The Ubiquitin-Proteasome System and Inflammatory Activity in Diabetic Atherosclerotic Plaques

The role of ubiquitin-proteasome system in the accelerated atherosclerotic progression of diabetic patients is unclear. We evaluated ubiquitin-proteasome activity in carotid plaques of asymptomatic diabetic and nondiabetic patients, as well as the effect of rosiglitazone, a peroxisome proliferator–activated receptor (PPAR)-γ activator, in diabetic plaques. Plaques were obtained from 46 type 2 diabetic and 30 nondiabetic patients undergoing carotid endarterectomy. Diabetic patients received 8 mg rosiglitazone (n = 23) or placebo (n = 23) for 4 months before scheduled endarterectomy. Plaques were analyzed for macrophages (CD68), T-cells (CD3), inflammatory cells (HLA-DR), ubiquitin, proteasome 20S activity, nuclear factor (NF)-κB, inhibitor of κB (IκB)-β, tumor necrosis factor (TNF)-α, nitrotyrosine, matrix metalloproteinase (MMP)-9, and collagen content (immunohistochemistry and enzyme-linked immunosorbent assay). Compared with nondiabetic plaques, diabetic plaques had more macrophages, T-cells, and HLA-DR+ cells (P < 0.001); more ubiquitin, proteasome 20S activity (TNF-α), and NF-κB (P < 0.001); and more markers of oxidative stress (nitrotyrosine and O2− production) and MMP-9 (P < 0.01), along with a lesser collagen content and IκB-β levels (P < 0.001). Compared with placebo-treated plaques, rosiglitazone-treated diabetic plaques presented less inflammatory cells (P < 0.01); less ubiquitin, proteasome 20S, TNF-α, and NF-κB (P < 0.01); less nitrotyrosine and superoxide anion production (P < 0.01); and greater collagen content (P < 0.01), indicating a more stable plaque phenotype. Similar findings were obtained in circulating monocytes obtained from the two groups of diabetic patients and cultured in the presence or absence of rosiglitazone (7.0 μmol/l). Ubiquitin-proteasome over-activity is associated with enhanced inflammatory reaction and NF-κB expression in diabetic plaques. The inhibition of ubiquitin-proteasome activity in atherosclerotic lesions of diabetic patients by rosiglitazone is associated with morphological and compositional characteristics of a potential stable plaque phenotype, possibly by downregulating NF-κB-mediated inflammatory pathways

Results of a prospective observational study of autologous peripheral blood mononuclear cell therapy for no-option critical limb-threatening ischemia and severe diabetic foot ulcers

Cell therapy with autologous peripheral blood mononuclear cells (PB-MNCs) may help restore limb perfusion in patients with diabetes mellitus and critical limb-threatening ischemia (CLTI) deemed not eligible for revascularization procedures and consequently at risk for major amputation (no-option). Fundamental is to establish its clinical value and to identify candidates with a greater benefit over time. Assessing the frequency of PB circulating angiogenic cells and extracellular vesicles (EVs) may help in guiding candidate selection

Identification and clinical characterization of adult patients with multigenerational diabetes mellitus

Background. Some patients diagnosed as having type 2 diabetes mellitus (T2DM) are, instead, affected by multigenerational diabetes whose clinical characteristics are mostly undefined. Objective. 1. To identify among patients who had been previously defined as affected by T2DM those, in fact, affected by multigenerational diabetes; 2. After excluding patients carrying the most common MODY genes and mitochondrial mutations, we compared clinical features of remaining patients with those of patients with T2DM. Methods. Among 2,583 consecutive adult patients who had been defined as affected by T2DM, we looked for those with diabetes in ≥3 consecutive generations. All probands were screened for mutations in six MODY genes (HNF4A, GCK, HNF1A, PDX1, HNF1B and NeuroD1) and for the A3243G mitochondrial mutation. After excluding patients with mutations in one of such genes, we compared clinical features of the remaining 67 patients (2.6% of the whole initial sample) affected by multigenerational “familial diabetes of the adulthood” (FDA) and of their diabetic relatives (n=63) to those with T2DM (n=1,028) by generalized hierarchical linear models followed by pairwise comparisons. Results. Age, age at diagnosis, proportion of hypertension (all p<0.001), and waist circumference (p<0.05) were lower in FDA than T2DM. Nonetheless, the two groups had similar age-adjusted incidence rate of all-cause mortality. Conclusions. Beside younger age at diagnosis, FDA patients show lower waist circumference and reduced proportion of hypertension as compared to those with T2DM; despite such reduced potential cardiovascular risk factors, FDA patients did not show a reduced mortality risk than patients with T2DM

