Biology subjects

Matynia, A.

Publications and source records attributed to Matynia, A..

5 recordsLinked to original sources

bioRxiv2025

The Cornea Harbors a Tricellular Neuro-Immune Niche that Underpins Touch Sensation

Piezo2 is a mechanosensitive ion channel essential for touch and proprioception, yet the mechanisms that maintain this sensory modality in adult tissues are unknown. Using multiphoton imaging of the cornea in live mice, we discovered that the Cx3cr1Cre locus targets not only macrophages, but also a distinct subset of nerves. Spatial-RNAseq resolved that Cx3cr1Cre-driven labeling was uniquely enriched in Piezo2-expressing neurons, a result of temporal Cx3cr1 expression during development. Through lineage tracing, scRNAseq, and imaging, we identified a novel tripartite cellular niche at the epithelial basement membrane, comprised of monocyte-derived macrophages, nerves, and Schwann cells. Additional scRNAseq and genetic studies revealed that Schwann cell-derived IL34 maintained corneal macrophages. Through pharmacologic and genetic perturbations, we also demonstrate corneal macrophages selectively maintained the structure-function of Piezo2-enriched nerve endings, with disruption of this niche causing specific deficits in mechanosensation while preserving other sensory modalities. Altogether, we describe a novel tricellular niche in the cornea required for Piezo2-mediated touch sensation, suggesting new directions for investigating mechanosensory circuits including proprioception.

immunology↗

bioRxiv2023

Systematic assessment of the contribution of structural variants to inherited retinal diseases

Despite increasing success in determining genetic diagnosis for patients with inherited retinal diseases (IRDs), mutations in about 30% of the IRD cases remain unclear or unsettled after targeted gene panel or whole exome sequencing. In this study, we aimed to investigate the contributions of structural variants (SVs) to settling the molecular diagnosis of IRD with whole-genome sequencing (WGS). A cohort of 755 IRD patients whose pathogenic mutations remain undefined was subjected to WGS. Four SV calling algorithms including include MANTA, DELLY, LUMPY, and CNVnator were used to detect SVs throughout the genome. All SVs identified by any one of these four algorithms were included for further analysis. AnnotSV was used to annotate these SVs. SVs that overlap with known IRD-associated genes were examined with sequencing coverage, junction reads, and discordant read pairs. PCR followed by Sanger sequencing was used to further confirm the SVs and identify the breakpoints. Segregation of the candidate pathogenic alleles with the disease was performed when possible. In total, sixteen candidate pathogenic SVs were identified in sixteen families, including deletions and inversions, representing 2.1% of patients with previously unsolved IRDs. Autosomal dominant, autosomal recessive, and X-linked inheritance of disease-causing SVs were observed in 12 different genes. Among these, SVs in CLN3, EYS, PRPF31 were found in multiple families. Our study suggests that the contribution of SVs detected by short-read WGS is about 0.25% of our IRD patient cohort and is significantly lower than that of single nucleotide changes and small insertions and deletions.

genetics↗

bioRxiv2022

Long wavelength light reduces the negative consequences of dim light at night in the Cntnap2 mouse model of autism.

Many patients with autism spectrum disorders (ASD) show disturbances in their sleep/wake cycles, and may be particularly vulnerable to the impact of circadian disruptors. We have previously shown that exposure to dim light at night (DLaN) in contactin associated protein-like 2 knock out (Cntnap2 KO) mice disrupts diurnal rhythms, increases repetitive behaviors while reducing social interactions. These negative effects of DLaN may be mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin, which is maximally sensitive to blue light (480nm). In this study, we used a light-emitting diode (LED) array that enabled us to shift the spectral properties of the DLaN while keeping the intensity at 10 lx. First, using wild-type (WT) mice, we confirmed that the short-wavelength enriched lighting produced strong acute suppression of locomotor activity (masking), robust light-induced phase shifts, and c-Fos expression in the suprachiasmatic nucleus, while the long-wavelength enriched lighting evoked much weaker responses. Furthermore, exposure of WT mice to the short-wavelength light at night reduced the amplitude of locomotor activity rhythms and impaired social interactions. Mice lacking the melanopsin expressing ipRGCs (Opn4DTA mice) were resistant to these negative effects of DLaN. Importantly, the shift of the DLaN stimulus to longer wavelengths ameliorated the negative impact on the activity rhythms and autistic behaviors (i.e. reciprocal social interactions, repetitive grooming) of the Cntnap2 KO model. The short-, but not the long-wavelength enriched, DLaN triggered cFos expression in the peri-habenula region as well as in the basolateral amygdala (BLA). Finally, DLaN-driven c-Fos induction in BLA glutamatergic neurons was about 3-fold higher in the Cntnap2 KO mice, suggesting that these cells may be particularly vulnerable to the effects of photic disruption. Broadly, our findings suggest that the spectral properties of light at night should be considered in the management of ASD and other neurodevelopmental disorders.

neuroscience↗

bioRxiv2019

Short-wavelength violet light (420nm) stimulates melanopsin-dependent acute alertness responses in zebrafish

Sunlight throughout the day and seasons strongly influences our biological rhythms and activity. In recent years, it has become evident that night-time overexposure to bright light in urban environments can profoundly affect physiology and behaviour in humans and animals. In particular, the artificial emission of short-wavelength light has been shown to stimulate alertness in humans, but the mechanisms remain largely unknown. Utilising a diurnal larval zebrafish model, we identified instant, non-image-forming (NIF) responses to short-wavelength violet light (~420nm), which are activated only during light exposure, and are reminiscent of alertness, including increased heart rate, enhanced locomotor activity, and pectoral fin beating (for increased oxygen supply). We further determined that these responses are driven by sympathetic neuronal circuits and depend on the zebrafish melanopsin homologue Opn4a. We also found that these responses can be modulated by the sleep-regulatory hormone melatonin, but that melatonin is not essential. Our findings reveal a previously unknown mechanism for violet light-dependent acute alertness.

animal behavior and cognition↗

bioRxiv2019

Resolving the dark matter of ABCA4 for 1,054 Stargardt disease probands through integrated genomics and transcriptomics

Missing heritability in human diseases represents a major challenge. Although whole-genome sequencing enables the analysis of coding and non-coding sequences, substantial costs and data storage requirements hamper its large-scale use to (re)sequence genes in genetically unsolved cases. The ABCA4 gene implicated in Stargardt disease (STGD1) has been studied extensively for 22 years, but thousands of cases remained unsolved. Therefore, single molecule molecular inversion probes were designed that enabled an automated and cost-effective sequence analysis of the complete 128-kb ABCA4 gene. Analysis of 1,054 unsolved STGD and STGD-like probands resulted in bi-allelic variations in 448 probands. Twenty-seven different causal deep-intronic variants were identified in 117 alleles. Based on in vitro splice assays, the 13 novel causal deep-intronic variants were found to result in pseudo-exon (PE) insertions (n=10) or exon elongations (n=3). Intriguingly, intron 13 variants c.1938-621G>A and c.1938-514G>A resulted in dual PE insertions consisting of the same upstream, but different downstream PEs. The intron 44 variant c.6148-84A>T resulted in two PE insertions that were accompanied by flanking exon deletions. Structural variant analysis revealed 11 distinct deletions, two of which contained small inverted segments. Uniparental isodisomy of chromosome 1 was identified in one proband. Integrated complete gene sequencing combined with transcript analysis, identified pathogenic deep-intronic and structural variants in 26% of bi-allelic cases not solved previously by sequencing of coding regions. This strategy serves as a model study that can be applied to other inherited diseases in which only one or a few genes are involved in the majority of cases.

genetics↗