A study protocol for identifying aging trajectories toward chronic neurodegenerative diseases by means of Marche regional administrative databases - TREND project

Background

People are living longer but an increasing number of older people experience chronicity and disability in the latest years of their life. The Marche region is one of the Italian regions where people live the longest lives; therefore, the number of people with age-related chronic diseases is expected to be at least similar, if not higher, compared to the rest of Italy. The identification of the aging trajectories is of huge interest in the arena of public health. Administrative healthcare databases represent valuable reservoirs for reconstructing the trajectories of aging. Here, we present the protocol for a study (TREND project) aimed to integrate existing administrative databases into a Marche regional dataset in order to estimate the prevalence and incidence rates of age-related neurodegenerative diseases (ND), with a specific focus on Parkinsonism and Dementia.

Methods

The TREND Project is a retrospective cross-sectional study. The source population includes permanent residents in the Marche region aged 40 years and older. A minimal dataset has been built up linking data on drug prescriptions, outpatient services, and diagnosis for hospital admission, from 2014 to 2021 in the Marche Region. Data on clinical outcomes (re-hospitalization, mortality, comorbidities), and therapeutic approaches (drugs and medicines) have been integrated with state-of-the-art statistical methods to define patients into different risk clusters and to analyze the aging trend by assessing the Comorbidity Index (CI) as a proxy for chronicity.

Discussion

Our research contributes to the integration of existing administrative databases on ND to create a Marche regional ND database, support regional health policy, and better understand patients' needs and their aging trajectories. This approach could be implemented also at the National level. Moreover, by linking different administrative data sources, this study sheds light on important issues related to ND, such as early-onset dementia; ethical aspects such as anticipated wills; problems of dementia in patients still in the job market, etc. The results of this study will contribute to the successful implementation of integrated care for patients affected by ND at regional or national levels.

Replicative senescence and high glucose induce the accrual of self-derived cytosolic nucleic acids in human endothelial cells

Recent literature shows that loss of replicative ability and acquisition of a proinflammatory secretory phenotype in senescent cells is coupled with the build-in of nucleic acids in the cytoplasm. Its implication in human age-related diseases is under scrutiny. In human endothelial cells (ECs), we assessed the accumulation of intracellular nucleic acids during in vitro replicative senescence and after exposure to high glucose concentrations, which mimic an in vivo condition of hyperglycemia. We showed that exposure to high glucose induces senescent-like features in ECs, including telomere shortening and proinflammatory cytokine release, coupled with the accrual in the cytoplasm of telomeres, double-stranded DNA and RNA (dsDNA, dsRNA), as well as RNA:DNA hybrid molecules. Senescent ECs showed an activation of the dsRNA sensors RIG-I and MDA5 and of the DNA sensor TLR9, which was not paralleled by the involvement of the canonical (cGAS) and non-canonical (IFI16) activation of the STING pathway. Under high glucose conditions, only a sustained activation of TLR9 was observed. Notably, senescent cells exhibit increased proinflammatory cytokine (IL-1β, IL-6, IL-8) production without a detectable secretion of type I interferon (IFN), a phenomenon that can be explained, at least in part, by the accumulation of methyl-adenosine containing RNAs. At variance, exposure to exogenous nucleic acids enhances both IL-6 and IFN-β1 expression in senescent cells. This study highlights the accrual of cytoplasmic nucleic acids as a marker of senescence-related endothelial dysfunction, that may play a role in dysmetabolic age-related diseases.

Senescent Endothelial Cells Sustain Their Senescence-Associated Secretory Phenotype (SASP) through Enhanced Fatty Acid Oxidation

Cellular senescence is closely linked to endothelial dysfunction, a key factor in age-related vascular diseases. Senescent endothelial cells exhibit a proinflammatory phenotype known as SASP, leading to chronic inflammation (inflammaging) and vascular impairments. Albeit in a state of permanent growth arrest, senescent cells paradoxically display a high metabolic activity. The relationship between metabolism and inflammation is complex and varies across cell types and senescence inductions. While some cell types shift towards glycolysis during senescence, others favor oxidative phosphorylation (OXPHOS). Despite the high availability of oxygen, quiescent endothelial cells (ECs) tend to rely on glycolysis for their bioenergetic needs. However, there are limited data on the metabolic behavior of senescent ECs. Here, we characterized the metabolic profiles of young and senescent human umbilical vein endothelial cells (HUVECs) to establish a possible link between the metabolic status and the proinflammatory phenotype of senescent ECs. Senescent ECs internalize a smaller amount of glucose, have a lower glycolytic rate, and produce/release less lactate than younger cells. On the other hand, an increased fatty acid oxidation activity was observed in senescent HUVECs, together with a greater intracellular content of ATP. Interestingly, blockade of glycolysis with 2-deoxy-D-glucose in young cells resulted in enhanced production of proinflammatory cytokines, while the inhibition of carnitine palmitoyltransferase 1 (CPT1), a key rate-limiting enzyme of fatty acid oxidation, ameliorated the SASP in senescent ECs. In summary, metabolic changes in senescent ECs are complex, and this research seeks to uncover potential strategies for modulating these metabolic pathways to influence the SASP.

