Adiponectin and Cognitive Decline Rizzo, Maria Rosaria; Fasano, Renata; Paolisso, Giuseppe
International journal of molecular sciences,
03/2020, Letnik:
21, Številka:
6
Journal Article
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Adiponectin (ADPN) is a plasma protein secreted by adipose tissue showing pleiotropic effects with anti-diabetic, anti-atherogenic, and anti-inflammatory properties. Initially, it was thought that ...the main role was only the metabolism control. Later, ADPN receptors were also found in the central nervous system (CNS). In fact, the receptors AdipoR1 and AdipoR2 are expressed in various areas of the brain, including the hypothalamus, hippocampus, and cortex. While AdipoR1 regulates insulin sensitivity through the activation of the AMP-activated protein kinase (AMPK) pathway, AdipoR2 stimulates the neural plasticity through the activation of the peroxisome proliferator-activated receptor alpha (PPARα) pathway that inhibits inflammation and oxidative stress. Overall, based on its central and peripheral actions, ADPN appears to have neuroprotective effects by reducing inflammatory markers, such as C-reactive protein (PCR), interleukin 6 (IL6), and Tumor Necrosis Factor a (TNFa). Conversely, high levels of inflammatory cascade factors appear to inhibit the production of ADPN, suggesting bidirectional modulation. In addition, ADPN appears to have insulin-sensitizing action. It is known that a reduction in insulin signaling is associated with cognitive impairment. Based on this, it is of great interest to investigate the mechanism of restoration of the insulin signal in the brain as an action of ADPN, because it is useful for testing a possible pharmacological treatment for the improvement of cognitive decline. Anyway, if ADPN regulates neuronal functioning and cognitive performances by the glycemic metabolic system remains poorly explored. Moreover, although the mechanism is still unclear, women compared to men have a doubled risk of developing cognitive decline. Several studies have also supported that during the menopausal transition, the estrogen reduction can adversely affect the brain, in particular, verbal memory and verbal fluency. During the postmenopausal period, in obese and insulin-resistant individuals, ADPN serum levels are significantly reduced. Our recent study has evaluated the relationship between plasma ADPN levels and cognitive performances in menopausal women. Thus, the aim of this review is to summarize both the mechanisms and the effects of ADPN in the central nervous system and the relationship between plasma ADPN levels and cognitive performances, also in menopausal women.
Leukocyte telomere length (LTL) and rate of telomere shortening are known biomarkers of aging while, numerous studies showed that Mediterranean diet (MD) may boost longevity. We studied association ...between telomere length, telomerase activity and different adherence to MD and its effects on healthy status. The study was conducted in 217 elderly subjects stratified according Mediterranean diet score (MDS) in low adherence (MDS≤3), medium adherence (MDS 4-5) and high adherence (MDS≥6) groups. LTL was measured by quantitative polymerase chain reaction and telomerase activity by a PCR-ELISA protocol. High adherence group showed longer LTL (p = 0.003) and higher telomerase activity (p = 0.013) compared to others. Linear regression analysis including age, gender, smoking habit and MDS showed that MDS was independently associated with LTL (p = 0.024) and telomerase activity levels (p = 0.006). Telomerase activity was independently associated with LTL (p = 0.007) and negatively modulated by inflammation and oxidative stress. Indeed, telomerase levels were associated with healthy status independently of multiple covariates (p = 0.048). These results support a novel role of MD in promoting health-span suggesting that telomere maintenance, rather than LTL variability is the major determinant of healthy status among elderly.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Evaluate the effects of two dipeptidyl peptidase-IV (DPP-4) inhibitors, sitagliptin and vildagliptin, known to have different efficacy on mean amplitude of glycemic excursions (MAGE), on oxidative ...stress, and on systemic inflammatory markers in patients with type 2 diabetes.
A prospective, randomized, open-label PROBE design (parallel group with a blinded end point) study was performed in 90 patients with type 2 diabetes inadequately controlled by metformin. The study assigned 45 patients to receive sitagliptin (100 mg once daily; sitagliptin group) and 45 patients to receive vildagliptin (50 mg twice daily; vildagliptin group) for 12 weeks. MAGE, evaluated during 48 h of continuous subcutaneous glucose monitoring, allowed an assessment of daily glucose fluctuations at baseline and after 12 weeks in all patients. Assessment of oxidative stress (nitrotyrosine) and systemic levels of inflammatory markers interleukin (IL)-6 and IL-18 was performed at baseline and after 12 weeks in all patients.
HbA(1c), fasting and postprandial glucose, MAGE, and inflammatory and oxidative stress markers were similar between the groups at baseline. After 12 weeks, MAGE (P < 0.01) was lower in the vildagliptin group than in the sitagliptin group. After treatment, HbA(1c) and postprandial glucose evidenced similar changes between the groups (P = NS). Vildagliptin treatment was associated with a stronger decrease in nitrotyrosine (P < 0.01), IL-6 (P < 0.05), and IL-18 (P < 0.05) than sitagliptin treatment. Nitrotyrosine and IL-6 changes significantly correlated with changes in MAGE but not in fasting glucose and HbA(1c).
