Vitamin D Switches BAF Complexes to Protect ß Cells.

A primary cause of disease progression in type 2 diabetes (T2D) is ß cell dysfunction due to inflammatory stress and insulin resistance. However, preventing ß cell exhaustion under diabetic conditions is a major therapeutic challenge. Here, we identify the vitamin D receptor (VDR) as a key modulator of inflammation and ß cell survival. Alternative recognition of an acetylated lysine in VDR by bromodomain proteins BRD7 and BRD9 directs association to PBAF and BAF chromatin remodeling complexes, respectively. Mechanistically, ligand promotes VDR association with PBAF to effect genome-wide changes in chromatin accessibility and enhancer landscape, resulting in an anti-inflammatory response. Importantly, pharmacological inhibition of BRD9 promotes PBAF-VDR association to restore ß cell function and ameliorate hyperglycemia in murine T2D models. These studies reveal an unrecognized VDR-dependent transcriptional program underpinning ß cell survival and identifies the VDR:PBAF/BAF association as a potential therapeutic target for T2D.

Glycogen metabolism links glucose homeostasis to thermogenesis in adipocytes.

Adipocytes increase energy expenditure in response to prolonged sympathetic activation via persistent expression of uncoupling protein 1 (UCP1)1,2. Here we report that the regulation of glycogen metabolism by catecholamines is critical for UCP1 expression. Chronic ß-adrenergic activation leads to increased glycogen accumulation in adipocytes expressing UCP1. Adipocyte-specific deletion of a scaffolding protein, protein targeting to glycogen (PTG), reduces glycogen levels in beige adipocytes, attenuating UCP1 expression and responsiveness to cold or ß-adrenergic receptor-stimulated weight loss in obese mice. Unexpectedly, we observed that glycogen synthesis and degradation are increased in response to catecholamines, and that glycogen turnover is required to produce reactive oxygen species leading to the activation of p38 MAPK, which drives UCP1 expression. Thus, glycogen has a key regulatory role in adipocytes, linking glucose metabolism to thermogenesis.

A Targeted Deep Sequencing Method to Quantify Endogenous Retrovirus Gag Sequence Variants and Open Reading Frames Expressed in Nonobese Diabetic Mice.

Endogenous retroviruses (ERVs) are involved in autoimmune diseases such as type 1 diabetes (T1D). ERV gene products homologous to murine leukemia retroviruses are expressed in the pancreatic islets of NOD mice, a model of T1D. One ERV gene, Gag, with partial or complete open reading frames (ORFs), is detected in the islets, and it contains many sequence variants. An amplicon deep sequencing analysis was established by targeting a conserved region within the Gag gene to compare NOD with T1D-resistant mice or different ages of prediabetic NOD mice. We observed that the numbers of different Gag variants and ORFs are linked to T1D susceptibility. More importantly, these numbers change during the course of diabetes development and can be quantified to calculate the levels of disease progression. Sequence alignment analysis led to identification of additional markers, including nucleotide mismatching and amino acid consensus at specific positions that can distinguish the early and late stages, before diabetes onset. Therefore, the expression of sequence variants and ORFs of ERV genes, particularly Gag, can be quantified as biomarkers to estimate T1D susceptibility and disease progression.

Transcription Factor Activity Regulating Macrophage Heterogeneity during Skin Wound Healing.

Monocytes and macrophages (Mos/Mϕs) play diverse roles in wound healing by adopting a spectrum of functional phenotypes; however, the regulation of such heterogeneity remains poorly defined. We enhanced our previously published Bayesian inference TF activity model, incorporating both single-cell RNA sequencing and single-cell ATAC sequencing data to infer transcription factor (TF) activity in Mos/Mϕs during skin wound healing. We found that wound Mos/Mϕs clustered into early-stage Mos/Mϕs, late-stage Mϕs, and APCs, and that each cluster showed differential chromatin accessibility and differential predicted TF activity that did not always correlate with mRNA or protein expression. Network analysis revealed two highly connected large communities involving a total of 19 TFs, highlighting TF cooperation in regulating wound Mos/Mϕs. This analysis also revealed a small community populated by NR4A1 and NFKB1, supporting a proinflammatory link between these TFs. Importantly, we validated a proinflammatory role for NR4A1 activity during wound healing, showing that Nr4a1 knockout mice exhibit decreased inflammatory gene expression in early-stage wound Mos/Mϕs, along with delayed wound re-epithelialization and impaired granulation tissue formation. In summary, our study provides insight into TF activity that regulates Mo/Mϕ heterogeneity during wound healing and provides a rational basis for targeting Mo/Mϕ TF networks to alter phenotypes and improve healing.

