Mitochondrial 8-hydroxy-2'-deoxyguanosine and coronary artery disease in patients with type 2 diabetes mellitus

Platelet bioenergetic profiling uncovers a metabolic pattern of high dependency on mitochondrial fatty acid oxidation in type 2 diabetic patients who developed in-stent restenosis

Although platelet bioenergetic dysfunction is evident early in the pathogenesis of diabetic macrovascular complications, the bioenergetic characteristics in type 2 diabetic patients who developed coronary in-stent restenosis (ISR) and their effects on platelet function remain unclear. Here, we performed platelet bioenergetic profiling to characterize the bioenergetic alterations in 28 type 2 diabetic patients with ISR compared with 28 type 2 diabetic patients without ISR (non-ISR) and 28 healthy individuals. Generally, platelets from type 2 diabetic patients with ISR exhibited a specific bioenergetic alteration characterized by high dependency on fatty acid (FA) oxidation, which subsequently induced complex III deficiency, causing decreased mitochondrial respiration, increased mitochondrial oxidant production, and low efficiency of mitochondrial ATP generation. This pattern of bioenergetic dysfunction showed close relationships with both α-granule and dense granule secretion as measured by surface P-selectin expression, ATP release, and profiles of granule cargo proteins in platelet releasates. Importantly, ex vivo reproduction of high dependency on FA oxidation by exposing non-ISR platelets to its agonist mimicked the bioenergetic dysfunction observed in ISR platelets and enhanced platelet secretion, whereas pharmaceutical inhibition of FA oxidation normalized the respiratory and redox states of ISR platelets and diminished platelet secretion. Further, causal mediation analyses identified a strong association between high dependency on FA oxidation and increased angiographical severity of ISR, which was significantly mediated by the status of platelet secretion. Our findings, for the first time, uncover a pattern of bioenergetic dysfunction in ISR and enhance current understanding of the mechanistic link of high dependency on FA oxidation to platelet abnormalities in the context of diabetes.

Association Between Triglyceride-Glucose Index and Hearing Threshold Shifts of Adults in the United States: National Health and Nutrition Examination Survey, 2015-2016

Objective

Sensorineural Hearing Loss (SNHL) is a representative human sensory impairment, few studies have paid attention to the correlation between the Triglyceride-Glucose (TyG) index and SNHL to date. We conducted this analysis to elucidate the correlation between the TyG index and pure tone hearing thresholds among US adults.

Methods

Our analysis included 1226 adults (age range: 20 to 69 years old) from the 2015-2016 National Health and Nutrition Examination Survey (NHANES) data. TyG index was scored into three quartiles. Weighted univariate analysis, weighted multivariate linear regression analyses as well as smooth curve fittings evaluated the associations between TyG index and pure tone hearing thresholds.

Results

In the multiple regression analysis, the second tertile of TyG index was negatively associated with high-frequency hearing thresholds shifts. Furthermore, the non-linear relationships between TyG index and speech-frequency and high-frequency hearing thresholds were identified by smooth curve fittings. After adjusting for potential confounders, the fitted smooth curves were approximately U-shaped, and the two-segment linear regression models were constructed to calculate their inflection points.

Conclusion

Our findings suggested that the TyG index was nearly U-shaped association with speech-frequency and high-frequency hearing thresholds. These results may imply the importance of maintaining a balanced TyG index in health management.

Albumin Redox Modifications Promote Cell Calcification Reflecting the Impact of Oxidative Status on Aortic Valve Disease and Atherosclerosis

Calcific aortic valve disease (CAVD) and coronary artery disease (CAD) are related cardiovascular diseases in which common mechanisms lead to tissue calcification. Oxidative stress plays a key role in these diseases and there is also evidence that the redox state of serum albumin exerts a significant influence on these conditions. To further explore this issue, we used multimarker scores (OxyScore and AntioxyScore) to assess the global oxidative status in patients with CAVD, with and without CAD, also evaluating their plasma thiol levels. In addition, valvular interstitial cells were treated with reduced, oxidized, and native albumin to study how this protein and its modifications affect cell calcification. The differences we found suggest that oxidative status is distinct in CAVD and CAD, with differences in redox markers and thiol levels. Importantly, the in vitro interstitial cell model revealed that modified albumin affects cell calcification, accelerating this process. Hence, we show here the importance of the redox system in the development of CAVD, emphasizing the relevance of multimarker scores, while also offering evidence of how the redox state of albumin influences vascular calcification. These data highlight the relevance of understanding the overall redox processes involved in these diseases, opening the door to new studies on antioxidants as potential therapies for these patients.

