The G Protein-First Mechanism for Activation of the Class B Glucagon-like Peptide 1 Receptor Coupled to N-Terminal Domain-Mediated Conformational Progression.

Recently, there has been a great deal of excitement about new glucagon-like peptide 1 receptor (GLP-1R) agonists (e.g., semaglutide and tirzepatide) that have received FDA approval for type 2 diabetes and obesity. Although effective, these drugs come with side effects that limit their use. While research efforts continue to focus intensively on long-lasting, orally administered GLP-1R medications with fewer side effects, a major impediment to developing improved GLP-1R medications is that the mechanism by which an agonist activates GLP-1R to imitate signaling is not known. Here we present and validate the G protein (GP)-first mechanism for the GLP-1R supported by extensive atomistic simulations. We propose that GLP-1R is preactivated through the formation of a GLP-1R-GP precoupled complex at the cell membrane prior to ligand binding. Despite a transmembrane helix 6 (TM6)-bentout conformation characteristic of activated GLP-1R, this precoupled complex remains unactivated until an agonist binds to elicit signaling. Notably, this new hypothesis offers a unified and predictive model for the activities of a series of full and partial agonists, including the peptides ExP5, GLP-1(7-36), and GLP-1(9-36). Most surprisingly, our simulations reveal an N-terminus domain (NTD)-swing/agonist-insertion mechanism wherein the long extracellular NTD of GLP-1R tightly holds the C-terminal half of the peptide agonist and progressively shifts the N-terminal head of the peptide to facilitate insertion into the orthosteric pocket. Our findings provide novel mechanistic insights into the activation and function of class B GPCRs and should provide a realistic basis for structure-based ligand design.

Ligand-Dependent and G Protein-Dependent Properties for the Sweet Taste Heterodimer, TAS1R2/1R3.

The heterodimeric sweet taste receptor, TAS1R2/1R3, is a class C G protein-coupled receptor (GPCR) that couples to gustducin (Gt), a G protein (GP) specifically involved in taste processing. This makes TAS1R2/1R3 a possible target for newly developing low caloric ligands that taste sweet to address obesity and diabetes. The activation of TAS1R2/1R3 involves the insertion of the GαP C-terminus of the GP into the GPCR in response to ligand binding. However, it is not known for sure whether the GP inserts into the TAS1R2 or TAS1R3 intracellular region of this GPCR dimer. Moreover, TAS1R2/1R3 can also connect to other GPs, such as Gs, Gi1, Gt3, Go, Gq, and G12. These GPs have different C-termini that may modify GPCR signaling. To understand the possible GP dependence of sweet perception, we use molecular dynamic (MD) simulations to examine the coupling of various GαP C20 termini to TAS1R2/1R3 for various steviol glycoside ligands and an artificial sweetener. Since the C20 could interact with the transmembrane domain (TMD) of either TAS1R2 (TMD2) or TAS1R3 (TMD3), we consider both cases. Without any sweetener, we find that the apo GPCR shows similar Go and Gt selectivities, while all steviol glycoside ligands increase the selectivity of Gt but decrease Go selectivity at TMD2. Interestingly, we find that high sweet rebaudioside M (RebM) and RebD ligands show better interactions of C20 at TMD3 for the Gt protein, but low sweet RebC and hydRebM ligands show better interaction of C20 at TMD2 for the Gt protein. Thus, our MD simulation suggests that TAS1R2/1R3 may couple the GP to either 1R2 or to 1R3 and that it can couple other GPs compared to Gt. This will likely lead to multimodal functions producing multiple patterns of intracellular signaling for sweet taste receptors, depending on the particular sweetener. Directing the GP to one of the other may have beneficial therapeutic outcomes.

Host-microbe interactions rewire metabolism in a C. elegans model of leucine breakdown deficiency.

In humans, defects in leucine catabolism cause a variety of inborn errors in metabolism. Here, we use Caenorhabditis elegans to investigate the impact of mutations in mccc-1, an enzyme that functions in leucine breakdown. Through untargeted metabolomic and transcriptomic analyses we find extensive metabolic rewiring that helps to detoxify leucine breakdown intermediates via conversion into previously undescribed metabolites and to synthesize mevalonate, an essential metabolite. We also find that the leucine breakdown product 3,3-hydroxymethylbutyrate (HMB), commonly used as a human muscle-building supplement, is toxic to C. elegans and that bacteria modulate this toxicity. Unbiased genetic screens revealed interactions between the host and microbe, where components of bacterial pyrimidine biosynthesis mitigate HMB toxicity. Finally, upregulated ketone body metabolism genes in mccc-1 mutants provide an alternative route for biosynthesis of the mevalonate precursor 3-hydroxy-3-methylglutaryl-CoA. Our work demonstrates that a complex host-bacteria interplay rewires metabolism to allow host survival when leucine catabolism is perturbed.

