👤 José A Pérez

Small dense low-density lipoprotein (sdLDL) is a highly atherogenic LDL subclass associated with cardiovascular disease (CVD). While type 1 diabetes confers increased cardiovascular risk despite adequate glycemic control, the role of sdLDL and its regulators remains unclear. In this cross-sectional observational study, plasma from 69 individuals with long-standing type 1 diabetes and 24 healthy controls was analyzed. sdLDL-cholesterol (sdLDL-C) concentration, sdLDL-C/LDL-cholesterol ratio, LDL size and subclasses were assessed using homogeneous assays, NMR spectroscopy, and gradient gel electrophoresis. Apolipoprotein C3 (ApoC3), hepatic lipase (HL), endothelial lipase (EL), and cholesteryl ester transfer protein (CETP) activity were measured by immunoturbidimetric, ELISA and functional assays. Despite adequate glycemic control (mean HbA1c 7.6% [60 mmol/mol]) and near-normal lipid levels, individuals with type 1 diabetes had significantly higher sdLDL-C (0.56 ± 0.28 mmol/L vs 0.43 ± 0.26 mmol/L), increased sdLDL-C/LDL-cholesterol ratio (0.20 ± 0.08 vs 0.12 ± 0.06) and smaller LDL particle size (26.32 ± 1.08 nm vs 26.81 ± 0.68 nm) compared with controls. ApoC3 and HL mass/activity were significantly increased (8.67 ± 3.22 mg/dL vs 6.53 ± 2.42; 46.60 ± 16.12 ng/mL vs 15.45 ± 7.40 ng/mL and 1.03 ± 0.24 U/mL vs 0.89 ± 0.23 U/mL; respectively), CETP activity significantly reduced (808.8 ± 197.0 pmol/mL/h vs 929.7 ± 149.6 pmol/mL/h), and endothelial lipase levels unchanged. sdLDL-C positively correlated with ApoC3 (r = 0.7517) and inversely with CETP activity (r = -0.2682). Long-standing type 1 diabetes with adequate glycemic control is associated with an atherogenic sdLDL profile despite near-normal conventional lipid levels. This first multi-method characterization study of sdLDL in type 1 diabetes highlights the contribution of ApoC3, CETP and HL to sdLDL-C enrichment and suggests that direct assessment of sdLDL may improve cardiovascular risk stratification. Show less

Homozygous familial hypercholesterolemia (HoFH) is a rare disease characterized by the presence of 2 pathogenic variants in the LDLR, APOB, PCSK9, or LDLRAP1 genes, which cause very high levels of LDL-cholesterol and premature atherosclerotic cardiovascular disease (ASCVD). To analyze the current situation regarding diagnosis, cardiovascular disease, lipid-lowering treatment, and degree of control of lipids in patients with HoFH in the National Dyslipidemia Registry of the Spanish Atherosclerosis Society. Subjects with HoFH, confirmed by the presence of 2 pathogenic variants in the genes mentioned above, included in the registry from 2013 to June 2023 with an updated review were analyzed. Of 71 included subjects with HoFH, 40.8% were women, aged 52 [24-62] years, 57 adults and 13 children. The median follow-up was 7 [4-13] years. Age of diagnosis was 14 [2-26] years, with 10% of ASCVD at diagnosis and 27% of current ASCVD at 40.6 (13.4) years of age; 38% were on PCSK9 inhibitors, 9 patients on lomitapide, 9 on LDL apheresis, and 1 patient on evinacumab. Subjects with more than 4 therapies achieved >80% reduction in LDLc. In the last visit, the median LDLc was 139.3 [89.4-204.2] mg/dL. ASCVD was strongly associated with male sex and family history of ASCVD, relative risk 5.26 (1.53-18.10) and 2.53 (1.03-6.26), P < .05, respectively. Only 18% and 10% meet the recommended LDLc goal in primary and secondary prevention respectively. The current situation of HoFH in Spain is better than expected, with marked reductions in LDLc levels with new treatments. In this population, recommended LDLc goals are difficult to achieve despite maximum lipid-lowering therapy. ASCVD has been reduced and delayed by 2 decades. Show less

Methylxanthines and their derivatives are of great interest due to their diverse biological activities. In this work, a new series of twenty-eight semisynthetic theobromine and theophylline derived compounds were designed and synthesized by applying a simple and efficient strategy. First, the corresponding methylxanthine was reacted with a dibromoalkane ( Show less