MAGE reduction is associated with reduction of oxidative stress and markers of systemic inflammation in type 2 diabetic patients. These effects were greater in the vildagliptin group than in the sitagliptin group.
Objectives This study evaluated whether subclinical episodes of atrial fibrillation (AF) were associated with an increased risk of silent cerebral infarct (SCI) and stroke in diabetic patients ...younger than 60 years who did not have other clinical evidence of AF and cerebrovascular disease at baseline. Background In type 2 diabetic patients, one-fourth of strokes are of unknown cause, and subclinical episodes of AF may be a common etiologic factor. Methods A total of 464 type 2 diabetic patients younger than 60 years were included in a longitudinal observational study and matched to patients without diabetes. Patients underwent 48-h electrocardiographic Holter monitoring quarterly to detect brief subclinical episodes of AF (duration of AF <48 h) and were followed up for 37 months. The outcomes were SCI, assessed by magnetic resonance imaging of the brain, and stroke events during the follow-up period. Results The prevalence of subclinical episodes of AF was significantly greater among patients with diabetes compared with matched healthy subjects (11% vs. 1.6%, p < 0.0001). During an average duration of 37 months, 43 stroke events occurred in the diabetic population and no events occurred in healthy subjects. Diabetic patients with silent episodes of AF (n = 176) had a higher baseline prevalence of SCI (61% vs. 29%; p < 0.01) and a higher number of stroke events (17.3% vs. 5.9%; p < 0.01) during the follow-up period than the other patients (n = 288). An episode of silent AF was an independent determinant of SCI (odds ratio: 4.441; p < 0.001; confidence interval: 2.42 to 8.16) and an independent predictor of the occurrence of stroke in diabetic patients (hazard ratio: 4.6; p < 0.01; confidence interval: 2.7 to 9.1). Conclusions Subclinical episodes of AF occurred frequently in type 2 diabetic patients and were associated with a significantly increased risk of SCI and stroke.
Prevalence of sarcopenia is substantial in most geriatrics settings, but estimates vary greatly across studies because of difference in population characteristics, diagnostic criteria, and methods ...used to assess muscle mass, muscle strength, and physical performance. We investigated the feasibility of the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm assessment in hospitalized older adults and analyzed prevalence and clinical correlates of sarcopenia.
Cross-sectional analysis of 655 participants enrolled in a multicenter observational study of older adults admitted to 12 acute hospital wards in Italy. Sarcopenia was assessed as low skeletal mass index (kg/m2) plus either low handgrip strength or low walking speed (EWGSOP criteria). Skeletal muscle mass was estimated using bioimpedance analysis.
Of the 655 patients (age 81.0 ± 6.8 years; women 51.9%) enrolled in the study, 275 (40.2%) were not able to perform the 4-m walking test because of medical problems. The overall prevalence of sarcopenia on hospital admission was 34.7% (95% confidence interval 28-37) and it steeply increased with aging (p < .001). In multivariable analysis, patients with sarcopenia on hospital admission were older and were more likely to be male and to have congestive heart failure, cerebrovascular disease, and severe basic activities of daily living disability. The prevalence of sarcopenia was inversely correlated with body mass index.
Based on EWGSOP criteria, prevalence of sarcopenia is extremely high among older adults on admission to acute hospital wards. Older age, male gender, congestive heart failure, cerebrovascular disease, severe activities of daily living disability, and body mass index were the clinical variables significantly associated with the presence of sarcopenia.
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.
Background
New evidence is emerging on the importance of lean body mass during periods of illness and recovery. The preservation of lean body mass during such periods of intense stress impacts both ...patient and treatment outcomes. However, data concerning the incidence of sarcopenia among older people during hospitalization are scarce. The objective of this study was to evaluate the development of sarcopenia in a sample of hospitalized older subjects.
Methods
We used data of 394 participants from the multicentre Italian Study conducted by the Gruppo Lavoro Italiano Sarcopenia—Trattamento e Nutrizione (GLISTEN) in 12 Acute Care Wards (Internal Medicine and Geriatrics) of University Hospitals across Italy. This study was designed to determine the prevalence of sarcopenia at hospital admission and the change in muscle mass and strength during hospitalization. Sarcopenia was defined as low skeletal mass index (kg/m2) along with either low handgrip strength or slow walking speed European Working Groups on Sarcopenia in Older People (EWGSOP) criteria. Estimation of skeletal muscle mass was performed by bioelectrical impedance analysis (BIA).
Results
The mean age of the 394 enrolled patients (including 211 females who accounted for 53% of the sample) was 79.6 ± 6.4 years. Among those without sarcopenia at hospital admission, 14.7% of the study sample met the EWGSOP sarcopenia diagnostic criteria at discharge. The incidence of sarcopenia during hospitalization was significantly associated with the number of days spent in bed but was not correlated with the total length of hospital stay. In particular, patients who developed sarcopenia spent an average of 5.1 days in bed compared with 3.2 days for those with no sarcopenia at discharge (P = 0.02). Patients with sarcopenia showed a significantly lower body mass index compared with non‐sarcopenic peers (25.0 ± 3.8 kg/m2 vs. 27.6 ± 4.9 kg/m2, respectively; P < 0.001). Similarly, the skeletal mass index at admission was significantly lower among patients who developed sarcopenia during hospital stay.
