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Cano, M.

Publications and source records attributed to Cano, M..

12 recordsLinked to original sources

Molecular Imaging of the TGF-β Activating Integrin αvβ6 Detects Chronic Lung Allograft Dysfunction

TGF-{beta}-activating integrins promote solid-organ fibrosis, suggesting their use as a molecular marker of disease. Chronic lung allograft dysfunction (CLAD), a progressive fibrotic complication that limits lung transplant survival, is driven by intragraft TGF-{beta} activation. However, the expression patterns of TGF-{beta}-activating integrins remain undefined in lung transplants. Single-cell RNA sequencing in a mouse CLAD model revealed high levels of the TGF-{beta}-activating integrin v{beta}6, which was mainly localized to fibrosis-associated Krt8+ transitional alveolar cells (AT1/2), while tolerant transplants lacked both v{beta}6 expression and Krt8+AT1/2 cells. Molecular imaging with a newly developed positron emission tomography radiotracer specific for v{beta}6, [64Cu]Cu-DOTA-A20-K16R, showed significantly higher uptake in CLAD versus tolerant transplants. In contrast, [64Cu]Cu-DOTA-A20-K16R allograft uptake was reduced by treatments that lowered v{beta}6 expression and CLAD severity. Finally, [64Cu]Cu-DOTA-A20-K16R autoradiographic analysis on human explanted lungs with CLAD showed elevated activity that correlated with v{beta}6 expression. Collectively, these findings demonstrate the potential utility of v{beta}6 molecular imaging to detect CLAD pathogenesis.

immunology↗

Atg16l1 promotes lung transplant tolerance by regulating glycolysis in macrophages

Lung transplant survival is limited by the development of chronic lung allograft dysfunction (CLAD), a type of graft rejection that lacks effective treatments. Autophagy plays a crucial role in maintaining cellular homeostasis. In a single-nucleotide polymorphism screen, we found that lung recipients with two copies of a common hypofunctional genetic variant of autophagy-related 16-like 1 rs2241880 (ATG16L1T300A/T300A), known to deplete this protein from macrophages, were more likely to develop early CLAD. To understand this, we used a mouse orthotopic lung transplant model. Recipients encoding myeloid cell-specific deletion of Atg16l1 (Atg16l1{Delta}/{Delta}) or who harbor an engineered orthologous mutation (Atg16l1T316A/T316A) showed similar susceptibility to CLAD. Transcript profiling and mitochondrial tracking studies indicated that increased mitochondrial damage and decreased autophagic removal of mitochondria in Atg16l1-deficient macrophages were associated with heightened activation of the hypoxia-inducible factor 1 (Hif1) pathway and accumulation of glycolytic transcripts. Metabolic analysis revealed reduced oxidative phosphorylation, increased glycolytic activity, and higher IL-1{beta} expression in Atg16l1-deficient macrophages. Notably, the development of CLAD in Atg16l1{Delta}/{Delta} lung recipients could be significantly prevented by additionally deleting Hif1 in myeloid cells or by treating with the glycolysis inhibitor 2-deoxyglucose. Our results show how a common autophagy-related genetic variant disrupts macrophage metabolism and impairs lung transplant tolerance, pointing toward potential therapeutic strategies to combat CLAD.

immunology↗

Phosphorylation of Ser81 in human AGT reversibly inactivate enzyme function and mimics catalytic defects of certain PH1-causing mutations

Phosphorylation is fundamental to modulate protein function and stabilty. There have detected about 300000 site-specic Phosphorylation sites in over 20000 human proteins. However, only 5% of the sites have been experimenrally characterized. In this work, we investigated a phosphorylation event in AGT, an important enzyme due to its detoxifying role of glyoxylate and hundreds of mutations cause a rare disease (primary hyperoxaluria type I or PH1). We analyzed the effect of phosphomimetic mutations Ser81 on the WT proten, the common polymorpshim LM, and the most common disease-associted variants (LM-G170R and LM-I244T). Using biochemical, biophysical and cell biology approaches, we show that phosphorylation at S81 dramatically affects PLP/PMP binding pose and disrupts enzyme activity, without pertubing its subcellular location to peroxisomes. This reversible phenotype is similar to the irreversible effects of some PH1-causing mutaions. Thus, we provide evidence for a novel regulatory mechanism for PH1, in health and disease.

biophysics↗

Nanobodies as therapies for loss-of-function misfolding diseases.