Association between exercise habits and incident type 2 diabetes mellitus in patients with thyroid cancer: nationwide population-based study.

BACKGROUND: We investigated the association between exercise habits before or after thyroidectomy and incident type 2 diabetes mellitus (T2DM) in patients with thyroid cancer. METHODS: An observational cohort study of 69,526 thyroid cancer patients who underwent thyroidectomy for the treatment of thyroid cancer between 2010 and 2016 was performed using the Korean National Health Information Database. Regular exercise was defined as mid-term or vigorous exercise at least 1 day in a week based on a self-reported questionnaire. Patients were divided into four groups according to exercise habits before and after thyroidectomy: persistent non-exercisers, new exercisers, exercise dropouts, and exercise maintainers. RESULTS: During a median follow-up of 4.5 years, 2,720 (3.91%) patients developed T2DM. The incidence of T2DM per 1,000 person years was lower in patients who performed regular exercise before or after thyroidectomy than in persistent non-exercisers (10.77 in persistent non-exerciser group, 8.28 in new exerciser group, 8.59 in exercise dropout group, and 7.61 in exercise maintainer group). Compared with the persistent non-exerciser group, the new exerciser group (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.78-0.97), the exercise dropout group (HR 0.81, 95% CI 0.72-0.91), and the exercise maintainer group (HR 0.84, 95% CI 0.76-0.93) had lower risks of incident T2DM. Exercising < 1,500 MET-minutes/week in the exercise maintainer group was associated with a lower risk of incident T2DM compared with persistent non-exercisers (< 500: HR 0.80, 95% CI 0.67-0.96, P = 0.002; 500 to < 1,000: HR 0.81, 95% CI 0.71-0.93, P < 0.001; 1,000 to < 1,500: HR 0.81, 95% CI 0.69-0.94, P < 0.001). CONCLUSIONS: Regular exercise before or after thyroidectomy was associated with a lower risk of incident T2DM in patients with thyroid cancer.

Association between upper and lower respiratory disease among patients with primary ciliary dyskinesia: an international study.

Introduction: Nearly all patients with primary ciliary dyskinesia (PCD) report ear-nose-throat (ENT) symptoms. However, scarce evidence exists about how ENT symptoms relate to pulmonary disease in PCD. We explored possible associations between upper and lower respiratory disease among patients with PCD in a multicentre study. Methods: We included patients from the ENT Prospective International Cohort (EPIC-PCD). We studied associations of several reported ENT symptoms and chronic rhinosinusitis (defined using patient-reported information and examination findings) with reported sputum production and shortness of breath, using ordinal logistic regression. In a subgroup with available lung function results, we used linear regression to study associations of chronic rhinosinusitis and forced expiratory volume in 1 s (FEV1) accounting for relevant factors. Results: We included 457 patients (median age 15 years, interquartile range 10-24 years; 54% males). Shortness of breath associated with reported nasal symptoms and ear pain of any frequency, often or daily hearing problems, headache when bending down (OR 2.1, 95% CI 1.29-3.54) and chronic rhinosinusitis (OR 2.3, 95% CI 1.57-3.38) regardless of polyp presence. Sputum production associated with daily reported nasal (OR 2.2, 95% CI 1.20-4.09) and hearing (OR 2.0, 95% CI 1.10-3.64) problems and chronic rhinosinusitis (OR 2.1, 95% CI 1.48-3.07). We did not find any association between chronic rhinosinusitis and FEV1. Conclusion: Reported upper airway symptoms and signs of chronic rhinosinusitis associated with reported pulmonary symptoms, but not with lung function. Our results emphasise the assessment and management of upper and lower respiratory disease as a common, interdependent entity among patients with PCD.

Effectiveness of a media literacy-based smoking prevention program in female adolescents.

