Direct interrogation of context-dependent GPCR activity with a universal biosensor platform.

G protein-coupled receptors (GPCRs) are the largest family of druggable proteins encoded in the human genome, but progress in understanding and targeting them is hindered by the lack of tools to reliably measure their nuanced behavior in physiologically relevant contexts. Here, we developed a collection of compact ONE vector G-protein Optical (ONE-GO) biosensor constructs as a scalable platform that can be conveniently deployed to measure G-protein activation by virtually any GPCR with high fidelity even when expressed endogenously in primary cells. By characterizing dozens of GPCRs across many cell types like primary cardiovascular cells or neurons, we revealed insights into the molecular basis for G-protein coupling selectivity of GPCRs, pharmacogenomic profiles of anti-psychotics on naturally occurring GPCR variants, and G-protein subtype signaling bias by endogenous GPCRs depending on cell type or upon inducing disease-like states. In summary, this open-source platform makes the direct interrogation of context-dependent GPCR activity broadly accessible.

Revealing the Activity of Trimeric G-proteins in Live Cells with a Versatile Biosensor Design.

Heterotrimeric G-proteins (Gαßγ) are the main transducers of signals from GPCRs, mediating the action of countless natural stimuli and therapeutic agents. However, there are currently no robust approaches to directly measure the activity of endogenous G-proteins in cells. Here, we describe a suite of optical biosensors that detect endogenous active G-proteins with sub-second resolution in live cells. Using a modular design principle, we developed genetically encoded, unimolecular biosensors for endogenous Gα-GTP and free Gßγ: the two active species of heterotrimeric G-proteins. This design was leveraged to generate biosensors with specificity for different heterotrimeric G-proteins or for other G-proteins, such as Rho GTPases. Versatility was further validated by implementing the biosensors in multiple contexts, from characterizing cancer-associated G-protein mutants to neurotransmitter signaling in primary neurons. Overall, the versatile biosensor design introduced here enables studying the activity of endogenous G-proteins in live cells with high fidelity, temporal resolution, and convenience.

Fine-tuning GPCR-mediated neuromodulation by biasing signaling through different G protein subunits.

G-protein-coupled receptors (GPCRs) mediate neuromodulation through the activation of heterotrimeric G proteins (Gαßγ). Classical models depict that G protein activation leads to a one-to-one formation of Gα-GTP and Gßγ species. Each of these species propagates signaling by independently acting on effectors, but the mechanisms by which response fidelity is ensured by coordinating Gα and Gßγ responses remain unknown. Here, we reveal a paradigm of G protein regulation whereby the neuronal protein GINIP (Gα inhibitory interacting protein) biases inhibitory GPCR responses to favor Gßγ over Gα signaling. Tight binding of GINIP to Gαi-GTP precludes its association with effectors (adenylyl cyclase) and, simultaneously, with regulator-of-G-protein-signaling (RGS) proteins that accelerate deactivation. As a consequence, Gαi-GTP signaling is dampened, whereas Gßγ signaling is enhanced. We show that this mechanism is essential to prevent the imbalances of neurotransmission that underlie increased seizure susceptibility in mice. Our findings reveal an additional layer of regulation within a quintessential mechanism of signal transduction that sets the tone of neurotransmission.

An atlas of cortical arealization identifies dynamic molecular signatures.

The human brain is subdivided into distinct anatomical structures, including the neocortex, which in turn encompasses dozens of distinct specialized cortical areas. Early morphogenetic gradients are known to establish early brain regions and cortical areas, but how early patterns result in finer and more discrete spatial differences remains poorly understood1. Here we use single-cell RNA sequencing to profile ten major brain structures and six neocortical areas during peak neurogenesis and early gliogenesis. Within the neocortex, we find that early in the second trimester, a large number of genes are differentially expressed across distinct cortical areas in all cell types, including radial glia, the neural progenitors of the cortex. However, the abundance of areal transcriptomic signatures increases as radial glia differentiate into intermediate progenitor cells and ultimately give rise to excitatory neurons. Using an automated, multiplexed single-molecule fluorescent in situ hybridization approach, we find that laminar gene-expression patterns are highly dynamic across cortical regions. Together, our data suggest that early cortical areal patterning is defined by strong, mutually exclusive frontal and occipital gene-expression signatures, with resulting gradients giving rise to the specification of areas between these two poles throughout successive developmental timepoints.