Circulating PCSK9 as a prognostic biomarker of cardiovascular events in individuals with type 2 diabetes: evidence from a 16.8-year follow-up study

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality, being twofold to fourfold more common in patients with type 2 diabetes mellitus (T2DM) than in individuals without diabetes. However, despite this decade-old knowledge, the identification of a specific prognostic risk biomarker remains particularly challenging.

METHODS

Taking advantage of a large sample of Caucasian patients (n = 529) with a diagnosis of T2DM followed for a median of 16.8 years, the present study was aimed at testing the hypothesis that fasting serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels could be prognostic for major adverse cardiovascular events (MACE) and all-cause mortality.

RESULTS

Median levels of PCSK9 were 259.8 ng/mL, being higher in women compared to men and increasing even more in the presence of a complication (e.g., diabetic kidney disease). PCSK9 positively correlated with markers of blood glucose homeostasis (e.g., HbA1c, fasting insulin and HOMA-IR) and the atherogenic lipid profile (e.g., non-HDL-C, apoB and remnant cholesterol). Serum PCSK9 predicted new-onset of MACE, either fatal or non-fatal, only in women (Odds Ratio: 2.26, 95% CI 1.12-4.58) and all-cause mortality only in men (Hazard Ratio: 1.79, 95% CI 1.13-2.82).

CONCLUSIONS

Considering that up to two-thirds of individuals with T2DM develop ASCVD in their lifetime, the assessment of circulating PCSK9 levels can be envisioned within the context of a biomarker-based strategy of risk stratification. However, the sex difference found highlights an urgent need to develop sex-specific risk assessment strategies.

TRIAL REGISTRATION

It is a retrospective study.

Anti-Inflammatory Effects of Olive Leaf Extract and Its Bioactive Compounds Oleacin and Oleuropein-Aglycone on Senescent Endothelial and Small Airway Epithelial Cells

Olive tree by-products have been deeply studied as an invaluable source of bioactive compounds. Several in vitro and in vivo studies showed that olive leaf extract (OLE) has anti-inflammatory and antioxidant properties. Here, we wanted to assess the valuable benefits of two less-studied OLE components-3,4-DHPEA-EDA (Oleacin, OC) and 3,4-DHPEA-EA (Oleuropein-Aglycone, OA)-directly purified from OLE using a cost-effective and environmentally sustainable method, in line with the principles of circular economy. OLE, OC and OA were then tested in human cellular models involved in acute and chronic inflammation and in the pathogenesis of viral infections, i.e., lipopolysaccharide (LPS)-treated monocyte/macrophages (THP-1) and endothelial cells (HUVECs), senescent HUVECs and Poly(I:C)-treated small airway epithelial cells (hSAECs). Results showed that OC and OA are efficient in ameliorating almost all of the pro-inflammatory readouts (IL-1β, TNF-α, IL-8, ICAM, VCAM) and reducing the release of IL-6 in all the cellular models. In hSAECs, they also modulate the expression of SOD2, NF-kB and also ACE2 and TMPRSS2, whose expression is required for SARS-CoV-2 virus entry. Overall, these data suggest the usefulness of OLE, OC and OA in controlling or preventing inflammatory responses, in particular those associated with viral respiratory infections and aging.

Zingiber officinale Roscoe Rhizome Extract Exerts Senomorphic and Anti-Inflammatory Activities on Human Endothelial Cells

