Interruption of p38MAPK-MSK1-CREB-MITF-M pathway to prevent hyperpigmentation in the skin.

Background: Melanocortin 1 receptor (MC1R), a receptor of α-melanocyte-stimulating hormone (α-MSH), is exclusively present in melanocytes where α-MSH/MC1R stimulate melanin pigmentation through microphthalmia-associated transcription factor M (MITF-M). Toll-like receptor 4 (TLR4), a receptor of endotoxin lipopolysaccharide (LPS), is distributed in immune and other cell types including melanocytes where LPS/TLR4 activate transcriptional activity of nuclear factor (NF)-κB to express cytokines in innate immunity. LPS/TLR4 also up-regulate MITF-M-target melanogenic genes in melanocytes. Here, we propose a molecular target of antimelanogenic activity through elucidating inhibitory mechanism on α-MSH-induced melanogenic programs by benzimidazole-2-butanol (BI2B), an inhibitor of LPS/TLR4-activated transcriptional activity of NF-κB. Methods: Ultraviolet B (UV-B)-irradiated skins of HRM-2 hairless mice and α-MSH-activated melanocyte cultures were employed to examine melanogenic programs. Results: Topical treatment with BI2B ameliorated UV-B-irradiated skin hyperpigmentation in mice. BI2B suppressed the protein or mRNA levels of melanogenic markers, such as tyrosinase (TYR), MITF-M and proopiomelanocortin (POMC), in UV-B-exposed and pigmented skin tissues. Moreover, BI2B inhibited melanin pigmentation in UV-B-irradiated co-cultures of keratinocyte and melanocyte cells and that in α-MSH-activated melanocyte cultures. Mechanistically, BI2B inhibited the activation of cAMP response element-binding protein (CREB) in α-MSH-induced melanogenic programs and suppressed the expression of MITF-M at the promoter level. As a molecular target, BI2B primarily inhibited mitogen-activated protein kinase (MAPK) kinase 3 (MKK3)-catalyzed kinase activity on p38MAPK. Subsequently, BI2B interrupted downstream pathway of p38MAPK-mitogen and stress-activated protein kinase-1 (MSK1)-CREB-MITF-M, and suppressed MITF-M-target melanogenic genes, encoding enzymes TYR, TYR-related protein-1 (TRP-1) and dopachrome tautomerase (DCT) in melanin biosynthesis, and encoding proteins PMEL17 and Rab27A in the transfer of pigmented melanosomes to the overlaying keratinocytes in the skin. Conclusion: Targeting the MKK3-p38MAPK-MSK1-CREB-MITF-M pathway was suggested as a rationale to inhibit UV-B- or α-MSH-induced facultative melanogenesis and as a strategy to prevent acquired pigmentary disorders in the skin.

Erratum: Correction of Text in the Article "The Impact of COVID-19 on the Use of Radiology Resources in a Tertiary Hospital".

This corrects the article on p. e368 in vol. 35, PMID: 33075859.

Design, synthesis and anticancer activity of 2-amidomethoxy-1,4-naphthoquinones and its conjugates with Biotin/polyamine.

In continuation with the previous work, a series of 5-hydroxy-2-amidomethoxy-1,4-naphthoquinones were prepared to establish the structure-activity relationship studies toward anticancer activity (IC50 in µM) against three cell lines; colo205 (colon adenocarcinoma), T47D (breast ductal carcinoma) and K562 (chronic myelogenous leukemia). Among the synthesized compounds, naphthoquinone amines, 5 (0.8; 0.6; 0.8), 14 (0.8; 0.6; 0.5) and the amine precursor, 4 (1.3; 0.3; 1.0) displayed potent anticancer activities. A tumor targeting drug delivery system was achieved by synthesizing the conjugate 6 (1.4; 0.5; 1.1) of naphthoquinone-amine 5 and Biotin which also proved its potency. Finally, to introduce polyamine conjugate, spermidine was attached with 2-amidomethoxy-1,4-naphthoquinone. The naphthoquinone-spermidine conjugate 27 (1.2; 1.7; 1.7) also retained the activity. Thus, potent naphthoquinone amines were explored and Biotin/polyamine conjugate was developed as tumor targeting drug delivery system.