Conclusions
Incident sarcopenia during hospital stay is relatively common and is associated with nutritional status and the number of days of bed rest.
Sodium-glucose co-transporters (SGLT) inhibitors (SGLT2i) showed many beneficial effects at the cardiovascular level. Several mechanisms of action have been identified. However, no data on their ...capability to act via epigenetic mechanisms were reported. Therefore, this study aimed to investigate the ability of SGLT2 inhibitors (SGLT2i) to induce protective effects at the cardiovascular level by acting on DNA methylation.
To better clarify this issue, the effects of empagliflozin (EMPA) on hyperglycemia-induced epigenetic modifications were evaluated in human ventricular cardiac myoblasts AC16 exposed to hyperglycemia for 7 days. Therefore, the effects of EMPA on DNA methylation of NF-κB, SOD2, and IL-6 genes in AC16 exposed to high glucose were analyzed by pyrosequencing-based methylation analysis. Modifications of gene expression and DNA methylation of NF-κB and SOD2 were confirmed in response to a transient SGLT2 gene silencing in the same cellular model. Moreover, chromatin immunoprecipitation followed by quantitative PCR was performed to evaluate the occupancy of TET2 across the investigated regions of NF-κB and SOD2 promoters.
Seven days of high glucose treatment induced significant demethylation in the promoter regions of NF-kB and SOD2 with a consequent high level in mRNA expression of both genes. The observed DNA demethylation was mediated by increased TET2 expression and binding to the CpGs island in the promoter regions of analyzed genes. Indeed, EMPA prevented the HG-induced demethylation changes by reducing TET2 binding to the investigated promoter region and counteracted the altered gene expression. The transient SGLT2 gene silencing prevented the DNA demethylation observed in promoter regions, thus suggesting a role of SGLT2 as a potential target of the anti-inflammatory and antioxidant effect of EMPA in cardiomyocytes.
In conclusion, our results demonstrated that EMPA, mainly acting on SGLT2, prevented DNA methylation changes induced by high glucose and provided evidence of a new mechanism by which SGLT2i can exert cardio-beneficial effects.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Breakthrough SARS-CoV-2 infections in fully vaccinated individuals are considered a consequence of waning immunity. Serum antibodies represent the most measurable outcome of vaccine-induced B cell ...memory. When antibodies decline, memory B cells are expected to persist and perform their function, preventing clinical disease. We investigated whether BNT162b2 mRNA vaccine induces durable and functional B cell memory in vivo against SARS-CoV-2 3, 6, and 9 months after the second dose in a cohort of health care workers (HCWs). While we observed physiological decline of SARS-CoV-2-specific antibodies, memory B cells persist and increase until 9 months after immunization. HCWs with breakthrough infections had no signs of waning immunity. In 3–4 days, memory B cells responded to SARS-CoV-2 infection by producing high levels of specific antibodies in the serum and anti-Spike IgA in the saliva. Antibodies to the viral nucleoprotein were produced with the slow kinetics typical of the response to a novel antigen.
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•Anti-Spike antibodies decline 9 months after vaccination, but memory B cells increase•Breakthrough infections are not associated with waning immunity•Breakthrough infections lead to increase of specific antibodies in serum and saliva•Parenterally administered vaccines do not generate mucosal immunity
Terreri, Piano Mortari, and colleagues show that memory B cells persist and increase months after SARS-CoV-2 vaccination even if specific antibodies physiologically decline. Health care workers with breakthrough infections had no signs of waning immunity, as memory B cells produce high levels of specific antibodies in the serum and saliva.
Our study aimed to investigate the effect of dipeptidyl peptidase 4 inhibitors (DPP4-I) on sarcopenic parameters in elderly type 2 diabetic patients.
All elderly diabetic patients were invited to ...present themselves at our outpatient Geriatric Centre to undergo to evaluation of glycemic, inflammatory, and sarcopenic parameters and to perform a meal test for glucagon-like peptide-1 analogue (GLP-1) activity evaluation.
According to European Working Group on Sarcopenia in Older People (EWGSOP) criteria, sarcopenic parameters were assessed by bioelectrical impedance analysis (BIA) and Kern dynamometer and 4-m gait speed tests. All patients received standardized meals for the assessment of postprandial levels of GLP-1 activity.
Data of 80 elderly diabetic patients treated with oral glucose-lowering drugs (DPP4-I or Sulfonylureas Group) for at least 24 months before enrollment were analyzed.
The DPP4-I Group showed appropriate glycemic control, lower levels of inflammatory parameters, a significant and greater increase, during interprandial periods, of GLP-1 activity, and better sarcopenic parameters (fat-free mass, skeletal muscle mass, and related indices, muscle strength, and gait speed) compared with the Sulfonylureas Group. Univariate analysis showed that sarcopenic parameters correlated with glycemic control and with GLP-1 area under the curve values. Multivariate analysis confirms these relationships.
The results are consistent with the hypothesis that DPP4-I use might have a positive effect on the loss of muscle mass and its function.
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