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Romero, L. O.

Publications and source records attributed to Romero, L. O..

5 recordsLinked to original sources

PIEZO1-mediated mechanosensation links aging to bladder dysfunction

Aging is accompanied by profound changes in bladder function, leading to increased urinary frequency and incontinence that impair quality of life in humans and are recapitulated in mouse models. Bladder filling and emptying rely on precise mechanosensory feedback, yet how aging alters this sensory control remains unclear. PIEZO ion channels convert mechanical forces into cellular signals essential for bladder fullness sensation. Using inducible smooth-muscle specific Piezo1 deletion, we find that loss of Piezo1 attenuates aging-related bladder dysfunction. Dietary enrichment with margaric acid, a membrane-active fatty acid previously shown to inhibit PIEZO channels, reduced urinary dysfunction in aged mice. In humans, genotype-phenotype analyses reveal an association between a PIEZO1 gain-of-function variant and early-onset neuromuscular bladder dysfunction. Together, these findings define a smooth-muscle, PIEZO1-mediated mechanosensory basis for aging-related bladder dysfunction and introduce a non-invasive strategy for targeting PIEZO channels in vivo.

physiology↗

Enhanced PIEZO1 Function Contributes to the Pathogenesis of Sickle Cell Disease

Sickle cell disease (SCD), an inherited blood disorder caused by a mutation in the {beta}-globin gene, is characterized by sickle erythrocytes that are prone to hemolysis, causing anemia and vaso-occlusion crises. In sickle erythrocytes, hemoglobin aggregation is followed by altered cation permeability and subsequent dehydration. Interventions to restore cation permeability can decrease hemolysis and ameliorate the symptoms associated with SCD. PIEZO1 is a non-selective mechanosensitive cation channel that regulates erythrocyte volume. Gain-of-function (GOF) mutations in PIEZO1 cause hemolytic anemia by increasing cation permeability, leading to erythrocyte dehydration in humans and mice. Although PIEZO1 plays a key role in erythrocyte homeostasis, its role in SCD remains unknown. Here, we demonstrate that the function of the PIEZO1 channel is upregulated in sickle erythrocytes of humans and mice, and this enhancement can be restored through a dietary intervention. We found that PIEZO1 function in sickle erythrocytes resembles that of the GOF mutation causing hemolytic anemia. A diet enriched in the{omega} -3 fatty acid eicosapentaenoic (EPA) acid decreases PIEZO1 function in sickle erythrocytes and hemolysis in a mouse model of SCD. Furthermore, EPA decreases hemolysis and reduces inflammatory markers. We propose that PIEZO1 contributes to the increase in nonselective cationic conductance (i.e., Psickle), which leads to dehydration downstream of hemoglobin polymerization. Our results suggest that reducing PIEZO1 function is a promising therapeutic approach to reestablishing normal cation permeability in SCD.

physiology↗

Mutation in F-actin Polymerization Factor Suppresses Distal Arthrogryposis Type 5 (DA5) PIEZO2 Pathogenic Variant in Caenorhabditis elegans

The mechanosensitive PIEZO channel family has been linked to over 26 disorders and diseases. Although progress has been made in understanding these channels at the structural and functional levels, the underlying mechanisms of PIEZO-associated diseases remain elusive. In this study, we engineered four PIEZO-based disease models using CRISPR/Cas9 gene editing. We performed an unbiased chemical mutagen-based genetic suppressor screen to identify putative suppressors of a conserved gain-of-function variant pezo-1[R2405P] that in human PIEZO2 causes distal arthrogryposis type 5 (DA5; p. R2718P). Electrophysiological analyses indicate that pezo-1(R2405P) is a gain-of-function allele. Using genomic mapping and whole genome sequencing approaches, we identified a candidate suppressor allele in the C. elegans gene gex-3. This gene is an ortholog of human NCKAP1(NCK-associated protein 1), a subunit of the Wiskott-Aldrich syndrome protein (WASP)-verprolin homologous protein (WAVE/SCAR) complex, which regulates F-actin polymerization. Depletion of gex-3 by RNAi, or with the suppressor allele gex-3(av259[L353F]), significantly restored the small brood size and low ovulation rate, as well as alleviated the crushed oocyte phenotype of the pezo-1(R2405P) mutant. Auxin-inducible degradation of GEX-3 revealed that only somatic-specific degradation of GEX-3 restored the reduced brood size in the pezo-1(R2405P) mutants. Additionally, actin organization and orientation were disrupted and distorted in the pezo-1 mutants. Mutation of gex-3(L353F) partially alleviated these defects. The identification of gex-3 as a suppressor of the pathogenic variant pezo-1(R2405P) suggests that the cytoskeleton plays an important role in regulating PIEZO channel activity and provides insight into the molecular mechanisms of DA5 and other PIEZO-associated diseases.

genetics↗

Excessive Mechanotransduction in Sensory Neurons Causes Joint Contractures in a Mouse Model of Arthrogryposis

Distal arthrogryposis (DA) is a collection of rare disorders characterized by congenital joint contractures. Most DA mutations are in muscle- and joint-related genes, and the anatomical defects originate cell-autonomously within the musculoskeletal system. However, gain-of-function (GOF) mutations in PIEZO2, a principal mechanosensor in somatosensation, cause DA subtype 5 via unknown mechanisms. We show that expression of a GOF PIEZO2 mutation in proprioceptive sensory neurons mainly innervating muscle spindles and tendons is sufficient to induce DA5-like phenotypes in mice. Overactive PIEZO2 causes anatomical defects via increased activity within the peripheral nervous system during postnatal development. Remarkably, Botox and a dietary fatty acid that modulates PIEZO2 activity markedly reduce DA5-like deficits. This reveals an unexpected role for somatosensory neurons: excessive mechanosensation within these neurons disrupts musculoskeletal development.

neuroscience↗

C. elegans PEZO-1 is a Mechanosensitive Channel Involved in Food Sensation

PIEZO channels are force sensors essential for physiological processes, including baroreception and proprioception. The Caenorhabditis elegans genome encodes an ortholog gene of the Piezo family, pezo-1, which is expressed in several tissues, including the pharynx. This myogenic pump is an essential component of the C. elegans alimentary canal, whose contraction and relaxation are modulated by mechanical stimulation elicited by food content. Whether pezo-1 encodes a mechanosensitive ion channel and contributes to pharyngeal function remain unknown. Here, we leverage genome editing, genetics, microfluidics, and electropharyngeogram recording to establish that pezo-1 is expressed in the pharynx, including in a proprioceptive-like neuron, and regulates pharyngeal function. Knockout (KO) and gain-of-function (GOF) mutants reveal that pezo-1 is involved in fine-tuning pharyngeal pumping frequency, sensing osmolarity, and food mechanical properties. Using pressure-clamp experiments in primary C. elegans embryo cultures, we determine that pezo-1 KO cells do not display mechanosensitive currents, whereas cells expressing wild-type or GOF PEZO-1 exhibit mechanosensitivity. Moreover, infecting the Spodoptera frugiperda cell line with a baculovirus containing the G-isoform of pezo-1 (among the longest isoforms) demonstrates that pezo-1 encodes a mechanosensitive channel. Our findings reveal that pezo-1 is a mechanosensitive ion channel that regulates food sensation in worms.

physiology↗