Aging is related to a low-grade and sterile inflammation called inflammaging, recognized as the main risk factor for age-related disease (ARD) development. Inflammaging is fostered by the repeated activation of immune cells, as well as by the accumulation of senescent cells. Recently, a number of natural compounds have gained attention to be tested as anti-aging therapies, based on their anti-inflammatory activity and/or ability to reduce the pro-inflammatory secretome of senescent cells (senomorphyc activity). Here, we investigated the anti-inflammatory and senomorphic properties of an Asian-native Zingiber officinale Roscoe extract (ZOE), commonly consumed as a food spice and herbal medicine. We employed two models of primary endothelial cells (HUVECs), such as the replicative-senescence and LPS-induced response, to investigate the anti-inflammatory/senomorphic effect of ZOE, and one cellular model of neuroinflammation, i.e., immortalized murine microglial cells (BV2). First, we found that the ZOE treatment induced the inhibition of NF-kB activation in BV2 cells. Among the constituents of ZOE, we showed that the terpenoid-enriched fraction (ZTE) was the component able to counteract the phosphorylation of NF-kB(p65), while 6-gingerol (GIN) and 6-shogaol (SHO) did not produce any significant effect. Further, we observed that the treatment with 10 µg/mL of ZOE exerted anti-inflammatory activity on LPS-stimulated young (y)HUVEC and senomorphyc activity on replicative senescent (s)HUVEC, significantly reducing the expression levels of IL-1β, TNF -α, IL-8, MCP-1, and ICAM-1. Moreover, the ZTE treatment was able to significantly reduce the IL-8 levels secreted in the medium of both LPS-stimulated yHUVEC and sHUVEC. Overall, our data suggest a potential protective role of ZOE on neuroinflammation and endothelial inflammation/activation, thus suggesting its potential relevance in delaying/postponing ARD development and progression, characterized by endothelial dysfunction.

MiR-422a promotes adipogenesis via MeCP2 downregulation in human bone marrow mesenchymal stem cells

Methyl-CpG binding protein 2 (MeCP2) is a ubiquitous transcriptional regulator. The study of this protein has been mainly focused on the central nervous system because alterations of its expression are associated with neurological disorders such as Rett syndrome. However, young patients with Rett syndrome also suffer from osteoporosis, suggesting a role of MeCP2 in the differentiation of human bone marrow mesenchymal stromal cells (hBMSCs), the precursors of osteoblasts and adipocytes. Here, we report an in vitro downregulation of MeCP2 in hBMSCs undergoing adipogenic differentiation (AD) and in adipocytes of human and rat bone marrow tissue samples. This modulation does not depend on MeCP2 DNA methylation nor on mRNA levels but on differentially expressed miRNAs during AD. MiRNA profiling revealed that miR-422a and miR-483-5p are upregulated in hBMSC-derived adipocytes compared to their precursors. MiR-483-5p, but not miR-422a, is also up-regulated in hBMSC-derived osteoblasts, suggesting a specific role of the latter in the adipogenic process. Experimental modulation of intracellular levels of miR-422a and miR-483-5p affected MeCP2 expression through direct interaction with its 3' UTR elements, and the adipogenic process. Accordingly, the knockdown of MeCP2 in hBMSCs through MeCP2-targeting shRNA lentiviral vectors increased the levels of adipogenesis-related genes. Finally, since adipocytes released a higher amount of miR-422a in culture medium compared to hBMSCs we analyzed the levels of circulating miR-422a in patients with osteoporosis-a condition characterized by increased marrow adiposity-demonstrating that its levels are negatively correlated with T- and Z-scores. Overall, our findings suggest that miR-422a has a role in hBMSC adipogenesis by downregulating MeCP2 and its circulating levels are associated with bone mass loss in primary osteoporosis.

Sex/gender-related differences in inflammaging

Geroscience puts mechanisms of aging as a driver of the most common age-related diseases and dysfunctions. Under this perspective, addressing the basic mechanisms of aging will produce a better understanding than addressing each disease pathophysiology individually. Worldwide, despite greater functional impairment, life expectancy is higher in women than in men. Gender differences in the prevalence of multimorbidity lead mandatory to the understanding of the mechanisms underlying gender-related differences in multimorbidity patterns and disability-free life expectancy. Extensive literature suggested that inflammaging is at the crossroad of aging and age-related diseases. In this review, we highlight the main evidence on sex/gender differences in the mechanisms that foster inflammaging, i.e. the age-dependent triggering of innate immunity, modifications of adaptive immunity, and accrual of senescent cells, underpinning some biomarkers of inflammaging that show sex-related differences. In the framework of the "gender medicine perspective", we will also discuss how sex/gender differences in inflammaging can affect sex differences in COVID-19 severe outcomes.

Biomarkers of cell damage, neutrophil and macrophage activation associated with in-hospital mortality in geriatric COVID-19 patients

BACKGROUND

The risk for symptomatic COVID-19 requiring hospitalization is higher in the older population. The course of the disease in hospitalised older patients may show significant variation, from mild to severe illness, ultimately leading to death in the most critical cases. The analysis of circulating biomolecules involved in mechanisms of inflammation, cell damage and innate immunity could lead to identify new biomarkers of COVID-19 severity, aimed to improve the clinical management of subjects at higher risk of severe outcomes. In a cohort of COVID-19 geriatric patients (n= 156) who required hospitalization we analysed, on-admission, a series of circulating biomarkers related to neutrophil activation (neutrophil elastase, LL-37), macrophage activation (sCD163) and cell damage (nuclear cfDNA, mithocondrial cfDNA and nuclear cfDNA integrity). The above reported biomarkers were tested for their association with in-hospital mortality and with clinical, inflammatory and routine hematological parameters. Aim of the study was to unravel prognostic parameters for risk stratification of COVID-19 patients.

