From Dish to Bedside: Lessons Learned While Translating Findings from a Stem Cell Model of Disease to a Clinical Trial

While iPSCs have created unprecedented opportunities for drug discovery, there remains uncertainty concerning the path to the clinic for candidate therapeutics discovered with their use. Here we share lessons that we learned, and believe are generalizable to similar efforts, while taking a discovery made using iPSCs into a clinical trial

A collaborative approach to socio-economic assessment to increase coastal marsh and community resilience on the Chesapeake Bay

Sea level rise and other stressors in the mid-Atlantic U.S. are impacting the resilience of coastal communities, and increase their overall physical and socio-economic vulnerabilities. The Deal Island Peninsula on the Eastern Shore of the Chesapeake Bay, MD is used as a case study of a coastal heritage community that is undergoing these stressors and is involved in stakeholder-driven resilience and adaptation planning. In this interdisciplinary socio-ecological project funded by the NERRS Science Collaborative, a socio-economic analysis of a culturally rich coastal community is performed as a sub-study. The goals of the socio-economic analysis are to 1) better understand stakeholder relationships with marsh ecosystems and services they provide, 2) bring stakeholder perceptions and values of socio-ecological services into a coastal decision-making framework, and 3) bridge the gap between science and decision-making through improved communication and collaboration. The methodologies employed take the nature of a collaborative learning approach, coupled with the Q-sort technique. In this presentation, discussion topics include the collaborative approach taken toward a socio-economic assessment, preliminary results of the Q-sort, and indicators of community adaptation efforts

Conversion of Mouse and Human Fibroblasts into Functional Spinal Motor Neurons

The mammalian nervous system is composed of a multitude of distinct neuronal subtypes, each with its own phenotype and differential sensitivity to degenerative disease. Although specific neuronal types can be isolated from rodent embryos or engineered from stem cells for translational studies, transcription factor mediated reprogramming might provide a more direct route to their generation. Here we report that the forced expression of select transcription factors is sufficient to convert mouse and human fibroblasts into induced motor neurons (iMNs). iMNs displayed a morphology, gene expression signature, electrophysiology, synaptic functionality, in vivo engraftment capacity and sensitivity to degenerative stimuli, similar to embryo-derived motor neurons. We show that the converting fibroblasts do not transit through a proliferative neural progenitor state, and thus form bona fide motor neurons via a route distinct from embryonic development. Our findings demonstrate that fibroblasts can be converted directly into a specific differentiated and functional neural subtype, the spinal motor neuron.Stem Cell and Regenerative Biolog

Modeling pain in vitro using nociceptor neurons reprogrammed from fibroblasts

Reprogramming somatic cells from one cell fate to another can generate specific neurons suitable for disease modeling. To maximize the utility of patient-derived neurons, they must model not only disease-relevant cell classes but also the diversity of neuronal subtypes found in vivo and the pathophysiological changes that underlie specific clinical diseases. Here, we identify five transcription factors that reprogram mouse and human fibroblasts into noxious stimulus-detecting (nociceptor) neurons that recapitulate the expression of quintessential nociceptor-specific functional receptors and channels found in adult mouse nociceptor neurons as well as native subtype diversity. Moreover, the derived nociceptor neurons exhibit TrpV1 sensitization to the inflammatory mediator prostaglandin E2 and the chemotherapeutic drug oxaliplatin, modeling the inherent mechanisms underlying inflammatory pain hypersensitivity and painful chemotherapy-induced neuropathy. Using fibroblasts from patients with familial dysautonomia (hereditary sensory and autonomic neuropathy type III), we show that the technique can reveal novel aspects of human disease phenotypes in vitro

Neuroma Analysis in Humans:Standardizing Sample Collection and Documentation

Introduction: The biology of symptomatic neuromas is poorly understood, particularly the factors causing pain in human neuromas. Pain presence varies among and within individuals, with some having painful and nonpainful neuromas. To bridge these knowledge gaps, our group developed a protocol for assessing neuroma pain and collecting tissue for molecular analysis. This manuscript outlines our workflow and challenges and aims to inspire other centers to share their experiences with these tissues. Methods: For every included patient and collected nerve or bone tissue specimens, we perform a detailed chart review and a multifaceted analysis of pain and pain perception immediately before surgery. We collect patient-reported outcome measures (PROMs) on pain, function, and mental well-being outcomes at preoperative assessment and at the 6-month follow-up postoperatively. Before surgery, the patient is assessed once again to obtain an immediate preoperative pain status and identify potential differences in pain intensity of different neuromas. Intraoperatively, specimens are obtained and their gross anatomical features are recorded, after which they are stored in paraformaldehyde or frozen for later sample analyses. Postoperatively, patients are contacted to obtain additional postoperative PROMs. Results: A total of 220 specimens of nerve tissue have been successfully obtained from 83 limbs, comprising 95 specimens of neuromas and 125 specimens of nerves located proximal to the neuromas or from controls.Conclusions: Our approach outlines the methods combining specimen collection and examination, including both macroscopic and molecular biological features, with PROMs, encompassing physical and psychological aspects, along with clinical metadata obtained through clinical teams and chart review.</p

