RhoA/rho kinase pathway activation in age-associated endothelial cell dysfunction and thrombosis.

The small GTPase RhoA and the downstream Rho kinase (ROCK) regulate several cell functions and pathological processes in the vascular system that contribute to the age-dependent risk of cardiovascular disease, including endothelial dysfunction, excessive permeability, inflammation, impaired angiogenesis, abnormal vasoconstriction, decreased nitric oxide production and apoptosis. Frailty is a loss of physiological reserve and adaptive capacity with advanced age and is accompanied by a pro-inflammatory and pro-oxidative state that promotes vascular dysfunction and thrombosis. This review summarises the role of the RhoA/Rho kinase signalling pathway in endothelial dysfunction, the acquisition of the pro-thrombotic state and vascular ageing. We also discuss the possible role of RhoA/Rho kinase signalling as a promising therapeutic target for the prevention and treatment of age-related cardiovascular disease.

Effect of frailty status on mortality risk among chilean community-dwelling older adults.

INTRODUCTION: The study of frailty and its effect on the risk of mortality in older people is of utmost importance, but understanding the critical factors is still limited. Our main objective was to analyze the association of frailty with all-cause mortality in a prospective community cohort of older people. METHODS: A five-year longitudinal follow-up study was conducted with 1,174 community-dwelling older adults (men and women≥65 years old) from different Family Health Centers and community groups from Chile. We evaluated the functional risk, socioeconomic status, and anthropometric variables. The frailty status was evaluated by modified Fried criteria. RESULTS: The diagnosis of frailty was reached in 290 older adult participants, who had significantly increased 5-year all-cause mortality independently of age, sex, cognitive impairment, and socioeconomic status (adjusted HR 1.51, 1.06-2.15). CONCLUSION: Frailty is a predictor of increased mortality independently of age, sex, socio-economic and cognitive factors.

A Comprehensive Literature Review on Cardioprotective Effects of Bioactive Compounds Present in Fruits of Aristotelia chilensis Stuntz (Maqui).

Some fruits and vegetables, rich in bioactive compounds such as polyphenols, flavonoids, and anthocyanins, may inhibit platelet activation pathways and therefore reduce the risk of suffering from CVD when consumed regularly. Aristotelia chilensis Stuntz (Maqui) is a shrub or tree native to Chile with outstanding antioxidant activity, associated with its high content in anthocyanins, polyphenols, and flavonoids. Previous studies reveal different pharmacological properties for this berry, but its cardioprotective potential has been little studied. Despite having an abundant composition, and being rich in bioactive products with an antiplatelet role, there are few studies linking this berry with antiplatelet activity. This review summarizes and discusses relevant information on the cardioprotective potential of Maqui, based on its composition of bioactive compounds, mainly as a nutraceutical antiplatelet agent. Articles published between 2000 and 2022 in the following bibliographic databases were selected: PubMed, ScienceDirect, and Google Scholar. Our search revealed that Maqui is a promising cardiovascular target since extracts from this berry have direct effects on the reduction in cardiovascular risk factors (glucose index, obesity, diabetes, among others). Although studies on antiplatelet activity in this fruit are recent, its rich chemical composition clearly shows that the presence of chemical compounds (anthocyanins, flavonoids, phenolic acids, among others) with high antiplatelet potential can provide this berry with antiplatelet properties. These bioactive compounds have antiplatelet effects with multiple targets in the platelet, particularly, they have been related to the inhibition of thromboxane, thrombin, ADP, and GPVI receptors, or through the pathways by which these receptors stimulate platelet aggregation. Detailed studies are needed to clarify this gap in the literature, as well as to specifically evaluate the mechanism of action of Maqui extracts, due to the presence of phenolic compounds.

Regulation of Key Antiplatelet Pathways by Bioactive Compounds with Minimal Bleeding Risk.

Cardiovascular disease is strongly influenced by platelet activation. Platelet activation and thrombus formation at atherosclerotic plaque rupture sites is a dynamic process regulated by different signaling networks. Therefore, there are now focused efforts to search for novel bioactive compounds which target receptors and pathways in the platelet activation process while preserving normal hemostatic function. The antiplatelet activity of numerous fruits and vegetables and their multiple mechanisms of action have recently been highlighted. In this review, we review the antiplatelet actions of bioactive compounds via key pathways (protein disulfide isomerase, mitogen-activated protein kinases, mitochondrial function, cyclic adenosine monophosphate, Akt, and shear stress-induced platelet aggregation) with no effects on bleeding time. Therefore, targeting these pathways might lead to the development of effective antiplatelet strategies that do not increase the risk of bleeding.

