👤 Bryan Sands

Severe gastrointestinal (GI) symptoms occur in people with CLN3 disease, a neurodegenerative disorder. If left untreated these GI symptoms compromise life quality and may contribute to death. We hypothesized GI symptoms in CLN3 disease are at least partially due to neurodegeneration in the enteric nervous system (ENS), the master regulator of bowel function. We examined the integrity of the ENS in human CLN3 autopsy small bowel and colon, and in CLN3 deficient ( The online version contains supplementary material available at 10.1186/s40478-025-02205-7. Show less

CLN3 disease is a neuronopathic lysosomal storage disorder that severely impacts the central nervous system (CNS) while also inducing notable peripheral neuromuscular symptoms. Although considerable attention has been directed towards the neurodegenerative consequences within the CNS, the involvement of peripheral tissues, including skeletal muscles and their innervation, has been largely neglected. We hypothesized that, CLN3 deficiency could directly influence peripheral nerves and investigated the neuromuscular system in Cln3 Show less

Severe gastrointestinal (GI) symptoms occur in people with CLN3 disease, a neurodegenerative disorder. If left untreated these GI symptoms compromise life quality and may contribute to death. We hypothesized GI symptoms in CLN3 disease are at least partially due to neurodegeneration in the enteric nervous system (ENS), the master regulator of bowel function. We examined the integrity of the ENS in human CLN3 autopsy small bowel and colon, and in CLN3 deficient ( Human CLN3 bowel displayed a profound loss of enteric neurons and their neurites, with pathological effects upon enteric glia. Our findings demonstrate that CLN3 deficiency profoundly damages enteric neurons and glia in both murine and human CLN3 disease, contributing to GI dysfunction. This study provides preclinical evidence that systemic gene therapy may effectively treat multiple aspects of bowel pathology, expanding the therapeutic landscape beyond the CNS.What you need to know. Significant gastrointestinal (GI) symptoms are evident in many pediatric neurological conditions. We hypothesized that, in addition to central nervous system (CNS) effects, defects in the enteric nervous system (ENS) may underlie these GI symptoms in some neurodegenerative diseases. Revealing such defects would open up new opportunities for treating these life-limiting and debilitating symptoms. The enteric nervous system is significantly impacted in human CLN3 disease, a feature that is recapitulated in CLN3 mice. Progressive enteric neurodegeneration in these mice follows a similar time course to neuron loss in the brain, resulting in severe bowel distention.Nevertheless, bowel distention and the majority of the pathology within the enteric nervous system can be mitigated via neonatal gene therapy. Our human data will need to be replicated in larger numbers of CLN3 cases, and methods will need to be developed to treat the human bowel, avoiding the risk of liver tumors. These results reveal that a neurodegenerative disease previously thought to primarily affect the CNS, damages the bowel's enteric nervous system and that ENS degeneration can be prevented in mice by gene therapy. These data provide a new perspective on this pediatric disorder and may have relevance to other pediatric neurologic diseases. The progressive loss of neurons in CLN3 disease is not confined to the brain but also occurs in the bowel enteric nervous system, contributing directly to GI dysfunction.Neurodegeneration in the enteric nervous system can be prevented by treating the bowel with gene therapy. Show less

A low respiratory arousal threshold (ArTH) has been linked to reduced continuous positive airway pressure (CPAP) adherence in obstructive sleep apnea (OSA) via a multi-trait model developed in the RICCADSA trial. Our objective was to validate the prior model in a large, real-world cohort and explore alternative linear and non-linear approaches for predicting CPAP adherence. Does a previously derived multi-trait model linking low ArTH to poor CPAP adherence remain valid in a diverse real-world population and do alternative linear or non-linear approaches offer improved predictive performance? Adults with OSA from the SNOOzzzE-cohort who initiated CPAP within 1 year of in-lab polysomnography (2017-2019) were included. Pathophysiological traits (Vpassive, Vactive, loop gain, ArTH, ventilatory response to arousal) were estimated from polysomnography. Poor (vs good) adherence was defined as ≤2.48h/night at month 1 (1 Among 744 participants (45% women, 47% non-White), median CPAP adherence was 4.8 h/night at 1 month. The prior model's AUC was 0.51 (95%-CI 0.46-0.55), with no usage differences between predicted poor vs good adherers. A new linear model overfit in training (AUC=0.85) but failed in testing (AUC=0.55). LPA identified a "Low ArTH Driven" cluster with persistently lower adherence at months 2-3 (P<.05) and a "Low ArTH & High loop gain" cluster whose usage stabilized after month 1. The prior model did not generalize to this diverse clinical cohort. LPA identified a "Low ArTH Driven" endotype with persistently low CPAP adherence, suggesting potential for targeted interventions pending external validation. Show less

