Bryostatin-1 alleviates experimental multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory disorder targeting the central nervous system (CNS). The relapsing-remitting phase of MS is largely driven by peripheral activation of autoreactive T-helper (Th) 1 and Th17 lymphocytes. In contrast, compartmentalized inflammation within the CNS, including diffuse activation of innate myeloid cells, characterizes the progressive phase of MS, the most debilitating phase that currently lacks satisfactory treatments. Recently, bryostatin-1 (bryo-1), a naturally occurring, CNS-permeable compound with a favorable safety profile in humans, has been shown to act on antigen-presenting cells to promote differentiation of lymphocytes into Th2 cells, an action that might benefit Th1-driven inflammatory conditions such as MS. In the present study, we show that bryo-1 provides marked benefit in mice with experimental autoimmune encephalomyelitis (EAE), an experimental MS animal model. Preventive treatment with bryo-1 abolishes the onset of neurologic deficits in EAE. More strikingly, bryo-1 reverses neurologic deficits after EAE onset, even when treatment is initiated at a late stage of disease when peak adaptive immunity has subsided. Treatment with bryo-1 in vitro promotes an anti-inflammatory phenotype in antigen-presenting dendritic cells, macrophages, and to a lesser extent, lymphocytes. These findings suggest the potential for bryo-1 as a therapeutic agent in MS, particularly given its established clinical safety. Furthermore, the benefit of bryo-1, even in late treatment of EAE, combined with its targeting of innate myeloid cells suggests therapeutic potential in progressive forms of MS.

Does Formation of Multicellular Colonies by Choanoflagellates Affect Their Susceptibility to Capture by Passive Protozoan Predators?

Microbial eukaryotes, critical links in aquatic food webs, are unicellular, but some, such as choanoflagellates, form multicellular colonies. Are there consequences to predator avoidance of being unicellular vs. forming larger colonies? Choanoflagellates share a common ancestor with animals and are used as model organisms to study the evolution of multicellularity. Escape in size from protozoan predators is suggested as a selective factor favoring evolution of multicellularity. Heterotrophic protozoans are categorized as suspension feeders, motile raptors, or passive predators that eat swimming prey which bump into them. We focused on passive predation and measured the mechanisms responsible for the susceptibility of unicellular vs. multicellular choanoflagellates, Salpingoeca helianthica, to capture by passive heliozoan predators, Actinosphaerium nucleofilum, which trap prey on axopodia radiating from the cell body. Microvideography showed that unicellular and colonial choanoflagellates entered the predator's capture zone at similar frequencies, but a greater proportion of colonies contacted axopodia. However, more colonies than single cells were lost during transport by axopodia to the cell body. Thus, feeding efficiency (proportion of prey entering the capture zone that were engulfed in phagosomes) was the same for unicellular and multicellular prey, suggesting that colony formation is not an effective defense against such passive predators.

TPPB modulates PKC activity to attenuate neuroinflammation and ameliorate experimental multiple sclerosis.

Protein kinase C (PKC) plays a key role in modulating the activities of the innate immune cells of the central nervous system (CNS). A delicate balance between pro-inflammatory and regenerative activities by microglia and CNS-associated macrophages is necessary for the proper functioning of the CNS. Thus, a maladaptive activation of these CNS innate immune cells results in neurodegeneration and demyelination associated with various neurologic disorders, such as multiple sclerosis (MS) and Alzheimer's disease. Prior studies have demonstrated that modulation of PKC activity by bryostatin-1 (bryo-1) and its analogs (bryologs) attenuates the pro-inflammatory processes by microglia/CNS macrophages and alleviates the neurologic symptoms in experimental autoimmune encephalomyelitis (EAE), an MS animal model. Here, we demonstrate that (2S,5S)-(E,E)-8-(5-(4-(trifluoromethyl)phenyl)-2,4-pentadienoylamino)benzolactam (TPPB), a structurally distinct PKC modulator, has a similar effect to bryo-1 on CNS innate immune cells both in vitro and in vivo, attenuating neuroinflammation and resulting in CNS regeneration and repair. This study identifies a new structural class of PKC modulators, which can therapeutically target CNS innate immunity as a strategy to treat neuroinflammatory and neurodegenerative disorders.

TPPB modulates PKC activity to attenuate neuroinflammation and ameliorate experimental multiple sclerosis.

