Biology subjects

Flores, I.

Publications and source records attributed to Flores, I..

10 recordsLinked to original sources

bioRxiv2026

Disruption of the SYNGAP1 PDZ ligand motif accelerates differentiation of human iPSC-derived GABAergic neurons

SYNGAP1 haploinsufficiency is a leading genetic cause of neurodevelopmental disorders (NDD), including intellectual disability and epileptic encephalopathy. While most studies on SYNGAP1 function have focused on glutamatergic neurons, its role in GABAergic neurons and during early neuronal development is unclear. Using human iPSC-derived GABAergic neurons, we demonstrate that SYNGAP1 haploinsufficiency accelerates neuronal maturation, characterized by increased dendritic length, synaptic density, and maturation of synaptic structures. Disruption of the isoform-specific SYNGAP1 PDZ binding motif reproduces these phenotypes, highlighting the critical role of PDZ-mediated interactions in regulating GABAergic neuronal differentiation. Proteomic and phosphoproteomic analyses reveal significant dysregulation of synaptic proteins, RNA processing, and transcriptional control, with a significant increase in postsynaptic density proteins content. RNA-seq analysis suggest that the acceleration in neuronal differentiation starts few hours after neuronal induction setting a path to a faster neuronal and synapse maturation. These findings establish that SYNGAP1 acts as a key regulator of neuronal differentiation across both excitatory and inhibitory neurons. Our work underscores the importance of the SYNGAP1 PDZ ligand motif for normal neuronal development and suggests translational strategies targeting SYNGAP1 alpha1 isoform levels to mitigate SYNGAP1-related NDD.

neuroscience↗

bioRxiv2024

Bacteria-powered living materials enable coral larval settlement

The global decline of coral reefs calls for new strategies to rapidly restock coral populations and maintain ecosystem functions and services. Low recruitment success on degraded reefs hampers coral sexual propagation and contributes to limited genetic diversity and reef resilience. Here, we introduce a living bacteria-powered reef ink (Brink) for assisted coral recruitment. Brink can be rapidly applied to restoration substrates via photopolymerization, and it has been formulated to cultivate two settlement-inducing bacterial strains (Cellulophaga lytica and Thalassotalea euphylliae). Settlement assays performed with broadcast spawning (Montipora capitata) and brooding (Pocillopora acuta) Indo-Pacific corals showed that Brink-coated substrates increased settlement >5-fold compared to uncoated control substrates. Brink can be applied as a coating or 3D bioprinted, leading to various potential applications for integration with reef engineering. Our approach underscores the potential of using functional living materials for augmented ecosystem engineering and reef rehabilitation. SynopsisThis study introduces a functional and sustainable bacteria-powered living material that enhances coral settlement, promoting coral reef rehabilitation and ecosystem resilience.

bioengineering↗

bioRxiv2024

Accurate quantitation of 16S gene copies in low biomass samples post-antibiotic treatment through deep sequencing with a balanced nucleotide synthetic spike-in approach

The microbiota significantly impacts health and treatment outcomes. While 16S rRNA gene sequencing reveals relative bacterial abundances, it does not provide absolute quantification. We developed a cost-effective solution incorporating synthetic DNA standards designed to ensure balanced nucleotide representation at each position. These standards are spiked into samples before DNA extraction, enabling simultaneous quantification of both relative and absolute bacterial abundances. We applied this method to samples collected from mice and patients, both before and after antibiotic treatment. Our approach showed a reduction in total bacterial density in mice and patients post-antibiotic treatment. This spike-in standard method can be adapted to samples with varying bacterial densities, allowing quantification of absolute taxonomical abundances without the need for an additional quantitative PCR assessment. Our approach also improves sequencing quality scores for low biomass samples.

microbiology↗

bioRxiv2024

Spatial Transcriptomic Analysis Identifies Epithelium-Macrophage Crosstalk in Endometriotic Lesions

