Comprehensive Analyses of the Effects of the Small-Molecule Inhibitor of the UHM Domain in the Splicing Factor U2AF1 in Leukemia Cells.

Mutations in RNA splicing factor genes including SF3B1, U2AF1, SRSF2, and ZRSR2 have been reported to contribute to development of myeloid neoplasms including myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (sAML). Chemical tools targeting cells carrying these mutant genes remain limited and underdeveloped. Among the four proteins, mutant U2AF1 (U2AF1mut) acquires an altered 3' splice site selection preference and co-operates with the wild-type U2AF1 (U2AF1wt) to change various gene isoform patterns to support MDS cells survival and proliferation. U2AF1 mutations in MDS cells are always heterozygous and the cell viability is reduced when exposed to additional insult affecting U2AF1wt function. To investigate if the pharmacological inhibition of U2AF1wt function can provoke drug-induced vulnerability of cells harboring U2AF1 mut , we conducted a fragment-based library screening campaign to discover compounds targeting the U2AF homology domain (UHM) in U2AF1 that is required for the formation of the U2AF1/U2AF2 complex to define the 3' splice site. The most promising hit (SF1-8) selectively inhibited growth of leukemia cell lines overexpressingU2AF1 mut and human primary MDS cells carrying U2AF1 mut . RNA-seq analysis of K562-U2AF1mut following treatment with SF1-8 further revealed alteration of isoform patterns for a set of proteins that impair or rescue pathways associated with endocytosis, intracellular vesicle transport, and secretion. Our data suggested that further optimization of SF1-8 is warranted to obtain chemical probes that can be used to evaluate the therapeutic concept of inducing lethality to U2AF1 mut cells by inhibiting the U2AF1wt protein.

Myeloid Cell Glucocorticoid, Not Mineralocorticoid Receptor Signaling, Contributes to Salt-Sensitive Hypertension in Humans via Cortisol.

BACKGROUND: Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular morbidity and mortality, yet the etiology is poorly understood. We previously found that serum/glucocorticoid-regulated kinase 1 (SGK1) and epoxyeicosatrienoic acids (EETs) regulate epithelial sodium channel (ENaC)-dependent sodium entry into monocyte-derived antigen-presenting cells (APCs) and activation of NADPH oxidase, leading to the formation of isolevuglandins (IsoLGs) in SSBP. Whereas aldosterone via the mineralocorticoid receptor (MR) activates SGK1 leading to hypertension, our past findings indicate that levels of plasma aldosterone do not correlate with SSBP, and there is little to no MR expression in APCs. Thus, we hypothesized that cortisol acting via the glucocorticoid receptor (GR), not the MR in APCs mediates SGK1 actions to induce SSBP. METHODS: We performed cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) analysis on peripheral blood mononuclear cells of humans rigorously phenotyped for SSBP using an inpatient salt loading/depletion protocol to determine expression of MR, GR, and SGK1 in immune cells. In additional experiments, we performed bulk transcriptomic analysis on isolated human monocytes following in vitro treatment with high salt from a separate cohort. We then measured urine and plasma cortisol, cortisone, renin, and aldosterone. Subsequently, we measured the association of these hormones with changes in systolic, diastolic, mean arterial pressure and pulse pressure as well as immune cell activation via IsoLG formation. RESULTS: We found that myeloid APCs predominantly express the GR and SGK1 with no expression of the MR. Expression of the GR in APCs increased after salt loading and decreased with salt depletion in salt-sensitive but not salt-resistant people and was associated with increased expression of SGK1. Moreover, we found that plasma and urine cortisol/cortisone but not aldosterone/renin correlated with SSBP and APCs activation via IsoLGs. We also found that cortisol negatively correlates with EETs. CONCLUSION: Our findings suggest that renal cortisol signaling via the GR but not the MR in APCs contributes to SSBP via cortisol. Urine and plasma cortisol may provide an important currently unavailable feasible diagnostic tool for SSBP. Moreover, cortisol-GR-SGK1-ENaC signaling pathway may provide treatment options for SSBP.

Home Blood Pressure Telemonitoring and Nurse Case Management in Black and Hispanic Patients With Stroke: A Randomized Clinical Trial.

