Stem Cell Lineage Infidelity Drives Wound Repair and Cancer.

Tissue stem cells contribute to tissue regeneration and wound repair through cellular programs that can be hijacked by cancer cells. Here, we investigate such a phenomenon in skin, where during homeostasis, stem cells of the epidermis and hair follicle fuel their respective tissues. We find that breakdown of stem cell lineage confinement-granting privileges associated with both fates-is not only hallmark but also functional in cancer development. We show that lineage plasticity is critical in wound repair, where it operates transiently to redirect fates. Investigating mechanism, we discover that irrespective of cellular origin, lineage infidelity occurs in wounding when stress-responsive enhancers become activated and override homeostatic enhancers that govern lineage specificity. In cancer, stress-responsive transcription factor levels rise, causing lineage commanders to reach excess. When lineage and stress factors collaborate, they activate oncogenic enhancers that distinguish cancers from wounds.

The BRAF pseudogene functions as a competitive endogenous RNA and induces lymphoma in vivo.

Research over the past decade has suggested important roles for pseudogenes in physiology and disease. In vitro experiments demonstrated that pseudogenes contribute to cell transformation through several mechanisms. However, in vivo evidence for a causal role of pseudogenes in cancer development is lacking. Here, we report that mice engineered to overexpress either the full-length murine B-Raf pseudogene Braf-rs1 or its pseudo "CDS" or "3' UTR" develop an aggressive malignancy resembling human diffuse large B cell lymphoma. We show that Braf-rs1 and its human ortholog, BRAFP1, elicit their oncogenic activity, at least in part, as competitive endogenous RNAs (ceRNAs) that elevate BRAF expression and MAPK activation in vitro and in vivo. Notably, we find that transcriptional or genomic aberrations of BRAFP1 occur frequently in multiple human cancers, including B cell lymphomas. Our engineered mouse models demonstrate the oncogenic potential of pseudogenes and indicate that ceRNA-mediated microRNA sequestration may contribute to the development of cancer.

Phosphatidylinositol-5-Phosphate 4-Kinases Regulate Cellular Lipid Metabolism By Facilitating Autophagy.

While the majority of phosphatidylinositol-4, 5-bisphosphate (PI-4, 5-P2) in mammalian cells is generated by the conversion of phosphatidylinositol-4-phosphate (PI-4-P) to PI-4, 5-P2, a small fraction can be made by phosphorylating phosphatidylinositol-5-phosphate (PI-5-P). The physiological relevance of this second pathway is not clear. Here, we show that deletion of the genes encoding the two most active enzymes in this pathway, Pip4k2a and Pip4k2b, in the liver of mice causes a large enrichment in lipid droplets and in autophagic vesicles during fasting. These changes are due to a defect in the clearance of autophagosomes that halts autophagy and reduces the supply of nutrients salvaged through this pathway. Similar defects in autophagy are seen in nutrient-starved Pip4k2a-/-Pip4k2b-/- mouse embryonic fibroblasts and in C. elegans lacking the PI5P4K ortholog. These results suggest that this alternative pathway for PI-4, 5-P2 synthesis evolved, in part, to enhance the ability of multicellular organisms to survive starvation.

Lymphatic endothelial S1P promotes mitochondrial function and survival in naive T cells.

Effective adaptive immune responses require a large repertoire of naive T cells that migrate throughout the body, rapidly identifying almost any foreign peptide. Because the production of T cells declines with age, naive T cells must be long-lived. However, it remains unclear how naive T cells survive for years while constantly travelling. The chemoattractant sphingosine 1-phosphate (S1P) guides T cell circulation among secondary lymphoid organs, including spleen, lymph nodes and Peyer's patches, where T cells search for antigens. The concentration of S1P is higher in circulatory fluids than in lymphoid organs, and the S1P1 receptor (S1P1R) directs the exit of T cells from the spleen into blood, and from lymph nodes and Peyer's patches into lymph. Here we show that S1P is essential not only for the circulation of naive T cells, but also for their survival. Using transgenic mouse models, we demonstrate that lymphatic endothelial cells support the survival of T cells by secreting S1P via the transporter SPNS2, that this S1P signals through S1P1R on T cells, and that the requirement for S1P1R is independent of the established role of the receptor in guiding exit from lymph nodes. S1P signalling maintains the mitochondrial content of naive T cells, providing cells with the energy to continue their constant migration. The S1P signalling pathway is being targeted therapeutically to inhibit autoreactive T cell trafficking, and these findings suggest that it may be possible simultaneously to target autoreactive or malignant cell survival.