Immune-evasive human islet-like organoids ameliorate diabetes.

Islets derived from stem cells hold promise as a therapy for insulin-dependent diabetes, but there remain challenges towards achieving this goal1-6. Here we generate human islet-like organoids (HILOs) from induced pluripotent stem cells and show that non-canonical WNT4 signalling drives the metabolic maturation necessary for robust ex vivo glucose-stimulated insulin secretion. These functionally mature HILOs contain endocrine-like cell types that, upon transplantation, rapidly re-establish glucose homeostasis in diabetic NOD/SCID mice. Overexpression of the immune checkpoint protein programmed death-ligand 1 (PD-L1) protected HILO xenografts such that they were able to restore glucose homeostasis in immune-competent diabetic mice for 50 days. Furthermore, ex vivo stimulation with interferon-γ induced endogenous PD-L1 expression and restricted T cell activation and graft rejection. The generation of glucose-responsive islet-like organoids that are able to avoid immune detection provides a promising alternative to cadaveric and device-dependent therapies in the treatment of diabetes.

DROEG: a method for cancer drug response prediction based on omics and essential genes integration.

Predicting therapeutic responses in cancer patients is a major challenge in the field of precision medicine due to high inter- and intra-tumor heterogeneity. Most drug response models need to be improved in terms of accuracy, and there is limited research to assess therapeutic responses of particular tumor types. Here, we developed a novel method DROEG (Drug Response based on Omics and Essential Genes) for prediction of drug response in tumor cell lines by integrating genomic, transcriptomic and methylomic data along with CRISPR essential genes, and revealed that the incorporation of tumor proliferation essential genes can improve drug sensitivity prediction. Concisely, DROEG integrates literature-based and statistics-based methods to select features and uses Support Vector Regression for model construction. We demonstrate that DROEG outperforms most state-of-the-art algorithms by both qualitative (prediction accuracy for drug-sensitive/resistant) and quantitative (Pearson correlation coefficient between the predicted and actual IC50) evaluation in Genomics of Drug Sensitivity in Cancer and Cancer Cell Line Encyclopedia datasets. In addition, DROEG is further applied to the pan-gastrointestinal tumor with high prevalence and mortality as a case study at both cell line and clinical levels to evaluate the model efficacy and discover potential prognostic biomarkers in Cisplatin and Epirubicin treatment. Interestingly, the CRISPR essential gene information is found to be the most important contributor to enhance the accuracy of the DROEG model. To our knowledge, this is the first study to integrate essential genes with multi-omics data to improve cancer drug response prediction and provide insights into personalized precision treatment.

Complement Receptor C3aR1 Contributes to Paclitaxel-Induced Peripheral Neuropathic Pain in Mice and Rats.

Cancer chemotherapy-induced neuropathic pain is a devastating pain syndrome without effective therapies. We previously reported that rats deficient in complement C3, the central component of complement activation cascade, showed a reduced degree of paclitaxel-induced mechanical allodynia (PIMA), suggesting that complement is integrally involved in the pathogenesis of this model. However, the underlying mechanism was unclear. Complement activation leads to the production of C3a, which mediates inflammation through its receptor C3aR1. In this article, we report that the administration of paclitaxel induced a significantly higher expression level of C3aR1 on dorsal root ganglion (DRG) macrophages and expansion of these macrophages in DRGs in wild-type (WT) compared with in C3aR1 knockout (KO) mice. We also found that paclitaxel induced less severe PIMA, along with a reduced DRG expression of transient receptor potential channels of the vanilloid subtype 4 (TRPV4), an essential mediator for PIMA, in C3aR1 KO than in WT mice. Treating WT mice or rats with a C3aR1 antagonist markedly attenuated PIMA in association with downregulated DRG TRPV4 expression, reduced DRG macrophages expansion, suppressed DRG neuron hyperexcitability, and alleviated peripheral intraepidermal nerve fiber loss. Administration of C3aR1 antagonist to TRPV4 KO mice further protected them from PIMA. These results suggest that complement regulates PIMA development through C3aR1 to upregulate TRPV4 on DRG neurons and promote DRG macrophage expansion. Targeting C3aR1 could be a novel therapeutic approach to alleviate this debilitating pain syndrome.