Exogenous Melatonin Alleviates Atrazine-Induced Glucose Metabolism Disorders in Mice Liver via Suppressing Endoplasmic Reticulum Stress

Atrazine (ATZ) is a widely used herbicide that has toxic effects on animals. Melatonin (MLT) is a natural hormone with strong antioxidant properties. However, the effect of MLT on the glucose metabolism disorder caused by ATZ is still unclear. Mice were divided into four groups randomly and given 21 days of gavage: blank control group (Con), 5 mg/kg MLT group (MLT), 170 mg/kg ATZ group (ATZ), and 170 mg/kg ATZ and 5 mg/kg MLT group (ATZ + MLT). The results show that ATZ alters mRNA levels of metabolic enzymes related to glycogen synthesis and glycolysis and increased metabolites (glycogen, lactate, and pyruvate). ATZ causes abnormalities in glucose metabolism in mouse liver, interfering with glycemia regulation ability. MLT can regulate the endoplasmic reticulum to respond to disordered glucose metabolism in mice liver. This study suggested that MLT has the power to alleviate the ATZ-induced glycogen overdeposition and glycolytic deficit.

Ubiquinol attenuates γ-radiation induced coronary and aortic changes via PDGF/p38 MAPK/ICAM-1 related pathway

Endothelial vascular injury is one of the most pivotal disorders emerging during radiotherapy. It is crucial to rely on strong antioxidants to defend against vascular damage. The current study was carried out to investigate the ameliorative effect of ubiquinol (Ubq) against gamma (γ)-radiation induced aortic and coronary changes, with highlighting its role in suppression of p38 mitogen activated protein kinase (MAPK). Exposure to γ-radiation was adopted as a potent detrimental model that induces vascular tissue damage. Concisely, male albino rats were irradiated at a dose level of 7 Gy and treated daily with Ubq (10 mg/kg/day, p.o.) for 7 days pre-and post-irradiation. At the end of the experiment, lipid profile, 8-hydroxydeoxyguanosine (8-OHdG), gene expression of intercellular adhesion molecule (ICAM-1), platelet derived growth factor (PDGF), p38 MAPK and matrix metalloproteinase-9 (MMP-9) were estimated. Exposure to radiation significantly deteriorates aortic and coronary tissues. Conversely, administration of Ubq significantly reduced serum t-cholesterol, LDL and triglycerides (p = 0.001). In addition, Ubq prevented oxidative DNA damage (8-OHdG) (p = 0.1) and reduced serum MMP-9 (p = 0.001) which contributed to the endothelial cells damage. The positive impact of Ubq was more apparent in suppression of both PDGF (p = 0.001) and p38 MAPK (p = 0.1) protein concentrations, leading subsequently in reduction of ICAM-1 (p = 0.001) gene expression. As a conclusion, vascular endothelial damage brought on by γ-radiation is one of the leading causes of coronary and aortic deteriorations which could be successfully mitigated by Ubq.

Holistic Assessment Based On Hepatocyte Mitochondria: Lycopene Repairs Oxidized mtDNA to Alleviate Mitochondrial Stress Induced by Atrazine

Atrazine (ATZ) is a highly persistent herbicide that harms organism health. Lycopene (LYC) is an antioxidant found in plants and fruits. The aim of this study is to investigate the mechanisms of atrazine-induced mitochondrial damage and lycopene antagonism in the liver. The mice were divided into seven groups by randomization: blank control (Con group), vehicle control (Vcon group), 5 mg/kg lycopene (LYC group), 50 mg/kg atrazine (ATZ1 group), ATZ1+LYC group, 200 mg/kg atrazine (ATZ2 group), and ATZ2+LYC group. The present study performed a holistic assessment based on mitochondria to show that ATZ causes the excessive fission of mitochondria and disrupts mitochondrial biogenesis. However, the LYC supplementation reverses these changes. ATZ causes increased mitophagy and exacerbates the production of oxidized mitochondrial DNA (Ox-mtDNA) and mitochondrial stress. This study reveals that LYC could act as an antioxidant to repair Ox-mtDNA and restore the disordered mitochondrial function caused by ATZ.