The aging skin microenvironment dictates stem cell behavior.

Aging manifests with architectural alteration and functional decline of multiple organs throughout an organism. In mammals, aged skin is accompanied by a marked reduction in hair cycling and appearance of bald patches, leading researchers to propose that hair follicle stem cells (HFSCs) are either lost, differentiate, or change to an epidermal fate during aging. Here, we employed single-cell RNA-sequencing to interrogate aging-related changes in the HFSCs. Surprisingly, although numbers declined, aging HFSCs were present, maintained their identity, and showed no overt signs of shifting to an epidermal fate. However, they did exhibit prevalent transcriptional changes particularly in extracellular matrix genes, and this was accompanied by profound structural perturbations in the aging SC niche. Moreover, marked age-related changes occurred in many nonepithelial cell types, including resident immune cells, sensory neurons, and arrector pili muscles. Each of these SC niche components has been shown to influence HF regeneration. When we performed skin injuries that are known to mobilize young HFSCs to exit their niche and regenerate HFs, we discovered that aged skin is defective at doing so. Interestingly, however, in transplantation assays in vivo, aged HFSCs regenerated HFs when supported with young dermis, while young HFSCs failed to regenerate HFs when combined with aged dermis. Together, our findings highlight the importance of SC:niche interactions and favor a model where youthfulness of the niche microenvironment plays a dominant role in dictating the properties of its SCs and tissue health and fitness.

Molecular pathogenesis of Japanese encephalitis and possible therapeutic strategies.

Japanese encephalitis virus (JEV), a single-stranded, enveloped RNA virus, is a health concern across Asian countries, associated with severe neurological disorders, especially in children. Primarily, pigs, bats, and birds are the natural hosts for JEV, but humans are infected incidentally. JEV requires a few host proteins for its entry and replication inside the mammalian host cell. The endoplasmic reticulum (ER) plays a significant role in JEV genome replication and assembly. During this process, the ER undergoes stress due to its remodelling and accumulation of viral particles and unfolded proteins, leading to an unfolded protein response (UPR). Here, we review the overall strategy used by JEV to infect the host cell and various cytopathic effects caused by JEV infection. We also highlight the role of JEV structural proteins (SPs) and non-structural proteins (NSPs) at various stages of the JEV life cycle that are involved in up- and downregulation of different host proteins and are potentially relevant for developing efficient therapeutic drugs.

Blood biomarkers reflect the effects of obesity and inflammation on the human breast transcriptome.

Obesity is a risk factor for the development of post-menopausal breast cancer. Breast white adipose tissue (WAT) inflammation, which is commonly found in women with excess body fat, is also associated with increased breast cancer risk. Both local and systemic effects are probably important for explaining the link between excess body fat, adipose inflammation and breast cancer. The first goal of this cross-sectional study of 196 women was to carry out transcriptome profiling to define the molecular changes that occur in the breast related to excess body fat and WAT inflammation. A second objective was to determine if commonly measured blood biomarkers of risk and prognosis reflect molecular changes in the breast. Breast WAT inflammation was assessed by immunohistochemistry. Bulk RNA-sequencing was carried out to assess gene expression in non-tumorous breast. Obesity and WAT inflammation were associated with a large number of differentially expressed genes and changes in multiple pathways linked to the development and progression of breast cancer. Altered pathways included inflammatory response, complement, KRAS signaling, tumor necrosis factor α signaling via NFkB, interleukin (IL)6-JAK-STAT3 signaling, epithelial mesenchymal transition, angiogenesis, interferon γ response and transforming growth factor (TGF)-ß signaling. Increased expression of several drug targets such as aromatase, TGF-ß1, IDO-1 and PD-1 were observed. Levels of various blood biomarkers including high sensitivity C-reactive protein, IL6, leptin, adiponectin, triglycerides, high-density lipoprotein cholesterol and insulin were altered and correlated with molecular changes in the breast. Collectively, this study helps to explain both the link between obesity and breast cancer and the utility of blood biomarkers for determining risk and prognosis.

