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1.
Int J Mol Sci ; 25(13)2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-39000523

RESUMO

The dental implant surface plays a crucial role in osseointegration. The topography and physicochemical properties will affect the cellular functions. In this research, four distinct titanium surfaces have been studied: machined acting (MACH), acid etched (AE), grit blasting (GBLAST), and a combination of grit blasting and subsequent acid etching (GBLAST + AE). Human amniotic mesenchymal (hAMSCs) and epithelial stem cells (hAECs) isolated from the amniotic membrane have attractive stem-cell properties. They were cultured on titanium surfaces to analyze their impact on biological behavior. The surface roughness, microhardness, wettability, and surface energy were analyzed using interferometric microscopy, Vickers indentation, and drop-sessile techniques. The GBLAST and GBLAST + AE surfaces showed higher roughness, reduced hydrophilicity, and lower surface energy with significant differences. Increased microhardness values for GBLAST and GBLAST + AE implants were attributed to surface compression. Cell viability was higher for hAMSCs, particularly on GBLAST and GBLAST + AE surfaces. Alkaline phosphatase activity enhanced in hAMSCs cultured on GBLAST and GBLAST + AE surfaces, while hAECs showed no mineralization signals. Osteogenic gene expression was upregulated in hAMSCs on GBLAST surfaces. Moreover, α2 and ß1 integrin expression enhanced in hAMSCs, suggesting a surface-integrin interaction. Consequently, hAMSCs would tend toward osteoblastic differentiation on grit-blasted surfaces conducive to osseointegration, a phenomenon not observed in hAECs.


Assuntos
Âmnio , Implantes Dentários , Propriedades de Superfície , Titânio , Humanos , Titânio/química , Âmnio/citologia , Âmnio/metabolismo , Osteogênese , Diferenciação Celular , Células Cultivadas , Osseointegração , Células-Tronco/citologia , Células-Tronco/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Sobrevivência Celular , Fosfatase Alcalina/metabolismo
2.
Cardiovasc Diabetol ; 23(1): 253, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014420

RESUMO

BACKGROUND: Type 2 diabetes (T2D) patients have an increased risk of heart failure (HF). There are limited data on the association between HF and T2D in specific healthcare settings. This study sought to analyse the prevalence and incidence of HF in a contemporary cohort of T2D patients attending cardiology and endocrinology outpatient clinics. METHODS: We conducted an observational multicentre prospective study (DIABET-IC) that enrolled patients with a T2D diagnosis attending cardiology and endocrinology outpatient clinics in 30 centres in Spain between 2018 and 2019. The prevalence at the start of the study and the incidence of HF after a 3 year follow-up were calculated. HF was defined as the presence of typical symptoms and either: a) LVEF < 40%; or b) LVEF ≥ 40% with elevated natriuretic peptides and echocardiographic abnormalities. RESULTS: A total of 1249 T2D patients were included in the present analysis (67.6 ± 10.1 years, 31.7% female). HF was present in 490 participants at baseline (prevalence 39.2%), 150 (30.6%) of whom had a preserved ejection fraction. The presence of adverse social determinants and chronic conditions such as chronic kidney disease and atherosclerotic cardiovascular disease were more frequent in HF patients. During the study period, there were 58 new diagnoses of HF (incidence 7.6%) among those without baseline HF. The incidence rate was 3.0 per 100 person-years. Independent predictors of incident HF were smoking, left ventricular ejection fraction, NT-ProBNP, history of tachyarrhythmia and treatment with pioglitazone, oral anticoagulants, or diuretics. Despite an average suboptimal glycaemic control, the use of antidiabetic drugs with cardiovascular benefits was low (30.4% for sodium-glucose cotransporter-2 inhibitors and 12.5% for glucagon-like peptide-1 receptor agonists). CONCLUSIONS: In this contemporary cohort of T2D patients attending cardiology and endocrinology outpatient clinics, the prevalence and incidence of HF were high, comorbidities were frequent, and the use of antidiabetic agents with cardiovascular benefit was low. Outpatient care seems to be a unique opportunity for a comprehensive T2D approach that encompasses HF prevention, diagnosis, and treatment.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência Cardíaca , Humanos , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Feminino , Masculino , Estudos Prospectivos , Incidência , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/fisiopatologia , Prevalência , Pessoa de Meia-Idade , Espanha/epidemiologia , Idoso , Fatores de Tempo , Medição de Risco , Fatores de Risco , Prognóstico , Função Ventricular Esquerda , Hipoglicemiantes/uso terapêutico
3.
Biol Reprod ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38924703