RESULTS

Lower n-cfDNA integrity, higher neutrophil elastase and higher sCD163 levels were significantly associated with an increased risk of in-hospital decease. Median (IQR) values observed in discharged vs. deceased patients were: 0.50 (0.30-0.72) vs. 0.33 (0.22-0.62) for n-cfDNA integrity; 94.0 (47.7-154.0) ng/ml vs. 115.7 (84.2-212.7) ng/ml for neutrophil elastase; 614.0 (370.0-821.0) ng/ml vs. 787.0 (560.0-1304.0) ng/ml for sCD163. The analysis of survival curves in patients stratified for tertiles of each biomarker showed that patients with n-cfDNA integrity < 0.32 or sCD163 in the range 492-811 ng/ml had higher risk of in-hospital decease than, respectively, patients with higher n-cfDNA integrity or lower sCD163. These associations were further confirmed in multivariate models adjusted for age, sex and outcome-related clinical variables. In these models also high levels of neutrophil elastase (>150 ng/ml) appeared to be independent predictor of in-hospital death. An additional analysis of neutrophil elastase in patients stratified for n-cfDNA integrity levels was conducted to better describe the association of the studied parameters with the outcome.

CONCLUSIONS

On the whole, biomarkers of cell-free DNA integrity, neutrophil and macrophage activation might provide a valuable contribution to identify geriatric patients with high risk of COVID-19 in-hospital mortality.

Replicative Senescence-Associated LINE1 Methylation and LINE1-Alu Expression Levels in Human Endothelial Cells

One of the main challenges of current research on aging is to identify the complex epigenetic mechanisms involved in the acquisition of the cellular senescent phenotype. Despite some evidence suggested that epigenetic changes of DNA repetitive elements, including transposable elements (TE) sequences, are associated with replicative senescence of fibroblasts, data on different types of cells are scarce. We previously analysed genome-wide DNA methylation of young and replicative senescent human endothelial cells (HUVECs), highlighting increased levels of demethylated sequences in senescent cells. Here, we aligned the most significantly demethylated single CpG sites to the reference genome and annotated their localization inside TE sequences and found a significant hypomethylation of sequences belonging to the Long-Interspersed Element-1 (LINE-1 or L1) subfamilies L1M, L1P, and L1HS. To verify the hypothesis that L1 demethylation could be associated with increased transcription/activation of L1s and/or Alu elements (non-autonomous retroelements that usually depend on L1 sequences for reverse transcription and retrotransposition), we quantified the RNA expression levels of both L1 (generic L1 elements or site-specific L1PA2 on chromosome 14) and Alu elements in young and senescent HUVECs and human dermal fibroblasts (NHDFs). The RNA expression of Alu and L1 sequences was significantly increased in both senescent HUVECs and NHDFs, whereas the RNA transcript of L1PA2 on chromosome 14 was not significantly modulated in senescent cells. Moreover, we found an increased amount of TE DNA copies in the cytoplasm of senescent HUVECs and NHDFs. Our results support the hypothesis that TE, which are significantly increased in senescent cells, could be retrotranscribed to DNA sequences.

Prognostic value of soluble ST2, high-sensitivity cardiac troponin, and NT-proBNP in type 2 diabetes: a 15-year retrospective study

Background

Patients with type 2 diabetes (T2DM) present an increased risk of cardiovascular (CV) disease and excess CV-related mortality. Beyond the established role of brain natriuretic peptide (BNP) and cardiac troponins (cTn), other non-cardiac-specific biomarkers are emerging as predictors of CV outcomes in T2DM.

Methods

Serum levels of soluble suppression of tumorigenesis 2 (sST2), high-sensitivity (hs)-cTnI, and N-terminal (NT)-proBNP were assessed in 568 patients with T2DM and 115 healthy controls (CTR). Their association with all-cause mortality and the development of diabetic complications was tested in T2DM patients over a median follow-up of 16.8 years using Cox models and logistic regressions.

