Search

Additional file 1: Supplementary Figure 1. Risk of ISR-related MACE according to the use of different SGLT2i. Kaplan-Meier curves showing the risk of MACE in patients treated with either empagliflozin, canagliflozin, or dapagliflozin and compared with no-SGLT2i users, along with the relative values derived from Log Rank tests. No differences were observed between different drugs.

The role of sirtuin 6 (SIRT6) in adipose abdominal tissue of pre-diabetic (pre-DM) patients is poorly known. Here, we evaluated SIRT6 expression in visceral abdominal fat of obese pre-diabetic patients and the potential effects of metformin therapy. Results indicated that obese pre-DM subjects showed low SIRT6 protein expression and high expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding transcription factor 1 (SREBP-1). Obese pre-DM patients showed high values of glucose, insulin resistance (HOMA-IR), C reactive protein (CRP), nitrotyrosine, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), and low values of insulin (p < 0.05). Of note, abdominal fat tissue of obese pre-DM patients treated with metformin therapy presented higher SIRT6 expression and lower NF-κB, PPAR-γ, and SREBP-1 expression levels compared to pre-DM control group. Collectively, results show that SIRT6 is involved in the inflammatory pathway of subcutaneous abdominal fat of obese pre-DM patients and its expression responds to metformin therapy. The role of sirtuin 6 (SIRT6) in adipose abdominal tissue of pre-diabetic (pre-DM) patients is poorly known. Here, we evaluated SIRT6 expression in visceral abdominal fat of obese pre-diabetic patients and the potential effects of metformin therapy. Results indicated that obese pre-DM subjects showed low SIRT6 protein expression and high expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding transcription factor 1 (SREBP-1). Obese pre-DM patients showed high values of glucose, insulin resistance (HOMA-IR), C reactive protein (CRP), nitrotyrosine, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), and low values of insulin (p < 0.05). Of note, abdominal fat tissue of obese pre-DM patients treated with metformin therapy presented higher SIRT6 expression and lower NF-κB, PPAR-γ, and SREBP-1 expression levels compared to pre-DM control group. Collectively, results show that SIRT6 is involved in the inflammatory pathway of subcutaneous abdominal fat of obese pre-DM patients and its expression responds to metformin therapy.

Additional file 1: Figure S1. Western blot analysis of GlycACE2. Representative immunoblotting of recombinant hACE2 protein (ab151852, Abcam) after in vitro long-term exposure to glucose 120 mM was separated on SDS-PAGE by using 7% gels in reducing and non-reducing conditions and then transferred on nitrocellulose membrane. Membrane was incubated with specific primary antibody against GlycACE2 (1:1000) (#4355, Cell Signaling Technology). Molecular weight indicators are displayed at the center. Figure S2. Ejection fraction, TAPSE, and the E/e′ at week 1 (Basal) and week 48 (follow-up) in nondiabetic and diabetic patients treated with ACE-inhibitors (ACE-I) and angiotensin receptor blocker (ARB). Data are mean ± SD. *P < 0.05 vs non-diabetics, §P < 0.05 vs basal values. Figure S3. GlycACE2 at week 1 (Basal) and week 48 (Follow-up) in the diabetic patients with good glycemic control (HbA1c < 7%) and diabetic patients with poor glycemic control (HbA1c ≥ 7%) treated with ACE-inhibitors (ACE-I) and angiotensin receptor blocker (ARB). Data are mean ± SD. *P < 0.05 vs non-diabetics, §P < 0.05 vs basal values. Figure S4. A Angiotensin-1–9 (Ang-1–9), Ang 1–7, Mas receptor (MasR), Nuclear factor of activated T-cells (NFAT), in explanted hearts (HTX) at week 1 (Basal) and week 48 (Follow-up) from HTX, in nondiabetic and diabetic patients, treated with ACE-inhibitors (ACE-I) and angiotensin receptor blocker (ARB). B Ang-1–9, Ang 1–7, MasR, and NFAT, in explanted hearts (HTX) at week 1 (Basal) and week 48 (Follow-up) from HTX,in the diabetic patients with good glycemic control (HbA1c < 7%) and diabetic patients with poor glycemic control (HbA1c ≥ 7%) treated with ACE-inhibitors (ACE-I) and angiotensin receptor blocker (ARB). Data are mean ± SD. *P < 0.05 vs non-diabetics, §P < 0.05 vs basal values. Figure S5. Fibrosis percentage in explanted hearts (HTX), at week 1 (Basal) and week 48 (follow-up) from HTX, in the diabetic patients with good glycemic control (HbA1c < 7%) and diabetic patients with poor glycemic control (HbA1c ≥ 7%) treated with ACE-inhibitors (ACE-I) and angiotensin receptor blocker (ARB). Data are mean ± SD. *P < 0.05 vs non-diabetics, §P < 0.05 vs basal values. Table S1. Multivariate linear regression analysis with GlycACE2 as dependent variable.

Additional file 2: Figure S2. Mass spectra of the triply charged hACE2 tryptic peptide 342-357 in the glycated (panel A) and non-glycated (panel B) form. hACE2 is for human Angiotensin Converting enzyme 2 type.