A Bayesian inference transcription factor activity model for the analysis of single-cell transcriptomes.

Single-cell RNA sequencing (scRNA-seq) has emerged as a powerful experimental approach to study cellular heterogeneity. One of the challenges in scRNA-seq data analysis is integrating different types of biological data to consistently recognize discrete biological functions and regulatory mechanisms of cells, such as transcription factor activities and gene regulatory networks in distinct cell populations. We have developed an approach to infer transcription factor activities from scRNA-seq data that leverages existing biological data on transcription factor binding sites. The Bayesian inference transcription factor activity model (BITFAM) integrates ChIP-seq transcription factor binding information into scRNA-seq data analysis. We show that the inferred transcription factor activities for key cell types identify regulatory transcription factors that are known to mechanistically control cell function and cell fate. The BITFAM approach not only identifies biologically meaningful transcription factor activities, but also provides valuable insights into underlying transcription factor regulatory mechanisms.

The relationship between leptin-to-adiponectin ratio and HOMA-IR and metabolic syndrome in five African-origin populations.

OBJECTIVE: This cross-sectional study aims to assess the associations between serum leptin, adiponectin, leptin-to-adiponectin ratio (L/A ratio), and metabolic syndrome (MS) and HOMA-IR in five African-origin populations: Ghana, South Africa, Jamaica, Seychelles, and US. METHODS: Clinical measures included serum glucose, insulin, adipokines, blood pressure and anthropometric measures. MS was determined using the Harmonized criteria. The final sample included 2087 adults. RESULTS: After adjusting for age, sex, and fat mass, L/A ratio, unlike HOMA-IR, was significantly associated with MS across all sites (p < 0.001). Within sites, L/A ratio was only associated with MS and HOMA-IR in the US (p < 0.001) and South Africa (p < 0.01), respectively. Leptin was associated with MS in South Africa only (p < 0.05) but was significantly associated with HOMA-IR across all five sites and within the US (p < 0.05). Similarly, adiponectin was associated with HOMA-IR in South Africa (p < 0.05) and with MS across all five sites (p < 0.001) and within each site separately, except Ghana. CONCLUSIONS: Our study suggests that individuals of the African diaspora in different geographical locations may differ in the determinants of MS. Future studies should investigate the determinants for the disparate relationships between MS, IS and adipokines across different African-origin populations.

Excessive accumulation of epicardial adipose tissue promotes microvascular obstruction formation after myocardial ischemia/reperfusion through modulating macrophages polarization.

BACKGROUND: Owing to its unique location and multifaceted metabolic functions, epicardial adipose tissue (EAT) is gradually emerging as a new metabolic target for coronary artery disease risk stratification. Microvascular obstruction (MVO) has been recognized as an independent risk factor for unfavorable prognosis in acute myocardial infarction patients. However, the concrete role of EAT in the pathogenesis of MVO formation in individuals with ST-segment elevation myocardial infarction (STEMI) remains unclear. The objective of the study is to evaluate the correlation between EAT accumulation and MVO formation measured by cardiac magnetic resonance (CMR) in STEMI patients and clarify the underlying mechanisms involved in this relationship. METHODS: Firstly, we utilized CMR technique to explore the association of EAT distribution and quantity with MVO formation in patients with STEMI. Then we utilized a mouse model with EAT depletion to explore how EAT affected MVO formation under the circumstances of myocardial ischemia/reperfusion (I/R) injury. We further investigated the immunomodulatory effect of EAT on macrophages through co-culture experiments. Finally, we searched for new therapeutic strategies targeting EAT to prevent MVO formation. RESULTS: The increase of left atrioventricular EAT mass index was independently associated with MVO formation. We also found that increased circulating levels of DPP4 and high DPP4 activity seemed to be associated with EAT increase. EAT accumulation acted as a pro-inflammatory mediator boosting the transition of macrophages towards inflammatory phenotype in myocardial I/R injury through secreting inflammatory EVs. Furthermore, our study declared the potential therapeutic effects of GLP-1 receptor agonist and GLP-1/GLP-2 receptor dual agonist for MVO prevention were at least partially ascribed to its impact on EAT modulation. CONCLUSIONS: Our work for the first time demonstrated that excessive accumulation of EAT promoted MVO formation by promoting the polarization state of cardiac macrophages towards an inflammatory phenotype. Furthermore, this study identified a very promising therapeutic strategy, GLP-1/GLP-2 receptor dual agonist, targeting EAT for MVO prevention following myocardial I/R injury.