Importance: Black and Hispanic patients have high rates of recurrent stroke and uncontrolled hypertension in the US. The effectiveness of home blood pressure telemonitoring (HBPTM) and telephonic nurse case management (NCM) among low-income Black and Hispanic patients with stroke is unknown. Objective: To determine whether NCM plus HBPTM results in greater systolic blood pressure (SBP) reduction at 12 months and lower rate of stroke recurrence at 24 months than HBPTM alone among Black and Hispanic stroke survivors with uncontrolled hypertension. Design, Setting, and Participants: Practice-based, multicenter, randomized clinical trial in 8 stroke centers and ambulatory practices in New York City. Black and Hispanic study participants were enrolled between April 18, 2014, and December 19, 2017, with a final follow-up visit on December 31, 2019. Interventions: Participants were randomly assigned to receive either HBPTM alone (12 home BP measurements/week for 12 months, with results transmitted to a clinician; n = 226) or NCM plus HBPTM (20 counseling calls over 12 months; n = 224). Main Outcomes and Measures: Primary outcomes were change in SBP at 12 months and rate of recurrent stroke at 24 months. Final statistical analyses were completed March 14, 2024. Results: Among 450 participants who were enrolled and randomized (mean [SD] age, 61.7 [11.0] years; 51% were Black [n = 231]; 44% were women [n = 200]; 31% had ≥3 comorbid conditions [n = 137]; 72% had household income <$25 000/y [n = 234/324]), 358 (80%) completed the trial. Those in the NCM plus HBPTM group had a significantly greater SBP reduction than those in the HBPTM alone group at 12 months (-15.1 mm Hg [95% CI, -17.2 to -13.0] vs -5.8 mm Hg [95% CI, -7.9 to -3.7], respectively; P < .001). The between-group difference in SBP reduction at 12 months, adjusted for primary care physician clustering, was -8.1 mm Hg (95% CI, -11.2 to -5.0; P < .001) at 12 months. The rate of recurrent stroke was similar between both groups at 24 months (4.0% in the NCM plus HBPTM group vs 4.0% in the HBPTM alone group, P > .99). Conclusions and Relevance: Among predominantly low-income Black and Hispanic stroke survivors with uncontrolled hypertension, addition of NCM to HBPTM led to greater SBP reduction than HBPTM alone. Additional studies are needed to understand the long-term clinical outcomes, cost-effectiveness, and generalizability of NCM-enhanced telehealth programs among low-income Black and Hispanic stroke survivors with significant comorbidity. Trial Registration: Clinical Trials.gov Identifier: NCT02011685.

Human SIRT5 variants with reduced stability and activity do not cause neuropathology in mice.

SIRT5 is a sirtuin deacylase that removes negatively charged lysine modifications, in the mitochondrial matrix and elsewhere in the cell. In benign cells and mouse models, under basal conditions, the phenotypes of SIRT5 deficiency are quite subtle. Here, we identify two homozygous SIRT5 variants in patients suspected to have mitochondrial disease. Both variants, P114T and L128V, are associated with reduced SIRT5 protein stability and impaired biochemical activity, with no evidence of neomorphic or dominant negative properties. The crystal structure of the P114T enzyme was solved and shows only subtle deviations from wild-type. Via CRISPR-Cas9, we generated a mouse model that recapitulates the human P114T mutation; homozygotes show reduced SIRT5 levels and activity, but no obvious metabolic abnormalities, neuropathology, or other gross phenotypes. We conclude that these human SIRT5 variants most likely represent severe hypomorphs, but are likely not by themselves the primary pathogenic cause of the neuropathology observed in the patients.

Estimated Prevalence of Resident-to-Resident Aggression in Assisted Living.