Results

sST2 followed an increasing trend from CTR to uncomplicated T2DM patients (T2DM-NC) to patients with at least one complication (T2DM-C), while hs-cTnI was significantly higher in T2DM-C compared to CTR but not to T2DM-NC. A graded association was found between sST2 (HR 2.76 [95% CI 1.20–6.33] for ≥ 32.0 ng/mL and 2.00 [1.02–3.94] for 16.5–32.0 ng/mL compared to < 16.5 ng/mL, C-statistic = 0.729), NT-proBNP (HR 2.04 [1.90–4.55] for ≥ 337 ng/L and 1.48 [1.05–2.10] for 89–337 ng/L compared to < 89 ng/L, C-statistic = 0.741), and 15-year mortality in T2DM, whereas increased mortality was observed in patients with hs-cTnI ≥ 7.8 ng/L (HR 1.63 [1.01–2.62]). A ‘cardiac score’ based on the combination of sST2, hs-cTnI, and NT-proBNP was significantly associated with all-cause mortality (HR 1.35 [1.19–1.53], C-statistic = 0.739) and development of CV events.

Conclusions

sST2, hs-cTnI, and NT-proBNP are associated with 15-year mortality and onset of CV events in T2DM. The long-term prognostic value of sST2 and its ability to track variables related to insulin resistance and associated metabolic disorders support its implementation into routine clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01616-3.

Circulating levels of AGEs and soluble RAGE isoforms are associated with all-cause mortality and development of cardiovascular complications in type 2 diabetes: a retrospective cohort study

BACKGROUND

Advanced glycation end-products (AGEs) and their interaction with the receptor for advanced glycation end-products (RAGE) play a pivotal role in the development and progression of type 2 diabetes. In this retrospective cohort study, we explored the association of circulating levels of soluble RAGE (sRAGE) isoforms, i.e., endogenous secretory esRAGE and cleaved cRAGE, AGEs and their respective ratios with 15-year all-cause mortality in type 2 diabetes.

METHODS

Baseline AGEs and sRAGE isoforms concentration were measured by ELISA in 362 patients with type 2 diabetes and in 125 age- and gender-matched healthy control subjects (CTR). Independent predictors of mortality were determined using Cox proportional-hazards models and used to build and validate a nomogram for all-cause mortality prediction in type 2 diabetes.

RESULTS

AGEs, total sRAGE, cRAGE and the AGEs/sRAGE and AGEs/esRAGE ratios were significantly increased in patients with type 2 diabetes compared to CTR (p < 0.001). In CTR subjects, but not in type 2 diabetes patients, a significant negative correlation between cRAGE and age was confirmed (p = 0.003), whereas the AGEs/sRAGE (p = 0.032) and AGEs/cRAGE (p = 0.006) ratios were positively associated with age. At an average follow-up of 15 years (4,982 person-years), 130 deaths were observed. The increase in the AGEs/cRAGE ratio was accompanied by a higher risk of all-cause mortality in patients with type 2 diabetes (HR per each SD increment = 1.30, 95% CI 1.15-1.47; p < 0.001). Moreover, sRAGE was associated with the development of major adverse cardiovascular events (MACE) in type 2 diabetes patients without previous MACE (OR for each SD increase: 1.48, 95% CI 1.11-1.89). A nomogram based on age, sex, HbA1c, systolic blood pressure, and the AGEs/cRAGE ratio was built to predict 5-, 10- and 15-year survival in type 2 diabetes. Patients were categorized into quartiles of the monogram scores and Kaplan-Meier survival curves confirmed the prognostic accuracy of the model (log-rank p = 6.5 × 10- 13).

CONCLUSIONS

The ratio between AGEs and the cRAGE isoform is predictive of 15-year survival in patients with type 2 diabetes. Our data support the assessment of circulating AGEs and soluble RAGE isoforms in patients with type 2 diabetes as predictors of MACE and all-cause mortality.

Circulating biomarkers of inflammaging as potential predictors of COVID-19 severe outcomes

The COVID-19 pandemic caused by SARS-CoV-2 infection has been of unprecedented clinical and socio-economic worldwide relevance. The case fatality rate for COVID-19 grows exponentially with age and the presence of comorbidities. In the older patients, COVID-19 manifests predominantly as a systemic disease associated with immunological, inflammatory, and procoagulant responses. Timely diagnosis and risk stratification are crucial steps to define appropriate therapies and reduce mortality, especially in the older patients. Chronically and systemically activated innate immune responses and impaired antiviral responses have been recognized as the results of a progressive remodeling of the immune system during aging, which can be described by the words 'immunosenescence' and 'inflammaging'. These age-related features of the immune system were highlighted in patients affected by COVID-19 with the poorest clinical outcomes, suggesting that the mechanisms underpinning immunosenescence and inflammaging could be relevant for COVID-19 pathogenesis and progression. Increasing evidence suggests that senescent myeloid and endothelial cells are characterized by the acquisition of a senescence-associated pro-inflammatory phenotype (SASP), which is considered as the main culprit of both immunosenescence and inflammaging. Here, we reviewed this evidence and highlighted several circulating biomarkers of inflammaging that could provide additional prognostic information to stratify COVID-19 patients based on the risk of severe outcomes.