Perfluorooctanesulfonic acid (PFOS) is a persistent environmental pollutant widely present in ecosystems and humans, linked to numerous diseases, including cancers, due to its potent toxicity. Despite its harmful effects, effective strategies for mitigating PFOS-induced toxicity remain undeveloped or at best underdeveloped. In this effort, we explore the concept of toxicity reversal by loci-specific DNA methylation editing to reverse PFOS-induced toxicity, whereby key cellular processes such as proliferation, migration, and apoptosis are restored. To demonstrate our concept, we employed CRISPR-dCas9 epigenome editing tools, utilizing catalytically deactivated Cas9 fused with either DNA methyltransferases or ten-eleven translocation ( Show less

The melanocortin receptor 4 (MC4R) belongs to the melanocortin receptor family of G-protein coupled receptors and is a key switch in the leptin-melanocortin molecular axis that controls hunger and satiety. Brain-produced hormones such as α-melanocyte-stimulating hormone (agonist) and agouti-related peptide (inverse agonist) regulate the molecular communication of the MC4R axis but are promiscuous for melanocortin receptor subtypes and induce a wide array of biological effects. Here, we use a chimeric construct of conformation-selective, nanobody-based binding domain (a ConfoBody Cb80) and active state-stabilized MC4R-β2AR hybrid for efficient de novo discovery of a sequence diverse panel of MC4R-specific, potent and full agonistic nanobodies. We solve the active state MC4R structure in complex with the full agonistic nanobody pN162 at 3.4 Å resolution. The structure shows a distinct interaction with pN162 binding deeply in the orthosteric pocket. MC4R peptide agonists, such as the marketed setmelanotide, lack receptor selectivity and show off-target effects. In contrast, the agonistic nanobody is highly specific and hence can be a more suitable agent for anti-obesity therapeutic intervention via MC4R. Show less

The neuronal ceroid lipofuscinoses (NCLs) are the most common cause of childhood dementia and are invariably fatal. Early localized glial activation occurs in these disorders, and accurately predicts where neuronal loss is most pronounced. Recent evidence suggests that glial dysfunction may contribute to neuron loss, and we have now explored this possibility in infantile NCL (INCL, CLN1 disease). We grew primary cultures of astrocytes, microglia, and neurons derived from Ppt1 deficient mice (Ppt1 Show less

Axon regeneration in the adult CNS is prevented by inhibitors in myelin. These inhibitors seem to modulate RhoA activity by binding to a receptor complex comprising a ligand-binding subunit (the Nogo-66 receptor NgR1) and a signal transducing subunit (the neurotrophin receptor p75). However, in reconstituted non-neuronal systems, NgR1 and p75 together are unable to activate RhoA, suggesting that additional components of the receptor may exist. Here we describe LINGO-1, a nervous system-specific transmembrane protein that binds NgR1 and p75 and that is an additional functional component of the NgR1/p75 signaling complex. In non-neuronal cells, coexpression of human NgR1, p75 and LINGO-1 conferred responsiveness to oligodendrocyte myelin glycoprotein, as measured by RhoA activation. A dominant-negative human LINGO-1 construct attenuated myelin inhibition in transfected primary neuronal cultures. This effect on neurons was mimicked using an exogenously added human LINGO-1-Fc fusion protein. Together these observations suggest that LINGO-1 has an important role in CNS biology. Show less