Importance: Resident-to-resident aggression in assisted living facilities can result in physical and psychological harm, but its prevalence is unknown. Objective: To estimate the prevalence of resident-to-resident aggression, including physical, verbal, and sexual, among residents in assisted living facilities. Design, Setting, and Participants: This study used cross-sectional, observational data from a clinical trial, in which residents of assisted living facilities were monitored for events over a 1-month period. All residents of 14 large facilities randomly selected from 2 geographic locations (N = 1067), except those receiving hospice care (n = 11), were invited to participate; 93 died or moved prior to enrollment. There were 33 family and resident refusals; 930 residents were enrolled. Data were collected between May 30, 2018, and August 11, 2022. Main Outcomes and Measures: The data are from a clinical trial testing the effectiveness of an intervention to reduce resident-to-resident aggression. In addition, the study was designed to assess prevalence using the Time 1 (baseline) data, using a probability sample of facilities to allow for this analysis. Resident-to-resident aggression was identified using a mixed-method, case-finding strategy involving 6 sources: (1) cognitively capable resident reports regarding 22 possible events, (2) direct care staff report, (3) staff member reports collected from event-reporting forms, (4) research assistant observation of events in real time, (5) facility accident or incident reports, and (6) resident records. Results: The prevalence of resident-to-resident aggression among the 930 participants (mean [SD] age, 88.0 [7.2] years; 738 women [79.4%]) during the past month was estimated to be 15.2% (141 of 930 residents; 95% CI, 12.1%-18.8%). The most common forms of aggression included verbal (11.2% [104 of 930 residents; 95% CI, 8.8%-14.2%]), physical (41 of 930 residents; 4.4% [95% CI, 3.1%-6.3%]), sexual (0.8% [7 of 930 residents; 95% CI, 0.4%-1.6%]), and other (70 of 930 residents; 7.5% [95% CI, 5.5%-10.2%]). These categories are not mutually exclusive as residents could be involved with more than 1 type of aggressive behavior. Conclusions and Relevance: In this cross-sectional, observational prevalence study, resident-to-resident aggression in assisted living facilities was highly prevalent. Verbal aggression was the most common form, and physical aggression also occurred frequently. The effects of resident-to-resident aggression can be both morbid and mortal; therefore, intervention research is needed to prevent it and to treat it when it occurs.

Measurement of Allostatic Load in Caregivers of Older Hispanic People With Alzheimer Disease and Related Disorders.

BACKGROUND: Allostatic load (AL) has been studied in the context of biomarkers that may be affected by environmental and contextual stressors, including social determinants of health. The specific stressor studied here is the provision of caregiving to older persons with Alzheimer disease and related disorders. The aims were to examine the factor structure of stress and nonstress biomarkers, different methods for calculating AL, and the relationship of AL with other variables. METHODS: Latent variable models were used to examine biomarkers. Regression analyses were performed with the outcomes: AL calculated as percentile-based and clinically-based for both stress and nonstress components. The sample was 187 Hispanic caregivers to individuals with dementia. RESULTS: The results of the confirmatory factor analyses (CFAs) suggested defining 2 factors: nonstress and stress-related. Performance was better for the CFA results and the associations with covariates when stress and nonstress components were examined separately. Despite some limitations, this is one of the first studies of biomarkers in Hispanic caregivers to patients with dementia. It was possible to explain almost 30% of the variance in the nonstress AL component. CONCLUSION: It may be important to differentiate among biomarkers indicative of cardiovascular, metabolic, and immune response as contrasted with the more stress-related biomarkers.

Evaluation of microbial occurrence in reusable robotic instruments for minimally invasive surgery: A pilot study.

In recent decades, minimally invasive surgery has become the favoured surgical technique, with increasing utilisation of robotic surgery to enhance patient outcomes. However, the design complexity of surgical robotic instruments can pose challenges in maintaining adequate cleaning, disinfection and sterilisation-particularly of the device's interior. In our hospital, robotic instruments are reused for a maximum of ten successive patients, following the manufacturer's guidelines. To the best of our knowledge, neither the manufacturer nor ISO standards have specified any methods to determine the sterility of robotic instruments after cleaning, disinfection and sterilisation procedures. In a small pilot study, we used a locally developed protocol to evaluate the sterility of 20 da Vinci SI robotic instruments, with the aim of determining whether the recommended cleaning, disinfection and sterilisation process is adequate to achieve safe usage in subsequent patients. None of the 20 instruments showed viable micro-organisms, therefore the robotic instruments were considered sterile, and suitable for re-use. We recommend our protocol to other hospitals, to be used as an essential control element in the assessment of their unique reprocessing technique for robotic instruments.

FIGO Preconception Checklist: Preconception care for mother and baby.