SIGNIFICANCE: Oxidative stress represents the common hallmark of pathological conditions associated with cardiovascular disease (CVD), including atherosclerosis, heart failure, hypertension, aging, diabetes, and other vascular system-related diseases. The sirtuin (SIRT) family, comprising seven proteins (SIRT1-SIRT7) sharing a highly conserved nicotinamide adenine dinucleotide (NAD+)-binding catalytic domain, attracted a great attention for the past few years as stress adaptor and epigenetic enzymes involved in the cellular events controlling aging-related disorder, cancer, and CVD. Recent Advances: Among sirtuins, SIRT1 and SIRT6 are the best characterized for their protective roles against inflammation, vascular aging, heart disease, and atherosclerotic plaque development. This latest role has been only recently unveiled for SIRT6. Of interest, in recent years, complex signaling networks controlled by SIRT1 and SIRT6 common to stress resistance, vascular aging, and CVD have emerged. CRITICAL ISSUES: We provide a comprehensive overview of recent developments on the molecular signaling pathways controlled by SIRT1 and SIRT6, two post-translational modifiers proven to be valuable tools to dampen inflammation and oxidative stress at the cardiovascular level. FUTURE DIRECTIONS: A deeper understanding of the epigenetic mechanisms through which SIRT1 and SIRT6 act in the signalings responsible for onset and development CVD is a prime scientific endeavor of the upcoming years. Multiple "omic" technologies will have widespread implications in understanding such mechanisms, speeding up the achievement of selective and efficient pharmacological modulation of sirtuins for future applications in the prevention and treatment of CVD. Antioxid. Redox Signal. 28, 711-732.

Green beans of Robusta and Arabica coffee species were examined by HPLC-ESI-MS2 analysis for the content of glycosylated forms of serotonin and its N-methylated derivatives. The results showed for the first time the occurrence of serotonin 5-O-β-glucoside and tryptophan-N1-glucoside in coffee beans. Both substances were identified by their product ion spectra and by comparison with synthesized authentic standards. Interestingly, serotonin 5-O-β-glucoside occurs at similar levels in beans of all varieties of Robusta and Arabica coffee species, whereas tryptophan-N1-glucoside is present at high levels in beans of Robusta and at much lower levels in those of Arabica species. This striking difference in the content of tryptophan-N1-glucoside could afford a new tool to discriminate between beans of Arabica and Robusta coffee species.

Aims Glucagon like peptide 1 (GLP-1) analogues and dipeptidyl peptidase IV (DPP-4) inhibitors reduce atherosclerosis progression in type 2 diabetes mellitus (T2DM) patients and are associated with morphological and compositional characteristics of stable plaque phenotype. GLP-1 promotes the secretion of adiponectin which exerts anti-inflammatory effects through the adaptor protein PH domain and leucine zipper containing 1 (APPL1). The potential role of APPL1 expression in the evolution of atherosclerotic plaque in TDM2 patients has not previously evaluated. Methods The effect of incretin therapy in the regulation of adiponectin/APPL1 signaling was evaluated both on carotid plaques of asymptomatic diabetic (n=71) and non-diabetic patients (n=52), and through in vitro experiments on endothelial cell (EC). Results Atherosclerotic plaques of T2DM patients showed lower adiponectin and APPL1 levels compared with non-diabetic patients, along with higher oxidative stress, tumor necrosis factor-α (TNF-α), vimentin, and matrix metalloproteinase-9 (MMP-9) levels. Among T2DM subjects, current incretin-users presented higher APPL1 and adiponectin content compared with never incretin-users. Similarly, in vitro observations on endothelial cells co-treated with high-glucose (25mM) and GLP-1 (100nM) showed a greater APPL1 protein expression compared with high-glucose treatment alone. Conclusions Our findings suggest a potential role of adiponectin/APPL1 signaling in mediating the effect of incretin in the prevention of atherosclerosis progression or plaque vulnerability in T2DM.

The role of sirtuin 6 (SIRT6) in atherosclerotic progression of diabetic patients is unknown. We evaluated SIRT6 expression and the effect of incretin-based therapies in carotid plaques of asymptomatic diabetic and nondiabetic patients. Plaques were obtained from 52 type 2 diabetic and 30 nondiabetic patients undergoing carotid endarterectomy. Twenty-two diabetic patients were treated with drugs that work on the incretin system, GLP-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors for 26 ± 8 months before undergoing the endarterectomy. Compared with nondiabetic plaques, diabetic plaques had more inflammation and oxidative stress, along with a lesser SIRT6 expression and collagen content. Compared with non-GLP-1 therapy–treated plaques, GLP-1 therapy–treated plaques presented greater SIRT6 expression and collagen content, and less inflammation and oxidative stress, indicating a more stable plaque phenotype. These results were supported by in vitro observations on endothelial progenitor cells (EPCs) and endothelial cells (ECs). Indeed, both EPCs and ECs treated with high glucose (25 mmol/L) in the presence of GLP-1 (100 nmol/L liraglutide) presented a greater SIRT6 and lower nuclear factor-κB expression compared with cells treated only with high glucose. These findings establish the involvement of SIRT6 in the inflammatory pathways of diabetic atherosclerotic lesions and suggest its possible positive modulation by incretin, the effect of which is associated with morphological and compositional characteristics of a potential stable plaque phenotype.