Small-molecule targeting of GPCR-independent noncanonical G-protein signaling in cancer.

Activation of heterotrimeric G-proteins (Gαßγ) by G-protein-coupled receptors (GPCRs) is a quintessential mechanism of cell signaling widely targeted by clinically approved drugs. However, it has become evident that heterotrimeric G-proteins can also be activated via GPCR-independent mechanisms that remain untapped as pharmacological targets. GIV/Girdin has emerged as a prototypical non-GPCR activator of G proteins that promotes cancer metastasis. Here, we introduce IGGi-11, a first-in-class small-molecule inhibitor of noncanonical activation of heterotrimeric G-protein signaling. IGGi-11 binding to G-protein α-subunits (Gαi) specifically disrupted their engagement with GIV/Girdin, thereby blocking noncanonical G-protein signaling in tumor cells and inhibiting proinvasive traits of metastatic cancer cells. In contrast, IGGi-11 did not interfere with canonical G-protein signaling mechanisms triggered by GPCRs. By revealing that small molecules can selectively disable noncanonical mechanisms of G-protein activation dysregulated in disease, these findings warrant the exploration of therapeutic modalities in G-protein signaling that go beyond targeting GPCRs.

Heterotrimeric G protein signaling without GPCRs: The Gα-binding-and-activating (GBA) motif.

Heterotrimeric G proteins (Gαßγ) are molecular switches that relay signals from 7-transmembrane receptors located at the cell surface to the cytoplasm. The function of these receptors is so intimately linked to heterotrimeric G proteins that they are named G protein-coupled receptors (GPCRs), showcasing the interdependent nature of this archetypical receptor-transducer axis of transmembrane signaling in eukaryotes. It is generally assumed that activation of heterotrimeric G protein signaling occurs exclusively by the action of GPCRs, but this idea has been challenged by the discovery of alternative mechanisms by which G proteins can propagate signals in the cell. This review will focus on a general principle of G protein signaling that operates without the direct involvement of GPCRs. The mechanism of G protein signaling reviewed here is mediated by a class of G protein regulators defined by containing an evolutionarily conserved sequence named the Gα-binding-and-activating (GBA) motif. Using the best characterized proteins with a GBA motif as examples, Gα-interacting vesicle-associated protein (GIV)/Girdin and dishevelled-associating protein with a high frequency of leucine residues (DAPLE), this review will cover (i) the mechanisms by which extracellular cues not relayed by GPCRs promote the coupling of GBA motif-containing regulators with G proteins, (ii) the structural and molecular basis for how GBA motifs interact with Gα subunits to facilitate signaling, (iii) the relevance of this mechanism in different cellular and pathological processes, including cancer and birth defects, and (iv) strategies to manipulate GBA-G protein coupling for experimental therapeutics purposes, including the development of rationally engineered proteins and chemical probes.

Do All Roads Lead to Rome in G-Protein Activation?

High-resolution structural studies on G-protein-coupled receptors (GPCRs) have flourished recently, providing long-sought insights into the dynamic process of guanine nucleotide-binding protein (G-protein) activation. In parallel, analogous studies are starting to shed light on how the same G-proteins are activated by non-GPCR proteins. Can we learn about common themes and variations in G-protein activation from them?

Get ready to sharpen your tools: A short guide to heterotrimeric G protein activity biosensors.

