Indazole MRL-871 interacts with PPARγ via a binding mode that induces partial agonism.

The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) plays a central role in metabolic processes. PPARγ full agonists have side effects, arguing for the discovery of PPARγ partial agonists with novel chemotypes. We report the unique binding mode of the known allosteric retinoic acid receptor-related orphan receptor gamma t (RORγt) ligand MRL-871 to PPARγ. MRL-871 binds between PPARγ helices 3, 5, 7 and 11, where it stabilizes the beta-sheet region with a hydrogen bond between its carboxylic acid moiety and PPARγ Ser370. Its unique binding mode differs from that of the benzoyl 2-methyl indoles which are well-studied, structurally similar, PPARγ ligands. MRL-871's high affinity for PPARγ induces only limited coactivator stabilization, highlighting its attractive partial agonistic characteristics. Affinity comparison of MRL-871 and related compounds towards both RORγt and PPARγ indicates the possibility for tuning of selectivity, bringing MRL-871 forward as an interesting starting point for novel PPARγ ligands.

Associations between Hair Mineral Concentrations and Skeletal Muscle Mass in Korean Adults.

OBJECTIVES: Muscle health plays an important role in maintaining function and independence in the elderly, and some nutrients provide protection against the age-related decline of muscle strength and function. Minerals are important nutrients that may contribute to the prevention and treatment of sarcopenia, but they have not been well-studied. This study investigated whether hair mineral concentrations differ between subjects with low muscle mass (LMM) and subjects with normal muscle mass. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: A total of 232 adults ≥ 20 years of age who visited the Health Promotion Center of the University Hospital in Gyeonggi-do, Republic of Korea. MEASUREMENTS: The data from 232 subjects were analyzed and divided into LMM and normal groups based on the appendicular skeletal muscle mass index (ASMI) (LMM was defined as ASMI < 7.0 kg/m2 in men and < 5.7 kg/m2 in women). Skeletal muscle mass was estimated using a multi-frequency bioelectrical impedance analysis (BIA) device with a body composition analyzer. RESULTS: Overall mean age of participants was 50.4±11.6 years (29.7% women). Subjects with LMM showed significantly lower triglyceride levels, greater high-density lipoprotein cholesterol levels, and lower body mass index (BMI), compared with subjects who had normal muscle mass. No significant differences in hair mineral concentrations were observed between subjects with LMM and subjects with normal muscle mass, with the exception of copper. Hair copper concentrations were significantly greater in subjects with LMM than in subjects with normal muscle mass after adjustment for covariates and factors (65.7±14.2 vs 33.1±4.3 µg/g, P = 0.035). CONCLUSION: These results suggest that hair mineral status may play a role in the development of LMM. Therefore, further studies with larger numbers of subjects are required to identify the effects of mineral imbalances, their relationships with sarcopenia, and the differences between subjects with LMM and subjects with normal muscle mass.

Racial and ethnic disparities in COVID-19 disease incidence independent of comorbidities, among people with HIV in the US.

OBJECTIVES: To define the incidence of clinically-detected COVID-19 in people with HIV (PWH) in the US and evaluate how racial and ethnic disparities, comorbidities, and HIV-related factors contribute to risk of COVID-19. DESIGN: Observational study within the CFAR Network of Integrated Clinical Systems cohort in 7 cities during 2020. METHODS: We calculated cumulative incidence rates of COVID-19 diagnosis among PWH in routine care by key characteristics including race/ethnicity, current and lowest CD4 count, and geographic area. We evaluated risk factors for COVID-19 among PWH using relative risk regression models adjusted with disease risk scores. RESULTS: Among 16,056 PWH in care, of whom 44.5% were Black, 12.5% were Hispanic, with a median age of 52 years (IQR 40-59), 18% had a current CD4 count < 350, including 7% < 200; 95.5% were on antiretroviral therapy, and 85.6% were virologically suppressed. Overall in 2020, 649 PWH were diagnosed with COVID-19 for a rate of 4.94 cases per 100 person-years. The cumulative incidence of COVID-19 was 2.4-fold and 1.7-fold higher in Hispanic and Black PWH respectively, than non-Hispanic White PWH. In adjusted analyses, factors associated with COVID-19 included female sex, Hispanic or Black identity, lowest historical CD4 count <350 (proxy for CD4 nadir), current low CD4/CD8 ratio, diabetes, and obesity. CONCLUSIONS: Our results suggest that the presence of structural racial inequities above and beyond medical comorbidities increased the risk of COVID-19 among PWHPWH with immune exhaustion as evidenced by lowest historical CD4 or current low CD4:CD8 ratio had greater risk of COVID-19.