Temperature distribution inversion in infrared multispectral imaging based on ensemble network.

Temperature distribution can be acquired through non-contact temperature measurement using multispectral imaging. However, the challenge lies in radiometric temperature inversion owing to the unknown emissivity. Despite the promising results demonstrated by traditional algorithms and neural networks, enhancing the precision and reliability of temperature inversion remains a challenge. To tackle these challenges, in this work, we propose the use of ensemble learning for temperature distribution inversion in infrared multispectral imaging. The network comprises a base-learner and a meta-learner, trained to establish the nonlinear relationship between temperature and multispectral distribution measurements. Moreover, the network architecture exhibits high robustness against noise arising in the testing environment. Simulations and real experiments on multispectral imaging measurements illustrate that ensemble learning can be a potent tool for multispectral imaging radiation temperature distribution measurement, achieving superior inversion performance compared to other neural networks. The reproducible code will be available at https://github.com/shuowenyang/Temperature-Inversion.

Alterations in microbiome associated with acute pancreatitis.

PURPOSE OF REVIEW: This review evaluates the current knowledge of gut microbiome alterations in acute pancreatitis, including those that can increase acute pancreatitis risk or worsen disease severity, and the mechanisms of gut microbiome driven injury in acute pancreatitis. RECENT FINDINGS: Recent observational studies in humans showed the association of gut microbiome changes (decreased gut microbiome diversity, alterations in relative abundances of certain species, and association of unique species with functional pathways) with acute pancreatitis risk and severity. Furthermore, in-vivo studies highlighted the role of gut microbiome in the development and severity of acute pancreatitis using FMT models. The gut barrier integrity, immune cell homeostasis, and microbial metabolites appear to play key roles in acute pancreatitis risk and severity. SUMMARY: Large human cohort studies that assess gut microbiome profile, its metabolites and impact on acute pancreatitis risk and severity will be crucial for development of innovative prediction, prevention and treatment strategies.

Structural mechanism underpinning Thermus oshimai Pif1-mediated G-quadruplex unfolding.

G-quadruplexes (G4s) are unusual stable DNA structures that cause genomic instability. To overcome the potential barriers formed by G4s, cells have evolved different families of proteins that unfold G4s. Pif1 is a DNA helicase from superfamily 1 (SF1) conserved from bacteria to humans with high G4-unwinding activity. Here, we present the first X-ray crystal structure of the Thermus oshimai Pif1 (ToPif1) complexed with a G4. Our structure reveals that ToPif1 recognizes the entire native G4 via a cluster of amino acids at domains 1B/2B which constitute a G4-Recognizing Surface (GRS). The overall structure of the G4 maintains its three-layered propeller-type G4 topology, without significant reorganization of G-tetrads upon protein binding. The three G-tetrads in G4 are recognized by GRS residues mainly through electrostatic, ionic interactions, and hydrogen bonds formed between the GRS residues and the ribose-phosphate backbone. Compared with previously solved structures of SF2 helicases in complex with G4, our structure reveals how helicases from distinct superfamilies adopt different strategies for recognizing and unfolding G4s.

Serum levels of lipoprotein-associated phospholipase A2 are associated with coronary atherosclerotic plaque progression in diabetic and non-diabetic patients.

