👤 Rafael Duran

Cell communication systems based on polypeptide ligands use transmembrane receptors to transmit signals across the plasma membrane. In their biogenesis, receptors depend on the endoplasmic reticulum (ER)-Golgi system for folding, maturation, transport and localization to the cell surface. ER stress, caused by protein overproduction and misfolding, is a well-known pathology in neurodegeneration, cancer and numerous other diseases. How ER stress affects cell communication via transmembrane receptors is largely unknown. In disease models of multiple myeloma, chronic lymphocytic leukemia and osteogenesis imperfecta, we show that ER stress leads to loss of the mature transmembrane receptors FGFR3, ROR1, FGFR1, LRP6, FZD5 and PTH1R at the cell surface, resulting in impaired downstream signaling. This is caused by downregulation of receptor production and increased intracellular retention of immature receptor forms. Reduction of ER stress by treatment of cells with the chemical chaperone tauroursodeoxycholic acid or by expression of the chaperone protein BiP resulted in restoration of receptor maturation and signaling. We show a previously unappreciated pathological effect of ER stress; impaired cellular communication due to altered receptor processing. Our findings have implications for disease mechanisms related to ER stress and are particularly important when receptor-based pharmacological approaches are used for treatment. Show less

The surgical management of complicated diverticulitis varies across Europe. EAES members prioritized this topic to be addressed by a clinical practice guideline through an online questionnaire. To develop evidence-informed clinical practice recommendations for key stakeholders involved in the treatment of complicated diverticulitis; to improve operative and perioperative outcomes, patient experience and quality of life through a systematic evidence-to-decision approach by a diverse, multidisciplinary panel. Informed by a linked individual participant data network meta-analysis of resection and primary anastomosis (PRA) versus Hartmann's resection (HR) versus laparoscopic lavage (LPL), a panel of general and colorectal surgeons, patient partners, trialists, and fellows appraised the certainty of the evidence using GRADE and CINeMA. The panel discussed the evidence using the evidence-to-decision framework during a synchronous consensus meeting. An asynchronous modified Delphi survey was used to establish consensus. The panel suggests that patients with complicated diverticulitis without sepsis receive PRA over HR or LPL when there is availability of a surgeon with skills and experience in colorectal surgery. HR is suggested over PRA or LPL in the subgroups of septic, frail, as well as immunocompromised patients. These recommendations apply to patients with an indication for surgery. Surgeons and patients should first consider conditionally recommended interventions, then conditionally recommended against. Based on the evidence, the key benefit of PRA was a higher likelihood of not having a stoma at 1 year, with similar risks across comparisons. Conditional recommendations call for shared decision-making when considering management options. The full guideline with user-friendly decision aids is available in https://app.magicapp.org/#/guideline/7490 . This clinical practice guideline provides evidence-informed recommendations on the management of patients with complicated diverticulitis in accordance with the highest methodological standards through a structured framework informed by an international, multidisciplinary panel of stakeholders. Show less

We performed a systematic review and network meta-analysis (NMA) of individualized patient data (IPD) to inform the development of evidence-informed clinical practice recommendations. We searched MEDLINE, Embase, and Cochrane Central in October 2023 to identify RCTs comparing Hartmann's resection (HR), primary resection and anastomosis (PRA), or laparoscopic peritoneal lavage (LPL) among patients with class Ib-IV Hinchey diverticulitis. Outcomes of interest were prioritized by an international, multidisciplinary panel including two patient partners. Article screening, data extraction for IPD, and risk of bias appraisal were performed by two reviewers. We used a random-effects NMA to synthesize direct and indirect evidence. Heterogeneity was evaluated using the I Fourteen reports of seven RCTs were derived from 4,659 articles. IPD data were available for 595/678 patients (88.8%) across trials. Patients had a mean age ± SD of 64.61 ± 13.64 years and a mean BMI ± SD of 26.12 ± 5.20 kg/m PRA likely confers a lower stoma rate at 1 year compared to HR, while there may be no difference in 30-day/in-hospital mortality. LPL likely confers a higher in-hospital/30-day mortality rate compared to HR and PRA. Show less