Comparison of Clinical Features and Mortality Rate of Adult Patients with Multigenerational Diabetes and of Patients with Type 2 Diabetes Mellitus

Clinical experience teaches us that some adult patients who are diagnosed as having type 2 diabetes (T2D) are, instead, components of families with a multigenerational form of diabetes. We investigated clinical features and mortality rate of such patients as compared to those with T2D. From 2,583 consecutive Italian patients who had been routinely defined as affected by T2D, we looked for those belonging to families with diabetes in 3 or more consecutive generations. After excluding patients carrying known MODY gene mutations (n=22), clinical features of those affected by what we propose to define as “familial diabetes of the adulthood” (FDA; n=134) were compared to those of 1,208 T2D patients, not belonging to multigenerational (>2) pedigrees, who have been previously characterized for studying risk factors of all-cause mortality. In an age-adjusted model, age at diagnosis (p<0.001), waist circumference (p=0.03) and proportion of hypertension (p=0.001) were lower in FDA than in T2D. The two groups were similar for BMI, HbA1c, anti-hyperglycemic treatment, albuminuria and the proportion of dyslipidemia. In 121 FDA and 837 T2D patients, age-adjusted incidence rate of all-cause mortality was similar: 1.92 vs. 1.90 event per 100 person-years. In conclusion, this is the first report on clinical characteristics of adult patients from families with a multigenerational form of diabetes, we propose to define as FDA. FDA patients are characterized by a younger age at diagnosis, a lower waist circumference and a reduced proportion of hypertension, as compared to T2D patients. Though all-cause mortality rate is superimposable, it remains to be investigated whether such differences shape a different cardiovascular risk in these two groups of patients

Insights from Molecular Characterization of Adult Patients of Families with Multigenerational Diabetes Mellitus

Multigenerational diabetes of the adulthood is a mostly overlooked entity, simplistically comprised in the large basin of type 2 diabetes. The general aim we are pursuing in last years is to unravel the genetic causes of such form of diabetes. Identifying among families with multigenerational diabetes those carrying mutations in known monogenic diabetes genes is the first step to then concentrate on remaining pedigrees where to unravel new diabetogenes.Targeted Next Generation Sequencing of 27 monogenic diabetes-genes has been carried out in 55 family probands and identified mutations verified among their relatives by Sanger sequencing.Nine variants (in 8 probands) survived our filtering/prioritization strategy. After likelihood of causality assessment by established guidelines, 6 variants were classified as "pathogenetic/likely pathogenetic" and 2 as "of uncertain significance".Combining present with our previous data on the six genes causing the most common forms of maturity-onset diabetes of the young allows inferring that 23.6% families with multigenerational diabetes of the adulthood carry mutations in known monogenic diabetes-genes.Our findings indicate that the genetic background of hyperglycemia is unrecognized in the vast majority of families with multigenerational diabetes of the adulthood. These families now become the object of further research aimed at unraveling new diabetogenes

Clinical characteristics of patients (probands and their relatives) with either MODY, FDA or T2DM.

<p>Continuous variables were reported as mean <u>+</u> SD, whereas categorical variables are reported as percentages. FDA: Familial Diabetes of the Adulthood; MODY: Maturity Onset Diabetes of the Young; T2DM: Type 2 Diabetes Mellitus; HbA1c: Glycated hemoglobin; OADs: Oral Antidiabetes Drugs</p><p>*: p<0.001 vs. T2DM patients</p><p>^†: p≤0.01 vs. MODY patients</p><p>**: p<0.05 vs. T2DM patients</p><p>^††: p≤0.05 vs. MODY patients.</p><p>Because of the well-known differences across the two clinical entities, no comparisons were carried out between MODY and T2DM.</p><p>Clinical characteristics of patients (probands and their relatives) with either MODY, FDA or T2DM.</p