RESUMO

During pregnancy, apoptosis is a physiological event critical in the remodeling and aging of the placenta. Increasing evidence has pointed towards the relevance of hypoxia as modulator of trophoblast cell death. Previous reports have shown that leptin, a placental cytokine, promotes cell survival in both cell culture and placental explant models. The aim of this work is to establish the role of leptin in apoptosis under hypoxic condition in trophoblast cells. In this study, we evaluated the effect of cobalt chloride, a hypoxia mimicking agent that stabilizes the expression of hypoxia inducible factor-1 alpha (HIF-1α), on Swan-71 and human placental explants. Hypoxia chamber was also used to generate 2% oxygen. Apoptosis was determined by the presence of apoptotic nucleus, fragmentation of DNA and Caspase-3 and PARP-1 cleavage. The pro-apoptotic proteins BAX, BID, BAD and BAK and the anti-apoptotic effectors BCL-2, BCL-xL and MCL-1 were also analyzed. We found that HIF-1α stabilization increased the appearance of apoptotic nucleus, fragmentation of DNA, and Caspase-3 and PARP-1 cleavage. Hypoxia mimicking conditions enhanced the expression of pro-apoptotic effectors BAX, BID, BAD and BAK. HIF-1α stabilization also downregulated the level of BCL-2, BCL-xL and MCL-1. All these apoptotic parameters changes were reversed with leptin treatment. Moreover, we showed that leptin action on apoptosis modulation involves PI3K and MAPK signaling pathways. Obtained data demonstrate that HIF-1α stabilization induces apoptosis in human placenta and leptin counteracts this effect, reinforcing its role as a survival cytokine.

4.
Int J Oncol ; 65(2)2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38940351

RESUMO

Obesity is a chronic disease caused by the accumulation of excessive adipose tissue. This disorder is characterized by chronic low­grade inflammation, which promotes the release of proinflammatory mediators, including cytokines, chemokines and leptin. Simultaneously, chronic inflammation can predispose to cancer development, progression and metastasis. Proinflammatory molecules are involved in the recruitment of specific cell populations in the tumor microenvironment. These cell populations include myeloid­derived suppressor cells (MDSCs), a heterogeneous, immature myeloid population with immunosuppressive abilities. Obesity­associated MDSCs have been linked with tumor dissemination, progression and poor clinical outcomes. A comprehensive literature review was conducted to assess the impact of obesity­associated MDSCs on cancer in both preclinical models and oncological patients with obesity. A secondary objective was to examine the key role that leptin, the most important proinflammatory mediator released by adipocytes, plays in MDSC­driven immunosuppression Finally, an overview is provided of the different therapeutic approaches available to target MDSCs in the context of obesity­related cancer.


Assuntos
Progressão da Doença , Células Supressoras Mieloides , Neoplasias , Obesidade , Microambiente Tumoral , Humanos , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Obesidade/complicações , Obesidade/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias/etiologia , Microambiente Tumoral/imunologia , Animais , Leptina/metabolismo , Inflamação/imunologia , Inflamação/patologia
6.
ACS Phys Chem Au ; 4(3): 242-246, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38800722

RESUMO

Photon upconversion based on triplet-triplet annihilation (TTA-UC) is an attractive wavelength conversion with increasing use in organic synthesis in the homogeneous phase; however, this technology has not performed with canonical solid catalysts yet. Herein, a BOPHY dye covalently anchored on silica is successfully used as a sensitizer in a TTA system that efficiently catalyzes Mizoroki-Heck coupling reactions. This procedure has enabled the implementation of in-flow reaction conditions for the synthesis of a variety of aromatic compounds, and mechanistic proof has been obtained by means of transient absorption spectroscopy.