Primates, the most colorful mammalian radiation, have previously served as an interesting model to test the functions and evolutionary drivers of variation in eye color. We assess the contribution of photo-regulatory and communicative functions to the external eye appearance of nine macaque species representing all the branches of their radiation. Macaques' well described social structure and wide geographical distribution make them interesting to explore. We find that (1) the posterior option of the anterior eyeball is more pigmented closer to the equator, suggesting photoprotective functions. We also find that (2) the temporal side of the eyeball is more heavily pigmented than the nasal side. This suggests that eyeball pigmentation in macaques is distributed to reduce damage to the corneal limbus. The inclusion of a translocated population of M. fuscata in our analyses also suggests that external eye appearance may change quickly, perhaps owing to phenotypic plasticity. We find no evidence that communicative functions drive variation in external eye appearance in macaques. These results suggest that the amount of light in a species' environment drives variation in eye coloration across macaque species. Furthermore, the geographical distribution of macaques hints at important factors that have yet to be accounted for, such as the reflectivity of the terrain a given species inhabits. Show less

New blood vessel formation requires endothelial cells to transition from a quiescent to an invasive phenotype. Transcriptional changes are vital for this switch, but a comprehensive genome-wide approach focused exclusively on endothelial cell sprout initiation has not been reported. Using a model of human endothelial cell sprout initiation, we developed a protocol to physically separate cells that initiate the process of new blood vessel formation (invading cells) from noninvading cells. We used this model to perform multiple transcriptomics analyses from independent donors to monitor endothelial gene expression changes. Single-cell population analyses, single-cell cluster analyses, and bulk RNA sequencing revealed common transcriptomic changes associated with invading cells. We also found that collagenase digestion used to isolate single cells upregulated the Fos proto-oncogene transcription factor. Exclusion of Fos proto-oncogene expressing cells revealed a gene signature consistent with activation of signal transduction, morphogenesis, and immune responses. Many of the genes were previously shown to regulate angiogenesis and included multiple tip cell markers. Upregulation of SNAI1 (snail family transcriptional repressor 1), PTGS2 (prostaglandin synthase 2), and JUNB (JunB proto-oncogene) protein expression was confirmed in invading cells, and silencing JunB and SNAI1 significantly reduced invasion responses. Separate studies investigated rounding 3, also known as RhoE, which has not yet been implicated in angiogenesis. Silencing rounding 3 reduced endothelial invasion distance as well as filopodia length, fitting with a pathfinding role for rounding 3 via regulation of filopodial extensions. Analysis of in vivo retinal angiogenesis in Validation of multiple genes, including rounding 3, revealed a functional role for this gene signature early in the angiogenic process. This study expands the list of genes associated with the acquisition of a tip cell phenotype during endothelial cell sprout initiation. Show less

Gestational diabetes mellitus (GDM) entails a complex underlying pathogenesis, with a specific genetic background and the effect of environmental factors. This study examines the link between a set of single nucleotide polymorphisms (SNPs) associated with diabetes and the development of GDM in pregnant women with different ethnicities, and evaluates its potential modulation with a clinical intervention based on a Mediterranean diet. 2418 women from our hospital-based cohort of pregnant women screened for GDM from January 2015 to November 2017 (the San Carlos Cohort, randomized controlled trial for the prevention of GDM ISRCTN84389045 and real-world study ISRCTN13389832) were assessed for evaluation. Diagnosis of GDM was made according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Genotyping was performed by IPLEX MassARRAY PCR using the Agena platform (Agena Bioscience, SanDiego, CA). 110 SNPs were selected for analysis based on selected literature references. Statistical analyses regarding patients' characteristics were performed in SPSS (Chicago, IL, USA) version 24.0. Genetic association tests were performed using PLINK v.1.9 and 2.0 software. Bioinformatics analysis, with mapping of SNPs was performed using STRING, version 11.5. Quality controls retrieved a total 98 SNPs and 1573 samples, 272 (17.3%) with GDM and 1301 (82.7%) without GDM. 1104 (70.2%) were Caucasian (CAU) and 469 (29.8%) Hispanic (HIS). 415 (26.4%) were from the control group (CG), 418 (26.6%) from the nutritional intervention group (IG) and 740 (47.0%) from the real-world group (RW). 40 SNPs (40.8%) presented some kind of significant association with GDM in at least one of the genetic tests considered. The nutritional intervention presented a significant association with GDM, regardless of the variant considered. In CAU, variants rs4402960, rs7651090, IGF2BP2; rs1387153, rs10830963, MTNR1B; rs17676067, GLP2R; rs1371614, DPYSL5; rs5215, KCNJ1; and rs2293941, PDX1 were significantly associated with an increased risk of GDM, whilst rs780094, GCKR; rs7607980, COBLL1; rs3746750, SLC17A9; rs6048205, FOXA2; rs7041847, rs7034200, rs10814916, GLIS3; rs3783347, WARS; and rs1805087, MTR, were significantly associated with a decreased risk of GDM, In HIS, variants significantly associated with increased risk of GDM were rs9368222, CDKAL1; rs2302593, GIPR; rs10885122, ADRA2A; rs1387153, MTNR1B; rs737288, BACE2; rs1371614, DPYSL5; and rs2293941, PDX1, whilst rs340874, PROX1; rs2943634, IRS1; rs7041847, GLIS3; rs780094, GCKR; rs563694, G6PC2; and rs11605924, CRY2 were significantly associated with decreased risk for GDM. We identify a core set of SNPs in their association with diabetes and GDM in a large cohort of patients from two main ethnicities from a single center. Identification of these genetic variants, even in the setting of a nutritional intervention, deems useful to design preventive and therapeutic strategies. Show less