BACKGROUND: Lp-PLA2 is linked to cardiovascular diseases and poor outcomes, especially in diabetes, as it functions as a pro-inflammatory and oxidative mediator. OBJECTIVES: This research aimed to explore if there is a connection between the serum levels of Lp-PLA2 and the progression of coronary plaques (PP) in individuals with type 2 diabetes mellitus (T2DM) and those without the condition. MATERIALS AND METHODS: Serum Lp-PLA2 levels were measured in 137 T2DM patients with PP and 137 T2DM patients with no PP, and in 205 non-diabetic patients with PP and 205 non-diabetic patients with no PP. These individuals met the criteria for eligibility and underwent quantitative coronary angiography at the outset and again after about one year of follow-up. The attributes and parameters of the participants at the outset were recorded. RESULTS: Increased serum levels of Lp-PLA2 were closely associated with coronary artery PP, and also significantly correlated with change of MLD, change of diameter stenosis and change of cumulative coronary obstruction in both diabetic and non-diabetic groups, with higher correlation coefficients in diabetic patients as compared with non-diabetic patients. Moreover, multivariate logistic regression analysis showed that serum Lp-PLA2 level was an independent determinant of PP in both groups, with OR values more significant in diabetic patients than in non-diabetic patients. CONCLUSIONS: Levels of serum Lp-PLA2 show a significant association with the progression of coronary atherosclerotic plaque in patients with T2DM and those without, especially among individuals with diabetes.

Circulating secretoneurin level reflects angiographic coronary collateralization in stable angina patients with chronic total occlusion.

OBJECTIVE: To investigate the association between circulating secretoneurin (SN) and angiographic coronary collateralization in stable angina patients with chronic coronary total occlusion (CTO). METHODS: SN concentrations in serum were measured in 641 stable angina patients with CTO by radioimmunoassay. The status of coronary collaterals from the contra-lateral vessel was visually estimated using the Rentrop grading system, and was categorized into poor (grade 0 or 1) or good (grade 2 or 3) collateralization. RESULTS: Serum SN levels were significantly higher in patients with good coronary collaterals compared to those with poor collaterals (175.23 ± 52.09 pmol/L vs. 143.29 ± 42.01 pmol/L, P < 0.001). Serum SN increased stepwise across Rentrop score 0 to 3 (P < 0.001), and increasing SN tertiles were associated with higher proportion of good coronary collateralization (OR, 1.907; 95% CI, 1.558 ~ 2.335, P < 0.001). After adjustment for confounding variables, serum SN (per tertile) remained an independent factor for predicting good coronary collaterals (OR, 1.870; 95% CI, 1.515 ~ 2.309; P < 0.001). Moreover, the diagnostic value of serum SN (per tertile) was consistent after stratifying patients based on gender, age, body mass index, hypertension, diabetes, history of smoking, severity of coronary artery disease and kidney function (OR: 1.511 ~ 2.680, P interaction ≥ 0.327). CONCLUSION: Elevated circulating SN reflects good angiographic coronary collaterals in stable angina patients with CTO. The findings may provide insight into decision-making for these patients.

Promoting collateral formation in type 2 diabetes mellitus using ultra-small nanodots with autophagy activation and ROS scavenging.

BACKGROUND: Impaired collateral formation is a major factor contributing to poor prognosis in type 2 diabetes mellitus (T2DM) patients with atherosclerotic cardiovascular disease. However, the current pharmacological treatments for improving collateral formation remain unsatisfactory. The induction of endothelial autophagy and the elimination of reactive oxygen species (ROS) represent potential therapeutic targets for enhancing endothelial angiogenesis and facilitating collateral formation. This study investigates the potential of molybdenum disulfide nanodots (MoS2 NDs) for enhancing collateral formation and improving prognosis. RESULTS: Our study shows that MoS2 NDs significantly enhance collateral formation in ischemic tissues of diabetic mice, improving effective blood resupply. Additionally, MoS2 NDs boost the proliferation, migration, and tube formation of endothelial cells under high glucose/hypoxia conditions in vitro. Mechanistically, the beneficial effects of MoS2 NDs on collateral formation not only depend on their known scavenging properties of ROS (H2O2, •O2-, and •OH) but also primarily involve a molecular pathway, cAMP/PKA-NR4A2, which promotes autophagy and contributes to mitigating damage in diabetic endothelial cells. CONCLUSIONS: Overall, this study investigated the specific mechanism by which MoS2 NDs mediated autophagy activation and highlighted the synergy between autophagy activation and antioxidation, thus suggesting that an economic and biocompatible nano-agent with dual therapeutic functions is highly preferable for promoting collateral formation in a diabetic context, thus, highlighting their therapeutic potential.