Identification of diphenylalkylisoxazol-5-amine scaffold as novel activator of cardiac myosin.

To identify novel potent cardiac myosin activator, a series of diphenylalkylisoxazol-5-amine compounds 4-7 have been synthesized and evaluated for cardiac myosin ATPase activation. Among the 37 compounds, 4a (CMA at 10 µM = 81.6%), 4w (CMA at 10 µM = 71.2%) and 6b (CMA at 10 µM = 67.4%) showed potent cardiac myosin activation at a single concentration of 10 µM. These results suggested that the introduction of the amino-isoxazole ring as a bioisostere for urea group is acceptable for the cardiac myosin activation. Additional structure-activity relationship (SAR) studies were conducted. Para substitution (-Cl, -OCH3, -SO2N(CH3)2) to the phenyl rings or replacement of a phenyl ring with a heterocycle (pyridine, piperidine and tetrahydropyran) appeared to attenuate cardiac myosin activation at 10 µM. Additional hydrogen bonding acceptor next to the amino group of the isoxazoles did not enhance the activity. The potent isoxazole compounds showed selectivity for cardiac myosin activation over skeletal and smooth muscle myosin, and therefore these potent and selective isoxazole compounds could be considered as a new series of cardiac myosin ATPase activators for the treatment of systolic heart failure.

The Impact of COVID-19 on the Use of Radiology Resources in a Tertiary Hospital.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has escalated to be a global threat to public health. Analysis of the use of radiology resources may render us insight regarding the public health behavior during pandemic. We measured the influence COVID-19 had on the use of radiology resources in terms of the number of examinations performed, and turnaround time for portable radiography. METHODS: This study was conducted at a tertiary hospital located in area where the prevalence of COVID-19 infection was low (0.01%). We compared the number of radiology examinations 1) before pandemic (in 2019) vs. during peak of pandemic (January to March 2020), and 2) before pandemic vs. after the peak of pandemic (April to June 2020) via t-tests. We repeated similar analyses for subgroups as follows: gender, age, department (outpatient, inpatient, emergency, screening), body parts, and modality. We also performed a survey of radiologic technologists regarding the turnaround time and rate-limiting step of portable radiography for patients with and without suspicion or confirmation of COVID-19. RESULTS: Although not statistically significant, the daily number of examinations during the peak of pandemic decreased by 9 percentage points (2,638 vs. 2,413; difference [95% CI], -225 [-489, 38]; P = 0.094). The percentage change was especially notable for children, emergency, and screening department (25, 19, and 44 percentage points, respectively). After the peak of the pandemic, the number of examinations increased back to near the pre-pandemic level (2,638 vs. 2,588; -50 [-317, 218]; P = 0.71). The turnaround time for portable radiography tended to be longer for patients with suspicion or confirmation of COVID-19, with donning personal protective equipment being the major rate-limiting step. CONCLUSION: The number of examinations decreased during the pandemic, reflecting the tendency of the public to refrain from seeking medical care even in a community of low infection risk. Nevertheless, burden of healthcare providers may not have decreased as much, considering longer turnaround time required for COVID-19 related examinations.

Stem Cell Factor-Inducible MITF-M Expression in Therapeutics for Acquired Skin Hyperpigmentation.

Rationale: Microphthalmia-associated transcription factor M (MITF-M) plays important roles in the pigment production, differentiation and survival of melanocytes. Stem cell factor (SCF) and its receptor KIT stimulate MITF-M activity via phosphorylation at the post-translation level. However, the phosphorylation shortens half-life of MITF-M protein over the course of minutes. Here, we investigated novel hypotheses of (i) whether SCF/KIT can regulate MITF-M activity through gene expression as the alternative process, and (ii) whether chemical inhibition of KIT activity can mitigate the acquired pigmentation in skin by targeting the expression of MITF-M. Methods: We employed melanocyte cultures in vitro and pigmented skin samples in vivo, and applied immunoblotting, RT-PCR, siRNA-based gene knockdown and confocal microscopy. Results: The protein and mRNA levels of MITF-M in epidermal melanocytes and the promoter activity of MITF-M in B16-F0 melanoma cells demonstrated that SCF/KIT could trigger the expression of MITF-M de novo, following the phosphorylation-dependent proteolysis of pre-existing MITF-M protein. SCF/KIT regulated the transcription abilities of cAMP-responsive element-binding protein (CREB), CREB-regulated co-activator 1 (CRTC1) and SRY-related HMG-box 10 (SOX10) but not ß-catenin at the MITF-M promoter. Meanwhile, chemical inhibition of KIT activity abolished SCF-induced melanin production in epidermal melanocyte cultures, as well as protected the skin from UV-B-induced hyperpigmentation in HRM2 mice or brownish guinea pigs, in which it down-regulated the expression of MITF-M de novo at the promoter level. Conclusion: We propose the targeting of SCF/KIT-inducible MITF-M expression as a strategy in the therapeutics for acquired pigmentary disorders.