The Association between Single Nucleotide Polymorphisms, including miR-499a Genetic Variants, and Dyslipidemia in Subjects Treated with Pharmacological or Phytochemical Lipid-Lowering Agents

Disorders of lipoprotein metabolism are among the major risk factors for cardiovascular disease (CVD) development. Single nucleotide polymorphisms (SNPs) have been associated with the individual variability in blood lipid profile and response to lipid-lowering treatments. Here, we genotyped 34 selected SNPs located in coding genes related to lipid metabolism, inflammation, coagulation, and a polymorphism in the MIR499 gene—a microRNA previously linked to CVD—to evaluate the association with lipid trait in subjects with moderate dyslipidemia not on lipid-lowering treatment (Treatment-naïve (TN) cohort, n = 125) and in patients treated with statins (STAT cohort, n = 302). We also explored the association between SNPs and the effect of a novel phytochemical lipid-lowering treatment in the TN cohort. We found that 6 SNPs (in the MIR499, TNFA, CETP, SOD2, and VEGFA genes) were associated with lipid traits in the TN cohort, while no association was found with the response to twelve-week phytochemical treatment. In the STAT cohort, nine SNPs (in the MIR499, CETP, CYP2C9, IL6, ABCC2, PON1, IL10, and VEGFA genes) were associated with lipid traits, three of which were in common with the TN cohort. Interestingly, in both cohorts, the presence of the rs3746444 MIR499 SNP was associated with a more favorable blood lipid profile. Our findings could add information to better understand the individual genetic variability in maintaining a low atherogenic lipid profile and the response to different lipid-lowering therapies.

Circulating miR-320b and miR-483-5p levels are associated with COVID-19 in-hospital mortality

The stratification of mortality risk in COVID-19 patients remains extremely challenging for physicians, especially in older patients. Innovative minimally invasive molecular biomarkers are needed to improve the prediction of mortality risk and better customize patient management. In this study, aimed at identifying circulating miRNAs associated with the risk of COVID-19 in-hospital mortality, we analyzed serum samples of 12 COVID-19 patients by small RNA-seq and validated the findings in an independent cohort of 116 COVID-19 patients by qRT-PCR. Thirty-four significantly deregulated miRNAs, 25 downregulated and 9 upregulated in deceased COVID-19 patients compared to survivors, were identified in the discovery cohort. Based on the highest fold-changes and on the highest expression levels, 5 of these 34 miRNAs were selected for the analysis in the validation cohort. MiR-320b and miR-483-5p were confirmed to be significantly hyper-expressed in deceased patients compared to survived ones. Kaplan-Meier and Cox regression models, adjusted for relevant confounders, confirmed that patients with the 20% highest miR-320b and miR-483-5p serum levels had three-fold increased risk to die during in-hospital stay for COVID-19. In conclusion, high levels of circulating miR-320b and miR-483-5p can be useful as minimally invasive biomarkers to stratify older COVID-19 patients with an increased risk of in-hospital mortality.

Potential prognostic value of circulating inflamma-miR-146a-5p and miR-125a-5p in relapsing-remitting multiple sclerosis

BACKGROUND

Inflamma-miRs are a group of microRNAs involved in the regulation of innate and adaptive immune responses. Increasing evidence support the contribution of dysregulated inflamma-miRs in the pathogenesis of multiple sclerosis. The aim of this study was to evaluate the expression of selected inflamma-miRs, i.e., miR-34a-5p, -125a-5p, -146a-5p, and -155, in relapsing-remitting multiple sclerosis (RRMS) and their modulation after treatment with dimethyl fumarate (DMF).

METHODS

Circulating levels of microRNAs involved in inflammatory response (inflamma-miRs) were compared between healthy controls (CTRs, n=21) and patients with RRMS (n=24) who started treatment with DMF.

RESULTS

Plasma levels of miR-34a (p<0.001) and miR-125a-5p (p=0.034) were higher, whereas miR-146a-5p levels were lower (p=0.041) in RRMS patients compared to CTRs. Circulating miR-125a-5p (p=0.001), miR-146a-5p (p<0.001), and miR-155 (p=0.013) were reduced after 4-month treatment with DMF. Among these, baseline and 4-month follow up miR-125a-5p (p=0.028) and miR-146a-5p (p=0.042) levels were related to disability progression.

CONCLUSION

Circulating inflamma-miRs could represent candidate tools to predict MS clinical course and evaluate the effectiveness of disease-modifying treatments in RRMS.

