Biology subjects

Sanchez-Martin, I.

Publications and source records attributed to Sanchez-Martin, I..

3 recordsLinked to original sources

bioRxiv2026

Deciphering epileptogenic and activity-dependent gene programs in the human brain

Neuronal activity is fundamental to brain function, yet chronically elevated activity underlies neurological disorders such as drug-resistant epilepsy (DRE). In animal models, activity induces defined transcriptional programs within activated neurons; however, the nature, cellular specificity, and pathological relevance of such programs in the human brain remain poorly understood. Here, we apply single-nucleus and spatial transcriptomics to epileptogenic, non-epileptogenic, and intraoperatively stimulated non-epileptogenic cortical tissue obtained from individuals with DRE. Across 26 cell types profiled, glutamatergic neurons projecting from cortical layers 2/3, 5, and 6 to intratelencephalic targets exhibit pronounced sensitivity to the epileptogenic microenvironment, inducing shared immediate-early genes alongside cell-type-specific programs linked to synaptic remodeling and cellular stress. Approximately one-third of transcripts enriched in the epileptogenic microenvironment were also induced by acute stimulation, suggesting that a fraction of epilepsy-associated gene expression reflects conserved responses to heightened activity rather than disease-specific programs. While transcripts induced by both epileptogenic and acute activity converged upon immediate-early genes and heat-shock proteins, only acute stimulation triggered a rapid, multicellular induction of transcripts involved in mitochondrial ATP synthesis. This divergence suggests that neurons within epileptogenic cortex may be unable to mount appropriate metabolic adaptations to sustained energetic demands. In parallel, both microglia and circulating CD14+ monocytes exhibit signs of immune activation in epilepsy, suggesting myeloid-driven inflammatory rewiring that extends beyond the brain. Together, these findings illuminate human activity-dependent gene programs and reveal signatures of neuronal vulnerability and inflammation in DRE.

neuroscience↗

bioRxiv2026

Maternal-fetal immune conflict contributes to male-specific impairments in a mouse model of neurodevelopmental disorders

Autism spectrum disorder (ASD) arises from genetic and environmental risk factors. One environmental factor, maternal immune activation (MIA)--in which pathogenic infection during pregnancy increases ASD risk in offspring--disproportionately affects males. However, the basis for this male-specific vulnerability, and the mechanisms by which inflammatory signals cross the maternal-fetal interface to affect the male embryo, remain largely unknown. Using the poly(I:C) mouse model of neurodevelopmental disorders, we characterize fetal, placental, and amniotic changes occurring within twenty-four hours of MIA. We find that 30% of embryos exhibit large-scale teratogenic abnormalities--ranging from decreased fetal weight to altered sensory organ development--while 70% develop normally. These abnormalities occur exclusively in a subset of males, never in females. Single-nucleus transcriptomics revealed robust induction of pro-inflammatory gene programs in the placentas of affected males across a broad range of cell types, and most prominently in spongiotrophoblasts--fetally derived cells that partly form the maternal-fetal border. These cells simultaneously down-regulate extracellular matrix and hormone biosynthesis pathways, coinciding with a breakdown in placental structural integrity and the accumulation of immune cells and cytokines in the amniotic fluid. One such cytokine, IL-6, is required for MIA-evoked developmental abnormalities to emerge. Our data indicate that MIA drives a rapid shift from an immunosuppressive to a pro-inflammatory maternal-fetal interface in a vulnerable subset of male embryos, producing acute, sex-restricted developmental deficits. We propose that male embryos may express unique proteins capable of triggering this inflammatory response, which--combined with MIA-induced loss of maternal immunosuppression--selectively derails male embryonic development.

developmental biology↗

bioRxiv2021

Haploinsufficiency of the mouse Tshz3 gene leads to kidney dysfunction

Renal tract defects and autism spectrum disorder (ASD) deficits represent the phenotypic core of the 19q12 deletion syndrome caused by the loss of one copy of the TSHZ3 gene. While a proportion of Tshz3 heterozygous (Tshz3+/lacZ) mice display ureteral defects, no kidney defects have been reported in these mice. The purpose of this study was to characterize the expression of Tshz3 in adult kidney as well as the renal physiological consequences of embryonic haploinsufficiency of Tshz3 by analyzing the morphology and function of Tshz3 heterozygous adult kidney. Here, we described Tshz3 expression in the smooth muscle and stromal cells lining the renal pelvis, the papilla and glomerular endothelial cells (GEnCs) of the adult kidney. Histological analysis showed that Tshz3+/lacZ adult kidney had an average of 29% fewer glomeruli than wild type kidney. Transmission electron microscopy (TEM) of Tshz3+/lacZ glomeruli revealed ultrastructural defects. Compared to wild type, Tshz3+/lacZ mice showed no difference in their urine parameters but lower blood urea, phosphates, magnesium and potassium at 2 months of age. At the molecular level, transcriptome analysis identified differentially expressed genes related to inflammatory processes in Tshz3+/lacZ compare to wild type (WT; control) adult kidneys. Lastly, analysis of the urinary peptidome revealed 33 peptides associated with Tshz3+/lacZ adult mice. These results provide the first evidence that in the mouse Tshz3 haploinsufficiency leads to cellular, molecular and functional abnormalities in the adult mouse kidney.

genetics↗