G protein-coupled receptors (GPCRs) are the largest class of transmembrane receptors encoded in the human genome, and they initiate cellular responses triggered by a plethora of extracellular stimuli ranging from neurotransmitters or hormones to photons. Upon stimulation, GPCRs activate heterotrimeric G proteins (Gαßγ) in the cytoplasm, which then convey signals to their effectors to elicit cellular responses. Given the broad biological and biomedical relevance of GPCRs and G proteins in physiology and disease, there is great interest in developing and optimizing approaches to measure their signaling activity with high accuracy and across experimental systems pertinent to their functions in cellular communication. This review provides a historical perspective on approaches to measure GPCR-G protein signaling, from quantification of second messengers and other indirect readouts of activity, to biosensors that directly detect the activity of G proteins. The latter is the focus of a more detailed overview of the evolution of design principles for various optical biosensors of G protein activity with different experimental capabilities. We will highlight advantages and limitations of biosensors that detect different G protein activation hallmarks, like dissociation of Gα and Gßγ or nucleotide exchange on Gα, as well as their suitability to detect signaling mediated by endogenous versus exogenous signaling components, or in physiologically-relevant systems like primary cells. Overall, this review intends to provide an assessment of the state-of-the-art for biosensors that directly measure G protein activity to allow readers to make informed decisions on the selection and implementation of currently available tools. Significance Statement G protein activity biosensors have become essential and widespread tools to assess GPCR signaling and pharmacology. Yet, investigators face the challenge of choosing from a growing list of G protein activity biosensors. This review provides an overview of the features and capabilities of different optical biosensor designs for the direct detection of G protein activity in cells, with the aim of facilitating the rational selection of systems that align with the specific scientific questions and needs of investigators.

Design of a Stem Cell-Based Therapy for Ependymal Repair in Hydrocephalus Associated With Germinal Matrix Hemorrhages.

BACKGROUND: In preterm birth germinal matrix hemorrhages (GMHs) and the consequent posthemorrhagic hydrocephalus (PHH), the neuroepithelium/ependyma development is disrupted. This work is aimed to explore the possibilities of ependymal repair in GMH/PHH using a combination of neural stem cells, ependymal progenitors (EpPs), and mesenchymal stem cells. METHODS: GMH/PHH was induced in 4-day-old mice using collagenase, blood, or blood serum injections. PHH severity was characterized 2 weeks later using magnetic resonance, immunofluorescence, and protein expression quantification with mass spectrometry. Ependymal restoration and wall regeneration after stem cell treatments were tested in vivo and in an ex vivo experimental approach using ventricular walls from mice developing moderate and severe GMH/PHH. The effect of the GMH environment on EpP differentiation was tested in vitro. Two-tailed Student t or Wilcoxon-Mann-Whitney U test was used to find differences between the treated and nontreated groups. ANOVA and Kruskal-Wallis tests were used to compare >2 groups with post hoc Tukey and Dunn multiple comparison tests, respectively. RESULTS: PHH severity was correlated with the extension of GMH and ependymal disruption (means, 88.22% severe versus 19.4% moderate). GMH/PHH hindered the survival rates of the transplanted neural stem cells/EpPs. New multiciliated ependymal cells could be generated from transplanted neural stem cells and more efficiently from EpPs (15% mean increase). Blood and TNFα (tumor necrosis factor alpha) negatively affected ciliogenesis in cells committed to ependyma differentiation (expressing Foxj1 [forkhead box J1] transcription factor). Pretreatment with mesenchymal stem cells improved the survival rates of EpPs and ependymal differentiation while reducing the edematous (means, 18% to 0.5% decrease in severe edema) and inflammatory conditions in the explants. The effectiveness of this therapeutical strategy was corroborated in vivo (means, 29% to 0% in severe edema). CONCLUSIONS: In GMH/PHH, the ependyma can be restored and edema decreased from either neural stem cell or EpP transplantation in vitro and in vivo. Mesenchymal stem cell pretreatment improved the success of the ependymal restoration.

Host-Guest Stimuli-Responsive Click Chemistry.