Heat shock proteins-driven stress granule dynamics: yet another avenue for cell survival.

Heat shock proteins (HSPs) are evolutionary conserved 'stress-response' proteins that facilitate cell survival against various adverse conditions. HSP-mediated cytoprotection was hitherto reported to occur principally in two ways. Firstly, HSPs interact directly or indirectly with apoptosis signaling components and suppress apoptosis. Secondly, through chaperon activity, HSPs suppress proteotoxicity and maintain protein-homeostasis. Recent studies highlight the interaction of HSPs with cytoplasmic stress granules (SGs). SGs are conserved cytoplasmic mRNPs granules that aid in cell survival under stressful conditions. We primarily aim to describe the distinct cell survival strategy mediated by HSPs as the crucial regulators of SGs assembly and disassembly. Based on the growing evidence, HSPs and associated co-chaperones act as important determinants of SG assembly, composition and dissolution. Under cellular stress, as a 'stress-coping mechanism', the formation of SGs reprograms protein translation machinery and modulates signaling pathways indispensable for cell survival. Besides their role in suppressing apoptosis, HSPs also regulate protein-homeostasis by their chaperone activity as well as by their tight regulation of SG dynamics. The intricate molecular signaling in and around the nexus of HSPs-SGs and its importance in diseases has to be unearthed. These studies have significant implications in the management of chronic diseases such as cancer and neurodegenerative diseases where SGs possess pathological functions.

Obesity-Associated Extracellular Matrix Remodeling Promotes a Macrophage Phenotype Similar to Tumor-Associated Macrophages.

Obesity is associated with adipose inflammation, defined by macrophages encircling dead adipocytes, as well as extracellular matrix (ECM) remodeling and increased risk of breast cancer. Whether ECM affects macrophage phenotype in obesity is uncertain. A better understanding of this relationship could be strategically important to reduce cancer risk or improve outcomes in the obese. Using clinical samples, computational approaches, and in vitro decellularized ECM models, this study quantified the relative abundance of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages in human breast adipose tissue, determined molecular similarities between obesity and tumor-associated macrophages, and assessed the regulatory effect of obese versus lean ECM on macrophage phenotype. Our results suggest that breast adipose tissue contains more M2- than M1-biased macrophages across all body mass index categories. Obesity further increased M2-biased macrophages but did not affect M1-biased macrophage density. Gene Set Enrichment Analysis suggested that breast tissue macrophages from obese versus lean women are more similar to tumor-associated macrophages. These changes positively correlated with adipose tissue interstitial fibrosis, and in vitro experiments indicated that obese ECM directly stimulates M2-biased macrophage functions. However, mammographic density cannot be used as a clinical indicator of these changes. Collectively, these data suggest that obesity-associated interstitial fibrosis promotes a macrophage phenotype similar to tumor-associated macrophages, which may contribute to the link between obesity and breast cancer.

Supplemental estrogen and caloric restriction reduce obesity-induced periprostatic white adipose inflammation in mice.

Obesity is associated with an increased incidence of high-grade prostate cancer (PC) and worse prognosis for PC patients. Recently, we showed in men that obesity-related periprostatic white adipose tissue (WAT) inflammation, characterized by macrophages surrounding dead or dying adipocytes forming crown-like structures, was associated with high-grade PC. Possibly, interventions that suppress periprostatic WAT inflammation will improve outcomes for men with PC. Here, we tested the hypothesis that supplemental 17ß-estradiol (E2) could decrease periprostatic WAT inflammation in obese male mice. Mice were fed a high-fat diet to induce periprostatic WAT inflammation before being treated with supplemental E2. E2 supplementation suppressed caloric intake, induced weight loss, decreased periprostatic WAT inflammation and downregulated the expression of genes linked to inflammation including Cd68, Mcp1 and Tnf. Similar to the effects of E2 supplementation, treatment with diethylstilbestrol, a synthetic estrogen, also suppressed caloric intake and reduced periprostatic WAT inflammation. To determine whether the observed effects of supplemental estrogen could be reproduced by caloric restriction (CR) alone, obese mice were put on a 30% CR diet. Like estrogen treatment, CR was effective in reducing body weight, periprostatic WAT inflammation and the expression of pro-inflammatory genes. Transcriptomic analyses of periprostatic fat showed that obesity was associated with enrichment in inflammatory response pathways, which were normalized by both supplemental E2 and CR. Taken together, these findings strengthen the rationale for future efforts to determine whether either CR or supplemental estrogen will decrease periprostatic WAT inflammation and thereby improve outcomes for men with PC.