Misfolding diseases that result in loss of function represent a considerable burden for both individuals and society. Primary hyperoxaluria type 1 (PH1) is a rare genetic disorder caused by mutations in the alanine:glyoxylate aminotransferase 1 (AGT) enzyme. The underlying molecular mechanisms causing PH1 are associated with protein misfolding (enhanced aggregation and mitochondrial mistargeting). The main therapeutic approach to increase patients lifespan and quality of life is a double kidney and liver transplantation. Alternative treatments such as gene and enzyme replacement and pharmacological chaperones are currently being introduced, but other alternatives are necessary. In this work, we developed and characterized a novel biotechnological approach using six single-domain nanobodies (NB-AGT-1 to -6) as potential therapeutics for PH1 misfolding. We show that NB-AGTs are very stable proteins and bind to pathogenic and non-pathogenic variants of AGT with extreme affinities (with Kd values from low nM to low pM). Structural studies showed that NB-AGTs bind to different epitopes of AGT with selectivity for different AGT variants. Experiments in cellular PH1 models showed that internalization of engineered NB-AGT-3 enhanced the specific activity of disease-associated variants. Overall, we show that NBs are a novel and promising approach to treat PH1 and other loss-of-function misfolding diseases.

biophysics↗

Molecular impact of nicotine and smoking exposure on the developing and adult mouse brain

Maternal smoking during pregnancy (MSDP) is associated with significant cognitive and behavioral effects on offspring. While neurodevelopmental outcomes have been studied for prenatal exposure to nicotine, the main psychoactive component of cigarette smoke, its contribution to MSDP effects has never been explored. Comparing the effects of these substances on molecular signaling in the prenatal and adult brain may provide insights into nicotinic and broader tobacco consequences that are developmental-stage specific or age-independent. Pregnant mice were administered nicotine or exposed to chronic cigarette smoke, and RNA-sequencing was performed on frontal cortices of postnatal day 0 pups born to these mice, as well as on frontal cortices and blood of the adult dams. We identified 1,010 and 4,165 differentially expressed genes (DEGs) in nicotine and smoking-exposed pup brains, respectively (FDR<0.05, Ns = 19 nicotine-exposed vs 23 vehicle-exposed; 46 smoking-exposed vs 49 controls). Prenatal nicotine exposure (PNE) alone was related to dopaminergic synapses and long-term synaptic depression, whereas MSDP was associated with the SNARE complex and vesicle transport. Both substances affected SMN-Sm protein complexes and postsynaptic endosomes. Analyses at the transcript, exon, and exon-exon junction levels supported gene level results and revealed additional smoking-affected processes. No DEGs at FDR<0.05 were found in adult mouse brain for any substance (12 nicotine-administered vs 11 vehicle-administered; 12 smoking-exposed vs 12 controls), nor in adult blood (12 smoking-exposed vs 12 controls), and only 3% and 6.41% of the DEGs in smoking-exposed pup brain replicated in smoking-exposed blood and human prenatal brain, respectively. Together, these results demonstrate variable but overlapping molecular effects of PNE and MSDP on the developing brain, and attenuated effects of both smoking and nicotine on adult versus fetal brain.

neuroscience↗

Massive detection of cryptic recessive genetic defects in cattle mining millions of life histories

We present a data-mining framework designed to detect recessive defects in livestock that have been previously missed due to a lack of specific signs, incomplete penetrance, or incomplete linkage disequilibrium. This approach leverages the massive data generated by genomic selection. Its basic principle is to compare the observed and expected numbers of homozygotes for sliding haplotypes in animals with different life histories. Within three cattle breeds, we report 33 new loci responsible for increased risk of juvenile mortality and present a series of validations based on large-scale genotyping, clinical examination, and functional studies for candidate variants affecting the NOA1, RFC5, and ITGB7 genes. In particular, we describe disorders associated with NOA1 and RFC5 mutations for the first time in vertebrates. The discovery of these many new defects will help to characterize the genetic basis of inbreeding depression, while their management will improve animal welfare and reduce losses to the industry.