Loss of Caveolin-1 Is Associated with a Decrease in Beta Cell Death in Mice on a High Fat Diet.

Elevated free fatty acids (FFAs) impair beta cell function and reduce beta cell mass as a consequence of the lipotoxicity that occurs in type 2 diabetes (T2D). We previously reported that the membrane protein caveolin-1 (CAV1) sensitizes to palmitate-induced apoptosis in the beta pancreatic cell line MIN6. Thus, our hypothesis was that CAV1 knock-out (CAV1 KO) mice subjected to a high fat diet (HFD) should suffer less damage to beta cells than wild type (WT) mice. Here, we evaluated the in vivo response of beta cells in the pancreatic islets of 8-week-old C57Bl/6J CAV1 KO mice subjected to a control diet (CD, 14% kcal fat) or a HFD (60% kcal fat) for 12 weeks. We observed that CAV1 KO mice were resistant to weight gain when on HFD, although they had high serum cholesterol and FFA levels, impaired glucose tolerance and were insulin resistant. Some of these alterations were also observed in mice on CD. Interestingly, KO mice fed with HFD showed an adaptive response of the pancreatic beta cells and exhibited a significant decrease in beta cell apoptosis in their islets compared to WT mice. These in vivo results suggest that although the CAV1 KO mice are metabolically unhealthy, they adapt better to a HFD than WT mice. To shed light on the possible signaling pathway(s) involved, MIN6 murine beta cells expressing (MIN6 CAV) or not expressing (MIN6 Mock) CAV1 were incubated with the saturated fatty acid palmitate in the presence of mitogen-activated protein kinase inhibitors. Western blot analysis revealed that CAV1 enhanced palmitate-induced JNK, p38 and ERK phosphorylation in MIN6 CAV1 cells. Moreover, all the MAPK inhibitors partially restored MIN6 viability, but the effect was most notable with the ERK inhibitor. In conclusion, our results suggest that CAV1 KO mice adapted better to a HFD despite their altered metabolic state and that this may at least in part be due to reduced beta cell damage. Moreover, they indicate that the ability of CAV1 to increase sensitivity to FFAs may be mediated by MAPK and particularly ERK activation.

Lipid Metabolism and Signaling in Platelet Function.

Modern society has changed its diet composition, transitioning to a higher intake of saturated fat with a 50% increase of cardiovascular risk (CVD). Within the context of increased CVD, there is an induction of a prothrombotic phenotype mainly due to increased platelet reactivity as well as decreased platelet response to inhibitors. Platelets maintain haemostasis through both blood components and endothelial cells that secrete inhibitory or stimulatory molecules to regulate thrombus formation. There exist a correlation between platelets' polyunsaturated fatty acid (PUFA) and the increase in platelet reactivity. The aim of this chapter is to review the metabolism of the main PUFAs involved in platelet function associated with the role that their enzyme-derived oxidized metabolites exert in platelet function and fate. Finally, how lipid metabolism in the organism affect platelet aggregation and activation and the pharmacological modulation of these processes will also be discussed.

Phosphorylation of caveolin-1 on tyrosine-14 induced by ROS enhances palmitate-induced death of beta-pancreatic cells.

A considerable body of evidence exists implicating high levels of free saturated fatty acids in beta pancreatic cell death, although the molecular mechanisms and the signaling pathways involved have not been clearly defined. The membrane protein caveolin-1 has long been implicated in cell death, either by sensitizing to or directly inducing apoptosis and it is normally expressed in beta cells. Here, we tested whether the presence of caveolin-1 modulates free fatty acid-induced beta cell death by reexpressing this protein in MIN6 murine beta cells lacking caveolin-1. Incubation of MIN6 with palmitate, but not oleate, induced apoptotic cell death that was enhanced by the presence of caveolin-1. Moreover, palmitate induced de novo ceramide synthesis, loss of mitochondrial transmembrane potential and reactive oxygen species (ROS) formation in MIN6 cells. ROS generation promoted caveolin-1 phosphorylation on tyrosine-14 that was abrogated by the anti-oxidant N-acetylcysteine or the incubation with the Src-family kinase inhibitor, PP2 (4-amino-5-(4-chlorophenyl)-7(dimethylethyl)pyrazolo[3,4-d]pyrimidine). The expression of a non-phosphorylatable caveolin-1 tyrosine-14 to phenylalanine mutant failed to enhance palmitate-induced apoptosis while for MIN6 cells expressing the phospho-mimetic tyrosine-14 to glutamic acid mutant caveolin-1 palmitate sensitivity was comparable to that observed for MIN6 cells expressing wild type caveolin-1. Thus, caveolin-1 expression promotes palmitate-induced ROS-dependent apoptosis in MIN6 cells in a manner requiring Src family kinase mediated tyrosine-14 phosphorylation.