The preconception period is a unique and opportunistic time in a woman's life when she is motivated to adopt healthy behaviors that will benefit her and her child, making this time period a critical "window of opportunity" to improve short- and long-term health. Improving preconception health can ultimately improve both fetal and maternal outcomes. Promoting health before conception has several beneficial effects, including an increase in seeking antenatal care and a reduction in neonatal mortality. Preconception health is a broad concept that encompasses the management of chronic diseases, including optimal nutrition, adequate consumption of folic acid, control of body weight, adoption of healthy lifestyles, and receipt of appropriate vaccinations. Use of the FIGO Preconception Checklist, which includes the key elements of optimal preconception care, will empower women and their healthcare providers to better prepare women and their families for pregnancy.

Alanine aminotransferase elevation varies by ethnicity among Asian and Pacific Islander children with overweight or obesity.

BACKGROUND: Limited research on alanine aminotransferase (ALT) screening for metabolic dysfunction-associated steatotic liver disease (MASLD) among US Asian/Pacific Islander (PI) children necessitates investigation in this heterogeneous population. OBJECTIVE: Examine ALT elevation among Asian/PI children with overweight or obesity. METHODS: Elevated ALT prevalence (clinical threshold) and association with body mass index ≥85th percentile were compared among 18 402 Asian/PI and 25 376 non-Hispanic White (NHW) children aged 9-17 years using logistic regression. RESULTS: ALT elevation was more prevalent among Asian/PI (vs. NHW) males with overweight (4.0% vs. 2.7%), moderate (7.8% vs. 5.3%) and severe obesity (16.6% vs. 11.5%), and females with moderate (5.1% vs. 3.0%) and severe obesity (10.2% vs. 5.2%). Adjusted odds of elevated ALT were 1.6-fold and ~2-fold higher for Asian/PI (vs. NHW) males and females (with obesity), respectively. Filipino, Chinese and Southeast Asian males had 1.7-2.1-fold higher odds, but Native Hawaiian/PI (NHPI) and South Asian males did not significantly differ (vs. NHW). Filipina and Chinese females with obesity had >2-fold higher odds, Southeast and South Asian females did not differ and NHPI findings were mixed (vs. NHW). CONCLUSION: High elevated ALT prevalence among Asian/PI children with overweight and obesity emphasizes the need for MASLD risk assessment and examination of ethnic subgroups.

Hypertension Related Co-Morbidities and Complications in Women of Sub-Saharan Africa: A Brief Review.

Hypertension is the leading cause of cardiovascular disease in women, and sub-Saharan African (SSA) countries have some of the highest rates of hypertension in the world. Expanding knowledge of causes, management, and awareness of hypertension and its co-morbidities worldwide is an effective strategy to mitigate its harms, decrease morbidities and mortality, and improve individual quality of life. Hypertensive disorders of pregnancy (HDPs) are a particularly important subset of hypertension, as pregnancy is a major stress test of the cardiovascular system and can be the first instance in which cardiovascular disease is clinically apparent. In SSA, women experience a higher incidence of HDP compared with other African regions. However, the region has yet to adopt treatment and preventative strategies for HDP. This delay stems from insufficient awareness, lack of clinical screening for hypertension, and lack of prevention programs. In this brief literature review, we will address the long-term consequences of hypertension and HDP in women. We evaluate the effects of uncontrolled hypertension in SSA by including research on heart disease, stroke, kidney disease, peripheral arterial disease, and HDP. Limitations exist in the number of studies from SSA; therefore, we will use data from countries across the globe, comparing and contrasting approaches in similar and dissimilar populations. Our review highlights an urgent need to prioritize public health, clinical, and bench research to discover cost-effective preventative and treatment strategies that will improve the lives of women living with hypertension in SSA.

Remote submerged banks and mesophotic ecosystems can provide key habitat for endangered marine megafauna.

The importance of some ecosystems remains poorly understood. We showed that mesophotic ecosystems (30 to 150 m) are a key habitat for a critically endangered species, with strong evidence that a globally important population of adult hawksbill turtles (Eretmochelys imbricata) almost exclusively foraged at these depths on remote submerged banks. This discovery highlights the need for such areas to be included in conservation planning, for example, as part of the United Nations High Seas Treaty. We equipped nesting turtles with Fastloc-GPS (Global Positioning System) satellite tags at an Indian Ocean breeding area and they all traveled to deep foraging sites (6765 days of tracking data across 22 individuals including 183,921 dive-depth measurements) rather than shallow coral reef sites. Both chart depths and depth data relayed from the tags indicated that turtles foraged at mesophotic depths, the modal dive depths being between 35 and 40 m. We calculate that 55,554 km2 of the western Indian Ocean alone consists of submerged banks between 30 and 60 m.

