [RCR] group and 6 in the sigmoid colon resection [SCR] group) were collected, and DNA was extracted. After terminal restriction fragment length polymorphism (T-RFLP) analysis, the samples were subjected to 16S rRNA gene amplicon sequencing, and the metabolic function of the microbiota was predicted using PICRUSt2. RESULTS: T-RFLP analysis showed a reduced ratio of clostridial cluster XIVa in the SCC patients and clostridial cluster IX in the RCC patients, although these changes were not evident in the RCR or SCR patients. 16S rRNA gene amplicon sequencing demonstrated that the diversity of the gut microbiota in the RCC group was higher than that in the control group, and the diversity in the SCR group was significantly higher than that in the RCR group. Principal coordinate analysis (PCoA) revealed significant differences according to the group. Analyses of the microbiota revealed that Firmicutes was significantly dominant in the RCC group and that the SCC group had a higher abundance of Verrucomicrobia. At the genus level, linear discriminant analysis effect size (LEfSe) revealed several bacteria, such as Ruminococcaceae, Streptococcaceae, Clostridiaceae, Gemellaceae, and Desulfovibrio, in the RCC group and several oral microbiomes in the SCC group. Metabolic function prediction revealed that cholesterol transport- and metabolism-related enzymes were specifically upregulated in the RCC group and that cobalamin metabolism-related enzymes were downregulated in the SCC group. CONCLUSION: Gut microbial properties differ between RCC and SCC patients and between right hemicolectomy and sigmoidectomy patients and may contribute to clinical manifestations.

Proposal of Quick Diagnostic Criteria for Disseminated Intravascular Coagulation.

BACKGROUND: The diagnostic criteria for disseminated intravascular coagulation (DIC) vary and are complicated and the cut-off values are different. Simple and quick diagnostic criteria for DIC are required in physicians for critical care. MATERIAL AND METHODS: Platelet counts, prothrombin time-international normalized ratio (PT-INR) and D-dimer levels were examined in 1293 critical ill patients. Adequate cut-off values of these parameters were determined and a quick DIC score using these biomarkers was proposed. The quick DIC score was evaluated using a receiver operating characteristic (ROC) analysis. RESULTS: Using the Japanese Ministry of Health, Labor and Welfare diagnostic criteria, 70 and 109 patients were diagnosed with DIC and pre-DIC, respectively. The ROC analysis of factors difference between DIC and non-DIC, revealed the following cut-off values: PT-INR, 1.20; platelet count, 12.0 × 1010/L and D-dimer, 10.0 µg/mL. Based on the above results, the quick DIC score system was proposed. All patients with DIC had a quick DIC score of 3, 4 or 5, and 85.3% of the patients with pre-DIC had a quick DIC score of ≥3 points. All patients with pre-DIC had a score of ≥2 points. In the ROC analysis, the area under the curve was 0.997 for DIC vs. non-DIC, and 0.984 for pre-DIC + DIC vs. non-DIC, and the cut-off value was 3 points for DIC and 2 points for DIC + pre-DIC. The quick DIC scores of non-survivors were significantly higher than those of survivors. CONCLUSIONS: The Quick DIC score system is a simple and useful tool that can be used for the diagnosis of DIC and pre-DIC. Further evaluation of the quick DIC score system in a large-scale study is required.

A Clot Waveform Analysis Showing a Hypercoagulable State in Patients with Malignant Neoplasms.