Function and clinical relevance of RHAMM isoforms in pancreatic tumor progression.

The receptor for hyaluronic acid-mediated motility (RHAMM) is upregulated in various cancers. We previously screened genes upregulated in human hepatocellular carcinomas for their metastatic function in a mouse model of pancreatic neuroendocrine tumor (PNET) and identified that human RHAMMB promoted liver metastasis. It was unknown whether RHAMMB is upregulated in pancreatic cancer or contributes to its progression. In this study, we found that RHAMM protein was frequently upregulated in human PNETs. We investigated alternative splicing isoforms, RHAMMA and RHAMMB, by RNA-Seq analysis of primary PNETs and liver metastases. RHAMMB, but not RHAMMA, was significantly upregulated in liver metastases. RHAMMB was crucial for in vivo metastatic capacity of mouse and human PNETs. RHAMMA, carrying an extra 15-amino acid-stretch, did not promote metastasis in spontaneous and experimental metastasis mouse models. Moreover, RHAMMB was substantially higher than RHAMMA in pancreatic ductal adenocarcinoma (PDAC). RHAMMB, but not RHAMMA, correlated with both higher EGFR expression and poorer survival of PDAC patients. Knockdown of EGFR abolished RHAMMB-driven PNET metastasis. Altogether, our findings suggest a clinically relevant function of RHAMMB, but not RHAMMA, in promoting PNET metastasis in part through EGFR signaling. RHAMMB can thus serve as a prognostic factor for pancreatic cancer.

Colonoscopic-Guided Pinch Biopsies in Mice as a Useful Model for Evaluating the Roles of Host and Luminal Factors in Colonic Inflammation.

Colonic inflammation, a hallmark of inflammatory bowel disease, can be influenced by host intrinsic and extrinsic factors. There continues to be a need for models of colonic inflammation that can both provide insights into disease pathogenesis and be used to investigate potential therapies. Herein, we tested the utility of colonoscopic-guided pinch biopsies in mice for studying colonic inflammation and its treatment. Gene expression profiling of colonic wound beds after injury showed marked changes, including increased expression of genes important for the inflammatory response. Interestingly, many of these gene expression changes mimicked those alterations found in inflammatory bowel disease patients. Biopsy-induced inflammation was associated with increases in neutrophils, macrophages, and natural killer cells. Injury also led to elevated levels of sphingosine-1-phosphate (S1P), a bioactive lipid that is an important mediator of inflammation mainly through its receptor, S1P1. Genetic deletion of S1P1 in the endothelium did not alter the inflammatory response but led to increased colonic bleeding. Bacteria invaded into the wound beds, raising the possibility that microbes contributed to the observed changes in mucosal gene expression. In support of this, reducing bacterial abundance markedly attenuated the inflammatory response to wounding. Taken together, this study demonstrates the utility of the pinch biopsy model of colonic injury to elucidate the molecular underpinnings of colonic inflammation and its treatment.

Combinatorial targeting of nuclear export and translation of RNA inhibits aggressive B-cell lymphomas.