CypD induced ROS output promotes intracranial aneurysm formation and rupture by 8-OHdG/NLRP3/MMP9 pathway

Reactive Oxygen Species (ROS) are widely accepted as a pernicious factor in the progression of intracranial aneurysm (IA), which is eminently related to cell apoptosis and extracellular matrix degradation, but the mechanism remains to be elucidated. Recent evidence has identified that enhancement of Cyclophilin D (CypD) under stress conditions plays a critical role in ROS output, thus accelerating vascular destruction. However, no study has confirmed whether cypD is a detrimental mediator of cell apoptosis and extracellular matrix degradation in the setting of IA development. Our data indicated that endogenous cypD mRNA was significantly upregulated in human IA lesions and mouse IA wall, accompanied by higher level of ROS, MMPs and cell apoptosis. CypD-/- remarkably reversed vascular smooth muscle cells (VSMCs) apoptosis and elastic fiber degradation, and significantly decreased the incidence of aneurysm and ruptured aneurysm, together with the downregulation of ROS, 8-OHdG, NLRP3 and MMP9 in vivo and vitro. Furthermore, we demonstrated that blockade of cypD with CsA inhibited the above processes, thus preventing IA formation and rupture, these effects were highly dependent on ROS output. Mechanistically, we found that cypD directly interacts with ATP5B to promote ROS release in VSMCs, and 8-OHdG directly bind to NLRP3, which interacted with MMP9 to increased MMP9 level and activity in vivo and vitro. Our data expound an unexpected role of cypD in IA pathogenesis and an undescribed 8-OHdG/NLRP3/MMP9 pathway involved in accelerating VSMCs apoptosis and elastic fiber degradation. Repressing ROS output by CypD inhibition may be a promising therapeutic strategy for prevention IA development.

Radiopaque and X-ray-Responsive Nanomedicine for Preventive Therapy of Radiation-Induced Heart Disease

Radiation-induced heart disease (RIHD) is a common radiotherapy complication. Reducing radiation exposure and post-irradiation antioxidant therapy are promising approaches. Here, a liquid metal-based core-shell nanomedicine (LMN) composed of a gallium core and a multifunctional polymeric shell with radiopaque, X-ray shielding, and X-ray-responsive antioxidation properties for preventive therapy of RIHD is developed. The liquid metal provides radiopaque properties to enhance X-ray and computed tomography imaging and attenuate radiation to prevent primary myocardial damage. Under X-ray radiation, cleavage of the diselenide bond on the polymeric shell results in the release of LMN and controlled antioxidation. In vitro and in vivo experiments have demonstrated that LMN significantly reduces myocardial injury and impaired cardiac function, stabilizes mitochondrial function, and inhibits myocardial fibrosis. This nanomedicine with radiographic contrast, radiation shielding, and responsive features provides a new strategy for the prevention of radiation-related diseases.