The effectiveness of a fecal diverting device for prevention of septic complications in a dog model of ischemic bowel anastomosis.

OBJECTIVE: A type of bypass tube for a fecal diversion device (FDD) was created to protect colorectal anastomosis. We evaluated the effectiveness of the FDD in an animal study. METHODS: The study was performed in an experimental animal laboratory of a tertiary referral center hospital. Thirty mongrel dogs were randomized to the FDD or control group (n = 15, each). An ischemic anastomosis model was used to readily produce anastomotic leakage (AL) in both groups. The FDD was fixed intraluminally at 10 cm above the anastomotic site in the FDD group. No protective methods were used in the control group. The postoperative observation period was 3 weeks. RESULTS: The 3 week-survival rates were higher in the FDD group compare with the control group (80%, 12/15 vs. 40%, 6/15; log-rank, P = 0.024). The incidence of AL causing generalized peritonitis was lower in the FDD group than in the control group (20.0%, 3/15 vs. 60.0%, 9/15; P = 0.025) despite the overall incidence of complications being similar in the both groups (53.3%, 8/15 vs. 66.7%, 10/15; P = 0.456). Colonic wall erosions in the FDD fixing area were seen in two subjects (13.3%) in the FDD group. However, the two subjects survived to the end of the experimental period. In the FDD group, five subjects (33.3%, 5/15) did not retain their FDD, and three among them died from generalized peritonitis. CONCLUSION: This study shows the effectiveness of the FDD at preventing septic complications in a dog model of ischemic bowel anastomosis.

Discovery of benzimidazole analogs as a novel interleukin-5 inhibitors.

A series of novel hydroxyethylaminomethylbenzimidazole analogs 5a-y were synthesized and evaluated for their IL-5 inhibitory activity using pro-B Y16 cell line. Among them, 2-(((4-(cyclohexylmethoxy)-1H-benzo[d]imidazol-2-yl)methyl)amino)butan-1-ol (5e, 94.3% inhibition at 30 µM, IC50 = 3.5 µM, cLogP = 4.132) and 3-cyclohexyl-2-(((4-(cyclohexylmethoxy)-1H-benzo[d]imidazol-2-yl)methyl)amino) propan-1-ol (5k, 94.7% inhibition at 30 µM, IC50 = 5.0 µM, cLogP = 6.253) showed the most potent inhibitory activity. The essential feature of SAR (Fig. 5) indicated that the chromenone ring can be replaced by a benzimidazole ring to maintain the inhibitory activity. In addition, the hydroxyethylaminomethyl group was suitable for the IL-5 inhibitory activity. Moreover, the hydrophobic substituents on carbon play an important role in the IL-5 inhibitory activity of these analogs. However, N-substituted analogs did not improve inhibitory activity. In addition, MTT assay of 5e and 5k with normal B lymphoblasts revealed that they had no significant effects on cell viability.

Design and synthesis of sulfonamidophenylethylamides as novel cardiac myosin activator.

The sulfonamidophenylethylamide analogues were explored for finding novel and potent cardiac myosin activators. Among them, N-(4-(N,N-dimethylsulfamoyl)phenethyl-N-methyl-5-phenylpentanamide (13, CMA at 10 µM = 48.5%; FS = 26.21%; EF = 15.28%) and its isomer, 4-(4-(N,N-dimethylsulfamoyl)phenyl-N-methyl-N-(3-phenylpropyl)butanamide (27, CMA at 10 µM = 55.0%; FS = 24.69%; EF = 14.08%) proved to be efficient cardiac myosin activators both in in vitro and in vivo studies. Compounds 13 (88.2 + 3.1% at 5 µM) and 27 (46.5 + 2.8% at 5 µM) showed positive inotropic effect in isolated rat ventricular myocytes. The potent compounds 13 and 27 were highly selective for cardiac myosin over skeletal and smooth muscle myosin, and therefore these potent and selective amide derivatives could be considered a new class of cardiac myosin activators for the treatment of systolic heart failure.