(1) Objective: hypercoagulability in patients with malignant neoplasm were evaluated to examine the relationship with thrombosis. (2) Methods: clot waveform analysis (CWA)-activated partial thromboplastin time (APTT) and CWA-small amount of tissue factor induced FIX activation (sTF/FIXa) assays were performed in 92 patients with malignant neoplasm and the relationship between hypercoagulability and thrombosis was retrospectively examined. (3) Results: The study population included 92 patients with malignant neoplasms. Twenty-six (28.3%) had thrombotic diseases and 9 (9.8%) patients died within 28 days after the CWA. The peak time of the CWA-APTT could not show hypercoagulability in patients with malignant neoplasms. There were almost no significant differences in the peak times of the sTF/FIXa among patients with malignant neoplasms and healthy volunteers. In contrast, the peak heights of the CWA-sTF/FIXa in patients with various malignant neoplasms were significantly higher than those in healthy volunteers. Furthermore, among patients with malignant neoplasms, the peak heights of the sTF/FIXa in patients with thrombosis were significantly higher than those in patients without thrombosis. (4) Conclusions: although the routine APTT cannot evaluate the hypercoagulability, the peak heights of CWA-sTF/FIXa were significantly high in patients with malignant neoplasms, especially in those with thrombosis, suggesting that an elevated peak height of the CWA-sTF/FIXa may be a risk factor for thrombosis.

Evaluation of Biomarkers of Severity in Patients with COVID-19 Infection.

OBJECT: Although many Japanese patients infected with coronavirus disease 2019 (COVID-19) only experience mild symptoms, in some cases a patient's condition deteriorates, resulting in a poor outcome. This study examines the behavior of biomarkers in patients with mild to severe COVID-19. METHODS: The disease severity of 152 COVID-19 patients was classified into mild, moderate I, moderate II, and severe, and the behavior of laboratory biomarkers was examined across these four disease stages. RESULTS: The median age and male/female ratio increased with severity. The mortality rate was 12.5% in both moderate II and severe stages. Underlying diseases, which were not observed in 45% of mild stage patients, increased with severity. An ROC analysis showed that C-reactive protein (CRP), ferritin, procalcitonin (PCT), hemoglobin (Hb) A1c, albumin, and lactate dehydrogenase (LDH) levels were significantly useful for the differential diagnosis of mild/moderate I stage and moderate II/severe stage. In the severe stage, Hb levels, coagulation time, total protein, and albumin were significantly different on the day of worsening from those observed on the day of admission. The frequency of hemostatic biomarker abnormalities was high in the severe disease stage. CONCLUSION: The evaluation of severity is valuable, as the mortality rate was high in the moderate II and severe stages. The levels of CRP, ferritin, PCT, albumin, and LDH were useful markers of severity, and hemostatic abnormalities were frequently observed in patients in the severe disease stage.

Fibroblast growth factor receptor modulators employing diamines with reduced phospholipidosis-inducing potential.

SUN13837 (1), a fibroblast growth factor receptor modulator, has been an attractive candidate for treating neurodegenerative diseases. However, one of its metabolites, N-benzyl-4-(methylamino)piperidine (BMP), turned out to possess phospholipidosis-inducing potential (PLIP) in vitro. To obtain SUN13837 analogs with reduced phospholipidosis risk, we replaced BMP with other diamines possessing low PLIP. Our effort led to the discovery of compound 6 with increased efficacy. Further structural modifications to reduce hydrogen bond donors afforded 17 with improved brain exposure. Oral administration of 17 at 1 mg/kg once daily for 10 days showed enhanced recovery of coordinated movement in a rat acute stroke model, suggesting that it is a promising follow-up compound for 1 with reduced risk of phospholipidosis.

Second basic pKa: An overlooked parameter in predicting phospholipidosis-inducing potential of diamines.

In this paper, we present the phospholipidosis-inducing potential (PLIP) of forty fragment-sized diamines derived from N-benzyl-4-(methylamino)piperidine and discuss the relationship between their PLIP and the physicochemical properties. Our results demonstrate that the previously reported methods are not suitable for predicting the PLIP of fragment-sized diamines; the second basic pKa can distinguish PLIP-positive diamines from PLIP-negative diamines more accurately than ClogP or most basic pKa. To the best of our knowledge, this is the first report describing the relationship between PLIP and second basic pKa.

Discovery of a Potent, Selective, and Orally Available MTHFD2 Inhibitor (DS18561882) with in Vivo Antitumor Activity.