Understanding the Role of Oxidative Stress in Platelet Alterations and Thrombosis Risk among Frail Older Adults.

Frailty and cardiovascular diseases are increasingly prevalent in aging populations, sharing common pathological mechanisms, such as oxidative stress. The evidence shows that these factors predispose frail individuals to cardiovascular diseases but also increase the risk of thrombosis. Considering this background, this review aims to explore advances regarding the relationship between oxidative stress, platelet alterations, and cardiovascular diseases in frailty, examining the role of reactive oxygen species overproduction in platelet activation and thrombosis. The current evidence shows a bidirectional relationship between frailty and cardiovascular diseases, emphasizing how frailty not only predisposes individuals to cardiovascular diseases but also accelerates disease progression through oxidative damage and increased platelet function. Thus, oxidative stress is the central axis in the increase in platelet activation and secretion and the inadequate response to acetylsalicylic acid observed in frail people by mitochondrial mechanisms. Also, key biomarkers of oxidative stress, such as isoprostanes and derivate reactive oxygen metabolites, can be optimal predictors of cardiovascular risk and potential targets for therapeutic intervention. The potential of antioxidant therapies in mitigating oxidative stress and improving cardiovascular clinical outcomes such as platelet function is promising in frailty, although further research is necessary to establish the efficacy of these therapies. Understanding these mechanisms could prove essential in improving the health and quality of life of an aging population faced with the dual burden of frailty and cardiovascular diseases.

Physiological changes associated with aging: Identification of novel biomarkers for frailty syndrome in women.

This study explores the physiological changes associated with aging that lead to frailty syndrome, characterized by reduced vitality and degeneration across multiple bodily systems, increasing susceptibility to various pathologies. While established scales like the Fried Phenotype and Frailty Trait Scale (FTS) are commonly used for assessing frailty, incorporating biomarkers is crucial for accurate diagnosis and prognosis. Our research examines plasma oxylipin levels in frail elderly individuals to identify novel biomarkers. Diagnostic criteria for frailty included assessments using the Fried Phenotype and FTS-5, with blood samples collected from 71 elderly participants (50 women and 21 men) with mean ages of 73.6 ± 5.9 and 76.2 ± 6.2 years, respectively. Women exhibited elevated platelet counts (p-value 0.0035). The significant differences in oxylipin concentrations associated with the Fried Phenotype were particularly noteworthy, predominantly observed in women. Specifically, in women, decreased grip strength (<15 kg) and slow gait speed (<0.8 m/s) correlated with increased levels of thromboxane B2 (TxB2) and 7-HDoHE (p-values 0.0404, 0.0300, 0.0033, and 0.0033, respectively). Additionally, elevated 7-HDoHE levels correlated with a BMI exceeding 28 kg/m2 (p-value 0.0123) and Physical Activity Scale for the Elderly (PASE) scores surpassing 5 points (p-value 0.0134) in women. In summary, our findings emphasize that frail older individuals, particularly women, exhibit higher levels of TxB2 and 7-HDoHE compared to their non-frail counterparts, aligning with established frailty classification and scale parameters, suggesting their potential as indicative biomarkers.

Platelets and endothelial dysfunction in gestational diabetes mellitus.

The prevalence of gestational diabetes mellitus (GDM) has increased in recent years, along with the higher prevalence of obesity in women of reproductive age. GDM is a pathology associated with vascular dysfunction in the fetoplacental unit. GDM-associated endothelial dysfunction alters the transfer of nutrients to the foetus affecting newborns and pregnant women. Various mechanisms for this vascular dysfunction have been proposed, of which the most studied are metabolic alterations of the vascular endothelium. However, different cell types are involved in GDM-associated endothelial dysfunction, including platelets. Platelets are small, enucleated cell fragments that actively take part in blood haemostasis and thrombus formation. Thus, they play crucial roles in pathologies coursing with endothelial dysfunction, such as atherosclerosis, cardiovascular diseases, and diabetes mellitus. Nevertheless, platelet function in GDM is understudied. Several reports show a potential relationship between platelet volume and mass with GDM; however, platelet roles and signaling mechanisms in GDM-associated endothelial dysfunction are unclear. This review summarizes the reported findings and proposes a link among altered amount, volume, mass, reactivity, and function of platelets and placenta development, resulting in fetoplacental vascular dysfunction in GDM.