Click chemistry has reached its maturity as the weapon of choice for the irreversible ligation of molecular fragments, with over 20 years of research resulting in the development or improvement of highly efficient kinetically controlled conjugation reactions. Nevertheless, traditional click reactions can be disadvantageous not only in terms of efficiency (side products, slow kinetics, air/water tolerance, etc.), but also because they completely avoid the possibility to reversibly produce and control bound/unbound states. Recently, non-covalent click chemistry has appeared as a more efficient alternative, in particular by using host-guest self-assembled systems of high thermodynamic stability and kinetic lability. This review discusses the implementation of molecular switches in the development of such non-covalent ligation processes, resulting in what we have termed stimuli-responsive click chemistry, in which the bound/unbound constitutional states of the system can be favored by external stimulation, in particular using host-guest complexes. As we exemplify with handpicked selected examples, these supramolecular systems are well suited for the development of human-controlled molecular conjugation, by coupling thermodynamically regulated processes with appropriate temporally resolved extrinsic control mechanisms, thus mimicking nature and advancing our efforts to develop a more function-oriented chemical synthesis.

Plasma polyamines during pregnancy and their relationships with maternal allergies and the immune response of the neonates.

BACKGROUND: Some studies have reported that polyamine levels may influence immune system programming. The aim of this study was to evaluate the polyamine profile during gestation and its associations with maternal allergy and cytokine production in cord blood cells in response to different allergenic stimuli. METHODS: Polyamines were determined in plasma of pregnant women (24 weeks, N = 674) and in umbilical cord samples (N = 353 vein and N = 160 artery) from the Mediterranean NELA birth cohort. Immune cell populations were quantified, and the production of cytokines in response to different allergic and mitogenic stimuli was assessed in cord blood. RESULTS: Spermidine and spermine were the most prevalent polyamines in maternal, cord venous, and cord arterial plasma. Maternal allergies, especially allergic conjunctivitis, were associated with lower spermine in umbilical cord vein. Higher levels of polyamines were associated with higher lymphocyte number but lower Th2-related cells in cord venous blood. Those subjects with higher levels of circulating polyamines in cord showed lower production of inflammatory cytokines, especially IFN-α, and lower production of Th2-related cytokines, mainly IL-4 and IL-5. The effects of polyamines on Th1-related cytokines production were uncertain. CONCLUSIONS: Spermidine and spermine are the predominant polyamines in plasma of pregnant women at mid-pregnancy and also in umbilical cord. Maternal allergic diseases like allergic conjunctivitis are related to lower levels of polyamines in cord vein, which could influence the immune response of the newborn. Cord polyamine content is related to a decreased Th2 response and inflammatory cytokines production, which might be important to reduce an allergenic phenotype in the neonate.

Recommendations for asthma monitoring in children: A PeARL document endorsed by APAPARI, EAACI, INTERASMA, REG, and WAO.

Monitoring is a major component of asthma management in children. Regular monitoring allows for diagnosis confirmation, treatment optimization, and natural history review. Numerous factors that may affect disease activity and patient well-being need to be monitored: response and adherence to treatment, disease control, disease progression, comorbidities, quality of life, medication side-effects, allergen and irritant exposures, diet and more. However, the prioritization of such factors and the selection of relevant assessment tools is an unmet need. Furthermore, rapidly developing technologies promise new opportunities for closer, or even "real-time," monitoring between visits. Following an approach that included needs assessment, evidence appraisal, and Delphi consensus, the PeARL Think Tank, in collaboration with major international professional and patient organizations, has developed a set of 24 recommendations on pediatric asthma monitoring, to support healthcare professionals in decision-making and care pathway design.

2-Hydroxyethyl methacrylate (2-HEMA) sensitization, a global epidemic at its peak in Spain?