Advanced Image-Guided Percutaneous Technique Versus Advanced Laparoscopic Surgical Technique for Peritoneal Dialysis Catheter Placement.

Rationale & Objective: Timely placement of a functional peritoneal dialysis (PD) catheter is crucial to long-term PD success. Advanced image-guided percutaneous and advanced laparoscopic techniques both represent best practice catheter placement options. Advanced image-guided percutaneous is a minimally invasive procedure that does not require general anesthesia. Study Design: Retrospective cohort study comparing time from referral to procedure, complication rate, and 1-year catheter survival between placement techniques. Setting & Participants: Patients who had advanced laparoscopic or advanced image-guided percutaneous PD catheter placement from January 1, 2011 to December 31, 2013 in an integrated Northern California health care delivery system. Exposure: PD catheter placement using advanced laparoscopic or advanced image-guided percutaneous techniques. Outcomes: One-year PD catheter survival; major, minor, and infectious complications; time from referral to PD catheter placement; and procedure time. Analytical Approach: Wilcoxon rank sum tests to compare referral and procedure times; χ2/Fisher exact tests to compare complications; and modified least-squares regression to compare adjusted 1-year catheter survival between PD placement techniques. Results: We identified 191 and 238 PD catheters placed through advanced image-guided percutaneous and advanced laparoscopic techniques, respectively. Adjusted 1-year PD catheter survival was 80% (95% CI, 74%-87%) using advanced image-guided percutaneous technique vs 91% (87%-96%) using advanced laparoscopic technique (P = 0.01). Major complications were <1% in both groups. Minor and infectious complications were 45.6% and 38.7% in advanced image-guided percutaneous and advanced laparoscopic techniques, respectively (P = 0.01). Median days from referral to procedure were 12 and 33 for patients undergoing advanced image-guided percutaneous and advanced laparoscopic techniques, respectively (P < 0.001). Median procedure time was 30 and 44.5 minutes for patients undergoing advanced image-guided percutaneous and advanced laparoscopic techniques, respectively (P < 0.001). Limitations: Retrospective study with practice preference influenced by timing, local expertise, and resources. Conclusions: Both advanced image-guided percutaneous and advanced laparoscopic techniques reported rare major complications and demonstrated excellent (advanced laparoscopic) and acceptable (advanced image-guided percutaneous) 1-year PD catheter survival. For patients referred for PD catheter placement at centers where advanced laparoscopic resources or expertise remain limited, the advanced image-guided percutaneous technique can provide a complementary and timely option to support the utilization of PD. Plain-Language Summary: Peritoneal dialysis is a preferred dialysis modality for many patients. However, the lack of available skilled surgeons can limit the placement of the peritoneal dialysis catheter in a timely manner. In the past decade, interventional radiology has developed expertise in placing peritoneal dialysis catheters. Using data from an integrated health care system, we compared the outcome of peritoneal dialysis catheters placed using laparoscopic surgery and interventional radiology techniques. Our results showed excellent 1-year patency of peritoneal dialysis catheters placed using laparoscopic surgery, whereas interventional radiology placement of catheters had lower but acceptable 1-year patency survival, based on best practice guideline criteria. Hence, interventional radiology placement of peritoneal dialysis catheters may be a viable alternative when laparoscopic surgery is not available or feasible.

Recent Advances in Understanding Peripheral and Gut Immune Cell-Mediated Salt-Sensitive Hypertension and Nephropathy.

Hypertension is the primary modifiable risk factor for cardiovascular, renal, and cerebrovascular diseases and is considered the main contributing factor to morbidity and mortality worldwide. Approximately 50% of hypertensive and 25% of normotensive people exhibit salt sensitivity of blood pressure, which is an independent risk factor for cardiovascular disease. Human and animal studies demonstrate that the immune system plays an important role in the etiology and pathogenesis of salt sensitivity of blood pressure, kidney damage, and vascular diseases. Antigen-presenting and adaptive immune cells are implicated in salt-sensitive hypertension and salt-induced renal and vascular injury. Elevated sodium activates antigen-presenting cells to release proinflammatory cytokines including IL (interleukin) 6, tumor necrosis factor-α, IL-1ß, and accumulate isolevuglandin-protein adducts. In turn, these activate T cells release prohypertensive cytokines including IL-17A. Moreover, high-salt intake is associated with gut dysbiosis, leading to inflammation, oxidative stress, and blood pressure elevation but the mechanistic contribution to salt-sensitivity of blood pressure is not clearly understood. Here, we discuss recent advances in research investigating the cause, potential biomarkers, and therapeutic targets for salt-sensitive hypertension as they pertain to the gut microbiome, immunity, and inflammation.