Gene variants and clinical characteristics of children with sitosterolemia.

OBJECTIVE: To enhance the detection, management and monitoring of Chinese children afflicted with sitosterolemia by examining the physical characteristics and genetic makeup of pediatric patients. METHODS: In this group, 26 children were diagnosed with sitosterolemia, 24 of whom underwent genetic analysis. Patient family medical history, physical symptoms, tests for liver function, lipid levels, standard blood tests, phytosterol levels, cardiac/carotid artery ultrasounds, fundus examinations, and treatment were collected. RESULTS: The majority (19, 73.1%) of the 26 patients exhibited xanthomas as the most prevalent manifestation. The second most common symptoms were joint pain (7, 26.9%) and stunted growth (4, 15.4%). Among the 24 (92.3%) patients whose genetics were analyzed, 16 (66.7%) harbored ABCG5 variants (type 2 sitosterolemia), and nearly one-third (8, 33.3%) harbored ABCG8 variants (type 1 sitosterolemia). Additionally, the most common pathogenic ABCG5 variant was c.1166G > A (p.Arg389His), which was found in 10 patients (66.7%). Further analysis did not indicate any significant differences in pathological traits among those carrying ABCG5 and ABCG8 variations (P > 0.05). Interestingly, there was a greater abundance of nonsense variations in ABCG5 than in ABCG8 (P = 0.09), and a greater frequency of splicing variations in ABCG8 than ABCG5 (P = 0.01). Following a change in diet or a combination of ezetimibe, the levels of cholesterol and low-density lipoprotein were markedly decreased compared to the levels reported before treatment. CONCLUSION: Sitosterolemia should be considered for individuals presenting with xanthomas and increased cholesterol levels. Phytosterol testing and genetic analysis are important for early detection. Managing one's diet and taking ezetimibe can well control blood lipids.

The influence of genotype makeup on the effectiveness of growth hormone therapy in children with Prader-Willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare multisystemic hereditary illness. Recombinant human growth hormone (rhGH) therapy is widely recognized as the primary treatment for PWS. This study aimed to examine how different PWS genotypes influence the outcome of rhGH treatment in children with PWS. METHODS: A review was conducted on 146 Chinese children with PWS, genetically classified and monitored from 2017 to 2022. Unaltered and modified generalized estimating equations (GEE) were employed to examine the long-term patterns in primary outcomes (growth metrics) and secondary outcomes (glucose metabolism metrics and insulin-like growth factor-1 (IGF-1)) during rhGH therapy. The study also evaluated the prevalence of hypothyroidism, hip dysplasia, and scoliosis before and after rhGH treatment. RESULTS: Children with PWS experienced an increase in height/length standard deviation scores (SDS) following rhGH administration. The impact of rhGH therapy on growth measurements was similar in both the deletion and maternal uniparental diploidy (mUPD) cohorts. Nevertheless, the deletion group was more prone to insulin resistance (IR) compared to the mUPD group. No significant variations in growth metrics were noted between the two groups (P > 0.05). At year 2.25, the mUPD group showed a reduction in fasting insulin (FINS) levels of 2.14 uIU/ml (95% CI, -4.26, -0.02; P = 0.048) and a decrease in homeostasis model assessment of insulin resistance (HOMA-IR) of 0.85 (95% CI, -1.52, -0.17; P = 0.014) compared to the deletion group. Furthermore, there was a decrease in the IGF standard deviation scores (SDS) by 2.84 (95% CI, -4.84, -0.84; P = 0.005) in the mUPD group during the second year. The frequency of hip dysplasia was higher in the mUPD group compared to the deletion group (P < 0.05). CONCLUSIONS: rhGH treatment effectively increased height/length SDS in children with PWS, with similar effects observed in both deletion and mUPD genotypes. Children with mUPD genetype receiving rhGH treatment may experience enhanced therapeutic effects in managing PWS.