genetics↗

Connectivity-based Meta-Bands: A new approach for automatic frequency band identification in connectivity analyses

The majority of electroencephalographic (EEG) and magnetoencephalographic (MEG) studies filter and analyse neural signals in specific frequency ranges, known as "canonical" frequency bands. However, this segmentation, is not exempt from limitations, mainly due to the lack of adaptation to the neural idiosyncrasies of each individual. In this study, we introduce a new data-driven method to automatically identify frequency ranges based on the topological similarity of the frequency-dependent functional neural network. The resting-state neural activity of 195 cognitively healthy subjects from three different databases (MEG: 123 subjects; EEG1: 27 subjects; EEG2: 45 subjects) was analysed. In a first step, MEG and EEG signals were filtered with a narrow-band filter bank (1 Hz bandwidth) from 1 to 70 Hz with a 0.5 Hz step. Next, the connectivity in each of these filtered signals was estimated using the orthogonalized version of the amplitude envelope correlation to obtain the frequency-dependent functional neural network. Finally, a community detection algorithm was used to identify communities in the frequency domain showing a similar network topology. We have called this approach the "Connectivity-based Meta-Bands" (CMB) algorithm. Additionally, two types of synthetic signals were used to configure the hyper-parameters of the CMB algorithm. We observed that the classical approaches to band segmentation reflect the underlying network topologies at group level for the MEG signals, but they fail to adapt to the individual differentiating patterns revealed by our methodology. On the other hand, the sensitivity of EEG signals to reflect this underlying frequency-dependent network structure is limited. To the best of our knowledge, this is the first study that proposes an unsupervised band segmentation method based on the topological similarity of functional neural network across frequencies. This methodology fully accounts for subject-specific patterns, providing more robust and personalized analyses, and paving the way for new studies focused on exploring the frequency-dependent structure of brain connectivity.

bioinformatics↗

Assessment of dynamics of global DNA methylation during the cryopreservation process of Pinus pinaster embryogenic lines

Long-term in vitro maintenance of embryogenic lines of Pinus species has been associated with lower maturation capacity, because of this, cryopreservation protocols for the embryogenic lines are needed to maintain valuable genotypes. Since cryopreservation may induce epigenetic variations, we evaluate changes in DNA methylation levels through the course of the cryopreservation of maritime pine embryogenic lines, as compared to those lines maintained by repeated subcultures. Six maritime pine embryogenic lines were cryopreserved following a protocol that includes pre-treatments inducing osmotic stress in liquid media. The percentage of methylated cytosines (%5-mC) in total DNA was determined by using a colorimetric assay. Reactive oxygen species (ROS) accumulation in cell lines was also determined by quantifying dihydroethidium (DHE) fluorescence under a confocal laser-scanning microscope. In the first experiment, we found that global DNA methylation was significantly reduced during the cryopreservation protocol. Subsequently, we evaluated the methylation status of both cryopreserved and no cryopreserved lines (maintained by subcultures) and found differences among embryogenic lines but overall, cryopreservation did not alter %5-mC of the recovered lines while periodical subcultures increased methylation rates. In addition, maltose pretreatment did not increase significantly ROS production in embryogenic lines. Our results demonstrate that the genetic stability during cryopreservation highly depends on the embryogenic line studied, but the protocol allows maintaining methylation DNA rates in most of the recovered lines.

plant biology↗

Reprogramming Alveolar Macrophage Responses to TGF-β Reveals CCR2+ Monocyte Activity that Promotes Bronchiolitis Obliterans Syndrome