Protein kinase C (PKC) plays a key role in modulating the activities of the innate immune cells of the central nervous system (CNS). A delicate balance between pro-inflammatory and regenerative activities by microglia and CNS-associated macrophages is necessary for the proper functioning of the CNS. Thus, a maladaptive activation of these CNS innate immune cells results in neurodegeneration and demyelination associated with various neurologic disorders, such as multiple sclerosis (MS) and Alzheimer's disease. Prior studies have demonstrated that modulation of PKC activity by bryostatin-1 (bryo-1) and its analogs (bryologs) attenuates the pro-inflammatory processes by microglia/CNS macrophages and alleviates the neurologic symptoms in experimental autoimmune encephalomyelitis (EAE), an MS animal model. Here, we demonstrate that (2S,5S)-(E,E)-8-(5-(4(trifluoromethyl)phenyl)-2,4-pentadienoylamino)benzolactam (TPPB), a structurally distinct PKC modulator, has a similar effect to bryo-1 on CNS innate immune cells both in vitro and in vivo, attenuating neuroinflammation and resulting in CNS regeneration and repair. This study identifies a new structural class of PKC modulators, which can therapeutically target CNS innate immunity as a strategy to treat neuroinflammatory and neurodegenerative disorders.

A population health approach to workplace mental health: rationale, implementation and engagement.

Objectives: To describe a population health-based program to support employee and dependent mental health and learn from engagement trends. Methods: Retrospective analysis of a program utilizing an assessment of mental health risk. For scoring "at risk," a Care Concierge is offered to connect users with resources. Results: Participation was offered to 56,442 employees and dependents. Eight thousand seven hundred thirty-one completed the assessment (15%). Of those, 4,644 (53%) scored moderate or higher. A total of 418 (9%) engaged the Care Concierge. Factors that negatively influenced the decision to engage care included bodily pain, financial concerns. Positive influences were younger age, high stress, anxiety, PTSD and low social support. Conclusion: Proactive assessment plus access to a Care Concierge facilitates mental healthcare utilization. Several factors influence likelihood to engage in care. A better understanding of these factors may allow for more targeted outreach and improved engagement.

Aspartate racemase, generating neuronal D-aspartate, regulates adult neurogenesis.

D-aspartic acid is abundant in the developing brain. We have identified and cloned mammalian aspartate racemase (DR), which converts L-aspartate to D-aspartate and colocalizes with D-aspartate in the brain and neuroendocrine tissues. Depletion of DR by retrovirus-mediated expression of short-hairpin RNA in newborn neurons of the adult hippocampus elicits profound defects in the dendritic development and survival of newborn neurons and survival. Because D-aspartate is a potential endogenous ligand for NMDA receptors, the loss of which elicits a phenotype resembling DR depletion, D-aspartate may function as a modulator of adult neurogenesis.

Facilitating Mental Health Treatment Through Proactive Screening and Concierge Services in the Workplace.

OBJECTIVE: The aim of this study is to determine if a proactive employer-sponsored mental health program closed gaps in detection and treatment of mental health conditions. METHODS: Of n = 56,442 eligible, n = 8170 (14.5%) participated in the optional screening. Participants with mental health risk were offered care concierge services including support, care planning, and connection to care. Difference in behavioral health care utilization, diagnoses, and prescriptions were evaluated postintervention through claims analysis. RESULTS: Compared with controls (n = 2433), those receiving concierge services (n = 369) were more likely to fill mental health prescriptions (adjusted hazards ratio [HR], 1.2; 1.0-1.5; P = 0.042), use professional mental health services (adjusted HR, 1.4; 1.1-1.8; P = 0.02), and use new mental health services (adjusted HR, 1.9; 1.2-2.8; P = 0.004) in the following 6 months. CONCLUSIONS: This proactive mental health program with care concierge services identified risk, connected individuals to mental health care, and facilitated mental health treatment, among program participants.

PKC modulator bryostatin-1 therapeutically targets CNS innate immunity to attenuate neuroinflammation and promote remyelination.