In Vitro Effect of Mitochondria-Targeted Triphenylphosphonium-Based Compounds (Honokiol, Lonidamine, and Atovaquone) on the Platelet Function and Cytotoxic Activity.

Introduction: Obtaining triphenylphosphonium salts derived from anticancer compounds to inhibit mitochondrial metabolism is of major interest due to their pivotal role in reactive oxygen species (ROS) production, calcium homeostasis, apoptosis, and cell proliferation. However, the use of this type of antitumor compound presents a risk of bleeding since the platelet activation is especially dependent on the mitochondrial function. In this study, we evaluated the in vitro effect of three triphenylphosphonium-based compounds, honokiol (HNK), lonidamine (LDN), and atovaquone (ATO), on the platelet function linked to the triphenylphosphonium cation by a lineal 10-carbon alkyl chain and also the decyltriphenylphosphonium salt (decylphos). Methods: Platelets obtained by phlebotomy from healthy donors were exposed in vitro to different concentrations (0.1-10 µM) of the three compounds; cellular viability, exposure of phosphatidylserine, the mitochondrial membrane potential (∆Ψm), intracellular calcium release, and intracellular ROS generation were measured. Platelet activation and aggregation were induced by agonists (adenosine diphosphate, thrombin receptor-activating peptide-6, convulxin, or phorbol-12-myristate-13-acetate) and were evaluated by flow cytometry and light transmission, respectively. Results: The three compounds showed a slight cytotoxic effect from 1 µM, and this was concomitant with a decrease in ∆Ψm and intracellular calcium increase. Only ATO produced a modest but significant increase in intra-platelet ROS. Also, the three compounds increased the exposure to phosphatidylserine in platelets expressed in platelets positive for annexin V. None of the compounds had an inhibitory effect on the aggregation or activation markers of platelets stimulated with three different agonists. Similar results were obtained with decylphos. Conclusion: Triphenylphosphonium derivatives showed slight platelet toxicity below 1 µM, probably associated with their effect on ∆Ψm and exposure to phosphatidylserine, but no significant effect on platelet activation and aggregation, making them an antitumoral alternative with a low risk of bleeding. However, future assays on animal models and human trials are required to evaluate if their effects with a low risk for hemostasis are replicated in vivo.

An In Vitro and In Silico Study of Antioxidant Properties of Curcuminoid N-alkylpyridinium Salts: Initial Assessment of Their Antitumoral Properties.

In this work, we report the synthesis of curcuminoids with ionic liquid characteristics, obtained by incorporating alkyl-substituted pyridinium moiety rather than one phenyl group through a two-step process. The antioxidant capacity of the obtained compounds was evaluated in vitro by 1,1-diphenyl-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assays, showing that some derivatives are more potent than curcumin. Pyridine curcuminoids (group 4) and curcuminoid N-alkylpyridinium salts with two methoxyl groups in the phenyl ring (group 7), presented the best antioxidant capacity. The experimental results were rationalized by density functional theory (DFT) calculations of the bond dissociation enthalpy (BDE) for O-H in each compound. The computational calculations allowed for insight into the structural-antioxidant properties relationship in these series of compounds. BDEs, obtained in the gas phase and water, showed a notable impact of water solvation on the stabilization of some radicals. The lower values of BDEs in the water solution correspond to the structurally related compounds curcuminoid-pyridine 4c and curcuminoid pyridinium salt 7a, which is consistent with the experimental results. Additionally, an assessment of cell viability and cell migration assays was performed for human colon cancer (HT29), human breast cancer (MCF7) cells, in addition to NIH3T3 murine fibroblast, as a model of non-cancer cell type. These compounds mainly cause inhibition of the cell migration observed in MCF7 cancer cells without affecting the non-tumoral NIH3T3 cell line: Neither in viability nor in migration.

Characterization by Gender of Frailty Syndrome in Elderly People according to Frail Trait Scale and Fried Frailty Phenotype.