The association between subclinical inflammation and abnormal glucose and lipid metabolisms in normal-weight Korean individuals.

BACKGROUNDS AND AIMS: We aimed to reveal the association between subclinical inflammation and metabolic risk factors and to determine the difference in the association between normal-weight and obese Korean individuals. METHODS AND RESULTS: Data collected from the Korean National Health and Nutrition Examination Survey (KNHANES) 2015, conducted from January to December 2015, were analyzed. Overall, 4620 subjects were examined and divided into two subgroups: 2987 and 1633 subjects in the normal-weight and obese groups, respectively. The prevalence of obesity in the study population was 34.5% (n = 1633). After multivariate adjustment, impaired fasting glucose (IFG) (odds ratio [OR] 1.22, 95% confidence interval [CI] 1.05-1.42, P = 0.010), high triglyceride (TG) levels (OR 1.29, 95% CI 1.13-1.47, P < 0.001), and low high-density lipoprotein-cholesterol (HDL-C) levels (OR 1.47, 95% CI 1.31-1.64, P < 0.001) were significantly associated with increased high-sensitivity C-reactive protein (hs-CRP) levels in the normal-weight group but not in the obesity group. CONCLUSION: Subclinical inflammation was associated with IFG, high TG levels, and low HDL-C levels in normal-weight Korean individuals. Prospective and biochemical research is necessary to clarify the role of subclinical systemic inflammation in individuals with normal body weight and its impact on insulin resistance and abnormal lipid metabolism, which promote the incidence of metabolic syndrome and cardiovascular disease.

The analysis of scalp irritation by coacervates produced in hair shampoo via FTIR with focal plane array detector, X-ray photoelectron microscopy and HaCaT cells.

OBJECTIVE: Coacervates are inevitably formed on scalp on using hair washing products. Our goal was to analyse the coacervates in detail to identify the part responsible for scalp stimulation. METHODS: Shampoo that increases coacervate formation was applied to in vitro skin and was washed. The residue was then analysed using Fourier transform infrared spectroscopy-focal plane array (FTIR-FPA) and X-ray photoelectron microscopy (XPS). And HaCaT cells were used for irritant test of coacervate. RESULTS: Through this research, it was confirmed that the coacervate was a macromolecule structurally similar to a cationic polymer and contains an anionic surfactant. Its anionic surfactant was structurally semi-stable so that it released onto scalp when it absorbs moisture. CONCLUSION: Coacervate releases sulphate bonding into the matrix when it is exposed to water. Thus, the scalp stimulation would be expected.

Factors related to number of present teeth in Korean elderly adults aged 55-84 years.

OBJECTIVES: The aim of this study was to determine the associations between the number of present teeth (NT) and socio-economic, demographic and oral health behavioural factors among Korean adults aged 55-84 years. METHODS: The total subjects comprised 3767 individuals who were examined and who answered the questions on socio-economic status and oral health behaviour from the fourth Korean National Health and Nutrition Examination Survey conducted from 2007 to 2009. The dependent variable was NT, with binary status divided by the median. Socio-economic and demographic factors included gender, educational level, parent's educational levels, region of residence, household income, type of health insurance and mother's economic activity. Oral health behaviours were as follows: daily toothbrushing frequency, smoking status, recent dental visit and illegal dental treatment. Multivariate logistic regression models were applied to explain the associations between NT and other variables. RESULTS: In a model adjusted by socio-economic, demographic and oral health behavioural variables, subjects who lived in urban areas were more likely to have larger NT compared to those in suburban areas (OR: 1.22, P = 0.025). Males were more likely to have larger NT (OR: 1.90, P < 0.001), and daily toothbrushing frequency was associated with NT (OR = 1.25, P = 0.023). Non-smokers (OR: 2.44, P < 0.001) and past smokers (OR: 1.70, P < 0.001) were more likely to have lager NT compared to current smokers. Subjects without illegal dental treatments were more likely to have lager NT compared to those with illegal dental treatments (OR = 2.21, P < 0.001). CONCLUSIONS: Interventions aiming to preserve present teeth in elderly adults should consider socio-economic, demographic and oral health behavioural factors.

Pathway analysis of genome-wide association datasets of personality traits.