Association between HbA1c and hearing loss: a tertiary care center-based study

The purpose of this study was to investigate the correlation between glycated hemoglobin (HbA1c) levels and hearing loss (HL) using data from a tertiary hospital. Our hypothesis regarding the relationship between HL and HbA1c levels was that elevated HbA1c levels are associated with an increased risk of HL. We retrospectively reviewed the medical charts of patients diagnosed with sensorineural HL or diabetes between 2006 and 2021 at the Catholic Medical Center (CMC). Data were collected from the CMC's Clinical Data Warehouse. Participants were selected from patients who were prescribed pure-tone audiometry and an HbA1c blood test. The survey was completed for 5287 participants. The better ear pure-tone audiometry (PTA) for air conduction thresholds at 500, 1000, 2000, and 4000 Hz was calculated. Sensorineural HL was defined as a better ear PTA of 25 dB or higher. We used the HbA1c level as a diagnostic criterion for diabetes. The following criteria were used to define the HbA1c level: normal, HbA1c level below 5.6%; prediabetes, level between 5.6 and 6.4%; and diabetes, level of 6.5% or more. Among 5287 participants, 1129 were categorized as normal, 2119 as prediabetic, and 2039 as diabetic. The diabetic group was significantly older (p < 0.05). The PTA also significantly deteriorated in the diabetes group (p < 0.05). We analyzed the effects of age, sex, and HbA1c level on frequency-specific hearing using multiple regression. The hearing thresholds at all frequencies deteriorated significantly with increasing age and HbA1c level (p < 0.05). A case-control study was also performed to facilitate a comprehensive comparison between distinct groups. The participants were categorized into two groups: a case (PTA > 25 dB) and control group (PTA ≤ 25 dB), based on their PTA threshold of four frequencies. After adjusting for age and sex, we found no significant odds ratio (OR) of HL between the prediabetes group and the normal group. Notably, the OR of HL was significantly higher in the diabetes group with each PTA threshold and frequency. The 6.3% HbA1c level cutoff value was determined by analyzing the receiver operating characteristic curve for predicting hearing impairment > 25 dB. Diabetes was associated with hearing loss in all frequency ranges, particularly at high frequencies. Screening for HL is strongly recommended for patients with elevated HbA1c levels.

Quantitation of oxidized nuclear and mitochondrial DNA in plasma samples of patients with abdominal aortic aneurysm

There is accumulating evidence that pro-inflammatory features are inherent to mitochondrial DNA and oxidized DNA species. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is the most frequently studied oxidatively generated lesion. Modified DNA reaches the circulation upon cell apoptosis, necrosis or neutrophil extracellular trap (NET) formation. Standard chromatography-based techniques for the assessment of 8-oxodGuo imply degradation of DNA to a single base level, thus precluding the attribution to a nuclear or mitochondrial origin. We therefore aimed to establish a protocol for the concomitant assessment of oxidized mitochondrial and nuclear DNA from human plasma samples. We applied immunoprecipitation (IP) for 8-oxodGuo to separate oxidized from non-oxidized DNA species and subsequent quantitative polymerase chain reaction (qPCR) to assign them to their subcellular source. The IP procedure failed when applied directly to plasma samples, i.e. isotype control precipitated similar amounts of DNA as the specific 8-oxodGuo antibody. In contrast, DNA isolation from plasma prior to the IP process provided assay specificity with little impact on DNA oxidation status. We further optimized sensitivity and efficiency of qPCR analysis by reducing amplicon length and targeting repetitive nuclear DNA elements. When the established protocol was applied to plasma samples of abdominal aortic aneurysm (AAA) patients and control subjects, the AAA cohort displayed significantly elevated circulating non-oxidized and total nuclear DNA and a trend for increased levels of oxidized mitochondrial DNA. An enrichment of mitochondrial versus nuclear DNA within the oxidized DNA fraction was seen for AAA patients. Regarding the potential source of circulating DNA, we observed a significant correlation of markers of neutrophil activation and NET formation with nuclear DNA, independent of oxidation status. Thus, the established method provides a tool to detect and distinguish the release of oxidized nuclear and mitochondrial DNA in human plasma and offers a refined biomarker to monitor disease conditions of pro-inflammatory cell and tissue destruction.

Incremental effect of coronary obstruction on myocardial microvascular dysfunction in type 2 diabetes mellitus patients evaluated by first-pass perfusion CMR study

BACKGROUND

Type 2 diabetes mellitus (T2DM) frequently coexists with obstructive coronary artery disease (OCAD), which are at increased risk for cardiovascular morbidity and mortality. This study aimed to investigate the impact of coronary obstruction on myocardial microcirculation function in T2DM patients, and explore independent predictors of reduced coronary microvascular perfusion.

METHODS

Cardiac magnetic resonance (CMR) scanning was performed on 297 T2DM patients {188 patients without OCAD [T2DM(OCAD -)] and 109 with [T2DM(OCAD +)]} and 89 control subjects. CMR-derived perfusion parameters, including upslope, max signal intensity (MaxSI), and time to maximum signal intensity (TTM) in global and segmental (basal, mid-ventricular, and apical slices) were measured and compared among observed groups. According to the median of Gensini score (64), T2DM(OCAD +) patients were subdivided into two groups. Univariable and multivariable linear regression analyses were performed to identify independent predictors of microcirculation dysfunction.