Background: Frailty has emerged as one of the main geriatric syndromes to be prevented in order to improve quality of health and life in the elderly. In this sense, the characterization of this syndrome through reliable and feasible diagnostic tools for clinical use, such as the Frail Trait Scale 5 (FTS-5) and Frail Trait Scale 3 (FTS-3), represents the basis for this objective. Objectives: To characterize the frailty syndrome in a population of older adults using FTS-5, FTS-3, and Fried phenotype (FP) as frailty diagnostic tools. Design: Cross-sectional study. Participants: 300 adults ≥65 years recruited from different Family Health Centers and community groups of older people in Talca, Chile. Methods: The diagnosis of frailty was made according to FP, FTS-5, and FTS-3 tools. Data about sociodemographic characteristics and anthropometric measurements were collected by a clinical interview by a previously trained health professional. Results: A total prevalence of frailty according to the FP of 19.7% was observed; while in the group of women and men it was 21.4% and 15.0%, respectively. Concerning the FTS-5 tool, the total prevalence of frailty was 18%, while in the group of women and men was 18.0% and 17.5%, respectively. The FTS-3 tool shows a total prevalence of frailty of 23.3%, while in the group of women and men a prevalence of 22.7% and 25.0%, respectively. A significant difference is observed with respect to the presence of the Fried criteria of "weakness" (women: 21.4%, men: 38.8%) and "weight loss" (women: 16.8%, men: 7.5%; p < 0.05). A significant difference is observed concerning the average score of "Handgrip" criteria, "walking time", and "Physical Activity Scale for the Elderly" (PASE) between the group of women and men. Frailty, diagnosed by FTS-3, is significantly associated with the risk factors of overweight (body mass index ≥ 25) (OR: 10.225, 95% CI: 1.297−80.617) and advanced age (age ≥ 75 years) (OR: 1.839, 95% CI: 1.040−3.250). Conclusion: The prevalence of frailty observed with the FTS-5 (18%) and FTS-3 (23.3%) tools are similar to the prevalence observed through the FP (19.7%) and those reported in other observational studies. Considering the similar prevalence of frailty diagnosed with the three tools, FTS-3 should be a valuable tool for the screening of frailty in the community.

The Role of Coffee and its Bioactive Components in Platelet Function and Aging.

Cardiovascular diseases (CVD) are known to be the world's leading cause of death and different factors are known to increase the risk of death, including aging, mainly due to increased oxidative stress and inflammation observed in older people. Acute myocardial infarctions and cerebrovascular accidents belong to CVD, and are the ones that cause the most deaths and disabilities, where greater platelet activation plays an important role in pathophysiology. These diseases are more prevalent in older people, which have a clear relationship with increased platelet function and are strongly related to aging. Platelet function is affected by diet, which varies in its requirements and characteristics according to age. Coffee belongs to the family of diet elements that can alter platelet function and an increase in coffee consumption with advancing age, and a U-shaped correlation with the risk of CVD have been reported. However, the effect of coffee consumption and its bioactive compounds on platelet function and aging presents controversial evidence, and therefore, a complex effect is not fully elucidated in the cardiovascular system. This review focuses on the relationship between coffee consumption (and its constituent bioactive compounds), and platelet function, and aging.

Association of Kidney Disease, Potassium, and Cardiovascular Risk Factor Prevalence with Coronary Arteriosclerotic Burden, by Sex.

The present study aimed to determine the relationship between the prevalence of cardiovascular risk factors and the number and severity of coronary artery atherosclerotic lesions obtained by coronary angiography. We reviewed and analyzed 1642 records from consecutive patients at the Catheter Laboratory of Talca Regional Hospital in Chile between March 2018 and May 2019. Patients were stratified according to the presence and severity of atherosclerotic lesions: 632 (38.5%) had no lesions or <30% stenosis and 1010 (61.5%) had at least one coronary atherosclerotic lesion with ≥30% stenosis (CALS-30). CALS-30 was more frequent in males, smokers, and patients with diabetes and/or hypertension (all p-values < 0.02). Serum potassium, glycaemia, creatinine and glomerular filtration rates were also associated with CALS-30 (all p-values < 0.01) in males. The age and the proportion of males with CALS-30 increased with the number of risk factors (p-values for trends < 0.001). Our results showed a stronger association between the accumulation of risk factors and CALS-30 in women than in men. Serum potassium levels were inversely associated with CALS-30 in men but not in women.