Neuroma Analysis in Humans:Standardizing Sample Collection and Documentation

Introduction: The biology of symptomatic neuromas is poorly understood, particularly the factors causing pain in human neuromas. Pain presence varies among and within individuals, with some having painful and nonpainful neuromas. To bridge these knowledge gaps, our group developed a protocol for assessing neuroma pain and collecting tissue for molecular analysis. This manuscript outlines our workflow and challenges and aims to inspire other centers to share their experiences with these tissues. Methods: For every included patient and collected nerve or bone tissue specimens, we perform a detailed chart review and a multifaceted analysis of pain and pain perception immediately before surgery. We collect patient-reported outcome measures (PROMs) on pain, function, and mental well-being outcomes at preoperative assessment and at the 6-month follow-up postoperatively. Before surgery, the patient is assessed once again to obtain an immediate preoperative pain status and identify potential differences in pain intensity of different neuromas. Intraoperatively, specimens are obtained and their gross anatomical features are recorded, after which they are stored in paraformaldehyde or frozen for later sample analyses. Postoperatively, patients are contacted to obtain additional postoperative PROMs. Results: A total of 220 specimens of nerve tissue have been successfully obtained from 83 limbs, comprising 95 specimens of neuromas and 125 specimens of nerves located proximal to the neuromas or from controls.Conclusions: Our approach outlines the methods combining specimen collection and examination, including both macroscopic and molecular biological features, with PROMs, encompassing physical and psychological aspects, along with clinical metadata obtained through clinical teams and chart review.</p

Endothelial cells regulate astrocyte to neural progenitor cell trans-differentiation in a mouse model of stroke.

The concept of the neurovascular unit emphasizes the importance of cell-cell signaling between neural, glial, and vascular compartments. In neurogenesis, for example, brain endothelial cells play a key role by supplying trophic support to neural progenitors. Here, we describe a surprising phenomenon where brain endothelial cells may release trans-differentiation signals that convert astrocytes into neural progenitor cells in male mice after stroke. After oxygen-glucose deprivation, brain endothelial cells release microvesicles containing pro-neural factor Ascl1 that enter into astrocytes to induce their trans-differentiation into neural progenitors. In mouse models of focal cerebral ischemia, Ascl1 is upregulated in endothelium prior to astrocytic conversion into neural progenitor cells. Injecting brain endothelial-derived microvesicles amplifies the process of astrocyte trans-differentiation. Endothelial-specific overexpression of Ascl1 increases the local conversion of astrocytes into neural progenitors and improves behavioral recovery. Our findings describe an unexpected vascular-regulated mechanism of neuroplasticity that may open up therapeutic opportunities for improving outcomes after stroke.Supported in part by the Leducq Foundation.S

Biology and pathophysiology of symptomatic neuromas

Neuromas are a substantial cause of morbidity and reduction in quality of life. This is not only caused by a disruption in motor and sensory function from the underlying nerve injury but also by the debilitating effects of neuropathic pain resulting from symptomatic neuromas. A wide range of surgical and therapeutic modalities have been introduced to mitigate this pain. Nevertheless, no single treatment option has been successful in completely resolving the associated constellation of symptoms. While certain novel surgical techniques have shown promising results in reducing neuroma-derived and phantom limb pain, their effectiveness and the exact mechanism behind their pain-relieving capacities have not yet been defined. Furthermore, surgery has inherent risks, may not be suitable for many patients, and may yet still fail to relieve pain. Therefore, there remains a great clinical need for additional therapeutic modalities to further improve treatment for patients with devastating injuries that lead to symptomatic neuromas. However, the molecular mechanisms and genetic contributions behind the regulatory programs that drive neuroma formation - as well as the resulting neuropathic pain - remain incompletely understood. Here, we review the histopathological features of symptomatic neuromas, our current understanding of the mechanisms that favor neuroma formation, and the putative contributory signals and regulatory programs that facilitate somatic pain, including neurotrophic factors, neuroinflammatory peptides, cytokines, along with transient receptor potential, and ionotropic channels that suggest possible approaches and innovations to identify novel clinical therapeutics.</p