RESULTS

T2DM(OCAD -) patients, when compared to control subjects, had reduced upslope and prolonged TTM in global and all of three slices (all P < 0.05). T2DM(OCAD +) patients showed a significantly more severe impairment of microvascular perfusion than T2DM(OCAD -) patients and control subjects with a more marked decline upslope and prolongation TTM in global and three slices (all P < 0.05). From control subjects, through T2DM(OCAD +) patients with Gensini score ≤ 64, to those patients with Gensini score > 64 group, the upslope declined and TTM prolonged progressively in global and mid-ventricular slice (all P < 0.05). The presence of OCAD was independently correlated with reduced global upslope (β =  - 0.104, P < 0.05) and global TTM (β = 0.105, P < 0.05) in patients with T2DM. Among T2DM(OCAD +) patients, Gensini score was associated with prolonged global TTM (r = 0.34, P < 0.001).

CONCLUSIONS

Coronary artery obstruction in the context of T2DM exacerbated myocardial microcirculation damage. The presence of OCAD and Gensini score were independent predictors of decreased microvascular function.

TRIAL REGISTRATION

Retrospectively registered.

Clinical Relevance of lncRNA and Mitochondrial Targeted Antioxidants as Therapeutic Options in Regulating Oxidative Stress and Mitochondrial Function in Vascular Complications of Diabetes

Metabolic imbalances and persistent hyperglycemia are widely recognized as driving forces for augmented cytosolic and mitochondrial reactive oxygen species (ROS) in diabetes mellitus (DM), fostering the development of vascular complications such as diabetic nephropathy, diabetic cardiomyopathy, diabetic neuropathy, and diabetic retinopathy. Therefore, specific therapeutic approaches capable of modulating oxidative milieu may provide a preventative and/or therapeutic benefit against the development of cardiovascular complications in diabetes patients. Recent studies have demonstrated epigenetic alterations in circulating and tissue-specific long non-coding RNA (lncRNA) signatures in vascular complications of DM regulating mitochondrial function under oxidative stress. Intriguingly, over the past decade mitochondria-targeted antioxidants (MTAs) have emerged as a promising therapeutic option for managing oxidative stress-induced diseases. Here, we review the present status of lncRNA as a diagnostic biomarker and potential regulator of oxidative stress in vascular complications of DM. We also discuss the recent advances in using MTAs in different animal models and clinical trials. We summarize the prospects and challenges for the use of MTAs in treating vascular diseases and their application in translation medicine, which may be beneficial in MTA drug design development, and their application in translational medicine.

Inhibition of mitochondrial complex I leading to NAD+/NADH imbalance in type 2 diabetic patients who developed late stent thrombosis: Evidence from an integrative analysis of platelet bioenergetics and metabolomics

Type 2 diabetes mellitus (T2DM) is a strong indicator of late stent thrombosis (LST). Platelet bioenergetic dysfunction, although critical to the pathogenesis of diabetic macrovascular complications, remains uncharacterized in T2DM patients who developed LST. Here, we explored the mechanistic link between the alterations in platelet bioenergetics and LST in the setting of T2DM. Platelet bioenergetics, metabolomics, and their interactomes were analyzed in a nested case-control study including 15 T2DM patients who developed LST and 15 matched T2DM patients who did not develop LST (non-LST). Overall, we identified a bioenergetic alteration in T2DM patients with LST characterized by an imbalanced NAD+/NADH redox state resulting from deficient mitochondrial complex I (NADH: ubiquinone oxidoreductase) activity, which led to reduced ATP-linked and maximal mitochondrial respiration, increased glycolytic flux, and platelet hyperactivation compared with non-LST patients. Congruently, platelets from LST patients exhibited downregulation of tricarboxylic acid cycle and NAD+ biosynthetic pathways as well as upregulation of the proximal glycolytic pathway, a metabolomic change that was primarily attributed to compromised mitochondrial respiration rather than increased glycolytic flux as evidenced by the integrative analysis of bioenergetics and metabolomics. Importantly, both bioenergetic and metabolomic aberrancies in LST platelets could be recapitulated ex vivo by exposing the non-LST platelets to a low dose of rotenone, a complex I inhibitor. In contrast, normalization of the NAD+/NADH redox state, either by increasing NAD+ biosynthesis or by inhibiting NAD+ consumption, was able to improve mitochondrial respiration, inhibit mitochondrial oxidant generation, and consequently attenuate platelet aggregation in both LST platelets and non-LST platelets pretreated with low-dose rotenone. These data, for the first time, delineate the specific patterns of bioenergetic and metabolomic alterations for T2DM patients who suffer from LST, and establish the deficiency of complex I-derived NAD+ as a potential pathogenic mechanism in platelet abnormalities.