8.
Aten Primaria ; 56(10): 102953, 2024 May 04.
Artigo em Espanhol | MEDLINE | ID: mdl-38705132

RESUMO

The prevalence of overweight and obesity, and, consequently, associated comorbidities, is increasing significantly worldwide. The guidelines recommend a percentage of weight loss> 5% to achieve beneficial effects on metabolic comorbidities associated with obesity. Furthermore, greater weight losses (> 10%) produce more significant improvements, and may even produce remission of some of these comorbidities. In this chapter, we review the evidence of the effect of weight loss through different strategies (lifestyle intervention, pharmacological treatment, or bariatric surgery) on the main cardiometabolic pathologies associated with excess adipose tissue (type 2 diabetes, high blood pressure, dyslipidemia, metabolic dysfunction-associated steatotic liver disease, inflammation, cardiovascular diseases, and mortality).

9.
Biomed Pharmacother ; 175: 116779, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38776681

RESUMO

Diabetic patients present increased volume and functional alterations in epicardial adipose tissue (EAT). We aimed to analyze EAT from type 2 diabetic patients and the inflammatory and cytotoxic effects induced on cardiomyocytes. Furthermore, we analyzed the cardioprotective role of apolipoprotein J (apoJ). EAT explants were obtained from nondiabetic patients (ND), diabetic patients without coronary disease (DM), and DM patients with coronary disease (DM-C) after heart surgery. Morphological characteristics and gene expression were evaluated. Explants were cultured for 24 h and the content of nonesterified fatty acids (NEFA) and sphingolipid species in secretomes was evaluated by lipidomic analysis. Afterwards, secretomes were added to AC16 human cardiomyocytes for 24 h in the presence or absence of cardioprotective molecules (apoJ and HDL). Cytokine release and apoptosis/necrosis were assessed by ELISA and flow cytometry. The EAT from the diabetic samples showed altered expression of genes related to lipid accumulation, insulin resistance, and inflammation. The secretomes from the DM samples presented an increased ratio of pro/antiatherogenic ceramide (Cer) species, while those from DM-C contained the highest concentration of saturated NEFA. DM and DM-C secretomes promoted inflammation and cytotoxicity on AC16 cardiomyocytes. Exogenous Cer16:0, Cer24:1, and palmitic acid reproduced deleterious effects in AC16 cells. These effects were attenuated by exogenous apoJ. Diabetic secretomes promoted inflammation and cytotoxicity in cardiomyocytes. This effect was exacerbated in the secretomes of the DM-C samples. The increased content of specific NEFA and ceramide species seems to play a key role in inducing such deleterious effects, which are attenuated by apoJ.


Assuntos
Tecido Adiposo , Diabetes Mellitus Tipo 2 , Inflamação , Miócitos Cardíacos , Pericárdio , Humanos , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Tecido Adiposo/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Pericárdio/metabolismo , Pericárdio/patologia , Diabetes Mellitus Tipo 2/metabolismo , Inflamação/patologia , Inflamação/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Apoptose/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Ácidos Graxos não Esterificados/metabolismo , Ácidos Graxos não Esterificados/farmacologia , Tecido Adiposo Epicárdico
11.
Chemistry ; 30(37): e202400860, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38699858

RESUMO

2,5-Dimethyl-2,4-hexadiene is a readily available and easily managable compound, whose symmetric and polymethylated dienic structure should be prone to engage in cross-metathesis reactions with other alkenes, but this has not been apparently exploited so far. Here we show that this reactant enables the easy synthesis of tri- and tetra-susbtituted alkenes (i. e. isobutylenyl and prenyl groups) from simple alkenes under mild reaction conditions, not only with the conventional 2nd generation Grubbs catalyst but also with other Grela-type catalyts such as StickyCat,TM AquaMetTM and GreenCatTM. The use of liquid and low volatile 2,5-dimethyl-2,4-hexadiene avoids the use of gaseous alkene reactants and, besides, showcases the reactivity of polyisoprene (rubber), thus allowing to optimize the reaction conditions for rubber upcycling, after metathesis reaction of the pristine or used polymer with simple alkenes. These results bring low volatile isoprene-type compounds as privileged poly-substituted reactants for alkene cross-metathesis reactions.