Aggressive double- and triple-hit (DH/TH) diffuse large B-cell lymphomas (DLBCLs) feature activation of Hsp90 stress pathways. Herein, we show that Hsp90 controls posttranscriptional dynamics of key messenger RNA (mRNA) species including those encoding BCL6, MYC, and BCL2. Using a proteomics approach, we found that Hsp90 binds to and maintains activity of eIF4E. eIF4E drives nuclear export and translation of BCL6, MYC, and BCL2 mRNA. eIF4E RNA-immunoprecipitation sequencing in DLBCL suggests that nuclear eIF4E controls an extended program that includes B-cell receptor signaling, cellular metabolism, and epigenetic regulation. Accordingly, eIF4E was required for survival of DLBCL including the most aggressive subtypes, DH/TH lymphomas. Indeed, eIF4E inhibition induces tumor regression in cell line and patient-derived tumorgrafts of TH-DLBCL, even in the presence of elevated Hsp90 activity. Targeting Hsp90 is typically limited by counterregulatory elevation of Hsp70B, which induces resistance to Hsp90 inhibitors. Surprisingly, we identify Hsp70 mRNA as an eIF4E target. In this way, eIF4E inhibition can overcome drug resistance to Hsp90 inhibitors. Accordingly, rational combinatorial inhibition of eIF4E and Hsp90 inhibitors resulted in cooperative antilymphoma activity in DH/TH DLBCL in vitro and in vivo.

CHL1 expression differentiates Hürthle cell carcinoma from benign Hürthle cell nodules.

BACKGROUND AND OBJECTIVES: Hürthle cell carcinoma (HCC) is an unusual and relatively rare type of differentiated thyroid cancer. Currently, cytologic analysis of fine-needle aspiration biopsy is limited in distinguishing benign Hürthle cell neoplasms from malignant ones. The aim of this study was to determine whether differences in the expression of specific genes could differentiate HCC from benign Hürthle cell nodules by evaluating differential gene expression in Hürthle cell disease. METHODS: Eighteen benign Hürthle cell nodules and seven HCC samples were analyzed by whole-transcriptome sequencing. Bioinformatics analysis was carried out to identify candidate differentially expressed genes. Expression of these candidate genes was re-examined by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression was quantified by immunohistochemistry. RESULTS: Close homolog of L1 (CHL1) was identified as overexpressed in HCC. CHL1 was found to have greater than 15-fold higher expression in fragments per kilobase million in HCC compared with benign Hurthle cell tumors. This was confirmed by qRT-PCR. Moreover, the immunoreactivity score of the CHL1 protein was significantly higher in HCC compared with benign Hürthle cell nodules. CONCLUSIONS: CHL1 expression may represent a novel and useful prognostic biomarker to distinguish HCC from benign Hürthle cell disease.

Melanoma genome evolution across species.

BACKGROUND: Cancer genomes evolve in both space and time, which contributes to the genetic heterogeneity that underlies tumor progression and drug resistance. In human melanoma, identifying mechanistically important events in tumor evolution is hampered due to the high background mutation rate from ultraviolet (UV) light. Cross-species oncogenomics is a powerful tool for identifying these core events, in which transgenically well-defined animal models of cancer are compared to human cancers to identify key conserved alterations. RESULTS: We use a zebrafish model of tumor progression and drug resistance for cross-species genomic analysis in melanoma. Zebrafish transgenic tumors are initiated with just 2 genetic lesions, BRAFV600E and p53-/-, yet take 4-6 months to appear, at which time whole genome sequencing demonstrated >3,000 new mutations. An additional 4-month exposure to the BRAF inhibitor vemurafenib resulted in a highly drug resistant tumor that showed 3 additional new DNA mutations in the genes BUB1B, PINK1, and COL16A1. These genetic changes in drug resistance are accompanied by a massive reorganization of the transcriptome, with differential RNA expression of over 800 genes, centered on alterations in cAMP and PKA signaling. By comparing both the DNA and mRNA changes to a large panel of human melanomas, we find that there is a highly significant enrichment of these alterations in human patients with vemurafenib resistant disease. CONCLUSIONS: Our results suggest that targeting of alterations that are conserved between zebrafish and humans may offer new avenues for therapeutic intervention. The approaches described here will be broadly applicable to the diverse array of cancer models available in the zebrafish, which can be used to inform human cancer genomics.

The uncharted territory of host-pathogen interaction in tuberculosis.