Multitarget compounds have emerged as promising drug candidates to cope with complex multifactorial diseases, like Alzheimer's disease (AD). Most multitarget compounds are designed by linking two pharmacophores through a tether chain (linked hybrids), which results in rather large molecules that are particularly useful to hit targets with large binding cavities, but at the expense of suffering from suboptimal physicochemical/pharmacokinetic properties. Molecular size reduction by removal of superfluous structural elements while retaining the key pharmacophoric motifs may represent a compromise solution to achieve both multitargeting and favorable physicochemical/PK properties. Here, we report the stepwise structural simplification of the dihydroxyanthraquinone moiety of a rhein-huprine hybrid lead by hydroxy group removal-ring contraction-ring opening-ring removal, which has led to new analogs that retain or surpass the potency of the lead on its multiple AD targets while exhibiting more favorable drug metabolism and pharmacokinetic (DMPK) properties and safety profile. In particular, the most simplified acetophenone analog displays dual nanomolar inhibition of human acetylcholinesterase and butyrylcholinesterase (IC Show less

Feline osteochondromatosis is a spontaneous osteocartilaginous exostosis associated with feline leukaemia virus (FeLV) infection or due to a frameshift variant in the exostosin glycosyltransferase 1 (EXT1) gene. Osteochondromatosis was diagnosed in an indoor-only, 12-year-old, neutered female, Russian Blue cat. Radiographs revealed bilateral calcified proliferations in the elbow, costochondral and sternochondral joints, which distorted the normal skeletal structure. Grossly, the proliferated joints presented with consistent, rounded masses, causing complete ankylosis. The main histopathological finding was an osteocartilaginous proliferation composed of multiple irregular islands of well-differentiated hyaline cartilage surrounded and delimited by osteoid tissue. Immunohistochemistry of the osteochondromas, bone marrow and mediastinal lymph nodes, using a primary anti-FeLV gp70 antibody, and FeLV proviral DNA real-time polymerase chain reaction on bone marrow were negative. Sequencing of exon 6 of the EXT1 gene was performed and nucleotide BLAST analysis demonstrated the absence of a frameshift variant. This study reports the only case of spontaneous feline osteochondromatosis in an animal more than 10 years old. Show less

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease and a frequent cause of heart failure and sudden cardiac death. Our understanding of the genetic bases and pathogenic mechanisms underlying HCM has improved significantly in the recent past, but the combined effect of various pathogenic gene variants and the influence of genetic modifiers in disease manifestation are very poorly understood. Here, we set out to investigate genotype-phenotype relationships in 2 siblings with an extensive family history of HCM, both carrying a pathogenic truncating variant in the We used a combination of induced pluripotent stem cell (iPSC)-based disease modeling and CRISPR (clustered regularly interspersed short palindromic repeats)/Cas9 (CRISPR-associated protein 9)-mediated genome editing to generate patient-specific cardiomyocytes (iPSC-CMs) and isogenic controls lacking the pathogenic Mutant iPSC-CMs developed impaired mitochondrial bioenergetics, which was dependent on the presence of the mutation. Moreover, we could detect altered excitation-contraction coupling in iPSC-CMs from the severely affected individual. The pathogenic Our results indicate that the p.Ile1927Phe variant of unknown significance in Show less

The pathogenicity of the different genetic variants causing hypertrophic cardiomyopathy (HCM) and the genotype/phenotype correlations are difficult to assess in clinical practice, as most mutations are unique or identified in non-informative families. Pathogenic variants in the sarcomeric gene We describe the clinical characteristics of a new truncating Our cohort allows us to estimate the penetrance and prognosis of this variant. The penetrance of the disease increases with age, whereas 50% of males in our sample developed HCM by the age of 36 years old, and 50% of women developed the disease by the time they reached 48 years of age ( The p.Val931Glyfs*120 truncating variant in Show less

Multitarget drugs are a promising therapeutic approach against Alzheimer's disease. In this work, a new family of 5-substituted indazole derivatives with a multitarget profile including cholinesterase and BACE1 inhibition is described. Thus, the synthesis and evaluation of a new class of 5-substituted indazoles has been performed. Pharmacological evaluation includes Show less