Mitochondrial dysfunctions elicited by solid waste leachates provide insights into mechanisms of leachates induced cell death and pathophysiological disorders

Emissions (mainly leachates and landfill gases) from solid waste facilities are laden with mixtures of dangerous xenobiotics implicated with significant increase in various pathophysiological disorders including cancer, and eventual mortality of exposed wildlife and humans. However, the molecular mechanisms of solid waste leachates induce pathophysiological disorders and cell death are still largely unknown. Although, evolving evidence implicated generation of reactive oxygen species and oxidative stress as the possible mechanism. Recent scientific reports are linking reactive oxygen species and mitochondrial dysfunctions as the player mechanism in pathophysiological disorder and apoptosis induced by xenobiotics in solid waste leachates. This systematic review presents an explicit discussion of recent scientific findings on the structural and functional alterations in mitochondria induced by solid waste leachates as the molecular mechanisms plausibly responsible for the pathophysiological disorders, cancer and cell death reported in landfill toxicology and epidemiological studies. This review aims to increase scientific understanding on solid waste leachate induced mitochondria dysfunctions as the key player in molecular mechanisms of solid waste induced toxicity. The findings in this review were mainly from using primary cells, cell lines, Drosophila and fish. Whether the findings will similarly be observed in mammalian test systems in vivo and particularly in exposed humans, remained to be investigated. Improvement in technological advancements, enforcement of legislation and regulations, and creation of sophisticated health surveillance against exposure to solid waste leachates, will expectedly mitigate human exposure to solid waste emissions and contamination of the environment.

Recurrent Hypoglycemia Impaired Vascular Function in Advanced T2DM Rats by Inducing Pyroptosis

Background

Hypoglycemia is a dangerous side effect of intensive glucose control in diabetes. Even though it leads to adverse cardiovascular events, the effects of hypoglycemia on vascular biology in diabetes have not been adequately studied.

Methods

Aged Sprague-Dawley rats were fed a high-fat diet and given streptozotocin to induce type 2 diabetes mellitus (T2DM). Acute and recurrent hypoglycemia were then induced by glucose via insulin administration. Vascular function, oxidative stress, and pyroptosis levels in aortic tissue were assessed by physiological and biochemical methods.

Results

Hypoglycemia was associated with a marked decrease in vascular function, elevated oxidative stress, and elevated pyroptosis levels in the thoracic aorta. The changes in oxidative stress and pyroptosis were greater in rats with recurrent hypoglycemia than in those with acute hypoglycemia.

Conclusions

Hypoglycemia impaired vascular function in aged rats with T2DM by inducing pyroptosis. The extent of injury increased with the duration of blood glucose fluctuation.

A novel 6-metabolite signature for prediction of clinical outcomes in type 2 diabetic patients undergoing percutaneous coronary intervention

Background

Outcome prediction tools for patients with type 2 diabetes mellitus (T2DM) undergoing percutaneous coronary intervention (PCI) are lacking. Here, we developed a machine learning-based metabolite classifier for predicting 1-year major adverse cardiovascular events (MACEs) after PCI among patients with T2DM.

Methods

Serum metabolomic profiling was performed in a nested case–control study of 108 matched pairs of patients with T2DM occurring and not occurring MACEs at 1 year after PCI, then the matched pairs were 1:1 assigned into the discovery and internal validation sets. External validation was conducted using targeted metabolite analyses in an independent prospective cohort of 301 patients with T2DM receiving PCI. The function of candidate metabolites was explored in high glucose-cultured human aortic smooth muscle cells (HASMCs).