The mechanisms underlying the pathophysiology of endometriosis, characterized by the presence of endometrium-like tissue outside the uterus, remain poorly understood. This study aimed to identify cell type-specific gene expression changes in superficial peritoneal endometriotic lesions and elucidate the crosstalk among the stroma, epithelium, and macrophages compared to patient-matched eutopic endometrium. Surprisingly, comparison between lesions and eutopic endometrium revealed transcriptional similarities, indicating minimal alterations in the sub-epithelial stroma and epithelium of lesions. Spatial transcriptomics highlighted increased signaling between the lesion epithelium and macrophages, emphasizing the role of the epithelium in driving lesion inflammation. We propose that the superficial endometriotic lesion epithelium orchestrates inflammatory signaling and promotes a pro-repair phenotype in macrophages, providing a new role for Complement 3 in lesion pathobiology. This study underscores the significance of considering spatial context and cellular interactions in uncovering mechanisms governing disease in endometriotic lesions.

molecular biology↗

bioRxiv2024

A paternal cardiac lesion induces cardiac adaptation in offspring

BackgroundFollowing cardiac injury, whether the heart is permanently damaged or regenerating, distal organs are subjected to changes in physiological function. It remains largely unknown whether a cardiac lesion can affect gametes and transmit heritable changes to subsequent generations. Here, we report the influence of paternal cardiac injury on the following generation. MethodsWe studied the intergenerational influence of neonatal cardiac injury in the mouse, an animal model capable of regenerating the heart after early life injury. Neonatal male mice were subjected to ventricular cryoinjury, crossed at adulthood, and their sires were compared with litters derived from uninjured male mice. We used echocardiography, histology, and single nuclei RNA-sequencing to thoroughly characterize cardiac morphology, composition, function, and response to cardiac insult. ResultsWe show that paternal cardiac injury affects the heart morphology of offspring under physiological conditions. Furthermore, in response to the same injury, the F1 generation derived from injured fathers shows better systemic and cardiac recovery, with non-pathological left ventricular enlargement and improved cardiac function during the regenerative process. This is accompanied by the activation of the immune system healing program at 3 weeks post-injury, together with enhanced transcription of genes associated with physiological hypertrophy. ConclusionsThe memory of a paternal neonatal lesion can be transmitted to offspring and improve their recovery from a cardiac insult.

developmental biology↗

bioRxiv2023

Transcript errors generate a continuous stream of amyloid and prion-like proteins in human cells

Aging is characterized by the accumulation of amyloid and prion-like proteins. However, the molecular mechanisms by which these proteins arise remain unclear. Here, we demonstrate that transcript errors generate amyloid and prion-like proteins in a wide variety of human cell types, including stem cells, brain organoids, and fully differentiated neurons. Intriguingly, some of these proteins are identical to proteins previously implicated in familial cases of amyloid diseases, raising the possibility that both familial and non-familial cases are caused by identical mutant proteins. However, transcript errors also generate amyloid proteins that have not been observed before, suggesting that aging cells are exposed to a second class of pathogenic proteins we are currently unaware of. Finally, we show that transcript errors are readily generated by DNA damage, a hallmark of human aging and a staple of multiple proteotoxic diseases, including Alzheimers disease. Together, these observations greatly expand our understanding of mutagenesis in human aging and disease and suggest a new mechanism by which amyloid diseases can develop.

molecular biology↗

bioRxiv2022

Induction of telomerase in p21-positive cells counteracts capillaries rarefaction in aging mice lung

Telomerase is required for long-term cell proliferation and linked to stem cells. This is evident in the lung where short telomeres are associated with lung dysfunction. We constructed a mouse model in which the telomerase (Tert) is expressed from the p21Cdkn1a promoter. We found that this peculiar Tert expression curb age-related emphysema and pulmonary perivascular fibrosis in old mice. In old mice lungs, such Tert expression preferentially occurs in endothelial cells where it reduces the number of senescent endothelial cells. Remarkably, we report that Tert counteracts the age-related decline in capillary density. This was associated with an increased number of Cd34+ cells identified as a subclass of capillary cells with proliferative capacity. Expression of catalytically inactive Tert neither prevents the decline of capillary density in old mice nor protects against age-related emphysema and fibrosis. These findings reveal that telomerase decreases age-decline of pulmonary functions by sustaining microvasculature regeneration and outgrowth.