Hydrolysis of VLDL triacylglycerol (TG) by lipoprotein lipase (LpL) is a major step in energy metabolism and VLDL-to-LDL maturation. Most functional LpL is anchored to the vascular endothelium, yet a small amount circulates on TG-rich lipoproteins. As circulating LpL has low catalytic activity, its role in VLDL remodeling is unclear. We use pre-heparin plasma and heparin-sepharose affinity chromatography to isolate VLDL fractions from normolipidemic, hypertriglyceridemic, or type-2 diabetic subjects. LpL is detected only in the heparin-bound fraction. Transient binding to heparin activates this VLDL-associated LpL, which hydrolyses TG, leading to gradual VLDL remodeling into IDL/LDL and HDL-size particles. The products and the timeframe of this remodeling closely resemble VLDL-to-LDL maturation in vivo. Importantly, the VLDL fraction that does not bind heparin is not remodeled. This relatively inert LpL-free VLDL is rich in TG and apoC-III, poor in apoE and apoC-II, shows impaired functionality as a substrate for the exogenous LpL or CETP, and likely has prolonged residence time in blood, which is expected to promote atherogenesis. This non-bound VLDL fraction increases in hypertriglyceridemia and in type-2 diabetes but decreases upon diabetes treatment that restores the glycemic control. In stark contrast, heparin binding by LDL increases in type-2 diabetes triggering pro-atherogenic LDL modifications. Therefore, the effects of heparin binding are associated negatively with atherogenesis for VLDL but positively for LDL. Collectively, the results reveal that binding to glycosaminoglycans initiates VLDL remodeling by circulating LpL, and suggest heparin binding as a marker of VLDL functionality and a readout for treatment of metabolic disorders. Show less

Stress granules (SGs) are conserved biomolecular condensates that originate in response to many stress conditions. These membraneless organelles contain nontranslating mRNAs and a diverse subproteome, but our knowledge of their regulation and functional relevance is still incipient. Here, we describe a mutual-inhibition interplay between SGs and Cdc28, the budding yeast Cdk. Among Cdc28 interactors acting as negative modulators of Start, we have identified Whi8, an RNA-binding protein that localizes to SGs and recruits the mRNA of CLN3, the most upstream G1 cyclin, for efficient translation inhibition and Cdk inactivation under stress. However, Whi8 also contributes to recruiting Cdc28 to SGs, where it acts to promote their dissolution. As predicted by a mutual-inhibition framework, the SG constitutes a bistable system that is modulated by Cdk. Since mammalian cells display a homologous mechanism, we propose that the opposing functions of specific mRNA-binding proteins and Cdk's subjugate SG dynamics to a conserved hysteretic switch. Show less

Excessive alcohol intake affects hippocampal function and neuronal communication through oxidative stress and mitochondrial impairment. Previous studies have suggested that the melanocortin system (MCS) plays an essential role in alcohol consumption and addiction. The MCS is a hypothalamic region involved in regulating inflammatory processes in the brain, and its pharmacological activation through the melanocortin-4 receptor (MC4R) reduces both alcohol consumption and the neuroinflammatory responses in the brain. However, the cellular mechanisms involved in the beneficial actions of MCS against ethanol toxicity are not entirely understood. The objective of this study was to investigate the protective role of the MC4R pharmacological activator RO27-3225 on oxidative damage and mitochondrial impairment present in hippocampal neuronal cultures acutely exposed to ethanol (50, 75 mM, 24 h). Pre-treatment with RO27-3225 (250 nM, 1 h) prevented reactive oxygen species (ROS) increase, dysregulation of cytosolic calcium homeostasis, and mitochondrial potential loss induced by ethanol. Improvement of mitochondrial failure produced by RO27-3225 was accompanied by a significant increase in ATP production in ethanol-treated neurons. More importantly, RO27-3225 promoted the activation of the antioxidant pathway Nrf-2, demonstrated by an increase in the expression and nuclear translocation of Nrf-2, and upregulation of mRNA levels of NAD(P)H quinone oxidoreductase 1 (NQO1), an antioxidant enzyme which expression is activated by this pathway. These results suggest that the stimulation of MC4R prevents oxidative damage and mitochondrial stress induced by ethanol through the activation of the Nrf-2 pathway in cultured hippocampal neurons. These results are novel and demonstrate the critical function of MC4R in promoting antioxidant defense and reducing mitochondrial damage produced by ethanol in the brain. Show less