Polypharmacy Is Associated with Frailty, Nutritional Risk and Chronic Disease in Chilean Older Adults: Remarks from PIEI-ES Study.

AIM: To analyze the relationship between polypharmacy and variables as frailty and other chronic comorbidities in Chilean older adults. DESIGN: Cross-sectional study. PARTICIPANTS: One thousand two hundred and five older adults aged 65 and older. METHODS: The presence or absence of frailty syndrome was determined according to Fried criteria. Data collection was made through questionnaires conducted by an interview. RESULTS: The prevalence of polypharmacy was 37.59%. The prevalence of hyperpolypharmacy was 2%. Increased prevalence of frailty was demonstrated regarding the progression of the state of polypharmacy. When analyzing the contribution of frailty respect polypharmacy condition, frail state, nutritional risk and obesity are founded as a factor associated with polypharmacy. Regarding chronic disease, hypertension (OR: 8.039, p<0.0001), type 2 diabetes (OR: 4.001, p<0.0001) and respiratory diseases (OR: 2.930, p<0.0001) were associated to polypharmacy. It was found a strong and significant positive correlation between polypharmacy prevalence and frailty score (polypharmacy condition, Spearman R: 0.89, p=0.033; hyperpolypharmacy condition, Spearman R: 0.94, p=0.016). When analyzing the contribution of the polypharmacy to the presence of frailty, polypharmacy condition (OR: 1.510, p<0.05), cognitive impairment (OR: 3.887, p<0.001), obesity (OR: 1.560, p<0.01) and nutritional risk (OR: 2.590, p<0.001) are associated to frailty. CONCLUSION: Frailty and chronic conditions as nutritional risk, obesity, hypertension, type 2 diabetes and respiratory disease are an important risk factor for the development of polypharmacy in Chilean older adults. Likewise, polypharmacy condition was observed to be a risk factor for frailty, demonstrating the bidirectional relationship between both conditions. Frailty syndrome evaluation in Chilean older adults could be an important alternative for polypharmacy prevention.

Caveolin-1-Mediated Tumor Suppression Is Linked to Reduced HIF1α S-Nitrosylation and Transcriptional Activity in Hypoxia.

Caveolin-1 (CAV1) is a well-established nitric oxide synthase inhibitor, whose function as a tumor suppressor is favored by, but not entirely dependent on, the presence of E-cadherin. Tumors are frequently hypoxic and the activation of the hypoxia-inducible factor-1α (HIF1α) promotes tumor growth. HIF1α is regulated by several post-translational modifications, including S-nitrosylation. Here, we evaluate the mechanisms underlying tumor suppression by CAV1 in cancer cells lacking E-cadherin in hypoxia. Our main findings are that CAV1 reduced HIF activity and Vascular Endothelial Growth Factor expression in vitro and in vivo. This effect was neither due to reduced HIF1α protein stability or reduced nuclear translocation. Instead, HIF1α S-nitrosylation observed in hypoxia was diminished by the presence of CAV1, and nitric oxide synthase (NOS) inhibition by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) reduced HIF1α transcriptional activity in cells to the same extent as observed upon CAV1 expression. Additionally, arginase inhibition by (S)-(2-Boronoethyl)-L-cysteine (BEC) partially rescued cells from the CAV1-mediated suppression of HIF1α transcriptional activity. In vivo, CAV1-mediated tumor suppression was dependent on NOS activity. In summary, CAV1-dependent tumor suppression in the absence of E-cadherin is linked to reduced HIF1α transcriptional activity via diminished NOS-mediated HIF1α S-nitrosylation.

Supramolecular hydrogels based on cellulose for sustained release of therapeutic substances with antimicrobial and wound healing properties.

A multifaceted hydrogel-based formulation was reported. The hydrogel was prepared by crosslinking cellulose and substituted chalcone. Moreover, the formulation was conjugated with carbon nanotubes with the aim of increasing the loading amount of bioactive compounds such as allantoin, dexpanthenol, resveratrol and linezolid. The hydrogel formation was confirmed by swelling tests, FT-IR spectroscopy, thermogravimetric analysis and SEM. The hydrogel showed an improved release rate of therapeutic substances, exhibiting a simultaneous and coordinated release according to the chromatographic studies. The efficacy of drug release was confirmed by wound closure and in vivo wound healing studies that showed promising healing results. The antibacterial assays demonstrated that the sustained release of linezolid tends to be very effective. In conclusion, a multifaceted formulation based on carbon nanotube-containing cellulose-chalcone was developed that can potentially be utilized in treating complex wounds owing to its improved wound healing properties and prevention of potential infections.