Although several genome-wide association (GWA) studies of human personality have been recently published, genetic variants that are highly associated with certain personality traits remain unknown, due to difficulty reproducing results. To further investigate these genetic variants, we assessed biological pathways using GWA datasets. Pathway analysis using GWA data was performed on 1089 Korean women whose personality traits were measured with the Revised NEO Personality Inventory for the 5-factor model of personality. A total of 1042 pathways containing 8297 genes were included in our study. Of these, 14 pathways were highly enriched with association signals that were validated in 1490 independent samples. These pathways include association of: Neuroticism with axon guidance [L1 cell adhesion molecule (L1CAM) interactions]; Extraversion with neuronal system and voltage-gated potassium channels; Agreeableness with L1CAM interaction, neurotransmitter receptor binding and downstream transmission in postsynaptic cells; and Conscientiousness with the interferon-gamma and platelet-derived growth factor receptor beta polypeptide pathways. Several genes that contribute to top-ranked pathways in this study were previously identified in GWA studies or by pathway analysis in schizophrenia or other neuropsychiatric disorders. Here we report the first pathway analysis of all five personality traits. Importantly, our analysis identified novel pathways that contribute to understanding the etiology of personality traits.

Biological evaluation of intervertebral disc cells in different formulations of gellan gum-based hydrogels.

Gellan gum (GG)-based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine-tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG-MA) and high-acyl gellan gums (HA-GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA-GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA-GG content induced greater weight loss in the GG-MA/HA-GG formulation compared to GG-MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein-AM and ATP assays. Results showed that tunable GG-MA/HA-GG hydrogels were non-cytotoxic and supported viability of rabbit NP cells.

Effects of natural cartilaginous extracellular matrix on chondrogenic potential for cartilage cell transplantation.

Autologous chondrocyte transplantation (ACT) has been established to contribute cartilage regeneration over the past years; however, many obstacles need to be overcome. Recently, newer ACT technique involves cotransplantation of chondrocytes and biomaterial. Although various proposed intelligent biomaterials exist, many of them remain insufficient and controversial. In this study, we aimed to examine the effects of natural extracellular matrix (ECM) to the proliferation rate and differentiation on the chondrocytes. We first derived a natural ECM sheet from 10-µm-thick frozen sections of porcine knee cartilages. We then cultured the chondrocytes derived from a rabbit's knee on a dish precoated with the natural ECM. Then we assessed differentiation and chondrogenic potential of the cells compared with those grown in untreated culture dishes. We characterized the gene expression of chondrogenic markers, such as collagen type II, SOX-9, and aggrecan, as well as the level of ECM protein with the use of reverse-transcription polymerase chain reaction analysis. The cells cultured with the ECM sheet showed highest chondrogenic potential and differentiation. Therefore, we can induce good chondrogenesis by with the use of a natural ECM sheet on the culture dish. The readily available and easy-to-handle thin ECM sheets create an environment that promotes efficient cartilage regeneration. Our data suggest that this natural ECM scaffold improved the chondrogenic differentiation of the cells in vitro by providing a favorable microenvironment.

Replication of results of genome-wide association studies on esophageal squamous cell carcinoma susceptibility loci in a Korean population.

Two recent genome-wide association studies have identified that the rs2274223 single-nucleotide polymorphism inphospholipase C epsilon 1 and the single-nucleotide polymorphism rs13042395 in C20orf54 are involved in esophageal squamous cell carcinoma (ESCC) in Chinese populations. We hypothesized that genetic polymorphisms of phospholipase C epsilon 1 and C20orf54 are also associated with ESCC in a Korean population. The rs2274223 and rs13042395 genotyping was performed using high-resolution melting analysis. The rs2274223 GG genotype was significantly associated with an increased risk of ESCC (odds ratio [OR]=1.86, 95% confidence interval [CI]=1.08-3.25) compared with the rs2274223 AA genotype. The rs13042395 G allele showed a significantly decreased risk of ESCC in the younger age group (OR=0.71, 95% CI=0.52-0.97) and no significant association in the older group (OR=1.19, 95% CI=0.87-1.62). We observed that the rs2274223 polymorphism was associated with an increased risk of ESCC in this Korean case-control study and that age may modify the association between the rs13042395 polymorphism and the risk of ESCC.

Identification of a pivotal endocytosis motif in c-Met and selective modulation of HGF-dependent aggressiveness of cancer using the 16-mer endocytic peptide.