In multiple sclerosis (MS), microglia and macrophages within the central nervous system (CNS) play an important role in determining the balance between myelin repair and demyelination/neurodegeneration. Phagocytic and regenerative functions of these CNS innate immune cells support remyelination, whereas chronic and maladaptive inflammatory activation promotes lesion expansion and disability, particularly in the progressive forms of MS. No currently approved drugs convincingly target microglia and macrophages within the CNS, contributing to the critical lack of therapies promoting remyelination and slowing progression in MS. Here, we found that the protein kinase C (PKC)-modulating drug bryostatin-1 (bryo-1), a CNS-penetrant compound with an established human safety profile, produces a shift in microglia and CNS macrophage transcriptional programs from pro-inflammatory to regenerative phenotypes, both in vitro and in vivo. Treatment of microglia with bryo-1 prevented the activation of neurotoxic astrocytes while stimulating scavenger pathways, phagocytosis, and secretion of factors that promote oligodendrocyte differentiation. In line with these findings, systemic treatment with bryo-1 augmented remyelination following a focal demyelinating injury in vivo. Our results demonstrate the potential of bryo-1 and functionally related PKC modulators as myelin regenerative and neuroprotective agents in MS and other neurologic diseases through therapeutic targeting of microglia and CNS-associated macrophages.

Targeting PKC in microglia to promote remyelination and repair in the CNS.

Microglia and CNS-infiltrating macrophages play significant roles in the pathogenesis of neuroinflammatory and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Prolonged and dysregulated inflammatory responses by these innate immune cells can have deleterious effects on the surrounding CNS microenvironment, which can worsen neurodegeneration and demyelination. However, although chronic activation of pro-inflammatory microglia is maladaptive, other functional microglial subtypes play beneficial roles during CNS repair and regeneration. Therefore, there is a tremendous interest in understanding the underlying mechanism of the activation of these reparative/regenerative microglia. In this review, we focus on the potential role of PKC, a downstream signaling molecule of TREM2 and PLCγ2, and PKC modulators in promoting the activation of reparative/regenerative microglial subtypes as a novel therapy for neuroinflammatory and neurodegenerative diseases.

Designed PKC-targeting bryostatin analogs modulate innate immunity and neuroinflammation.

Neuroinflammation characterizes multiple neurologic diseases, including primary inflammatory conditions such as multiple sclerosis and classical neurodegenerative diseases. Aberrant activation of the innate immune system contributes to disease progression, but drugs modulating innate immunity, particularly within the central nervous system (CNS), are lacking. The CNS-penetrant natural product bryostatin-1 attenuates neuroinflammation by targeting innate myeloid cells. Supplies of natural bryostatin-1 are limited, but a recent scalable good manufacturing practice (GMP) synthesis has enabled access to it and its analogs (bryologs), the latter providing a path to more efficacious, better tolerated, and more accessible agents. Here, we show that multiple synthetically accessible bryologs replicate the anti-inflammatory effects of bryostatin-1 on innate immune cells in vitro, and a lead bryolog attenuates neuroinflammation in vivo, actions mechanistically dependent on protein kinase C (PKC) binding. Our findings identify bryologs as promising drug candidates for targeting innate immunity in neuroinflammation and create a platform for evaluation of synthetic PKC modulators in neuroinflammatory diseases.

Workplace Mental Health: Application of a Population Health Approach of Proactive Screening to Identify Risk and Engage in Care.

OBJECTIVE: To evaluate a proactive, voluntary screening program designed to identify employees with emerging mental health risk and engage them in care. METHODS: Risk was proactively identified through online screening of 344 participants. At-risk participants were offered a mental health care concierge to provide support, develop a care plan, and connect to care. RESULTS: Risk for common mental health conditions was identified in 244 (71%) participants, of whom 66 (27%) connected with a care concierge. Compared with participants who did not connect to a care concierge, those who did were more likely to report a financial crisis (68.2% vs 50.8%) and less likely to report verbal abuse (9.1% vs 19.6%) and difficulty meeting daily needs (12.1% vs 25.1%). CONCLUSION: Implementation of this screening program identified employees at risk for mental health conditions and facilitated connection to care.

An Unusual Case of a Fibular Sesamoid Phalangeal Ligament Tear Caused By Chronic Trauma.