Older adults with frailty syndrome present an altered platelet function and an increased level of circulating oxidative stress and mitochondrial dysfunction biomarker GDF-15.

INTRODUCTION: The elderly population is increasing worldwide and in Chile, it is expected to grow rapidly. The World Health Organization (WHO) ICOPE guideline (Integrated Care for Older People) emphasizes the importance of frailty diagnosis to prevent dependence. Frailty in older adults is considered an indicator of vulnerability and poor health outcomes, of multifactorial etiology. Our objective was to investigate the association of activation of coagulation and increased risk of thrombosis with frailty in people older than 64 years. A prevalent-case control study was designed with 28 frail older and 27 robust older adults (non-frail, control group) older than 64 years. Frailty was defined by Fried's Phenotype, Platelet aggregation and activation plasma levels of Thromboxane B2 (TXB2), 8-isoprostane and Growth Differentiation Factor-15 (GDF-15) were determined. RESULTS: Compared to healthy controls, frail older adults, had a) higher percentage of platelet aggregation induction with ADP 4 µM (82.85% (3.35) and 73.41% (3.26), p-value = 0.024) and subaggregant dose of ADP (30.83% (7.47) and 13.25% (3.21), p-value = 0.002); b) higher platelet activation: P-selectin exposure (18.23% (4.41) and 6.96% (1.08), p-value = 0.011), and activated GPIIß-IIIα (21.51% (3.41) and 8.26% (1.18), p-value = 0.001), at the baseline level and against a subaggregant dose ADP: P-selectin exposure (46.93% (5.95) and 13.41% (3.35), p-value = 0.002) and activated GPIIß-IIIα (43.29% (6.04) and 26.71% (4.92), p-value = 0.024); c) higher plasma levels of TXB2 (201.8 ng/mL (59.53-236.3) and 45.77 ng/mL (25.14-98.26), p-value<0.0001), d) elevated plasma levels of 8-isoprostane (70.94 pg/mL, IQ: 65.89-99,96 and 56.24 pg/mL, IQ: 42.18-74.81, p-value = 0.001), and e) higher plasma GDF-15 levels (2,379 pg/mL, IQ: 1,845-4,121and 1367 pg/mL, IQ: 1190-1747, p-value = 0.0001). DISCUSSION: Older adults with frailty syndrome have an upregulated platelet activity that may contribute to an increased risk of thrombosis and aspirin resistance. The elevated oxidative stress and increases of GDF-15 levels might be related to altered platelet responsiveness in frail patients. CONCLUSION: The determination of biomarkers of platelet dysfunction, oxidative stress and cell senescence/mitochondrial dysfunction may contribute to frailty diagnosis, and approaches aimed at regulating platelet function in frail older adults could contribute to its prevention and treatment.

The Helicobacter pylori Urease Virulence Factor Is Required for the Induction of Hypoxia-Induced Factor-1α in Gastric Cells.

Chronic Helicobacter pylori infection increases the risk of gastric cancer and induction of hypoxia-induced factor (HIF), which is frequently associated with the development and progression of several types of cancer. We recently showed that H. pylori activation of the PI3K-AKT-mTOR pathway in gastric cells increased HIF-1α expression. Here, we identified the H. pylori virulence factor responsible for HIF-1α induction. A mutant of the H. pylori 84-183 strain was identified with reduced ability to induce HIF-1α. Coomassie blue staining of extracts from these bacteria separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed poor expression of urease subunits that correlated with reduced urease activity. This finding was confirmed in the 26695 strain, where urease mutants were unable to induce HIF-1α expression. Of note, HIF-1α induction was also observed in the presence of the urease inhibitor acetohydroxamic acid at concentrations (of 20 mM) that abrogated urease activity in bacterial culture supernatants, suggesting that enzymatic activity of the urease is not required for HIF-1α induction. Finally, the pre-incubation of the human gastric adenocarcinoma cell line AGS with blocking antibodies against Toll-like receptor-2 (TLR2), but not TLR4, prevented HIF-1α induction. In summary, these results reveal a hitherto unexpected role for the urease protein in HIF-1α induction via TLR2 activation following H. pylori infection of gastric cells.