Since c-Met has an important role in the development of cancer, it is considered as an attractive target for cancer therapy. Although molecular mechanisms for oncogenic property of c-Met have been actively investigated, regulatory elements for c-Met endocytosis and its effect on c-Met signaling remain unclear. In this study, we identified a pivotal endocytic motif in c-Met and tested it for selective modulation of HGF-induced c-Met response. Using various chimeric constructs with the cytoplasmic tail of c-Met, we were able to demonstrate that a dileucine motif located in the C-terminus of c-Met acts to regulate its endocytosis. Synthetic peptide Ant-3S, consisting of antennapedia-derived protein transduction domain (designated as Ant) and c-Met-derived 16 amino-acids (designated as 3S, spanning amino-acids 1378 to 1393), rapidly moved into cancer cells and disrupted c-Met trafficking. Importantly, an extension of c-Met retention time on the membrane by Ant-3S peptide significantly decreased phosphorylation-dependent c-Met signal transduction. Additionally, the peptide effectively inhibited HGF-induced cell growth, scattering and migration. The underlying molecular mechanism for these observations has been investigated and revealed that the dileucine motif interacts with endocytic machinery, including adaptin ß and caveolin-1, for sustained and enhanced signal transduction. Finally, Ant-3S peptide specifically blocked internalization of interleukin-2 receptor α-subunit/3S chimeric protein, but not the other receptors, including Glut4, Glut8 and transferrin receptor. Such results indicate the presence of a selective endocytic assembly for c-Met. It also suggests a potential for c-Met-specific anti-cancer therapy using the identified endocytic motif in this study.

Modulation of the murine microbiome with a concomitant anti-obesity effect by Lactobacillus rhamnosus GG and Lactobacillus sakei NR28.

The microbiota of the gastrointestinal tract (GIT) constitutes the major part of the total human microbiome and is considered to be an important regulator of human health and host metabolism. Numerous investigations in recent years have focused on the connection between the human microbiota and metabolic diseases such as obesity, type II diabetes and atherosclerosis. Yet, little is known about the impact of probiotic consumption on the GIT microbial population and the potential effect on chronic diseases. In this study, the modulation of the microbial community in the murine small intestine resulting from probiotic feeding was investigated and was found to be associated with an anti-obesity effect. Changes in the microbiota of the mouse faeces and small intestine were monitored using quantitative real-time PCR and by following the mRNA expression levels of various obesity-related biomarkers following probiotic feeding in a mouse model. Lactobacillus rhamnosus GG and Lactobacillus sakei NR28 (a putative probiotic strain isolated from kimchi) were administered at a daily level of approximately 1×10(8) viable bacteria per mouse (C57BL/6J mice) for up to three weeks. Feeding these strains resulted in a significant reduction of epididymal fat mass, as well as obesity-related biomarkers like acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase-1 in the liver. The total number and ratio of the microbial groups, i.e. Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp. were modulated in the small intestine, and the Firmicutes:Bacteroidetes ratio was decreased. In contrast, no noticeable effect of probiotic feeding could be detected on the faecal microbiota, neither quantitatively, nor with regard to the bacterial groups (Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp.) studied.

HBV lamivudine resistance among hepatitis B and HIV coinfected patients starting lamivudine, stavudine and nevirapine in Kenya.

Widespread use of lamivudine in antiretroviral therapy may lead to hepatitis B virus resistance in HIV-HBV coinfected patients from endemic settings where tenofovir is not readily available. We evaluated 389 Kenyan HIV-infected adults before and for 18 months after starting highly active antiretroviral therapy with stavudine, lamivudine and nevirapine. Twenty-seven (6.9%) were HBsAg positive and anti-HBs negative, 24 were HBeAg negative, and 18 had HBV DNA levels ≤ 10,000 IU/mL. Sustained HBV suppression to <100 IU/mL occurred in 89% of 19 evaluable patients. Resistance occurred in only two subjects, both with high baseline HBV DNA levels. Lamivudine resistance can emerge in the setting of incomplete HBV suppression but was infrequently observed among HIV-HBV coinfected patients with low baseline HBV DNA levels.

p53 codon 72 polymorphism and the risk of esophageal cancer: a Korean case-control study.

The aim of this study was to assess whether p53 codon 72 polymorphism is associated with an increased risk of esophageal cancer (EC) in South Korea. We conducted a case-control study including 340 patients with EC, and 1700 controls. P53 codon 72 polymorphism was determined by real-time polymerase chain reaction. The frequencies of p53 codon 72 polymorphisms (Arg/Arg, Arg/Pro, and Pro/Pro) in EC were 39.4%, 45.6%, and 15.0%, respectively; frequencies in the controls were 43.2%, 45.6%, and 11.2%, respectively. Compared with the Arg/Arg genotype, the OR of the Arg/Pro genotype was 1.09 (95% CI = 0.85-1.41) and that of the Pro/Pro genotype was 1.47 (95% CI = 1.02-2.11) for EC overall. When adjusted by age, gender, and smoking status, the OR of the Arg/Pro genotype was 1.24 (95% CI = 0.92-1.67) and that of the Pro/Pro genotype was 1.77 (95% CI = 1.15-2.74) for EC overall. In never-smokers and ever-smokers, the OR of the Arg/Pro genotype was 0.59 (95% CI = 0.37-0.95) and 1.39 (95% CI = 1.00-1.91), respectively, and there was a significant difference in the homogeneity test (P= 0.011). We observed that the p53 codon 72 polymorphism was associated with an increased risk of EC in this Korean case-control study, and smoking status modified the association between the p53 codon 72 polymorphism and the risk of EC.