The Iberian Peninsula stands out as having variable levels of population admixture and isolation, making Spain an interesting setting for studying the genetic architecture of neurodegenerative diseases. To perform the largest PD genome-wide association study restricted to a single country. We performed a GWAS for both risk of PD and age at onset in 7,849 Spanish individuals. Further analyses included population-specific risk haplotype assessments, polygenic risk scoring through machine learning, Mendelian randomization of expression, and methylation data to gain insight into disease-associated loci, heritability estimates, genetic correlations, and burden analyses. We identified a novel population-specific genome-wide association study signal at PARK2 associated with age at onset, which was likely dependent on the c.155delA mutation. We replicated four genome-wide independent signals associated with PD risk, including SNCA, LRRK2, KANSL1/MAPT, and HLA-DQB1. A significant trend for smaller risk haplotypes at known loci was found compared to similar studies of non-Spanish origin. Seventeen PD-related genes showed functional consequence by two-sample Mendelian randomization in expression and methylation data sets. Long runs of homozygosity at 28 known genes/loci were found to be enriched in cases versus controls. Our data demonstrate the utility of the Spanish risk haplotype substructure for future fine-mapping efforts, showing how leveraging unique and diverse population histories can benefit genetic studies of complex diseases. The present study points to PARK2 as a major hallmark of PD etiology in Spain. © 2019 International Parkinson and Movement Disorder Society. Show less

This study aims to determine the prophylactic and therapeutic efficacy of inhibition of Wnt/β-catenin signaling pathway with paricalcitol in an experimental scleroderma model created with bleomycin (BLM). Sixty female BALB/c mice (8-week old and weighing 25 g to 30 g) were divided into six groups as prophylactic-early [group 1 (control I)], sham I (group 2), paricalcitol I (group 3), therapeutic-late [group 4 (control II)], sham II (group 5), and paricalcitol II (group 6) groups. Subcutaneous BLM (100 μg/day) injections were used to induce dermal fibrosis and paricalcitol (0.3 μg/kg/day) was applied subcutaneously to BLM-injected mice during the first three weeks for preventive interventions and in the second three weeks for therapeutic interventions. Tissue samples were harvested for subsequent pathological and real-time polymerase chain reaction analysis. Tissue transforming growth factor-beta 1, axin-1, and Wnt-2 messenger ribonucleic acid expressions were determined by real-time polymerase chain reaction. Repeated BLM applications increased the dermal inflammatory cell infiltration and dermal thickness, and led to dermal fibrosis, in both early and late stages. Similarly, transforming growth factor-beta 1, axin-1, and Wnt-2 expressions were significantly increased in the sham groups compared to the own control group (p<0.05 for all). Contrarily, prophylactic and therapeutic paricalcitol applications decreased the transforming growth factor-beta 1, axin-1, and Wnt-2 messenger ribonucleic acid expressions compared to the own sham group (p<0.05 for all). In addition, the regressions in dermal necro-inflammation and dermal fibrosis on pathological views were also observed in the paricalcitol applied groups. In this model, increased axin-1 and Wnt-2 messenger ribonucleic acid expressions suggest that Wnt/β-catenin pathway is active in dermal fibrosis. Show less