The HDL (high-density lipoprotein)-mediated stimulation of cellular cholesterol efflux initiates macrophage-specific reverse cholesterol transport (m-RCT), which ends in the fecal excretion of macrophage-derived unesterified cholesterol (UC). Early studies established that LDL (low-density lipoprotein) particles could act as efficient intermediate acceptors of cellular-derived UC, thereby preventing the saturation of HDL particles and facilitating their cholesterol efflux capacity. However, the capacity of LDL to act as a plasma cholesterol reservoir and its potential impact in supporting the m-RCT pathway in vivo both remain unknown. We investigated LDL contributions to the m-RCT pathway in hypercholesterolemic mice. Macrophage cholesterol efflux induced in vitro by LDL added to the culture media either alone or together with HDL or ex vivo by plasma derived from subjects with familial hypercholesterolemia was assessed. In vivo, m-RCT was evaluated in mouse models of hypercholesterolemia that were naturally deficient in CETP (cholesteryl ester transfer protein) and fed a Western-type diet. LDL induced the efflux of radiolabeled UC from cultured macrophages, and, in the simultaneous presence of HDL, a rapid transfer of the radiolabeled UC from HDL to LDL occurred. However, LDL did not exert a synergistic effect on HDL cholesterol efflux capacity in the familial hypercholesterolemia plasma. The m-RCT rates of the LDLr (LDL receptor)-KO (knockout), LDLr-KO/APOB100, and PCSK9 (proprotein convertase subtilisin/kexin type 9)-overexpressing mice were all significantly reduced relative to the wild-type mice. In contrast, m-RCT remained unchanged in HAPOB100 Tg (human APOB100 transgenic) mice with fully functional LDLr, despite increased levels of plasma APO (apolipoprotein)-B-containing lipoproteins. Hepatic LDLr plays a critical role in the flow of macrophage-derived UC to feces, while the plasma increase of APOB-containing lipoproteins is unable to stimulate m-RCT. The results indicate that, besides the major HDL-dependent m-RCT pathway via SR-BI (scavenger receptor class B type 1) to the liver, a CETP-independent m-RCT path exists, in which LDL mediates the transfer of cholesterol from macrophages to feces. Graphical Abstract: A graphical abstract is available for this article. Show less

Myocardial stretch increases cardiac force in two consecutive phases: The first one due to Frank-Starling mechanism, followed by the gradually developed slow force response (SFR). The latter is the mechanical counterpart of an autocrine/paracrine mechanism involving the release of angiotensin II (Ang II) and endothelin (ET) leading to Na⁺/H⁺ exchanger 1 (NHE-1) phosphorylation and activation. Since previous evidence indicates that p38-MAP kinase (p38-MAPK) negatively regulates the Ang II-induced NHE1 activation in vascular smooth muscle and the positive inotropic effect of ET in the heart, we hypothesized that this kinase might modulate the magnitude of the SFR to stretch. Experiments were performed in isolated rat papillary muscles subjected to sudden stretch from 92 to 98% of its maximal length, in the absence or presence of the p38-MAPK inhibitor SB202190, or its inactive analogous SB202474. Western blot technique was used to determine phosphorylation level of p38-MAPK, ERK1/2, p90RSK and NHE-1 (previously immunoprecipitated with NHE-1 polyclonal antibody). Dual specificity phosphatase 6 (DUSP6) expression was evaluated by RT-PCR and western blot. Additionally, the Na⁺-dependent intracellular pH recovery from an ammonium prepulse-induced acid load was used to asses NHE-1 activity. The SFR was larger under p38-MAPK inhibition (SB202190), effect that was not observed in the presence of an inactive analogous (SB202474). Myocardial stretch activated p38-MAPK, while pre-treatment with SB202190 precluded this effect. Inhibition of p38-MAPK increased stretched-induced NHE-1 phosphorylation and activity, key event in the SFR development. Consistently, p38-MAPK inhibition promoted a greater increase in ERK1/2-p90RSK phosphorylation/activation after myocardial stretch, effect that may certainly be responsible for the observed increase in NHE-1 phosphorylation under this condition. Myocardial stretch induced up-regulation of the DUSP6, which specifically dephosphorylates ERK1/2, effect that was blunted by SB202190. Taken together, our data support the notion that p38-MAPK activation after myocardial stretch restricts the SFR by limiting ERK1/2-p90RSK phosphorylation, and consequently NHE-1 phosphorylation/activity, through a mechanism that involves DUSP6 up-regulation. Show less