Ileostomy versus fecal diversion device to protect anastomosis after rectal surgery: a randomized clinical trial.

PURPOSE: Patients with rectal anastomosis commonly experience various ileostomy-related complications. This study aimed to elucidate the usefulness of a fecal diversion device (FDD) as an alternative to ileostomy for protecting rectal anastomosis. METHODS: Patients with rectal anastomosis were randomly assigned to the ileostomy and FDD groups except in cases of emergency surgery. The primary endpoint was the clinical safety and effectiveness of FDD. The mean operation time, delay of diet advancement, length of hospital stay, FDD and stoma durations, and anastomotic leakage (AL) management methods were compared. RESULTS: A total of 54 patients were enrolled in this study. No cases of mortality occurred. Overall morbidity was similar between groups (P = 0.551). Six patients (22.2%) in the FDD group and nine (29.0%) in the stoma group (P = 0.555) had AL. The mean total hospital stay was 16.4 ± 6.7 and 23.4 ± 8.7 days in the FDD and stoma groups, respectively (P = 0.002). The mean total hospital cost was 12,726.8 ± 3422.8 USD and 17,954.9 ± 9040.3 USD in the FDD and stoma groups, respectively (P = 0.008). The mean FDD and stoma durations were 21.6 ± 6.1 days and 114.9 ± 41.3 days, respectively (P < 0.0001). CONCLUSIONS: This study demonstrated FDD safety and effectiveness. We identified the possibility of FDD as an alternative technique to conventional stoma procedures.

Correction to: Identification of N-arylsulfonylpyrimidones as anticancer agents.

The author would like to include conflict of interest statement of the online published article. The correct conflict of interest statement should read as: The authors declare no conflict of interest.

Fecal diverting device for the substitution of defunctioning stoma: preliminary clinical study.

BACKGROUND: A novel fecal diverting device (FDD) made for the prevention of sepsis resulting from anastomotic leakage (AL) was tested successfully in an animal study. This study was undertaken to evaluate the clinical safety and effectiveness of the FDD. METHODS: A prospective observation trial was implemented in a tertiary referral university hospital. The study enrolled patients who needed a defunctioning stoma to preserve low-lying rectal anastomosis. The FDD was fixed to the proximal colon 15 cm from the anastomosis and scheduled to divert feces for 3 weeks. The duration could be extended for more than 3 weeks if AL was noted. Postoperative evaluations of AL were performed by obtaining a computed tomography (CT) scan after 1 week and a contrast study after 3 weeks. The outcomes were FDD-related complications, and the capacity of the FDD to preserve the anastomosis. The median follow-up period was 10 (range 5-40) months. RESULTS: Thirty-one patients, including 5 benign cases, were evaluated. There was no case of stoma conversion or surgical re-intervention. Evidence of AL was identified in 10 (32%) patients using the CT scan at 1 week after surgery. However, in the contrast study at 3 weeks after surgery, only 5 cases of AL sinus were noted. Conservative treatments including 1-3 weeks prolongation of FDD maintenance were enough to preserve the anastomosis. There were 3 cases of partial colonic wall erosions at the FDD attachment area. All of these patients showed improvement with conservative treatment. The limitations were that the study was performed in a single institute and without a control group. CONCLUSIONS: The FDD showed a sufficient capacity of fecal diversion and maintenance duration that prevented aggravation of sepsis in the case of AL without significant complications.

A thorough analysis of the effect of surfactant/s on the solubility and pharmacokinetics of (S)-zaltoprofen.

