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Guerra, M. E.

Publications and source records attributed to Guerra, M. E..

3 recordsLinked to original sources

Intra-Abdominal Bowel Dilation in Experimental Gastroschisis is Associated with a Modifiable Transcriptomic Program of Intestinal Dysfunction

STRUCTURED ABSTRACTO_ST_ABSObjectiveC_ST_ABSTo characterize intestinal transcriptional profiles in gastroschisis, their temporal evolution, and response to fetal intervention. Summary Background DataGastroschisis causes significant intestinal dysfunction, with intra-abdominal bowel dilation clinically shown to correlate with worse outcomes. While inflammation and neurovascular impairment have been implicated, genome-wide transcriptional characterization of disease severity remains lacking. MethodsUsing a fetal ovine model of complex gastroschisis, in which all gastroschisis animals demonstrated significant intra-abdominal bowel dilation at term, bulk RNA sequencing was performed on proximal small intestinal tissue from mid-gestation and term fetuses across three groups: normal, gastroschisis, and prenatally repaired gastroschisis. Differential gene expression (FDR [≤] .05, |log2 fold change| [≥] 1.5) and pathway enrichment analyses were performed, with targeted interrogation of extracellular matrix (ECM), enteric nervous system (ENS), angiogenic, and inflammatory pathways. ResultsAt mid-gestation, gastroschisis intestine showed minimal transcriptional differences (150 differentially expressed genes [DEGs]) and some bowel dilation. By term, dysregulation was substantial (2,423 DEGs) alongside significant dilation. Normal ontogenetic intestinal maturation patterns were altered, with fewer expected developmental gene changes and discordant pathway regulation. ECM pathway aberrations emerged early and persisted, while ENS, angiogenic, and inflammatory pathways were only dysregulated at term. Fetal repair was associated with normalization of gene expression at term (29 DEGs vs controls). ConclusionIntestinal transcriptional changes in experimental gastroschisis parallel progressive bowel dilation, consistent with a mechanical stress contribution to intestinal injury. Prenatal repair normalizes both dilation and gene expression, indicating a dynamic and potentially modifiable transcriptional program that supports the rationale for early fetal intervention. Mini AbstractIn a fetal ovine model, progressive bowel dilation in gastroschisis parallels transcriptomic dysregulation of ECM remodeling, neurovascular impairment, and inflammation which is normalized by prenatal repair.

developmental biology↗

Bioabsorbable Magnesium Metal ScaffoldsImprove Dermal Wound Healing and Tissue Regeneration

ObjectiveEvaluate the effects of bioabsorbable magnesium wires on dermal wound healing and tissue regeneration in a murine full-thickness wound model. Approach6 mm diameter stented dorsal skin wounds were created in C57BL/6J mice and treated with implanted WE43B magnesium alloy wires or PBS control. Wound healing was evaluated on days 7 and 28 by histology, immunohistochemistry, and micro-CT. Finite element analysis modeled mechanical strain distribution due to wire degradation during healing. ResultsAt day 7, magnesium wire-treated wounds showed 100% improved granulation tissue formation, reduced inflammation (37% fewer CD45+ leukocytes and 37% fewer F4/80+ macrophages), increased neovascularization (91% more CD31+ lumens), and 74% more nerve bundles. Improved wound closure (mean difference -1.48 mm) did not reach statistical significance (d = 1.06). By day 28, magnesium-treated wounds showed improved collagen organization and normalized epidermal thickness. The increase in dermal appendages (247%), and vascular density (41%) did not reach statistical significance. Micro-CT confirmed progressive wire degradation. Modeling revealed that degrading wires dynamically altered strain gradients in healing tissue, thereby modulating the spatial mechanical cues that govern fibroblast migration and extracellular matrix (ECM) remodeling. InnovationMagnesium is an essential trace element involved in cellular processes critical to wound repair, including angiogenesis, nerve growth, inflammation modulation, and ECM remodeling. Previous magnesium delivery systems incorporated polymers or other confounding materials that degrade rapidly. We directly applied bioabsorbable pure magnesium metal to provide sustained ion release and favorable mechanical properties to support regenerative healing. ConclusionBioabsorbable magnesium wires support regenerative wound healing by reducing inflammation, enhancing neovascularization, and promoting favorable ECM remodeling without adverse inflammatory reactions. These findings provide a strong rationale to harness magnesium metal use in wound healing applications.

bioengineering↗

In utero delivery of miRNA induces epigenetic alterations and corrects pulmonary pathology in congenital diaphragmatic hernia

Structural fetal diseases, such as congenital diaphragmatic hernia (CDH) can be diagnosed prenatally. Neonates with CDH are healthy in utero as gas exchange is managed by the placenta, but impaired lung function results in critical illness from the time a baby takes its first breath. During fetal development, lungs are capable of remarkable growth and the fetus does not yet require lung function for gas exchange. MicroRNA (miR) 200b and its downstream targets in the TGF{beta} pathway are critically involved lung branching morphogenesis. Here we characterize the expression of miR200b and the TGF{beta} pathway at different gestational times using a rat model of CDH. Fetal rats with CDH are deficient in miR200b at gestational day 18. We demonstrate that NPs loaded with miR200b given systemically to fetal rats result in changes in the TGF{beta} pathway; these epigenetic changes improve lung size, lung morphology, and lung vascularization. This is the first demonstration of in utero epigenetic therapy to improve lung growth and development in a pre-clinical model. With refinement, this technique could be applied to fetal cases of CDH or other forms of impaired lung development in a minimally invasive fashion. eTOC SynopsisIn utero treatment with NPs loaded with miR200b improves lung development in a rat model of CDH. miR200b treatment epigenetic changes in the TGF{beta}, leads to larger lungs with more airspace and favorable pulmonary vascular remodeling. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/482144v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@3531caorg.highwire.dtl.DTLVardef@57ff5aorg.highwire.dtl.DTLVardef@13d6ee9org.highwire.dtl.DTLVardef@3cb3d8_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