molecular biology↗

bioRxiv2022

The ALT pathway generates telomere fusions that can be detected in the blood of cancer patients

Telomere fusions (TFs) can trigger the accumulation of diverse genomic rearrangements and the acquisition of oncogenic alterations leading to malignant transformation and resistance to chemotherapy. Despite their relevance in tumour evolution, our understanding of the patterns and consequences of TFs in human cancer remains limited. Here, we have characterized the rates and spectrum of somatic TFs across >30 cancer types using whole-genome sequencing data. TFs are pervasive in human tumours with rates varying markedly across and within cancer types. In addition to end-to-end fusions, we find novel patterns of TFs that we mechanistically link to the activity of the alternative lengthening of telomeres (ALT) pathway. We show that TFs can be detected in the blood of cancer patients, which enables cancer detection with high specificity and sensitivity even for early-stage tumours and cancer types for which early detection remains a high unmet clinical need, such as pancreatic cancer and brain tumours. Overall, we report a novel genomic footprint that enables characterization of the telomere maintenance mechanism of tumours and liquid biopsy analysis, which has implications for early detection, prognosis, and treatment selection.

cancer biology↗

bioRxiv2020

Cognitive Flexibility Deficits in Rats with Dorsomedial Striatal 6-OHDA Lesions Tested Using a 3-Choice Serial Reaction Time Task with Reversal Learning

Lesions of the dorsomedial striatum elicit deficits in cognitive flexibility that are an early feature of Parkinsons disease (PD), and presumably reflect alterations in frontostriatal processing. The current study aimed to examine deficits in cognitive flexibility in rats with bilateral 6-hydroxydopamine (6-OHDA) lesions in the dorsomedial striatum. While deficits in cognitive flexibility have previously been examined in rodent PD models using the cross-maze, T-maze, and a food-digging task, the current study is the first to examine such deficits using a 3-choice serial reaction time task (3-CSRT) with reversal learning (3-CSRT-R). Although the rate of acquisition in 3-CSRT was slower in lesioned compared to control rats, lesioned animals were able to acquire a level of accuracy comparable to that of control animals following 16 days of training. In contrast, substantial and persistent deficits were apparent during the reversal learning phase. Our results demonstrate that deficits in cognitive flexibility can be robustly unmasked by reversal learning in the 3-CSRT-R paradigm, which can be a useful test for evaluating effects of dorsomedial striatal deafferentation.

animal behavior and cognition↗

bioRxiv2018

Antagonizing the corticotropin releasing hormone receptor 1 with antalarmin reduces the progression of endometriosis.

Endometriosis is a disorder in which endometrial tissue is found outside the uterus causing pain, infertility and stress. Finding an effective and long-term treatment for endometriosis still remains one of the most significant challenges in the field. Corticotropin releasing hormone (CRH) is one of the main signaling peptides within the hypothalamic pituitary adrenal (HPA) axis released in response to stress. CRH can affect nervous and visceral tissues such as the uterus and gut via activation of two types of CRH receptors: CRHR1 and CRHR2. Our aim was to determine if blocking CRHR1 with antalarmin will reduce endometriosis progression. First, we induced endometriosis in female rats by suturing uterine horn tissue next to the intestinal mesentery and allowed to progress for 7 days. We determined that after 7 days, there was a significant increase in CRHR1 within endometriotic vesicles as compared to normal uterus. A second group of rats received endometriosis but also antalarmin (20 mg/kg, i.p.) during the first 7 days after surgery. As separate group of sham surgery rats served as controls. Endometriosis was allowed to progress until 60 days after surgery. At time of sacrifice, rats were tested for anxiety behaviors and endometriotic vesicles, and uterus were collected. Rats with endometriosis that received antalarmin significantly reduced the size (67% decrease) and number (30% decrease) of endometriotic vesicles. Antalarmin also prevented the increase in CRH and CRHR1 within endometriotic vesicles but not of glucocorticoid receptor. Behaviorally, endometriosis increased anxiety in the zero-maze test but antalarmin did not modify it. Our data provides the first demonstration for the effective use on CRHR1 antagonist for the treatment of endometriosis with promising effects for long-term therapy of this debilitating disease.

physiology↗