Until now, there are no publications about the preformulation studies on (S)-zaltoprofen ((S)-ZPF). Hence, we first investigated the solubility of (S)-ZPF, screened solubilizers and performed the pharmacokinetic study of (S)-ZPF in the presence of the solubilizers. The measurement of the solubility of (S)-ZPF in 26 different solvents was carried out, including d-alpha tocopheryl polyethylene glycol 1000 succinate (TPGS), 2-hydroxypropyl-ß-cyclodextrin (HPCD), and mixtures of individual solvent. The plasma concentration of (S)-ZPF and the amount of (S)-ZPF retained in stomach were determined after oral (35.0 mg/kg) and intravenous (5.0 mg/kg) administration. The solubility of (S)-ZPF showed an increase of 484-fold in TPGS compared to its aqueous solubility. There was a significant increase of AUC0-24   h for pure (S)-ZPF in the TPGS group (813.59 ±â€¯64.17 µg⋅h/ml) in comparison with AUC0-24   h in the HPCD group (595.57  ±â€¯71.76 µg⋅h/ml) and water group (465.57 ±â€¯90.89 µg⋅h/ml). In addition, the Tmax of (S)-ZPF in the TPGS group was 2 h, much faster than that in the HPCD or water groups (5.50 or 5.67 h, respectively). This suggested that TPGS played a significant role in the increase of solubility and bioavailability of (S)-ZPF.

Exploration of diphenylalkyloxadiazoles as novel cardiac myosin activator.

To explore novel cardiac myosin activator, a series of diphenylalkyl substituted 1,3,4-oxadiazoles and 1,2,4-oxadiazoles have been prepared and tested for cardiac myosin ATPase activation in vitro. In all cases, three carbon spacer between the oxadiazole core and one of the phenyl ring was considered crucial. In case of 1,3,4-oxadiazole, zero to two carbon spacer between oxadiazole core and other phenyl ring are favorable. Phenyl ring can be replaced by cyclohexyl moiety. In case of 1,2,4-oxadiazole, zero or one carbon spacer between the oxadiazole and other phenyl ring are favorable. Introduction of hydrogen bonding donor (NH) group at the 2nd position of the 1,3,4-oxadiazole enhances the activity. Substitutions on either of the phenyl rings or change of phenyl ring to other heterocycle are not tolerated for both the oxadiazoles. The prepared oxadiazoles showed selective activation for cardiac muscle over smooth and skeleton muscles.

Investigation of chemical reactivity of 2-alkoxy-1,4-naphthoquinones and their anticancer activity.

To establish the structure-activity relationship of 5-hydroxy-1,4-naphthoquinones toward anticancer activity, a series of its derivatives were prepared and tested for the activity (IC50 in µM) against three cell lines; colo205 (colon adenocarcinoma), T47D (breast ductal carcinoma) and K562 (chronic myelogenous leukemia). Among them 2 (IC50: 2.3; 2.0; 1.4 µM), 6 (IC50: 1.9; 2.2; 1.3 µM), 9 (IC50: 0.7; 1.7; 0.9 µM) and 10 (IC50:1.7; 1.0; 1.2 µM) showed moderate to excellent activity. Our perception toward the DNA substitution of alkoxy groups at the C2 position of these naphthoquinones for the anticancer activity led us to investigate their reactivity of substitution toward dimethylamine as a nucleophile. The ease of the substitution of alkoxy groups at the C2 position with dimethylamine is strongly accelerated by hydroxyl group at C5 position and is well correlated with the found anticancer activity results.

Inhibitors of Melanogenesis: An Updated Review.

Melanins are pigment molecules that determine the skin, eye, and hair color of the human subject to its amount, quality, and distribution. Melanocytes synthesize melanin and provide epidermal protection from various stimuli, such as harmful ultraviolet radiation, through the complex process called melanogenesis. However, serious dermatological problems occur when there is excessive production of melanin in different parts of the human body. These include freckles, melasma, senile lentigo, pigmented acne scars, and cancer. Therefore, controlling the production of melanin is an important approach for the treatment of pigmentation related disorderes. In this Perspective, we focus on the inhibitors of melanogenesis that directly/indirectly target a key enzyme tyrosinase as well as its associated signaling pathways.

Identification of novel 2-benzyl-1-indanone analogs as interleukin-5 inhibitors.