12.
Biosensors (Basel) ; 14(4)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38667200

RESUMO

Organic electrochemical transistors appear as an alternative for relatively low-cost, easy-to-operate biosensors due to their intrinsic amplification. Herein, we present the fabrication, characterization, and validation of an immuno-detection system based on commercial sensors using gold electrodes where no additional surface treatment is performed on the gate electrode. The steady-state response of these sensors has been studied by analyzing different semiconductor organic channels in order to optimize the biomolecular detection process and its the application to monitoring human IgG levels due to SARS-CoV-2 infections. Detection levels of up to tens of µgmL-1 with sensitivities up to 13.75% [µg/mL]-1, concentration ranges of medical relevance in seroprevalence studies, have been achieved.


Assuntos
Técnicas Biossensoriais , COVID-19 , Técnicas Eletroquímicas , Imunoglobulina G , SARS-CoV-2 , Transistores Eletrônicos , Humanos , Técnicas Biossensoriais/instrumentação , Imunoglobulina G/sangue , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , COVID-19/diagnóstico , COVID-19/sangue , Ouro/química , Eletrodos , Anticorpos Antivirais , Imunoensaio
13.
J Clin Med ; 13(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38610687

RESUMO

Aims: To evaluate the metabolic and clinical outcomes in the Spanish type 1 diabetes mellitus (T1D) population before and after COVID-19 vaccination. Methods: A retrospective observational study was carried out in Spanish public hospitals previously enrolled in the SED1 study. Adults and children with T1D were included and their clinical electronic records were reviewed. Clinical, laboratory, and glucometric parameters from continuous glucose monitoring (CGM) data corresponding to the periods before and after administering the first COVID-19 vaccination were analyzed. Results: A total of 26 centers and 228 patients participated in this new phase of the SED1 study and 187 were finally evaluable (mean age 37.5 ± 15.6 years, 56.7% women). Overall, 94.6% of the sample was vaccinated, and this percentage increased with higher levels of education (p-value = 0.027). In the pre- and post-vaccination periods, respectively, the number of patients with acute hyperglycemic decompensation was 6/161 (3.7%) and 7/161 (4.3%) (p = 1) and with acute hypoglycemic decompensation was 6/161 (3.7%) and 6/161 (3.7%) (p = 1). The HbA1c level was lower in the post-vaccination period(mean ± SD, mg/dL): pre-vaccination 7.4 ± 0.9; post-vaccination 7.2 ± 1.0, (-0.19; p-value = 0.0006). A total of 31.9% of patients (95% CI: 24.7-39.7) in the pre-vaccination period and 45.0% (IC95%: 37.1-53.1) in the post-vaccine period had HbA1c < 7% (p-value < 0.001). Glucometrics from CGM data also showed numerical improvements post-vaccination. Conclusions: The COVID-19 vaccination was highly accepted in the Spanish T1D population, with hesitancy about the COVID-19 vaccine being higher in those with lower educational levels. A mildly better glycemic control was observed in the post-vaccination period.

15.
Plant Sci ; 344: 112087, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38599247

RESUMO

The circadian clock plays a critical role in regulating plant physiology and metabolism. However, the way in which the clock impacts the regulation of lipid biosynthesis in seeds is partially understood. In the present study, we characterized the seed fatty acid (FA) and glycerolipid (GL) compositions of pseudo-response regulator mutants. Among these mutants, toc1 (timing of cab expression 1) exhibited the most significant differences compared to control plants. These included an increase in total FA content, characterized by elevated levels of linolenic acid (18:3) along with a reduction in linoleic acid (18:2). Furthermore, our findings revealed that toc1 developing seeds showed increased expression of genes related to FA metabolism. Our results show a connection between TOC1 and lipid metabolism in Arabidopsis seeds.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Sementes , Ácido alfa-Linolênico , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Sementes/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Ácido alfa-Linolênico/metabolismo , Regulação da Expressão Gênica de Plantas , Relógios Circadianos/genética , Ácidos Graxos/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Metabolismo dos Lipídeos
16.
Surg Endosc ; 38(6): 3320-3328, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38684527