We report the discovery of a potent and isozyme-selective MTHFD2 inhibitor, DS18561882 (2). Through investigation of the substituents on our tricyclic coumarin scaffold (1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one), MTHFD2 inhibitory activity was shown to be elevated by incorporating an amine moiety at the 8-position and a methyl group at the 7-position of the initial lead 1. X-ray structure analysis revealed that a key interaction for enhanced potency was salt bridge formation between the amine moiety and the diphosphate linker of an NAD+ cofactor. Furthermore, ortho-substituted sulfonamide in place of benzoic acid of 1 significantly improved cell permeability and cell-based growth inhibition against a human breast cancer cell line. The thus-optimized DS18561882 showed the strongest cell-based activity (GI50 = 140 nM) in the class, a good oral pharmacokinetic profile, and thereby tumor growth inhibition in a mouse xenograft model upon oral administration.

Discovery of 1,2,3-triazole-based fibroblast growth factor receptor modulators.

To avoid production of a phospholipidosis-inducing metabolite, we replaced the amide structure of SUN13837 (1) with a 1,2,3-triazole. The resulting 1,2,3-triazole analog of 1 (compound 2) displayed greater neuroprotective activity than 1. Structural modification of 2 yielded compound 10, which showed improved neuroprotective activity and negligible mechanism-based inactivation against CYP3A4. In addition, installation of a methyl group at the 5-position of 1,2,3-triazole of 10 significantly boosted the neuroprotective activity. These 1,2,3-triazole derivatives displayed reduced phospholipidosis risk, sufficient systemic exposure, and high central nervous system penetration, and therefore may be potentially useful agents for the treatment of neurodegenerative diseases.

Structure-Based Design and Synthesis of an Isozyme-Selective MTHFD2 Inhibitor with a Tricyclic Coumarin Scaffold.

Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) plays a key role in one-carbon (1C) metabolism in human mitochondria, and its high expression correlates with poor survival of patients with various types of cancer. An isozyme-selective MTHFD2 inhibitor is highly attractive for potential use in cancer treatment. Herein, we disclose a novel isozyme-selective MTHFD2 inhibitor DS44960156, with a tricyclic coumarin scaffold, which was initially discovered via high-throughput screening (HTS) and improved using structure-based drug design (SBDD). DS44960156 would offer a good starting point for further optimization based on the following features: (1) unprecedented selectivity (>18-fold) for MTHFD2 over MTHFD1, (2) a molecular weight of less than 400, and (3) good ligand efficiency (LE).

Changing clinical and molecular characteristics of hepatitis E virus infection in Mie Prefecture, Japan: Disappearance of indigenous subtype 3e strains.

AIM: To evaluate the clinical and molecular characteristics of hepatitis E virus (HEV) infection in Mie Prefecture, Japan, from 2004 through 2018. METHODS: The clinical information of hepatitis E cases was collected from 21 medical institutions in Mie Prefecture. The nucleotide sequences of infecting HEV strains were determined for cases with available serum samples. The origins or transmission routes were inferred from phylogenetic analyses of the nucleotide sequences. RESULTS: Fifty-three patients were diagnosed with HEV infection. The number of cases increased each year through 2012 and then decreased. Analyses of the clinical characteristics of the cases indicated that even mild cases were detected in the latter 10 years of the study. Nucleotide sequence analyses were undertaken on 38 of the 53 cases. The HEV subtype 3e (HEV-3e) strains identified for 13 cases were closely related to a swine HEV-3e strain that was isolated from the liver of a pig bred in Mie Prefecture. The number of cases infected with the indigenous Mie HEV-3e strains increased until 2012 but have not been reported since 2014. In the latter half of the study, cases involving various HEV strains of different genotypes and subtypes emerged. CONCLUSIONS: The disappearance of indigenous Mie HEV-3e strains appeared to be the primary cause for the decrease in hepatitis E cases in Mie Prefecture. The disappearance might have been associated with improved hygienic conditions on pig farms or the closure of contaminated farms. The results suggest that indigenous HEV strains can be eradicated by appropriate management.