A novel series of 2-benzyl-1-indanone analogs were investigated as IL-5 inhibitory activity. Among the synthesized compounds, 7-(cyclohexylmethoxy)-2-(4-hydroxybenzyl)-2,3-dihydro-1H-inden-1-one (7s, 100.0% inhibition at 30 µM, IC50 = 4.0 µM), and 7-(cyclohexylmethoxy)-2-(3-hydroxybenzyl)-2,3-dihydro-1H-inden-1-one (7t, 95.0% inhibition at 30 µM, IC50 = 6.0 µM) showed the best inhibitory activity against IL-5. The 2-benzyl-1-indanone analogs showed moderate to strong IL-5 inhibitory activity. Especially, hydroxyl (HBD/HBA) substituent at position 3 or 4 on phenyl ring B showed potent IL-5 inhibition. Additionally, the bulky hydrophobic cyclohexylmethoxy group at position 7 of the 1-indanone ring is favorable for the inhibitory activity.

Melanogenesis inhibitory pregnane glycosides from Cynanchum atratum.

Bioassay-guided fractionation of the methanolic extract from the roots of Cynanchum atratum has resulted in the isolation of three new pregnane glycosides (1-3) along with four known compounds (4-7). Their structures were identified by analysis of the spectroscopic data including extensive 2D NMR. All of the isolates were evaluated for their potential to inhibit the melanin production in α-melanocyte stimulating hormone (α-MSH)-activated B16 melanoma cells. Of these, compounds 4-7 dose-dependently inhibited the melanin production with the IC50 values ranging from 4 µM to 33 µM.

Identification of N-arylsulfonylpyrimidones as anticancer agents.

For confirming the role of five membered ring of imidazolidinone moiety of N-arylsulfonylimidazolidinones (7) previously reported with highly potent anticancer agent, a series of N-arylsulfonylpyrimidones (10a-g) and N-arylsulfonyltetrahydropyrimidones (11a-e) were prepared and their anti-proliferating activity was measured against human cancer cell lines (renal ACHN, colon HCT-15, breast MDA-MB-231, lung NCI-H23, stomach NUGC-3, and prostate PC-3) using XTT assay. Among them, 1-(1-acetylindolin-5-ylsulfonyl)-4-phenyltetrahydropyrimidin-2(1H)-one (11d, mean GI50 = 3.50 µM) and ethyl 5-(2-oxo-4-phenyltetrahydropyrimidin-1(2H)-ylsulfonyl)-indoline-1-carboxylate (11e, mean GI50 = 0.26 µM) showed best growth inhibitory activity against human cancer cell lines. Considering the activity results, N-arylsulfonyltetrahydropyrimidones (11) exhibited more potent activity compared to N-arylsulfonylpyrimidones (10) and comparable activity to N-arylsulfonylimidazolidinones (7). Especially, tetrahydropyrimidin-2(1H)-one analogs containing acylindolin-5-ylsulfonyl moiety at position 1 demonstrated their strong growth inhibitory activity against human cancer cell lines.

Design and synthesis of sulfonamidophenylethylureas as novel cardiac myosin activator.

To optimize the lead urea scaffold 1 and 2 as selective cardiac myosin ATPase activator, a series of urea derivatives have been synthesized to explore its structure activity relationship. Among them N,N-dimethyl-4-(2-(3-(3-phenylpropyl)ureido)ethyl)benzenesulfonamide (13, CMA = 91.6%, FS = 17.62%; EF = 11.55%), N,N-dimethyl-4-(2-(1-methyl-3-(3-phenylpropyl)ureido)ethyl)benzene sulfonamide (40, CMA = 52.3%, FS = 38.96%; EF = 24.19%) and N,N-dimethyl-4-(2-(3-methyl-3-(3-phenylpropyl)ureido)ethyl)benzenesulfonamide (41, CMA = 47.6%, FS = 23.19%; EF = 15.47%) proved to be efficient to activate the cardiac myosin in vitro and in vivo. Further the % change in ventricular cell contractility at 5 µM of 13 (47.9 ± 3.2), 40 (45.5 ± 2.4) and 41 (63.5 ± 2.2) showed positive inotropic effect in isolated rat ventricular myocytes. The potent compounds 13, 40, 41 were highly selective for cardiac myosin over skeletal and smooth muscle myosin, thus proving them these new urea derivatives is a novel scaffold for discovery of cardiac myosin activators for the treatment of systolic heart failure.