BACKGROUND: A global epidemic of allergic contact dermatitis to (meth)acrylates has been described in relation to the widespread use of manicure products. OBJECTIVES: To evaluate the frequency of sensitization to 2-hydroxyethyl methacrylate (2-HEMA) among consecutively patch tested patients with eczema in Spain; the percentage of current relevance; the MOAHLFA index; and, the potential sources of exposure to (meth)acrylates. METHODS: From January 2019 to December 2022, 2-HEMA 2% pet. was prospectively patch tested in 24 REIDAC (Spanish Allergic Contact Dermatitis Registry) centres. RESULTS: Six thousand one hundred thirty-four patients were consecutively patch tested with 2-HEMA 2% pet. 265/6134 (4.3%) were positive. Positive reactions of current relevance were identified to involve 184/265 (69%). The efficiency (number of patch tests needed to detect relevant positive patch test reactions) was 34 (6134/184). The variable 'occupational' was found to be significantly associated with a higher risk for relevant positive reactions to 2-HEMA (OR: 10.9; 95% CI: 8.1-14.9). CONCLUSION: (Meth)acrylate sensitization is a prevalent health issue in Spain. 2-HEMA 2% pet. has been identified to be a highly effective (meth)acrylate allergy marker in the GEIDAC baseline series. The responsible authorities should implement policies guaranteeing accurate labelling of industrial, medical, and consumer materials while ensuring the enforcement of said labelling through appropriate legal means.

Cytokine production by newborns: influence of sex and season of birth.

BACKGROUND: Immune signatures at birth could be associated with clinical outcomes and will improve our understanding of immunity prenatal programming. METHODS: Data come from 235 newborns from the cohort study NELA. Production of cytokines was determined using Luminex technology. Associations between cytokine concentrations with sex and season of birth were examined by multivariate regression models. RESULTS: Umbilical cord blood cells produced high levels of inflammatory cytokines, moderate levels of Th1/Th2/Tr-related cytokines, and low levels of Th17 cytokines. Compared to females, male newborn cells secreted higher levels of Th2 (peptidoglycan-stimulated IL-13, odds ratio [OR] = 2.26; 95% CI 1.18, 4.31, p value = 0.013) and Th17 (polyinosinic:polycytidylic acid-stimulated IL-23, OR = 1.82, 95% CI 1.01, 3.27, p value = 0.046) and lower levels of Th1 (olive-stimulated IL-2, OR = 0.56, 95% CI 0.31, 0.99, p value = 0.047) cytokines. Also, children born during warm seasons showed decreased innate cytokine response to peptidoglycan (IL-6, OR = 0.28, 95% CI 0.15, 0.52, p value < 0.001) compared to those born in cold seasons; meanwhile, adaptive immunity cytokines were more frequently secreted by children born during warm seasons in response to allergen extracts (IL-10, OR = 2.11, 95% CI 1.12, 3.96, p value = 0.020; IL-17F, OR = 3.31, 95% CI 1.83, 5.99, p value < 0.001). CONCLUSION: Newborns showed specific cytokines signatures influenced by sex and season of birth. IMPACT: There is a limited number of population-based studies on the immune status at birth and the influence of prenatal and perinatal factors on it. Characterization of cytokine signatures at birth related to the prenatal environment could improve our understanding of immunity prenatal programming. Newborns exhibit specific unstimulated and stimulated cytokine signatures influenced by sex and season of birth. Unstimulated and stimulated cytokine signatures in newborns may be associated with the development of related clinical outcomes later in life.

Aqueous Three-Component Self-Assembly of a Pseudo[1]rotaxane Using Hydrazone Bonds.

We present herein the synthesis of a new polycationic pseudo[1]rotaxane, self-assembled in excellent yield through hydrazone bonds in aqueous media of three different aldehyde and hydrazine building blocks. A thermodynamically controlled process has been studied sequentially by analyzing the [1 + 1] reaction of a bisaldehyde and a trishydrazine leading to the macrocyclic part of the system, the ability of this species to act as a molecular receptor, the conversion of a hydrazine-pending cyclophane into the pseudo[1]rotaxane and, lastly, the one-pot [1 + 1 + 1] condensation process. The latter was found to smoothly produce the target molecule through an integrative social self-sorting process, a species that was found to behave in water as a discrete self-inclusion complex below 2.5 mM concentration and to form supramolecular aggregates in the 2.5-70 mM range. Furthermore, we demonstrate how the abnormal kinetic stability of the hydrazone bonds on the macrocycle annulus can be advantageously used for the conversion of the obtained pseudo[1]rotaxane into other exo-functionalized macrocyclic species.