Differences in femoral neck geometry associated with age and ethnicity.

SUMMARY: We studied femoral geometry in relation to age and ethnicity in a cross-sectional study. Age-associated cortical thinning showed the most pronounced effect, and Koreans studied here had thicker cortices and lower buckling ratios than those reported for other races. Cortical thickness may thus be a major determinant of hip fracture risk. INTRODUCTION: The rate of hip fracture varies by age and ethnicity. The geometric properties of the femur influence femoral strength and fragility, but differences in femoral geometry according to age and ethnicity are poorly understood. To explain the high prevalence of hip fractures in the elderly and the relatively low hip fracture rate in Asian populations, we studied age-related changes and ethnic differences in femoral geometry. METHODS: We recruited 214 peri- or postmenopausal women aged 46 to 85 years (mean age, 60.6 years). Their proximal femoral bone mineral densities (BMD) were measured by quantitative computed tomography and further analyzed geometric properties. RESULTS: We observed large declines in trabecular volumetric bone mineral density associated with aging (33.03% less than the reference value in the oldest group, respectively). Cortical thickness decreased remarkably with age as well, and only 53.94% of the baseline value remained in the oldest group. As a result, the cortical buckling ratio increased geometrically and reached 239.14% of the reference value in the oldest group. In comparisons with other ethnic groups, Korean subjects had thicker cortices than their American, European, and African counterparts. CONCLUSIONS: In this cross-sectional study, cortical thickness showed a pronounced age-associated decrease, and the cortical buckling ratio showed a strong age-associated increase. This may in part explain the higher rates of hip fractures in the elderly. When compared with other races, Asians had thicker cortical bone and lower buckling ratios, which may partially explain the lower prevalence of hip fractures in Asians.

Bowel preparation and colonoscopy technique to detect non-polypoid colorectal neoplasms.

Colonoscopy is considered the gold standard for colon cancer screening. In a recent study, however, 0.3% to 0.9% patients developed colorectal cancer within 3 years after removal of adenomas. Some reasons for the development of interval colorectal cancers include missed or incompletely removed lesions during the initial colonoscopy. Non-polypoid colorectal neoplasms are a potential contributor to the pool of missed lesions because they can be easily missed as a result of inadequate colon preparation or examination technique. This article discusses the methods that are useful to improve the quality of bowel preparation and examination technique.

Branched oligomerization of cell-permeable peptides markedly enhances the transduction efficiency of adenovirus into mesenchymal stem cells.

Cell-permeable peptides (CPPs) promote the transduction of nonpermissive cells by recombinant adenovirus (rAd) to improve the therapeutic efficacy of rAd. In this study, branched oligomerization of CPPs significantly enhanced the transduction of human mesenchymal stem cells (MSCs) by rAd in a CPP type-independent manner. In particular, tetrameric CPPs increased transduction efficiency at 3000-5000-fold lower concentrations than did monomeric CPPs. Although branched oligomerization of CPPs also increases cytotoxicity, optimal concentrations of tetrameric CPPs required for maximum transduction are at least 300-1000-fold lower than those causing 50% cytotoxicity. Furthermore, although only approximately 60% of MSCs were maximally transduced at 500 muM of monomeric CPPs, >95% of MSCs were transduced with 0.1 muM of tetrameric CPPs. Tetrameric CPPs also significantly increased the formation and net surface charge of CPP/rAd complexes, as well as the binding of rAd to cell membranes at a greater degree than did monomeric CPPs, followed by rapid internalization into MSCs. In a critical-size calvarial defect model, the inclusion of tetrameric CPPs in ex vivo transduction of rAd expressing bone morphogenetic protein 2 into MSCs promoted highly mineralized bone formation. In addition, MSCs that were transduced with rAd expressing brain-derived neurotrophic factor in the presence of tetrameric CPPs improved functional recovery in a spinal cord injury model. These results demonstrated the potential for tetrameric CPPs to provide an innovative tool for MSC-based gene therapy and for in vitro gene delivery to MSCs.