Hemoglobin A1c and Type 2 Diabetes Incidence Among Adolescents With Overweight and Obesity.

Importance: With the increase in prediabetes among adolescents with overweight and obesity, identifying those at highest risk for type 2 diabetes (T2D) can support prevention strategies. Objective: To assess T2D risk by hemoglobin A1c (HbA1c) levels among adolescents with overweight and obesity. Design, Setting, and Participants: This retrospective cohort study was conducted using data for January 1, 2010, to December 31, 2019, from a large California health care system. The study population comprised adolescents aged 10 to 17 years who had a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) at or above the 85th percentile, had HbA1c measured during 2010 to 2018, and did not have preexisting diabetes. Data abstraction and analyses were conducted from January 1, 2020, to November 16, 2023. Exposures: Baseline HbA1c, with covariates including BMI category (overweight: 85th to <95th percentile; moderate obesity: 100% to <120% of 95th percentile; or severe obesity: ≥120% of 95th percentile), age, sex, race and ethnicity, and Neighborhood Deprivation Index score. Main Outcomes and Measures: The main outcome was incident T2D during follow-up through 2019, including cumulative incidence and multivariable hazard ratios (HRs) with 95% CIs using Cox proportional hazard regression analyses. Results: This study included 74 552 adolescents with a mean (SD) age of 13.4 (2.3) years. More than half (50.6%) were female; 26.9% of individuals had overweight, 42.3% had moderate obesity, and 30.8% had severe obesity. Individuals identified as Asian or Pacific Islander (17.6%), Black (11.1%), Hispanic (43.6%), White (21.6%), and other or unknown race or ethnicity (6.1%). During follow-up, 698 adolescents (0.9%) developed diabetes, and 626 (89.7%) had T2D; 72 individuals (10.3%) who had type 1, secondary, or other diabetes were censored. The overall T2D incidence was 2.1 (95% CI, 1.9-2.3) per 1000 person-years, with a 5-year cumulative incidence of 1.0% (95% CI, 0.9%-1.1%). Higher baseline HbA1c (from <5.5% to 5.5%-5.6%, 5.7%-5.8%, 5.9%-6.0%, 6.1%-6.2%, and 6.3-6.4%) was associated with higher 5-year cumulative T2D incidence (from 0.3% [95% CI, 0.2%-0.4%] to 0.5% [0.4%-0.7%], 1.1% [0.8%-1.3%], 3.8% [3.2%-4.7%], 11.0% [8.9%-13.7%], and 28.5% [21.9%-36.5%], respectively). In addition, higher baseline HbA1c was associated with greater T2D risk (reference [HbA1c <5.5%]: HR, 1.7 [95% CI, 1.3-2.2], 2.8 [2.1-3.6], 9.3 [7.2-12.1], 23.3 [17.4-31.3], and 71.9 [51.1-101.1], respectively). Higher BMI category, older age, female sex, and Asian or Pacific Islander race (HR, 1.7 [95% CI, 1.3-2.2]), but not Black race or Hispanic ethnicity (compared with White race), were also independent indicators of T2D. In stratified analyses, incremental risk associated with higher HbA1c was greater for Asian or Pacific Islander and White adolescents than for Black and Hispanic adolescents. Conclusions and Relevance: In this cohort study of adolescents with overweight and obesity, T2D risk increased substantially with baseline HbA1c above 6.0%. Risk varied by BMI, age, sex, and race and ethnicity. These findings suggest that diabetes surveillance in adolescents should be tailored to optimize identification among high-risk subgroups.

A Non-Active-Site Inhibitor with Selectivity for Zika Virus NS2B-NS3 Protease.