Second-line triple therapy in failures with vonoprazan-based triple therapy for eradication of Helicobacter pylori.

Gastric acid inhibition during treatment is important for the eradication of Helicobacter pylori (H. pylori) infection. A novel potassium-competitive acid blocker, vonoprazan (VPZ), has been demonstrated to achieve high eradication rates; however, the efficacy of second-line treatment in failures of VPZ-based triple therapy has not been well studied. The aim of the current study was to determine the efficacy of VPZ in a first-line regimen for H. pylori eradication, and the efficacy of a second-line regimen using metronidazole (MTZ) in failures with the first-line regimen. Of 580 subjects enrolled in the study, 524 patients completed first-line treatment (275 patients who received VPZ and 249 patients who received LPZ). First-line regimens consisted of a combination of clarithromycin (CAM) 200 or 400 mg twice a day, amoxicillin (AMPC) 750 mg twice a day, and either LPZ 30 mg or VPZ 20 mg twice a day, administered orally for 7 days. CAM and VPZ/LPZ were replaced with metronidazole (MTZ) 250 mg and rabeprazole 10 mg in the second-line regimens. The eradication of H. pylori was assessed by the H. pylori stool antigen test. The overall first-line eradication rate with VPZ was significantly higher than that with LPZ [91.0% (250/275) vs. 84.7% (211/249), respectively, P=0.030]. The dose of CAM (400 vs. 800 mg) did not affect the eradication rate in either the VPZ or LPZ regimens. The overall eradication rates of the second-line regimens with MTZ did not differ significantly between the VPZ-failure and LPZ-failure groups [87.0% (20/23) vs. 87.9% (29/33), respectively, P=0.700]. Therefore, VPZ was significantly more effective than LPZ for first-line treatment. In patients with failure of first-line eradication therapy, successful results of second-line eradication therapy did not differ between the VPZ- and LPZ-failure groups. In conclusion, VPZ-based triple therapy should be recommended for eradication of H. pylori.

Changes in plasma ghrelin and leptin levels in patients with peptic ulcer and gastritis following eradication of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori (H. pylori) infection and eradication therapy have been known to influence gastric ghrelin and leptin secretion, which may lead to weight gain. However, the exact relationship between plasma ghrelin/leptin levels and H. pylori infection has remained controversial. The aim of this study was to investigate plasma ghrelin and leptin levels in H. pylori-positive and -negative patients, to compare the two levels of the hormones before and after H. pylori eradication, and to examine the correlation between body mass index (BMI) and active ghrelin or leptin levels, as well as that between atrophic pattern and active ghrelin or leptin levels. METHODS: Seventy-two H. pylori-positive patients who underwent upper gastrointestinal endoscopy, 46 diagnosed as having peptic ulcer and 26 as atrophic gastritis, were enrolled. Control samples were obtained from 15 healthy H. pylori-negative volunteers. The extent of atrophic change of the gastric mucosa was assessed endoscopically. Body weight was measured and blood was collected before and 12 weeks after H. pylori eradication therapy. Blood samples were taken between 8 and 10 AM after an overnight fast. RESULTS: Plasma ghrelin levels were significantly lower in H. pylori-positive patients than in H. pylori-negative patients. In particular, plasma active ghrelin levels were significantly lower in patients with gastritis compared with patients with peptic ulcer. Plasma ghrelin levels decreased after H. pylori eradication in both peptic ulcer and gastritis patients, while plasma leptin levels increased only in peptic ulcer patients. Plasma leptin levels and BMI were positively correlated, and active ghrelin levels and atrophic pattern were weakly negatively correlated in peptic ulcer patients. CONCLUSION: H. pylori infection and eradication therapy may affect circulating ghrelin/leptin levels. This finding suggests a relationship between gastric mucosal injury induced by H. pylori infection and changes in plasma ghrelin and leptin levels.