Pre-eclampsia predictive ability of maternal miR-125b: a clinical and experimental study

Pre-eclampsia (PE) is a systemic maternal syndrome affecting 2-8% of pregnancies worldwide and involving poor placental perfusion and impaired blood supply to the foetus. It manifests after the 20th week of pregnancy as new-onset hypertension and substantial proteinuria and is responsible for severe maternal and newborn morbidity and mortality. Identifying biomarkers that predict PE onset prior to its establishment would critically help treatment and attenuate outcome severity. MicroRNAs are ubiquitous gene expression modulators found in blood and tissues. Trophoblast cell surface antigen (Trop)-2 promotes cell growth and is involved in several cancers. We assessed the PE predictive ability of maternal miR-125b in the first trimester of pregnancy by measuring its plasma levels in women with normal pregnancies and with pregnancies complicated by PE on the 12th week of gestation. To gain insight into PE pathogenesis we investigated whether Trop-2 is targeted by miR-125b in placental tissue. Data analysis demonstrated a significant association between plasma miR-125b levels and PE, which together with maternal body mass index before pregnancy provided a predictive model with an area under the curve of 0.85 (95% confidence interval, 0.70-1.00). We also found that Trop-2 is a target of miR-125b in placental cells; its localization in the basal part of the syncytiotrophoblast plasma membrane suggests a role for it in the early onset of PE. Altogether, maternal miR-125b proved a promising early biomarker of PE, suggesting that it may be involved in placental development through its action on Trop-2 well before the clinical manifestations of PE.

Connecting vascular aging and frailty in Alzheimer's disease

Aging plays an important role in the etiology of the most common age-related diseases (ARDs), including Alzheimer's disease (AD). The increasing number of AD patients and the lack of disease-modifying drugs warranted intensive research to tackle the pathophysiological mechanisms underpinning AD development. Vascular aging/dysfunction is a common feature of almost all ARDs, including cardiovascular (CV) diseases, diabetes and AD. To this regard, interventions aimed at modifying CV outcomes are under extensive investigation for their pleiotropic role in ameliorating and slowing down cognitive impairment in middle-life and elderly individuals. Evidence from observational and clinical studies confirm the notion that the earlier the interventions are conducted, the most favorable are the effects on cognitive function. Therefore, epidemiological research should focus on the early detection of deviations from a healthy cognitive aging trajectory, through the stratification of adult individuals according to the rate of aging. Here, we review the interplay between vascular and cognitive dysfunctions associated with aging, to disentangle the complex mechanisms underpinning the development and progression of neurodegenerative disorders, with a specific focus on AD.

Long-term exposure of human endothelial cells to metformin modulates miRNAs and isomiRs

Increasing evidence suggest that the glucose-lowering drug metformin exerts a valuable anti-senescence role. The ability of metformin to affect the biogenesis of selected microRNAs (miRNAs) was recently suggested. MicroRNA isoforms (isomiRs) are distinct variations of miRNA sequences, harboring addition or deletion of one or more nucleotides at the 5′ and/or 3′ ends of the canonical miRNA sequence. We performed a comprehensive analysis of miRNA and isomiR profile in human endothelial cells undergoing replicative senescence in presence of metformin. Metformin treatment was associated with the differential expression of 27 miRNAs (including miR-100-5p, -125b-5p, -654-3p, -217 and -216a-3p/5p). IsomiR analysis revealed that almost 40% of the total miRNA pool was composed by non-canonical sequences. Metformin significantly affects the relative abundance of 133 isomiRs, including the non-canonical forms of the aforementioned miRNAs. Pathway enrichment analysis suggested that pathways associated with proliferation and nutrient sensing are modulated by metformin-regulated miRNAs and that some of the regulated isomiRs (e.g. the 5′ miR-217 isomiR) are endowed with alternative seed sequences and share less than half of the predicted targets with the canonical form. Our results show that metformin reshapes the senescence-associated miRNA/isomiR patterns of endothelial cells, thus expanding our insight into the cell senescence molecular machinery.

Prevalence of residual inflammatory risk and associated clinical variables in patients with type 2 diabetes

Residual inflammatory risk (RIR) is defined as persistent circulating levels of high sensitivity C-reactive protein (hs-CRP) >2 mg/L despite an optimal (<70 mg/dL) control of LDL-cholesterol (LDL-C) and represents an emerging risk factor for the development of cardiovascular events in patients at high risk of atherosclerosis. Sparse data are available regarding the prevalence of RIR in patients with type 2 diabetes (T2D) and the clinical variables associated with hs-CRP elevation. Here, we report data from a well-characterized cohort of patients with T2D (n = 511) stratified for statins use, LDL-C goal attainment and prevalent T2D complications. Statins use and having at-target LDL-C partially affect the number of patients with inflammatory risk when compared with the whole T2D population, with an RIR prevalence of 39.2%. Among the spectra of complications, only patients with nephropathy had a higher prevalence of inflammatory risk. Total cholesterol, non-HDL-cholesterol, triglycerides, body mass index and waist-hip ratio were associated with hs-CRP, with an increased magnitude in at-target patients. Conversely, glucose-related variables were strongly associated with hs-CRP only in at-target patients, overall suggesting glycaemic control, insulin resistance, non-LDL-C lipid variables and especially central obesity as possible contributors to RIR in patients with T2D and LDL-C <70 mg/dL.