RESUMO

BACKGROUND: Obesity-related comorbidities may relapse in patients with weight regain after bariatric surgery. However, HDL cholesterol (HDLc) levels increase after surgery and seem to remain stable despite a gradual increase in BMI. The aim of this study is to analyze the effects of weight regain after bariatric surgery on HDL cholesterol. MATERIALS AND METHODS: This is a retrospective, observational, cohort study in patients who underwent bariatric surgery in the Hospital de la Santa Creu i Sant Pau (Barcelona) between 2007 and 2015. Patients without at least 5 years of follow-up after surgery, under fibrate treatment, and those who required revisional surgery were excluded from the analysis. Data were collected at baseline, 3 and 6 months after surgery, and then annually until 5 years post-surgery. RESULTS: One hundred fifty patients were analyzed. 93.3% of patients reached > 20% of total weight loss after surgery. At 5th year, 37% of patients had regained > 15% of nadir weight, 60% had regained > 10%, and 22% had regained < 5% of nadir weight. No differences were found in HDLc levels between the different groups of weight regain, nor in the % of change in HDLc levels between nadir weight and 5 years, or in the proportion of patients with normal HDLc concentrations either. CONCLUSION: HDLc remains stable regardless of weight regain after bariatric surgery.


Assuntos
Cirurgia Bariátrica , HDL-Colesterol , Aumento de Peso , Redução de Peso , Humanos , Estudos Retrospectivos , Feminino , Masculino , HDL-Colesterol/sangue , Adulto , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Obesidade Mórbida/sangue , Índice de Massa Corporal , Recidiva
17.
Eur J Clin Invest ; 54(8): e14214, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38613414

RESUMO

The burden of cardiovascular disease is particularly high among individuals with diabetes, even when LDL cholesterol is normal or within the therapeutic target. Despite this, cholesterol accumulates in their arteries, in part, due to persistent atherogenic dyslipidaemia characterized by elevated triglycerides, remnant cholesterol, smaller LDL particles and reduced HDL cholesterol. The causal link between dyslipidaemia and atherosclerosis in T2DM is complex, and our contention is that a deeper understanding of lipoprotein composition and functionality, the vehicle that delivers cholesterol to the artery, will provide insight for improving our understanding of the hidden cardiovascular risk of diabetes. This narrative review covers three levels of complexity in lipoprotein characterization: 1-the information provided by routine clinical biochemistry, 2-advanced nuclear magnetic resonance (NMR)-based lipoprotein profiling and 3-the identification of minor components or physical properties of lipoproteins that can help explain arterial accumulation in individuals with normal LDLc levels, which is typically the case in individuals with T2DM. This document highlights the importance of incorporating these three layers of lipoprotein-related information into population-based studies on ASCVD in T2DM. Such an attempt should inevitably run in parallel with biotechnological solutions that allow large-scale determination of these sets of methodologically diverse parameters.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Fatores de Risco de Doenças Cardíacas , Lipoproteínas , Humanos , Diabetes Mellitus Tipo 2/complicações , Lipoproteínas/metabolismo , Lipoproteínas/sangue , Doenças Cardiovasculares/etiologia , Dislipidemias , Espectroscopia de Ressonância Magnética , Aterosclerose , LDL-Colesterol/metabolismo , LDL-Colesterol/sangue , HDL-Colesterol/metabolismo , Triglicerídeos/metabolismo
18.
Farm Hosp ; 2024 Apr 02.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38570210

RESUMO

BACKGROUND: Adalimumab biosimilar MSB11022 (Idacio ®) has been approved for the same indications as its originator (Humira ®), based on findings from clinical trials in plaque psoriasis. Data on its efficacy and safety in inflammatory bowel disease, however, are scarce. METHODS: Retrospective, observational study of 44 patients with inflammatory bowel disease: 30 were treated with originator adalimumab, 5 were directly started on MSB11022, and 9 switched from originator to biosimilar adalimumab. To evaluate the effectiveness of the use of adalimumab in inflammatory bowel disease, both laboratory markers (fecal calprotectin and C-reactive protein) and scales that measure the activity of inflammatory bowel disease using specific scales (Harvey-Bradshaw Index (HBI) have been usEd.) for Crohn's disease and Mayo Score for Ulcerative Colitis. Efficacy was evaluated by recording the adverse effects that could occur with the administration of adalimumab (original or biosimilar). The success of the switch was determined by analyzing meaningful differences in effectiveness and safety criteria. Concomitant therapy and the need for dose intensification were also analyzed. Objective of this study was to assess the effectiveness and safety of biosimilar adalimumab in adalimumab-naïve patients and patients switched from originator adalimumab. RESULTS: No significant differences were observed in clinical disease activity (P=.317) or biochemical parameters [fecal calprotectin (P=.445) and C-reactive protein P=.661)] after the switch from the originator adalimumab to MSB11022. There was not a significant reduction in the concomitant use of corticosteroids and thiopurines (P=.157). No emergency room visits or hospitalizations were observed during the study period and none of the patients experienced serious adverse effects. CONCLUSIONS: Between originator adalimumab and biosimilar-start cohorts, no differences were observed, between originator adalimumab and switch cohorts, no significant differences were found either, and with the pre- and post-switch to biosimilar comparison, 2 of the 9 patients experienced AEs after the switch. The biosimilar showed a favorable safety profile (one patient with a serious adverse effect (rash) with biosimilar discontinued treatment) and no significant changes to clinical or biochemical parameters were observed after the switch.