OBJECTIVES: To examine the effectiveness of a media literacy-based smoking prevention program based on Ajzen's theory of planned behavior in female adolescents. METHODS: This quasi-experimental study was conducted with female high school students aged 16-17 years in Seoul, Republic of Korea. The program provided eight sessions over 4 weeks. Quantitative data were collected before and after online surveys in an intervention (n = 21) and control (n = 21) groups, and analyzed using mixed analysis of variance. Qualitative data on participation experiences was collected by requesting the participants to answer open-ended questions once a week during the intervention and performing co-occurrence analysis of specific terms in the responses was conducted through text mining. RESULTS: Although the program decreased smoking intention and increased smoking media literacy in the intervention group, there were no significant differences between the groups. Qualitative results obtained from the intervention group showed cognitive and behavioral changes in the perception of the harmfulness of e-cigarettes in the media and the expression of a willingness to overcome the temptation to smoke. CONCLUSIONS: Our findings show that the enhancement of smoking media literacy, specifically by correcting misconceptions regarding e-cigarettes promoted by the new media, contributes smoking prevention in female adolescents. It supports calls for an expanded role of public health professionals in health education at the school level.

Regulation of proteostasis and innate immunity via mitochondria-nuclear communication.

Mitochondria are perhaps best known as the "powerhouse of the cell" for their role in ATP production required for numerous cellular activities. Mitochondria have emerged as an important signaling organelle. Here, we first focus on signaling pathways mediated by mitochondria-nuclear communication that promote protein homeostasis (proteostasis). We examine the mitochondrial unfolded protein response (UPRmt) in C. elegans, which is regulated by a transcription factor harboring both a mitochondrial- and nuclear-targeting sequence, the integrated stress response in mammals, as well as the regulation of chromatin by mitochondrial metabolites. In the second section, we explore the role of mitochondria-to-nuclear communication in the regulation of innate immunity and inflammation. Perhaps related to their prokaryotic origin, mitochondria harbor molecules also found in viruses and bacteria. If these molecules accumulate in the cytosol, they elicit the same innate immune responses as viral or bacterial infection.

Methotrexate Inhibits the Binding of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Receptor Binding Domain to the Host-Cell Angiotensin-Converting Enzyme-2 (ACE-2) Receptor.

As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus mutates, finding effective drugs becomes more challenging. In this study, we use ultrasensitive frequency locked microtoroid optical resonators in combination with in silico screening to search for COVID-19 drugs that can stop the virus from attaching to the human angiotensin-converting enzyme 2 (hACE2) receptor in the lungs. We found 29 promising candidates that could block the binding site and selected four of them that were likely to bind very strongly. We tested three of these candidates using frequency locked optical whispering evanescent resonator (FLOWER), a label-free sensing method based on microtoroid resonators. FLOWER has previously been used for sensing single macromolecules. Here we show, for the first time, that FLOWER can provide accurate binding affinities and sense the inhibition effect of small molecule drug candidates without labels, which can be prohibitive in drug discovery. One of the candidates, methotrexate, showed binding to the spike protein 1.8 million times greater than that to the receptor binding domain (RBD) binding to hACE2, making it difficult for the virus to enter cells. We tested methotrexate against different variants of the SARS-CoV-2 virus and found that it is effective against all four of the tested variants. People taking methotrexate for other conditions have also shown protection against the original SARS-CoV-2 virus. Normally, it is assumed that methotrexate inhibits the replication and release of the virus. However, our findings suggest that it may also block the virus from entering cells. These studies additionally demonstrate the possibility of extracting candidate ligands from large databases, followed by direct receptor-ligand binding experiments on the best candidates using microtoroid resonators, thus creating a workflow that enables the rapid discovery of new drug candidates for a variety of applications.

Placental expression quantitative trait loci in an East Asian population.

Expression quantitative trait loci (eQTL) analysis measures the contribution of genetic variation in gene expression on complex traits. Although this methodology has been used to examine gene regulation in numerous human tissues, eQTL research in solid tissues is relatively lacking. We conducted eQTL analysis on placentas collected from an East Asian population in an effort to identify gene regulatory mechanisms in this tissue. Placentas (n = 102) were collected at the time of cesarean delivery. mRNA was extracted, sequenced with NGS, and compared with matched maternal and fetal DNA arrays performed using maternal and neonatal cord blood. Linear regression modeling was performed using tensorQTL. Fine-mapping along with epigenomic annotation was used to select putative functional variants. We identified 2,703 coding genes that contained at least one eQTL with statistical significance (false discovery rate <0.05). After fine-mapping, we found 108 previously unreported eQTL variants with posterior inclusion probability >0.1. Of these, 19% were located in genomic regions with evidence from public placental epigenome suggesting that they may be functionally relevant. For example, variant rs28379289 located in the placenta-specific regulatory region changes the binding affinity of transcription factor leading to higher expression of LGALS3, which is known to affect placental function. This study expands the knowledge base of regulatory elements within the human placenta and identifies 108 previously unreported placenta eQTL signals, which are listed in our publicly available GMI eQTL database. Further studies are needed to identify and characterize genetic regulatory mechanisms that affect placental function in normal pregnancy and placenta-related diseases.