Functional mapping to reveal slow conduction and substrate progression in atrial fibrillation.

AIMS: The aim of our study was to analyse the response to short-coupled atrial extrastimuli to identify areas of hidden slow conduction (HSC) and their relationship with the atrial fibrillation (AF) phenotype. METHODS AND RESULTS: Twenty consecutive patients with paroxysmal AF and persistent AF (10:10) underwent the first pulmonary vein isolation procedure. Triple short-coupled extrastimuli were delivered in sinus rhythm (SR), and the evoked response was analysed: sites exhibiting double or highly fragmented electrograms (EGM) were defined as positive for HSC (HSC+). The delta of the duration of the bipolar EGM was analysed, and bipolar EGM duration maps were built. High-density maps were acquired using a multipolar catheter during AF, SR, and paced rhythm. Spatial co-localization of HSC+ and complex fractionated atrial EGMs (CFAE) during AF was evaluated. Persistent AF showed a higher number and percentage of HSC+ than paroxysmal AF (13.9% vs. 3.3%, P < 0.001). The delta of EGM duration was 53 ± 22 ms for HSC+ compared with 13 ± 11 (10) ms in sites with negative HSC (HSC-) (P < 0.001). The number and density of HSC+ were lower than CFAE during AF (19 vs. 56 per map, P < 0.001). The reproducibility and distribution of HSC+ in repeated maps were superior to CFAE (P = 0.19 vs. P < 0.001). Sites with negative and positive responses showed a similar bipolar voltage in the preceding sinus beat (1.65 ± 1.34 and 1.48 ± 1.47 mV, P = 0.12). CONCLUSION: Functional mapping identifies more discrete and reproducible abnormal substrates than mapping during AF. The HSC+ sites in response to triple extrastimuli are more frequent in persistent AF than in paroxysmal AF.

Serum Vitamins A and E at Mid-Pregnancy and Their Relationships with Both Maternal and Cord Blood Antioxidant Status and Perinatal Conditions: The NELA Cohort.

INTRODUCTION: Most of the pregnant women do not achieve the recommended dietary intake of vitamins A and E. These vitamins may counteract oxidative stress involved in some adverse perinatal outcomes. We aimed to assess the associations between maternal vitamin A and E at mid-pregnancy with both maternal and fetal outcomes and to identify possible early biomarkers during pregnancy to predict and prevent oxidative stress in the offspring. METHODS: Data on dietary and serum levels of vitamins A and E were collected from 544 pregnant women from the Nutrition in Early Life and Asthma (NELA) study, a prospective mother-child cohort set up in Spain. RESULTS: There were large discrepancies between low dietary vitamin E intake (78% of the mothers) and low serum vitamin E levels (3%) at 24 weeks of gestation. Maternal serum vitamins A and E at mid-pregnancy were associated with higher antioxidant status not only in the mother at this time point (lower hydroperoxides and higher total antioxidant activity [TAA]) but also with the newborn at birth (higher TAA). Gestational diabetes mellitus (GDM) was negatively associated with maternal serum vitamin A (OR: 0.95 CI: 0.91-0.99, p = 0.009) at mid-pregnancy. Nevertheless, we could not detect any association between GDM and oxidative stress parameters. CONCLUSIONS: In conclusion, maternal vitamin A and E serum levels may be used as an early potential biomarker of antioxidant status of the neonate at birth. Control of these vitamins during pregnancy could help avoid morbid conditions in the newborn caused by oxidative stress in GDM pregnancies.

Feasibility and outcomes of transjugular intrahepatic portosystemic shunts in infants.