Vasostatin-2 associates with coronary collateral vessel formation in diabetic patients and promotes angiogenesis via angiotensin-converting enzyme 2.

AIMS: Members of the chromogranin family play a role in angiogenesis. One such biologically active peptide, generated through the processing of chromogranin A, is vasostatin-2. This study aimed at assessing the association of serum vasostatin-2 levels with coronary collateral vessels (CCV) in diabetic patients with chronic total occlusions (CTO) and the effects of vasostatin-2 on angiogenesis in diabetic mice with hindlimb or myocardial ischemia. METHODS AND RESULTS: Serum levels of vasostatin-2 in 452 diabetic CTO patients were evaluated. The status of CCV was categorized according to the Rentrop score. Vasostatin-2 recombinant protein or phosphate-buffered saline were then injected intraperitoneally in diabetic mouse models of hindlimb or myocardial ischemia, followed by laser Doppler imaging and molecular biology examinations. The effects of vasostatin-2 were also ascertained in endothelial cells and macrophages, with mechanisms clarified using ribonucleic acid (RNA) sequencing. Serum levels of vasostatin-2 were significantly different and progressively higher across Rentrop score 0, 1, 2, and 3 groups (P < .001), with significantly lower levels in patients with poor CCV (Rentrop score 0 and 1) than in those with good CCV (Rentrop score 2 and 3) (P < .05). Vasostatin-2 significantly promoted angiogenesis in diabetic mice with hindlimb or myocardial ischemia. RNA-seq analyzes verified an angiotensin-converting enzyme 2 (ACE2)-mediated vasostatin-2-induction of angiogenesis in ischemic tissues. CONCLUSION: Lower serum levels of vasostatin-2 are associated with poor CCV in diabetic CTO patients compared with patients with good CCV. Vasostatin-2 significantly promotes angiogenesis in diabetic mice with hindlimb or myocardial ischemia. Such effects are mediated by ACE2.

Gestational Insulin Resistance Is Mediated by the Gut Microbiome-Indoleamine 2,3-Dioxygenase Axis.

BACKGROUND & AIMS: Normal gestation involves a reprogramming of the maternal gut microbiome (GM) that contributes to maternal metabolic changes by unclear mechanisms. This study aimed to understand the mechanistic underpinnings of the GM-maternal metabolism interaction. METHODS: The GM and plasma metabolome of CD1, NIH-Swiss, and C57 mice were analyzed with the use of 16S rRNA sequencing and untargeted liquid chromatography-mass spectrometry throughout gestation. Pharmacologic and genetic knockout mouse models were used to identify the role of indoleamine 2,3-dioxygenase (IDO1) in pregnancy-associated insulin resistance (IR). Involvement of gestational GM was studied with the use of fecal microbial transplants (FMTs). RESULTS: Significant variation in GM alpha diversity occurred throughout pregnancy. Enrichment in gut bacterial taxa was mouse strain and pregnancy time point specific, with the species enriched at gestation day 15/19 (G15/19), a point of heightened IR, being distinct from those enriched before or after pregnancy. Metabolomics revealed elevated plasma kynurenine at G15/19 in all 3 mouse strains. IDO1, the rate-limiting enzyme for kynurenine production, had increased intestinal expression at G15, which was associated with mild systemic and gut inflammation. Pharmacologic and genetic inhibition of IDO1 inhibited kynurenine levels and reversed pregnancy-associated IR. FMT revealed that IDO1 induction and local kynurenine level effects on IR derive from the GM in both mouse and human pregnancy. CONCLUSIONS: GM changes accompanying pregnancy shift IDO1-dependent tryptophan metabolism toward kynurenine production, intestinal inflammation, and gestational IR, a phenotype reversed by genetic deletion or inhibition of IDO1. (Gestational Gut Microbiome-IDO1 Axis Mediates Pregnancy Insulin Resistance; EMBL-ENA ID: PRJEB45047. MetaboLights ID: MTBLS3598).