Comparison of human gut microbiota in control subjects and patients with colorectal carcinoma in adenoma: Terminal restriction fragment length polymorphism and next-generation sequencing analyses.

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in Japan. The etiology of CRC has been linked to numerous factors including genetic mutation, diet, life style, inflammation, and recently, the gut microbiota. However, CRC-associated gut microbiota is still largely unexamined. This study used terminal restriction fragment length polymorphism (T-RFLP) and next-generation sequencing (NGS) to analyze and compare gut microbiota of Japanese control subjects and Japanese patients with carcinoma in adenoma. Stool samples were collected from 49 control subjects, 50 patients with colon adenoma, and 9 patients with colorectal cancer (3/9 with invasive cancer and 6/9 with carcinoma in adenoma) immediately before colonoscopy; DNA was extracted from each stool sample. Based on T-RFLP analysis, 12 subjects (six control and six carcinoma in adenoma subjects) were selected; their samples were used for NGS and species-level analysis. T-RFLP analysis showed no significant differences in bacterial population between control, adenoma and cancer groups. However, NGS revealed that i), control and carcinoma in adenoma subjects had different gut microbiota compositions, ii), one bacterial genus (Slackia) was significantly associated with the control group and four bacterial genera (Actinomyces, Atopobium, Fusobacterium, and Haemophilus) were significantly associated with the carcinoma-in-adenoma group, and iii), several bacterial species were significantly associated with each type (control: Eubacterium coprostanoligens; carcinoma in adenoma: Actinomyces odontolyticus, Bacteroides fragiles, Clostridium nexile, Fusobacterium varium, Haemophilus parainfluenzae, Prevotella stercorea, Streptococcus gordonii, and Veillonella dispar). Gut microbial properties differ between control subjects and carcinoma-in-adenoma patients in this Japanese population, suggesting that gut microbiota is related to CRC prevention and development.

Comparison of the gut microbiota composition between obese and non-obese individuals in a Japanese population, as analyzed by terminal restriction fragment length polymorphism and next-generation sequencing.

BACKGROUND: Obesity has become one of the most serious social problems in developed countries, including Japan. The relationship between the gut microbiota and obesity has recently attracted the attention of many researchers. Although the gut microbiota was long thought to contribute to obesity, the exact association remains largely unknown. We examined the human gut microbiota composition in a Japanese population in order to determine its relationship to obesity. METHODS: Stool samples from 23 non-obese subjects (body mass index [BMI] <20 kg/m(2)) and 33 obese subjects (BMI ≥25 kg/m(2)) were collected and DNA was extracted prior to colonoscopy. After terminal restriction fragment length polymorphism (T-RFLP) analysis, samples from 10 subjects (4 non-obese and 6 obese) were selected and subjected to next-generation sequencing for species-level analysis. RESULTS: T-RFLP analysis showed significantly reduced numbers of Bacteroidetes and a higher Firmicutes to Bacteroidetes ratio in obese subjects compared with non-obese subjects. Bacterial diversity was significantly greater in obese subjects compared with non-obese subjects. Next-generation sequencing revealed that obese and non-obese subjects had different gut microbiota compositions and that certain bacterial species were significantly associated with each group (obese: Blautia hydrogenotorophica, Coprococcus catus, Eubacterium ventriosum, Ruminococcus bromii, Ruminococcus obeum; non-obese: Bacteroides faecichinchillae, Bacteroides thetaiotaomicron, Blautia wexlerae, Clostridium bolteae, Flavonifractor plautii). CONCLUSION: Gut microbial properties differ between obese and non-obese subjects in Japan, suggesting that gut microbiota composition is related to obesity.

The expression and function of Toll-like receptors 3 and 9 in human colon carcinoma.