BACKGROUND: Experience with transjugular intrahepatic portosystemic shunts (TIPS) in the pediatric population, especially in infants, is limited. OBJECTIVE: To evaluate the feasibility, efficacy and safety of TIPS placement in infants. MATERIALS AND METHODS: This retrospective non-comparative observational cohort study analyzed all pediatric patients < 12 months of age treated with TIPS while waiting for liver transplant between October 2018 and April 2021. The sample consisted of 10 infants with chronic liver disease. All had refractory ascites and decreased portal vein size. Their mean age ± standard deviation was 5 ± 1 months and their mean weight was 5.4 ± 1.0 kg. We calculated the pediatric end-stage liver disease score and portosystemic gradients before and after TIPS placement. We used ultrasound to check for complications and to assess the presence of ascites. We used paired-sample t-test for the mean comparison of paired variables. RESULTS: Ten TIPS procedures were performed that were technically and hemodynamically successful except for one, in which an extrahepatic portal puncture required surgical repair. Ascites resolved in three infants and was reduced in six. The portal vein size remained stable after TIPS placement. Four infants had early stent thrombosis and two had late stent thrombosis treated with angioplasty or covered stents. CONCLUSION: TIPS placement in infants is a feasible, safe and effective procedure.

Receptor tyrosine kinases activate heterotrimeric G proteins via phosphorylation within the interdomain cleft of Gαi.

The molecular mechanisms by which receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major signaling hubs in eukaryotes, independently relay signals across the plasma membrane have been extensively characterized. How these hubs cross-talk has been a long-standing question, but answers remain elusive. Using linear ion-trap mass spectrometry in combination with biochemical, cellular, and computational approaches, we unravel a mechanism of activation of heterotrimeric G proteins by RTKs and chart the key steps that mediate such activation. Upon growth factor stimulation, the guanine-nucleotide exchange modulator dissociates Gαi•ßγ trimers, scaffolds monomeric Gαi with RTKs, and facilitates the phosphorylation on two tyrosines located within the interdomain cleft of Gαi. Phosphorylation triggers the activation of Gαi and inhibits second messengers (cAMP). Tumor-associated mutants reveal how constitutive activation of this pathway impacts cell's decision to "go" vs. "grow." These insights define a tyrosine-based G protein signaling paradigm and reveal its importance in eukaryotes.

The role of Human Development Index in the epidemiology of asthma in adolescents in Kosovo: A cross-sectional multicentre Global Asthma Network (GAN) study.

BACKGROUND: Very limited information is available on the prevalence and risk factors of asthma in adolescents in Kosovo, and no study has previously addressed the role of Human Development Index (HDI) on asthma in the region. The present study addresses these two issues. METHODS: Following the Global Asthma Network (GAN) methodology, a cross-sectional survey, through standardised self-completed questionnaires, was conducted in the following six centres of Kosovo: Ferizaj, Gjakova, Gjilan, Peja, Prishtina and Prizren. Current asthma symptoms (CAS) and severe current asthma symptoms (sCAS) were defined according to the GAN standards. Environmental questionnaire inquired about gender, exercise, screening time, siblings, truck traffic, use of paracetamol, pet ownership, and smoking habits. Height and weight were also measured. Multivariate logistic regression analyses were performed in each centre along with meta-analyses to summarise the overall effects of each factor in the centres as a whole. Meta-regression of the prevalence rates was calculated using HDI as a moderator. RESULTS: Participation rate was high (80.0-99.9%). Prevalence of CAS ranged from 4.6% to 11.3%, and sCAS from 1.7% to 4.5%. Factors associated with CAS were exercise, computer time, paracetamol use and dog ownership. sCAS was associated with paracetamol use and physical exercise. HDI explained 46% and 80% of prevalence variability of CAS and sCAS between centres, respectively. CONCLUSIONS: Prevalence of CAS and sCAS in Kosovo varies highly between centres. This variability is explained partly by HDI. Individual risk factors are common, with some determined in other studies conducted in other regions.