Results

Overall, serum metabolome profiles differed between diabetic patients with and without 1-year MACEs after PCI. Through VSURF, a machine learning approach for feature selection, we identified the 6 most important metabolic predictors, which mainly targeted the nicotinamide adenine dinucleotide (NAD⁺) metabolism. The 6-metabolite model based on random forest and XGBoost algorithms yielded an area under the curve (AUC) of ≥ 0.90 for predicting MACEs in both discovery and internal validation sets. External validation of the 6-metabolite classifier also showed good accuracy in predicting MACEs (AUC 0.94, 95% CI 0.91–0.97) and target lesion failure (AUC 0.89, 95% CI 0.83–0.95). In vitro, there were significant impacts of altering NAD⁺ biosynthesis on bioenergetic profiles, inflammation and proliferation of HASMCs.

Conclusion

The 6-metabolite model may help for noninvasive prediction of 1-year MACEs following PCI among patients with T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01561-1.

The adverse impact of coronary artery disease on left ventricle systolic and diastolic function in patients with type 2 diabetes mellitus: a 3.0T CMR study

Background

Coronary artery disease (CAD) confers considerable morbidity and mortality in diabetes. However, the role of CAD in additive effect of left ventricular (LV) function has rarely been explored in type 2 diabetes mellitus (T2DM) patients. This study aimed to investigate how CAD affect LV systolic and diastolic function in T2DM patients.

Materials and methods

A total of 282 T2DM patients {104 patients with CAD [T2DM (CAD +)] and 178 without [T2DM (CAD −)]} and 83 sex- and age- matched healthy controls underwent cardiac magnetic resonance scanning. LV structure, function, global strains [including systolic peak strain (PS), peak systolic (PSSR) and diastolic strain rate (PDSR) in radial, circumferential and longitudinal directions] and late gadolinium enhancement (LGE) parameters were measured. T2DM (CAD +) patients were divided into two subgroups based on the median of Gensini score (60) which was calculated to assess the severity of CAD. Multivariable linear regression analyses were constructed to investigate the determinants of reduced LV function.

Results

Compared with normal controls, T2DM (CAD −) patients exhibited increased LV end-diastolic and end-systolic volume index and decreased LV global strains, while T2DM(CAD +) patients showed more marked increase and decrease than T2DM(CAD-) and healthy controls, except for longitudinal PDSR (PDSR-L) (all P < 0.017). All of LV global strains demonstrated a progressive decrease from normal controls, through Gensini score ≤ 60, to Gensini score > 60 group, except for PDSR-L (all P < 0.017). CAD was an independent predictor of reduced LV global circumferential PS (GCPS, β = 0.22, p < 0.001), PSSR (PSSR-C, β = 0.17, p = 0.005), PDSR (PDSR-C, β = 0.22, p < 0.001), global radial PS (GRPS, β = 0.19, p = 0.001), and global longitudinal PS (GLPS, β = 0.18, p = 0.003) in T2DM. The Gensini score was associated with decreased GCPS, PSSR-C, PDSR-C, GRPS, and GLPS in T2DM (CAD +) (all p < 0.05).

Conclusion

CAD has an additive deleterious effect on LV systolic and diastolic function in T2DM patients. Among T2DM (CAD +) patients, the Gensini score is associated with reduced LV contractile and diastolic function.

Trial registration Retrospectively registered

IGF-1 as a Potential Therapy for Spinocerebellar Ataxia Type 3

Although the effects of growth hormone (GH) therapy on spinocerebellar ataxia type 3 (SCA3) have been examined in transgenic SCA3 mice, it still poses a nonnegligible risk of cancer when used for a long term. This study investigated the efficacy of IGF-1, a downstream mediator of GH, in vivo for SCA3 treatment. IGF-1 (50 mg/kg) or saline, once a week, was intraperitoneally injected to SCA3 84Q transgenic mice harboring a human ATXN3 gene with a pathogenic expanded 84 cytosine–adenine–guanine (CAG) repeat motif at 9 months of age. Compared with the control mice harboring a 15 CAG repeat motif, the SCA3 84Q mice treated with IGF-1 for 9 months exhibited the improvement only in locomotor function and minimized degeneration of the cerebellar cortex as indicated by the survival of more Purkinje cells with a more favorable mitochondrial function along with a decrease in oxidative stress caused by DNA damage. These findings could be attributable to the inhibition of mitochondrial fission, resulting in mitochondrial fusion, and decreased immunofluorescence staining in aggresome formation and ataxin-3 mutant protein levels, possibly through the enhancement of autophagy. The findings of this study show the therapeutic potential effect of IGF-1 injection for SCA3 to prevent the exacerbation of disease progress.