Lateral flow immunoassay based on surface-enhanced Raman scattering using pH-induced phage-templated hierarchical plasmonic assembly for point-of-care diagnosis of infectious disease.

The outbreak of emerging infectious diseases gave rise to the demand for reliable point-of-care testing methods to diagnose and manage those diseases in early onset. However, the current on-site testing methods including lateral flow immunoassay (LFIA) suffer from the inaccurate diagnostic result due to the low sensitivity. Herein, we present the surface-enhanced Raman scattering-based lateral flow immunoassay (SERS-LFIA) by introducing phage-templated hierarchical plasmonic assembly (PHPA) nanoprobes to diagnose a contagious disease. The PHPA was fabricated using gold nanoparticles (AuNPs) assembled on bacteriophage MS2, where inter-particle gap sizes can be adjusted by pH-induced morphological alteration of MS2 coat proteins to provide the maximum SERS amplification efficiency via plasmon coupling. The plasmonic probes based on the PHPA produce strong and reproducible SERS signal that leads to sensitive and reliable diagnostic results in SERS-LFIA. The developed SERS-LFIA targeting severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) antibodies for a proof of concept had <100 pg/mL detection limits with high specificity in serum, proving it as an effective diagnostic device for the infectious diseases. Clinical validation using human serum samples further confirmed that the PHPA-based SERS-LFIA can distinguish the patients with COVID-19 from healthy controls with significant accuracy. These outcomes prove that the developed SERS-LFIA biosensor can be an alternative point-of-care testing (POCT) method against the emerging infectious diseases, in combination with the commercially available portable Raman devices.

Real-World Treatment Patterns according to Clinical Practice Guidelines in Patients with Type 2 Diabetes Mellitus and Established Cardiovascular Disease in Korea: Multicenter, Retrospective, Observational Study.

BACKGRUOUND: Recent diabetes management guidelines recommend that sodium-glucose cotransporter 2 inhibitors (SGLT2is) or glucagon-like peptide 1 receptor agonists (GLP-1RAs) with proven cardiovascular benefits should be prioritized for combination therapy in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease (CVD). This study was aimed at evaluating SGLT2i or GLP-1RA usage rates and various related factors in patients with T2DM and established CVD. METHODS: We enrolled adults with T2DM aged ≥30 years who were hospitalized due to established CVD from January 2019 to May 2020 at 13 secondary and tertiary hospitals in Korea in this retrospective observational study. RESULTS: Overall, 2,050 patients were eligible for analysis among 2,107 enrolled patients. The mean patient age, diabetes duration, and glycosylated hemoglobin level were 70.0 years, 12.0 years, and 7.5%, respectively. During the mean follow-up duration of 9.7 months, 25.7% of the patients were prescribed SGLT2is after CVD events. However, only 1.8% were prescribed GLP-1RAs. Compared with SGLT2i non-users, SGLT2i users were more frequently male and obese. Furthermore, they had a shorter diabetes duration but showed worse glycemic control and better renal function at the time of the event. GLP-1RA users had a longer duration of diabetes and worse glycemic control at the time of the event than GLP-1RA non-users. CONCLUSION: The SGLT2i or GLP-1RA prescription rates were suboptimal in patients with T2DM and established CVD. Sex, body mass index, diabetes duration, glycemic control, and renal function were associated with the use of these agents.

An innovative microcoring technology: A novel approach to acne scar treatment.

BACKGROUND: Acne scars present a complex challenge in dermatology and cosmetics, despite advancements in technological interventions such as fractional lasers, microneedling, and surgical procedures. Effective treatment remains elusive for many individuals. OBJECTIVE: This study aims to evaluate the efficacy of rotational fractional resection using 1 mm diameter rotating scalpels as a primary treatment for icepick and boxcar scars on the cheeks and glabella region. METHODS: Three patients with acne scars underwent a single treatment session of rotational fractional resection. Evaluation occurred at the 2-month post-treatment mark to assess improvements in scar appearance and potential skin-related side effects. RESULTS: Following the treatment, significant improvements were observed in the targeted acne scars. Notable enhancements were noted without major skin-related adverse effects, except for minor suture marks. CONCLUSION: The outcomes of this study underscore the potential of rotational fractional resection as an innovative and effective approach in treating acne scars. This single-session cosmetic procedure shows promise in yielding lasting and quantifiable results, offering a hopeful solution for individuals seeking comprehensive acne scar treatment.