Diagnostic performance of new and classic CSF biomarkers in age-related dementias

The identification of diagnostic-prognostic biomarkers of dementia has become a global priority due to the prevalence of neurodegenerative diseases in aging populations. The objective of this study was to assess the diagnostic performance of cerebrospinal fluid (CSF) biomarkers across patients affected by either Alzheimer’s disease (AD), tauopathies other than AD (TP), or vascular dementia (VD), and cognitively normal subjects (CNS). One hundred fifty-three patients were recruited and tested for classical AD CSF biomarkers- Amyloid-ß42 and tau proteins - and novel candidate biomarkers - neurofilament (NF-) light and microRNA (miR) -21, -125b, -146a, and -222.

All dementia patients had significantly higher concentrations of NF-light compared to CNS, with the TP group displaying the highest NF-light values. A significant inverse correlation was also observed between NF-light and cognitive impairment. Of the four miRNAs analyzed, miR-222 levels were significantly increased in VD patients compared to both CNS and AD. In addition, while NF-light showed a better diagnostic performance than miR-222 and classical AD biomarkers in differentiating TP and VD from CNS, classical AD biomarkers revealed higher performance in discriminating AD from non-AD disorders.

Overall, our results suggest that CSF NF-light and miR-222 are promising biomarkers that may help to diagnose non-AD disorders.

Small extracellular vesicles deliver miR-21 and miR-217 as pro-senescence effectors to endothelial cells

The role of epigenetics in endothelial cell senescence is a cutting-edge topic in ageing research. However, little is known of the relative contribution to pro-senescence signal propagation provided by microRNAs shuttled by extracellular vesicles (EVs) released from senescent cells. Analysis of microRNA and DNA methylation profiles in non-senescent (control) and senescent (SEN) human umbilical vein endothelial cells (HUVECs), and microRNA profiling of their cognate small EVs (sEVs) and large EVs demonstrated that SEN cells released a significantly greater sEV number than control cells. sEVs were enriched in miR-21-5p and miR-217, which target DNMT1 and SIRT1. Treatment of control cells with SEN sEVs induced a miR-21/miR-217-related impairment of DNMT1-SIRT1 expression, the reduction of proliferation markers, the acquisition of a senescent phenotype and a partial demethylation of the locus encoding for miR-21. MicroRNA profiling of sEVs from plasma of healthy subjects aged 40-100 years showed an inverse U-shaped age-related trend for miR-21-5p, consistent with senescence-associated biomarker profiles. Our findings suggest that miR-21-5p/miR-217 carried by SEN sEVs spread pro-senescence signals, affecting DNA methylation and cell replication.

The telomere world and aging: Analytical challenges and future perspectives

Telomeres, the terminal nucleoprotein structures of eukaryotic chromosomes, play pleiotropic functions in cellular and organismal aging. Telomere length (TL) varies throughout life due to the influence of genetic factors and to a complex balancing between "shortening" and "elongation" signals. Telomerase, the only enzyme that can elongate a telomeric DNA chain, and telomeric repeat-containing RNA (TERRA), a long non-coding RNA involved in looping maintenance, play key roles in TL during life. Despite recent advances in the knowledge of TL, TERRA and telomerase activity (TA) biology and their measurement techniques, the experimental and theoretical issues involved raise a number of problems that should carefully be considered by researchers approaching the "telomere world". The increasing use of such parameters - hailed as promising clinically relevant biomarkers - has failed to be paralleled by the development of automated and standardized measurement technology. Consequently, associating given TL values to specific pathological conditions involves on the one hand technological issues and on the other clinical-biological issues related to the planning of clinically relevant association studies. Addressing these issues would help avoid major biases in association studies involving TL and a number of outcomes, especially those focusing on psychological and bio-behavioral variables. The main challenge in telomere research is the development of accurate and reliable measurement methods to achieve simple and sensitive TL, TERRA, and TA detection. The discovery of the localization of telomeres and TERRA in cellular and extracellular compartments had added an additional layer of complexity to the measurement of these age-related biomarkers. Since combined analysis of TL, TERRA and TA may well provide more exhaustive clinical information than a single parameter, we feel it is important for researchers in the various fields to become familiar with their most common measurement techniques and to be aware of the respective merits and drawbacks of these approaches.