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-{beta} bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes are engulfed primarily by alveolar macrophages (AM), which become reprogrammed to become less responsive to TGF-{beta} and reduce TGF-{beta} bioavailability through secretion of the TGF-{beta} antagonist Decorin. In untreated recipients, high airway TGF-{beta} activity stimulates AM to express CCL2 leading to CCR2+ monocyte-driven BOS development. Moreover, we find TGF-{beta} receptor 2-dependent differentiation of CCR2+ monocytes is required for the generation of monocyte-derived AM, which in turn promote BOS by expanding tissue-resident memory CD8+ T cells that inflict airway injury through Blimp-1-mediated Granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-{beta}-dependent network, which couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS. Alveolar macrophage plasticity can be harnessed to prevent Bronchiolitis Obliterans Syndrome.

immunology↗

Increased complement activation is a distinctive feature of severe SARS-CoV-2 infection.

Complement activation has been implicated in the pathogenesis of severe SARS-CoV-2 infection. However, it remains to be determined whether increased complement activation is a broad indicator of critical illness (and thus, no different in COVID-19). It is also unclear which pathways are contributing to complement activation in COVID-19, and, if complement activation is associated with certain features of severe SARS-CoV-2 infection, such as endothelial injury and hypercoagulability. To address these questions, we investigated complement activation in the plasma from patients with COVID-19 prospectively enrolled at two tertiary care centers. We compared our patients to two non-COVID cohorts: (a) patients hospitalized with influenza, and (b) patients admitted to the intensive care unit (ICU) with acute respiratory failure requiring invasive mechanical ventilation (IMV). We demonstrate that circulating markers of complement activation (i.e., sC5b-9) are elevated in patients with COVID-19 compared to those with influenza and to patients with non-COVID-19 respiratory failure. Further, the results facilitate distinguishing those who are at higher risk of worse outcomes such as requiring ICU admission, or IMV. Moreover, the results indicate enhanced activation of the alternative complement pathway is most prevalent in patients with severe COVID-19 and is associated with markers of endothelial injury (i.e., Ang2) as well as hypercoagulability (i.e., thrombomodulin and von Willebrand factor). Our findings identify complement activation to be a distinctive feature of COVID-19, and provide specific targets that may be utilized for risk prognostication, drug discovery and personalized clinical trials. SUMMMARYComplement has been implicated in COVID-19. However, whether this is distinctive of COVID-19 remains unanswered. Ma et al report increased complement activation in COVID-19 compared to influenza and non-COVID respiratory failure, and demonstrate alternative pathway activation as a key marker of multiorgan failure and death.

immunology↗

Circulating Mitochondrial DNA is an Early Indicator of Severe Illness and Mortality from COVID-19

Mitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether the appearance of cell-free MT-DNA is linked to poor COVID-19 outcomes remains undetermined. Here, we quantified circulating MT-DNA in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at the time of hospital presentation. Circulating MT-DNA were sharply elevated in patients who eventually died, required ICU admission or intubation. Multivariate regression analysis revealed that high circulating MT-DNA levels is an independent risk factor for all of these outcomes after adjusting for age, sex and comorbidities. Additionally, we found that circulating MT-DNA has a similar or superior area-under-the curve when compared to clinically established measures of systemic inflammation, as well as emerging markers currently of interest as investigational targets for COVID-19 therapy. These results show that high circulating MT-DNA levels is a potential indicator for poor COVID-19 outcomes.

immunology↗

A widespread decrease of chromatin accessibility in age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. The extent to which epigenetic changes regulate AMD progression is unclear. Here we globally profiled chromatin accessibility in the retina and retinal pigmented epithelium (RPE) from AMD patients and controls. Global decreases in chromatin accessibility occurr in RPE in early AMD, and in the retina with advanced disease, suggesting that dysfunction in RPE cells drives disease progression. Footprints of photoreceptor and RPE-specific transcription factors are enriched in differentially accessible regions (DARs). Genes associated with DARs show altered expression in AMD. Cigarette smoke treatment of RPE cells recapitulates epigenomic changes seen in AMD, providing an epigenetic link between the known risk factors for AMD and AMD pathology. Finally, overexpression of HDAC11 is partially responsible for the reduction in chromatin accessibility, identifying potential new targets for treatment of AMD.

genomics↗