Flavivirus infection usually results in fever accompanied by headache, arthralgia, and, in some cases, rash. Although the symptoms are mild, full recovery can take several months. Flaviviruses encode seven nonstructural proteins that represent potential drug targets for this viral family. Focusing on the Zika virus NS2B-NS3 protease, we uncovered a unique inhibitor, MH1, composed of aminothiazolopyridine and benzofuran moieties. MH1 inhibits ZVP with a biochemical IC50 of 440 nM and effectively blocks cleavage of ZVP substrates in cells. Surprisingly, MH1 inhibits the other flaviviral proteases at least 18-fold more weakly. This same phenomenon was observed in assays of the viral cytopathic effect, where only Zika virus showed sensitivity to MH1. This selectivity was unexpected since flaviviral proteases have high similarity in sequence and protein structure. MH1 binds at an allosteric site, as demonstrated by its ability to stabilize ZVP synergistically with an active site inhibitor. To understand its selectivity, we constructed a series of hybrid proteases composed of select segments of ZVP, which is sensitive to MH1, and dengue virus protease, which is essentially insensitive to MH1. Our results suggest that MH1 binds to the NS3 protease domain, disrupting its interaction with NS2B. These interactions are essential for substrate binding and cleavage. In particular, the unique dynamic properties of NS2B from Zika seem to be required for the function of MH1. Insights into the mechanism of MH1 function will aid us in developing non-active-site-directed, pan-flaviviral inhibitors, by highlighting the importance of evaluating and considering the dynamics of the NS2B regions.

Risk of Incident Asthma Among Young Asian American, Native Hawaiian, and Pacific Islander Children from Age 3 to 7 Years in a Northern California Healthcare System.

Incident childhood asthma risk has not been examined among diverse Asian American, Native Hawaiian, and Pacific Islander subgroups. In a large California healthcare system, incident asthma was higher among young Filipino/a, Native Hawaiian/Pacific Islander, and South Asian children compared with non-Hispanic White children, whereas Chinese and Japanese children were similar.

SIRT5 variants from patients with mitochondrial disease are associated with reduced SIRT5 stability and activity, but not with neuropathology.

SIRT5 is a sirtuin deacylase that represents the major activity responsible for removal of negatively-charged lysine modifications, in the mitochondrial matrix and elsewhere in the cell. In benign cells and mouse models, under basal non-stressed conditions, the phenotypes of SIRT5 deficiency are generally quite subtle. Here, we identify two homozygous SIRT5 variants in human patients suffering from severe mitochondrial disease. Both variants, P114T and L128V, are associated with reduced SIRT5 protein stability and impaired biochemical activity, with no evidence of neomorphic or dominant negative properties. The crystal structure of the P114T enzyme was solved and shows only subtle deviations from wild-type. Via CRISPR-Cas9, we generate a mouse model that recapitulates the human P114T mutation; homozygotes show reduced SIRT5 levels and activity, but no obvious metabolic abnormalities, neuropathology or other gross evidence of severe disease. We conclude that these human SIRT5 variants most likely represent severe hypomorphs, and are likely not the primary pathogenic cause of the neuropathology observed in the patients.

Prophylactic Mitigation of Acute Graft versus Host Disease by Novel 2-(Pyrrolidin-1-ylmethyl)pyrrole-Based Stimulation-2 (ST2) Inhibitors.

Hematopoietic cell transplantation (HCT) is a proven and potentially curable therapy for hematological malignancies and inherited hematological disease. The main risk of HCT is the development of graft versus host disease (GVHD) acquired in up to 50% of patients. Upregulation of soluble ST2 (sST2) is a key clinical biomarker for GVHD prognosis and was shown to be a potential therapeutic target for GVHD. Agents targeting sST2 to reduce the sST2 level after HCT have the potential to mitigate GVHD progression. Here, we report 32 (or XY52) as the lead ST2 inhibitor from our optimization campaign. XY52 had improved inhibitory activity and metabolic stability in vitro and in vivo. XY52 suppressed proinflammatory T-cell proliferation while increasing regulatory T cells in vitro. In a clinically relevant GVHD model, a 21-day prophylactic regimen of XY52 reduced plasma sST2 and IFN-γ levels and GVHD score and extended survival in mice. XY52 represented a significant improvement over our previous compound, iST2-1, and further optimization of XY52 is warranted. The small-molecule ST2 inhibitors can potentially be used as a biomarker-guided therapy for mitigating GVHD in future clinical applications.