Mycobacterium tuberculosis (M.tb) effectively manipulates the host processes to establish the deadly respiratory disease, Tuberculosis (TB). M.tb has developed key mechanisms to disrupt the host cell health to combat immune responses and replicate efficaciously. M.tb antigens such as ESAT-6, 19kDa lipoprotein, Hip1, and Hsp70 destroy the integrity of cell organelles (Mitochondria, Endoplasmic Reticulum, Nucleus, Phagosomes) or delay innate/adaptive cell responses. This is followed by the induction of cellular stress responses in the host. Such cells can either undergo various cell death processes such as apoptosis or necrosis, or mount effective immune responses to clear the invading pathogen. Further, to combat the infection progression, the host secretes extracellular vesicles such as exosomes to initiate immune signaling. The exosomes can contain M.tb as well as host cell-derived peptides that can act as a double-edged sword in the immune signaling event. The host-symbiont microbiota produces various metabolites that are beneficial for maintaining healthy tissue microenvironment. In juxtaposition to the above-mentioned mechanisms, M.tb dysregulates the gut and respiratory microbiome to support its replication and dissemination process. The above-mentioned interconnected host cellular processes of Immunometabolism, Cellular stress, Host Microbiome, and Extracellular vesicles are less explored in the realm of exploration of novel Host-directed therapies for TB. Therefore, this review highlights the intertwined host cellular processes to control M.tb survival and showcases the important factors that can be targeted for designing efficacious therapy.

Interactive Quiz-Based Anatomy Teaching for Medical Undergraduate Students.

BACKGROUND: Anatomy is one of the most volatile subjects and needs the learner to understand and retain a lot of information and terms. It is thus very important to continuously upgrade the methodology from the traditional didactive to interactive teaching to make the student an active learner and engage him in the learning process to categorize and analyze anatomical facts and knowledge. AIMS AND OBJECTIVES: The study was done to compare the learning outcomes and perception of medical students towards didactic lectures and interactive quiz-based lectures in anatomy. METHODOLOGY: The study was conducted amongst the 200 Year 1 medical undergraduate students enrolled in the Department of Anatomy at Dr. Ram Manohar Lohia Institute of Medical Sciences, located in Lucknow, India. The 200 students comprised 120 males (60%) and 80 females (40%). The mean age of male students was 19.67 years and of females was 19.52 years. The students were divided into two groups of hundred students each by a method of convenience sampling. Students of group I were taught by an interactive quiz-based lecture and group II by a traditional didactic lecture. A pre- and post-test were conducted for both groups and feedback for both methods was taken by using a pre-validated feedback form based on a 5-point Likert scale. RESULTS: On statistical analysis, it was found that in the post-test the performance of group I taught by the interactive quiz-based study was better as compared to group II taught by traditional didactive teaching, but was not statistically significant (p=0.233, p>0.05). The feedback from students revealed that 45.9% of them strongly agreed and 44.9% agreed with the fact that quiz-based lectures are better than routine lectures. CONCLUSIONS: Results of the present study clearly indicate that the introduction of quiz-based anatomy teaching for undergraduate medical students was well received and appeared to improve their learning outcomes in the form of increased attention and participation during class and would lead to better retention of the topics taught during interactive lectures. To the best of our knowledge, no previous study has been done to document the efficacy of quiz-based teaching for the subject of anatomy.

Immunoinhibitory effects of anti-tuberculosis therapy induce the host vulnerability to tuberculosis recurrence.