Diabetes mellitus and hearing loss: A review

Diabetes (type 2) and sensorineural hearing loss are common health problems manifested with ageing. While both type 1 and type 2 diabetes have been associated with hearing loss, a causal link has been difficult to establish. Individuals with diabetes have twice the incidence of hearing loss compared to those without diabetes and those with prediabetes have a 30% higher rate of hearing loss. Whether hearing loss is associated with diabetes independent of glycemic control remains to be determined. Hearing loss has its own set of risk factors and shares others with diabetes. This review will summarize the complex relationship between diabetes and sensorineural hearing loss.

Redox-related biomarkers in human cardiovascular disease - classical footprints and beyond

Global epidemiological studies show that chronic non-communicable diseases such as atherosclerosis and metabolic disorders represent the leading cause of premature mortality and morbidity. Cardiovascular disease such as ischemic heart disease is a major contributor to the global burden of disease and the socioeconomic health costs. Clinical and epidemiological data show an association of typical oxidative stress markers such as lipid peroxidation products, 3-nitrotyrosine or oxidized DNA/RNA bases with all major cardiovascular diseases. This supports the concept that the formation of reactive oxygen and nitrogen species by various sources (NADPH oxidases, xanthine oxidase and mitochondrial respiratory chain) represents a hallmark of the leading cardiovascular comorbidities such as hyperlipidemia, hypertension and diabetes. These reactive oxygen and nitrogen species can lead to oxidative damage but also adverse redox signaling at the level of kinases, calcium handling, inflammation, epigenetic control, circadian clock and proteasomal system. The in vivo footprints of these adverse processes (redox biomarkers) are discussed in the present review with focus on their clinical relevance, whereas the details of their mechanisms of formation and technical aspects of their detection are only briefly mentioned. The major categories of redox biomarkers are summarized and explained on the basis of suitable examples. Also the potential prognostic value of redox biomarkers is critically discussed to understand what kind of information they can provide but also what they cannot achieve.

Poly(ADP-Ribose) Polymerase Activity and Coronary Artery Disease in Type 2 Diabetes Mellitus: An Observational and Bidirectional Mendelian Randomization Study

OBJECTIVE

Experimental evidence suggests a close link between PARP (poly[ADP-ribose] polymerase) activation and diabetic endothelial dysfunction. Here, we tested whether PARP activity in circulating leukocytes was associated with coronary artery disease (CAD) among patients with type 2 diabetes mellitus (T2DM). Approach and Results: We performed observational and bidirectional Mendelian randomization studies of 3149 Chinese individuals with T2DM who underwent coronary angiography, with leukocyte PARP activity, 16 tag single-nucleotide polymorphisms in PARP1 and PARP2, and 17 CAD risk single-nucleotide polymorphisms analyzed. Of 3149 participants, 1180 who further received percutaneous coronary intervention were prospectively followed for 1 year to track major adverse cardiovascular and cerebrovascular events. Overall, greater PARP activity was cross-sectionally associated with an odds ratio of 1.23 for obstructive CAD, and prospectively with a hazard ratio of 1.34 for 1-year major adverse cardiovascular and cerebrovascular events after percutaneous coronary intervention (both P<0.001). Using a genetic score of 5 screened single-nucleotide polymorphisms in PARP1 and PARP2 as the instrumental variable, genetically predicted elevation in PARP activity showed a causal association with obstructive CAD (odds ratio=1.35, P<0.001). In contrast, the genetic risk of CAD had no significant effect on PARP activity. Ex vivo and in vitro cultures of human monocytes showed that rs747657, as the lead single-nucleotide polymorphism strongly associated with PARP activity, caused the differential binding of transcription factor GATA2 (GATA-binding protein 2) to an intronic regulatory region in PARP1, thus modulating PARP1 expression and PARP activity.

CONCLUSIONS

Greater PARP activity may have causal roles in the development of obstructive CAD among patients with diabetes mellitus.