To describe the clinical, biochemical, and genetic features of patients with congenital disorders of glycosylation (CDG) identified in Spain during the last 20 years. Patients were selected among those presenting with multisystem disease of unknown etiology. The isoforms of transferrin and of ApoC3 and dolichols were analyzed in serum; phosphomannomutase and mannosephosphate isomerase activities were measured in fibroblasts. Conventional or massive parallel sequencing (customized panel or Illumina Clinical-Exome Sequencing TruSight One Gene Panel) was used to identify genes and mutations. Ninety-seven patients were diagnosed with 18 different CDG. Eighty-nine patients had a type 1 transferrin profile; 8 patients had a type 2 transferrin profile, with 6 of them showing an alteration in the ApoC3 isoform profile. A total of 75% of the patients had PMM2-CDG presenting with a heterogeneous mutational spectrum. The remaining patients showed mutations in any of the following genes: MPI, PGM1, GFPT1, SRD5A3, DOLK, DPGAT1, ALG1, ALG6, RFT1, SSR4, B4GALT1, DPM1, COG6, COG7, COG8, ATP6V0A2, and CCDC115. Based on literature and on this population-based study of CDG, a comprehensive scheme including reported clinical signs of CDG is offered, which will hopefully reduce the timeframe from clinical suspicion to genetic confirmation. The different defects of CDG identified in Spain have contributed to expand the knowledge of CDG worldwide. A predominance of PMM2 deficiency was detected, with 5 novel PMM2 mutations being described. Show less

Dual-specificity phosphatase 6 (DUSP6/MKP-3) is a mitogen-activated protein kinase phosphatase that regulates extracellular signal-regulated kinases (ERKs) activity via feedback mechanisms, with an increasingly recognized role in tumour biology. The aim of this study was to explore the role of DUSP6 expression in the prognosis of human non-small cell lung cancer (NSCLC). DUSP6 expression levels were evaluated by real-time quantitative reverse transcription polymerase chain reaction (PCR) in 60 NSCLC samples from patients who underwent pulmonary resection at 12 de Octubre University Hospital. We performed a statistical analysis to investigate the correlation of DUSP6 expression and the clinical outcomes. We found that 66.7% of the tumour samples show the downregulation of DUSP6 at the messenger RNA (mRNA) levels compared to benign epithelial lung tissues and 55% of them show at least twofold downregulation of DUSP6 gene expression. Patients were classified into three groups according to their DUSP6 expression levels and those with very low levels (at least twofold downregulation) had the worst outcomes. Using the value of twice below the mean value in benign epithelial lung tissue as a cutoff, the overall survival of patients with very low DUSP6 levels was significantly lower than that in the rest of patients (31.9 ± 18.8 months vs. not reached, P = 0.049). This was most pronounced in adenocarcinoma histology and high-stage tumour samples. Our results suggest that DUSP6 gene expression in tumour samples may be a prognostic marker in NSCLC. Show less

The objective of this study was the description of a valid genetic risk score (GRS) to predict individuals with high susceptibility to childhood overweight by their genetic profiles. Case-control study including a group of children with high-risk familial predisposition to morbid obesity. Birth cohort from general population constituted the validation sample. For the discovery sample, 218 children with non-syndromic obesity and 190 control individuals were included. The validation sample was 653 children from two birth cohorts belonging to the INMA (Infancia y Medio Ambiente [Environment and Childhood] )project. 109 SNPs located in the genes FTO, SEC16B, BDNF, ETV5, SH2B1, GNPDA2, LYPLAL1, MSRA, TFAP2, KCTD15, MTCH2 and NEGR1, previously reported in association to body mass index (BMI) were analysed. For the validation sample, association between genome-wide data and BMI measurements between 3.5 and 5 years of age, were evaluated. The GRS includes six SNPs in the genes FTO, TFAP2B, SEC16B, ETV5 and SH2B1. The score distribution differs among cases and controls (P = 9.2 × 10(-14) ) showing a significant linear association with obesity (odds ratio [OR] per allele = 1.69; confidence interval [CI] 95% = 1.46-1.97; P = 4.3 × 10(-1) and area under the receiver operating characteristic curve [AUC] = 0.727; CI 95% = 0.676-0.778). The results were validated by the INMA cohort (OR per allele = 1.23 CI 95% = 1.03-1.48 and AUC = 0.601 CI 95% = 0.522-0.680). The use of our proposed genetic score provides useful information to determine those children who are susceptible to obesity. To improve the efficiency of clinical prevention and treatment of obesity, it is essential to design individualized based protocols in advance knowledge of the molecular basis of inherited susceptibility. Show less

We tested over 267,000 SNPs in 1,005 Northern Europeans and 248,000 in 1,006 Indian Asians for association with triglycerides and HDL cholesterol, with replication in 10,536 subjects. We found association of a nonsynonymous SNP (rs3812316, G771C, Gln241His) in MLXIPL with plasma triglyceride levels (combined P = 1.4 x 10(-10)). MLXIPL coordinates transcriptional regulation of enzymes that channel glycolytic end-products into lipogenesis and energy storage, making MLXIPL a plausible 'thrifty gene'. Show less