Toll-like receptors (TLRs) are pattern-recognition receptors that are important in immune signaling. TLR recognition of various viral components including double-stranded RNA (TLR3) and unmethylated CpG-DNA (TLR9) plays a crucial role in cell survival. However, TLR expression and function in colon carcinoma cells are not well clarified. We investigated the expression of TLR3 and TLR9 in colon carcinoma cells using immunohistochemical methods. The function of TLR3 and TLR9 signaling in carcinoma cell lines was studied by direct cell stimulation with, or by cell transfection of, polyinosinic-polycytidylic acid (Poly I:C), a synthetic form of dsRNA, and by cell stimulation with CpG-oligodeoxynucleotides (ODNs), respectively. Positive TLR3 and TLR9 immunohistochemical staining was observed in 91 and 86% of human hepatocellular carcinoma (HCC) tissues, respectively. Cell surface stimulation of TLR3 with Poly I:C did not affect cell viability but it did activate NF-κB activity. By contrast, stimulation of intracellular TLRs with transfected Poly I:C significantly induced apoptosis. Cell surface stimulation of TLR9 with CpG-ODNs promoted cell proliferation, and, furthermore, these CpG-ODN TLR9 agonists reduced the cytotoxicity of the anticancer drug adriamycin. Cell surface expression of TLR3 and TLR9 in colon carcinoma cells plays an important role in cell survival. In addition, the proapoptotic activity of intracellularly expressed TLR3 may provide the possibility of using TLR3 agonists as novel clinical cytotoxic agents against colon carcinoma cells.

Phosphodiesterase 7A inhibitor ASB16165 impairs proliferation of keratinocytes in vitro and in vivo.

Excessive proliferation of epidermal keratinocytes is a typical aspect of chronic skin diseases such as psoriasis. In the present study, the effect of phosphodiesterase 7A (PDE7A) inhibitor ASB16165 on proliferation of keratinocytes was investigated to examine the role of PDE7A in keratinocyte proliferation and the possible therapeutic relevance of PDE7A inhibition in psoriasis. Topical application of ASB16165 inhibited the increase of thickness of skin as well as epidermis in a skin inflammation model induced by repeated painting of 12-O-tetradecanoylphorbol-13-acetate (TPA) in a concentration-dependent manner. The ASB16165 treatment also suppressed the increase in the number of Ki67-positive keratinocytes in the model, showing the disturbance of keratinocyte proliferation by the treatment. In addition, both ASB16165 and dibutyryl cAMP significantly decreased the proliferation of human keratinocytes in vitro, suggesting that PDE7A participates in keratinocyte proliferation probably by controlling intracellular cAMP, while the contribution of other mechanism(s) is not completely denied. The findings in the present study indicate that the effect of ASB16165 on skin and epidermal hyperplasia in the TPA-induced skin inflammation is mediated, at least in part, by the inhibition of keratinocyte proliferation. The inhibitors for PDE7A including ASB16165 might be useful for the treatment of psoriasis.

Inhibition of phosphodiesterase 7A ameliorates Concanavalin A-induced hepatitis in mice.

An intravenous injection of Concanavalin A (Con A) elevated the serum level of alanine aminotransferase (ALT) activity, a marker for liver damage, and an oral administration of PDE7A inhibitor SUN11817 suppressed the increase of ALT activity in a dose-dependent manner. Histological analysis revealed that Con A injection caused extensive liver damage, and that the SUN11817 treatment improved the degenerative change in the liver. In addition, SUN11817 inhibited not only the production of IL-4 and TNF-alpha in the Con A-induced hepatitis model but also that in vitro by murine splenocytes stimulated with alpha-galactosylceramide, an activator specific for NKT cells. The Con A injection to mice also induced expression of Fas ligand (FasL) on NKT cells, which was significantly prevented by SUN11817. As NKT cells are known to contribute to the pathogenesis in Con A-induced hepatitis by producing cytokines such as IL-4 and TNF-alpha and inducing FasL-mediated hepatocyte injury, it is thought that PDE7A inhibitor SUN11817 improves liver injury in the Con A model by blocking cytokine production and FasL expression in NKT cells. PDE7A might be a novel pharmaceutical target for hepatitis.