Glucose-dependent insulinotropic peptide (GIP) has a central role in glucose homeostasis through its amplification of insulin secretion; however, its physiological role in adipose tissue is unclear. Our objective was to define the function of GIP in human adipose tissue in relation to obesity and insulin resistance. GIP receptor (GIPR) expression was analyzed in human sc adipose tissue (SAT) and visceral adipose (VAT) from lean and obese subjects in 3 independent cohorts. GIPR expression was associated with anthropometric and biochemical variables. GIP responsiveness on insulin sensitivity was analyzed in human adipocyte cell lines in normoxic and hypoxic environments as well as in adipose-derived stem cells obtained from lean and obese patients. GIPR expression was downregulated in SAT from obese patients and correlated negatively with body mass index, waist circumference, systolic blood pressure, and glucose and triglyceride levels. Furthermore, homeostasis model assessment of insulin resistance, glucose, and G protein-coupled receptor kinase 2 (GRK2) emerged as variables strongly associated with GIPR expression in SAT. Glucose uptake studies and insulin signaling in human adipocytes revealed GIP as an insulin-sensitizer incretin. Immunoprecipitation experiments suggested that GIP promotes the interaction of GRK2 with GIPR and decreases the association of GRK2 to insulin receptor substrate 1. These effects of GIP observed under normoxia were lost in human fat cells cultured in hypoxia. In support of this, GIP increased insulin sensitivity in human adipose-derived stem cells from lean patients. GIP also induced GIPR expression, which was concomitant with a downregulation of the incretin-degrading enzyme dipeptidyl peptidase 4. None of the physiological effects of GIP were detected in human fat cells obtained from an obese environment with reduced levels of GIPR. GIP/GIPR signaling is disrupted in insulin-resistant states, such as obesity, and normalizing this function might represent a potential therapy in the treatment of obesity-associated metabolic disorders. Show less

APOA5, a key gene regulating triglyceride (TG) levels, is reported to be expressed exclusively in the liver where it may regulate TG-rich particle synthesis and secretion. Since the same lipoprotein processing occurs in the intestine, we have postulated that this organ would also express APOA5. We have detected the APOA5 gene expression in C57BL/6J mouse and in human small intestine samples. In humans, it is expressed mainly in the duodenum and colon, with messenger RNA (mRNA) levels four orders of magnitude lower than in the liver, and the protein product being one-sixth of the liver equivalent. Subsequently, we carried out in vitro experiments in TC-7/CaCo(2) human intestinal cells to analyse the expression of APOA5, APOC3, APOB and MTP genes after the incubation with long- and short-chain fatty acids, and a peroxisome proliferator-activated receptor alpha (PPARα) agonist (Wy 14643, a fibrate therapeutic agent). In the TC-7 cell line, APOA5 expression was significantly upregulated by saturated fatty acids. The short-chain fatty acid butyrate increased APOA5 expression almost fourfold while APOB was downregulated by increasing butyrate concentrations. When TC-7 cells were incubated with PPARα agonist, the APOA5 expression was increased by 60%, while the expression of APOB, MTP and APOC3 was decreased by 50%, 30% and 45%, respectively. Our results demonstrate that APOA5 is expressed in the intestine, albeit at a much lower concentration than in the liver. While it remains to be determined whether intestinal apo A-V is functional, our in vitro experiments show that its expression is modifiable by dietary and pharmacological stimuli. Show less

Schizosaccharomyces pombe rho1(+) is required for maintenance of cell integrity and polarization of the actin cytoskeleton. However, no other effector besides the (1,3)beta-D-glucan synthase enzyme has been identified in S. pombe. We have further investigated if rho1(+ )signalling could be also mediated by the two protein kinase C homologues, pck1p and pck2p. We show in this study that both kinases interact with rho1p and rho2p only when bound to GTP, as most GTPase effectors do. Interestingly, the interaction was mapped in a different part of the proteins than in Saccharomyces cerevisiae Pkc1p. Thus, active rho1p binds to the amino-terminal region of the pcks where two HR1 motifs are located, and binding to the GTPase dramatically stabilizes the kinases. Detailed biochemical analysis suggests that pck2p is more important in the regulation of the enzyme (1-3)beta-D-glucan synthase. Thus, overexpression of pck2(+), but not pck1(+), caused a general increase in cell wall biosynthesis, mainly in beta-glucan, and (1-3)beta-D-glucan synthase activity was considerably augmented. When this activity was separated into soluble and membrane fractions and reconstituted, the increase caused by pck2(+) overexpression was exclusively detected in the membrane component. We also show that both protein kinase C homologues are required for the maintenance of cell integrity. pck1delta and pck2delta strains present a number of defects related to the cell wall, indicating that this structure might be co-ordinately regulated by both kinases. In addition, pck2p, but not pck1p, seems to be involved in keeping cell polarity. Genetic evidence indicates that both pck1(+) and pck2(+) interact with cps1(+) and gls2(+), two genes similar to S. cerevisiae FKS1 and FKS2 that encode membrane subunits of the (1-3)beta-D-glucan synthase. pck1(+ )also showed a genetic interaction with ras1(+) and ral1(+) suggesting the existence of a functional link between both signalling pathways. Show less