The host immune responses play a pivotal role in the establishment of long-term memory responses, which effectively aids in infection clearance. However, the prevailing anti-tuberculosis therapy, while aiming to combat tuberculosis (TB), also debilitates innate and adaptive immune components of the host. In this study, we explored how the front-line anti-TB drugs impact the host immune cells by modulating multiple signaling pathways and subsequently leading to disease relapse. Administration of these drugs led to a reduction in innate immune activation and also the cytokines required to trigger protective T cell responses. Moreover, these drugs led to activation-induced cell death in the mycobacterial-specific T cell leading to a reduced killing capacity. Furthermore, these drugs stalled the T cell differentiation into memory subsets by modulating the activation of STAT3, STAT4, FOXO1, and NFκB transcription factors and hampering the Th1 and Th17-mediated long-term host protective memory responses. These findings suggest the urgent need to augment directly observed treatment, short-course (DOTS) therapy with immunomodulatory agents to mitigate the adverse effects linked to the treatment.IMPORTANCEAs a central component of TB eradication initiatives, directly observed treatment, short-course (DOTS) therapy imparts immune-dampening effects during the course of treatment. This approach undermines the host immune system by delaying the activation process and lowering the immune response. In our investigation, we have unveiled the impact of DOTS on specific immune cell populations. Notably, the signaling pathways involving STAT3 and STAT4 critical for memory responses and NFκß associated with pro-inflammation were substantially declined due to the therapy. Consequently, these drugs exhibit limited effectiveness in preventing recurrence of the disease. These observations highlight the imperative integration of immunomodulators to manage TB infection.

Calibration of the IQVIA Core Diabetes Model to the stroke outcomes from the SUSTAIN 6 cardiovascular outcomes trial of once-weekly semaglutide.

AIMS: In the SUSTAIN 6 cardiovascular outcomes trial, once-weekly semaglutide was associated with a statistically significant reduction in major adverse cardiovascular events compared with placebo. To date, no studies have assessed how accurately existing diabetes models predict the outcomes observed in SUSTAIN 6. The aims of this analysis were to investigate the performance of the IQVIA Core Diabetes Model when used to predict the SUSTAIN 6 trial outcomes, to calibrate the model such that projected outcomes reflected observed outcomes, and to examine the impact of calibration on the cost-effectiveness of once-weekly semaglutide from a UK healthcare payer perspective. METHODS: The IQVIA Core Diabetes Model was calibrated to ensure that the projected non-fatal stroke event rates reflected the non-fatal stroke event rates observed in SUSTAIN 6 over a two-year time horizon. Cost-effectiveness analyses of once-weekly semaglutide versus placebo plus standard of care were conducted over a lifetime horizon using the uncalibrated and calibrated models to assess the impact on cost-effectiveness outcomes. RESULTS: To replicate the non-fatal stroke event rate in SUSTAIN 6, calibration of the model through the application of relative risks for stroke of 1.07 and 1.65 with once-weekly semaglutide and placebo, respectively, was required. In the long-term cost-effectiveness analysis, the uncalibrated model projected an incremental cost-effectiveness ratio for once-weekly semaglutide versus placebo plus standard of care of GBP 22,262 per quality-adjusted life year (QALY) gained, which fell to GBP 17,594 per QALY gained when the calibrated model was used. CONCLUSIONS: The requirement for calibration to replicate the outcomes observed in SUSTAIN 6 suggests that the reductions in risk of cardiovascular complications observed with once-weekly semaglutide cannot be solely explained by differences in conventional risk factors. Accurate estimation of the risk of diabetes-related complications using methods such as calibration is important to ensure accurate cost-effectiveness analyses are conducted.

SIRT2 inhibition by AGK2 enhances mycobacteria-specific stem cell memory responses by modulating beta-catenin and glycolysis.

Bacille Calmette-Guerin (BCG) generates limited long-lasting adaptive memory responses leading to short-lived protection against adult pulmonary tuberculosis (TB). Here, we show that host sirtuin 2 (SIRT2) inhibition by AGK2 significantly enhances the BCG vaccine efficacy during primary infection and TB recurrence through enhanced stem cell memory (TSCM) responses. SIRT2 inhibition modulated the proteome landscape of CD4+ T cells affecting pathways involved in cellular metabolism and T-cell differentiation. Precisely, AGK2 treatment enriched the IFNγ-producing TSCM cells by activating ß-catenin and glycolysis. Furthermore, SIRT2 specifically targeted histone H3 and NF-κB p65 to induce proinflammatory responses. Finally, inhibition of the Wnt/ß-catenin pathway abolished the protective effects of AGK2 treatment during BCG vaccination. Taken together, this study provides a direct link between BCG vaccination, epigenetics, and memory immune responses. We identify SIRT2 as a key regulator of memory T cells during BCG vaccination and project SIRT2 inhibitors as potential immunoprophylaxis against TB.