19.
Commun Chem ; 7(1): 76, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575790

RESUMO

Metal individual atoms and few-atom clusters show extraordinary catalytic properties for a variety of organic reactions, however, their implementation in total synthesis of complex organic molecules is still to be determined. Here we show a 11-step linear synthesis of the natural product (±)-Licarin B, where individual Pd atoms (Pd1) catalyze the direct aerobic oxidation of an alcohol to the carboxylic acid (steps 1 and 6), Cu2-7 clusters catalyze carbon-oxygen cross couplings (steps 3 and 8), Pd3-4 clusters catalyze a Sonogashira coupling (step 4) and Pt3-5 clusters catalyze a Markovnikov hydrosylilation of alkynes (step 5), as key reactions during the synthetic route. In addition, the new synthesis of Licarin B showcases an unexpected selective alkene hydrogenation with metal-free NaBH4 and an acid-catalyzed intermolecular carbonyl-olefin metathesis as the last step, to forge a trans-alkene group. These results, together, open new avenues in the use of metal individual atoms and clusters in organic synthesis, and confirm their exceptional catalytic activity in late stages during complex synthetic programmes.

20.
J Alzheimers Dis ; 98(2): 601-618, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427484

RESUMO

Background: Microglial dysfunction plays a causative role in Alzheimer's disease (AD) pathogenesis. Here we focus on a germline insertion/deletion variant mapping SIRPß1, a surface receptor that triggers amyloid-ß(Aß) phagocytosis via TYROBP. Objective: To analyze the impact of this copy-number variant in SIRPß1 expression and how it affects AD molecular etiology. Methods: Copy-number variant proxy rs2209313 was evaluated in GERALD and GR@ACE longitudinal series. Hippocampal specimens of genotyped AD patients were also examined. SIRPß1 isoform-specific phagocytosis assays were performed in HEK393T cells. Results: The insertion alters the SIRPß1 protein isoform landscape compromising its ability to bind oligomeric Aß and its affinity for TYROBP. SIRPß1 Dup/Dup patients with mild cognitive impairment show an increased cerebrospinal fluid t-Tau/Aß ratio (p = 0.018) and a higher risk to develop AD (OR = 1.678, p = 0.018). MRIs showed that Dup/Dup patients exhibited a worse initial response to AD. At the moment of diagnosis, all patients showed equivalent Mini-Mental State Examination scores. However, AD patients with the duplication had less hippocampal degeneration (p < 0.001) and fewer white matter hyperintensities. In contrast, longitudinal studies indicate that patients bearing the duplication allele show a slower cognitive decline (p = 0.013). Transcriptional analysis also shows that the SIRPß1 duplication allele correlates with higher TREM2 expression and an increased microglial activation. Conclusions: The SIRPß1 internal duplication has opposite effects over MCI-to-Dementia conversion risk and AD progression, affecting microglial response to Aß. Given the pharmacological approaches focused on the TREM2-TYROBP axis, we believe that SIRPß1 structural variant might be considered as a potential modulator of this causative pathway.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Receptores de Superfície Celular , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/genética , Disfunção Cognitiva/metabolismo , Microglia/metabolismo , Fagocitose , Receptores de Superfície Celular/metabolismo
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