Social determinants of health of racial and ethnic minority adolescents: An integrative literature review.

Integration of adolescents with diverse cultural backgrounds into the country of residence is associated with some form of rejection and discrimination, predisposing them to undesirable health outcomes. In this regard, the aim of this study was to identify the social determinants of the health of racial and ethnic minority adolescents. In this integrative literature review, PubMed, EMBASE, Cochrane Library, and CINAHL databases were searched from 2016 to 2021 and studies were selected according to the PRISMA 2020 guidelines. Health status was limited to health outcomes according to the definition proposed by the World Health Organization and Healthy People 2020. The social determinants of health were classified according to the research framework of the National Institute on Minority Health and Health Disparities. Six types of health status were identified: self-rated health, obesity and overweight, global self-worth, emotional well-being, anthropometric measurement, and psychosocial adjustment. The social determinants of health were at the individual and interpersonal level, and the domains included the biological (gender, illness experience), psychological (acculturative stress), and sociocultural environment (e.g., socioeconomic status, parents' educational level, household death due to violence). Therefore, future research must prioritize their sociocultural environments to reduce the negative impact of discrimination and sociocultural and structural differences on racial and ethnic minority adolescents.

Fully activated structure of the sterol-bound Smoothened GPCR-Gi protein complex.

Smoothened (SMO) is an oncoprotein and signal transducer in the Hedgehog signaling pathway that regulates cellular differentiation and embryogenesis. As a member of the Frizzled (Class F) family of G protein-coupled receptors (GPCRs), SMO biochemically and functionally interacts with Gi family proteins. However, key molecular features of fully activated, G protein-coupled SMO remain elusive. We present the atomistic structure of activated human SMO complexed with the heterotrimeric Gi protein and two sterol ligands, equilibrated at 310 K in a full lipid bilayer at physiological salt concentration and pH. In contrast to previous experimental structures, our equilibrated SMO complex exhibits complete breaking of the pi-cation interaction between R4516.32 and W5357.55, a hallmark of Class F receptor activation. The Gi protein couples to SMO at seven strong anchor points similar to those in Class A GPCRs: intracellular loop 1, intracellular loop 2, transmembrane helix 6, and helix 8. On the path to full activation, we find that the extracellular cysteine-rich domain (CRD) undergoes a dramatic tilt, following a trajectory suggested by positions of the CRD in active and inactive experimental SMO structures. Strikingly, a sterol ligand bound to a shallow transmembrane domain (TMD) site in the initial structure migrates to a deep TMD pocket found exclusively in activator-bound SMO complexes. Thus, our results indicate that SMO interacts with Gi prior to full activation to break the molecular lock, form anchors with Gi subunits, tilt the CRD, and facilitate migration of a sterol ligand in the TMD to an activated position.

2023 Clinical Practice Guidelines for Diabetes Mellitus of the Korean Diabetes Association.

In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.

Discovery of 3-Phenyl Indazole-Based Novel Chemokine-like Receptor 1 Antagonists for the Treatment of Psoriasis.

Chemokine-like receptor 1 (CMKLR1)─a G protein-coupled receptor─has functional roles in the immune system and related diseases, including psoriasis and metabolic diseases. Psoriasis is a chronic inflammatory disease characterized by skin redness, scaliness, and itching. In this study, we sought to develop novel CMKLR1 antagonists by screening our in-house GPCR-targeting compound library. Moreover, we optimized a phenylindazole-based hit compound with antagonistic activities and evaluated its oral pharmacokinetic properties in a murine model. A structure-based design on the human CMKLR1 homology model identified S-26d as an optimized compound that serves as a potent and orally available antagonist with a pIC50 value of 7.44 in hCMKLR1-transfected CHO cells. Furthermore, in the imiquimod-induced psoriasis-like mouse model, oral administration of S-26d for 1 week significantly alleviated modified psoriasis area and severity index scores (severity of erythema, scaliness, skin thickness) compared with the control group.