Injuries involving the first metatarsophalangeal joint and its associated structures are common, especially in athletes. However, injuries to the hallucal sesamoid complex constituted only 3% of all podiatric sports medicine injuries reported by Agosta. This case study reports a female ballet dancer with an isolated fibular sesamoid retraction injury that presented with a history of chronic microtrauma secondary to overuse. When consulting epidemiologic studies of forefoot injuries involving the hallucal sesamoid complex, we were unable to find a single instance of an isolated retraction of the fibular sesamoid resulting from chronic use, demonstrating the unusual nature of this case.

Piezo1 incorporates mechanical force signals into the genetic program that governs lymphatic valve development and maintenance.

The lymphatic system plays crucial roles in tissue homeostasis, lipid absorption, and immune cell trafficking. Although lymphatic valves ensure unidirectional lymph flows, the flow itself controls lymphatic valve formation. Here, we demonstrate that a mechanically activated ion channel Piezo1 senses oscillating shear stress (OSS) and incorporates the signal into the genetic program controlling lymphatic valve development and maintenance. Time-controlled deletion of Piezo1 using a pan-endothelial Cre driver (Cdh5[PAC]-CreERT2) or lymphatic-specific Cre driver (Prox1-CreERT2) equally inhibited lymphatic valve formation in newborn mice. Furthermore, Piezo1 deletion in adult lymphatics caused substantial lymphatic valve degeneration. Piezo1 knockdown in cultured lymphatic endothelial cells (LECs) largely abrogated the OSS-induced upregulation of the lymphatic valve signature genes. Conversely, ectopic Piezo1 overexpression upregulated the lymphatic valve genes in the absence of OSS. Remarkably, activation of Piezo1 using chemical agonist Yoda1 not only accelerated lymphatic valve formation in animals, but also triggered upregulation of some lymphatic valve genes in cultured LECs without exposure to OSS. In summary, our studies together demonstrate that Piezo1 is the force sensor in the mechanotransduction pathway controlling lymphatic valve development and maintenance, and Piezo1 activation is a potentially novel therapeutic strategy for congenital and surgery-associated lymphedema.

Endothelial lineage-specific interaction of Mycobacterium tuberculosis with the blood and lymphatic systems.

Mycobacterium tuberculosis (Mtb) has plagued humanity for tens of thousands of years, yet still remains a threat to human health. Its pathology is largely associated with pulmonary tuberculosis with symptoms including fever, hemoptysis, and chest pain. Mtb, however, also manifests in other extrapulmonary organs, such as the pleura, bones, gastrointestinal tract, central nervous system, and lymph nodes. Compared to the knowledge of pulmonary tuberculosis, extrapulmonary pathologies of Mtb are quite understudied. Lymph node tuberculosis is one of the most common extrapulmonary manifestations of tuberculosis, and presents significant challenges in its diagnosis, management, and treatment due to its elusive etiologies and pathologies. The objective of this review is to overview the current understanding of the tropism and pathogenesis of Mtb in endothelial cells of the extrapulmonary tissues, particularly, in lymph nodes. Lymphatic endothelial cells (LECs) are derived from blood vascular endothelial cells (BECs) during development, and these two types of endothelial cells demonstrate substantial molecular, cellular and genetic similarities. Therefore, systemic comparison of the differential and common responses of BECs vs. LECs to Mtb invasion could provide new insights into its pathogenesis, and may promote new investigations into this deadly disease.

Dimethyl fumarate targets GAPDH and aerobic glycolysis to modulate immunity.

Activated immune cells undergo a metabolic switch to aerobic glycolysis akin to the Warburg effect, thereby presenting a potential therapeutic target in autoimmune disease. Dimethyl fumarate (DMF), a derivative of the Krebs cycle intermediate fumarate, is an immunomodulatory drug used to treat multiple sclerosis and psoriasis. Although its therapeutic mechanism remains uncertain, DMF covalently modifies cysteine residues in a process termed succination. We found that DMF succinates and inactivates the catalytic cysteine of the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in mice and humans, both in vitro and in vivo. It thereby down-regulates aerobic glycolysis in activated myeloid and lymphoid cells, which mediates its anti-inflammatory effects. Our results provide mechanistic insight into immune modulation by DMF and represent a proof of concept that aerobic glycolysis is a therapeutic target in autoimmunity.

D-aspartate regulates melanocortin formation and function: behavioral alterations in D-aspartate oxidase-deficient mice.

D-aspartate, an abundant D-amino acid enriched in neuroendocrine tissues, can be degraded by D-aspartate oxidase (Ddo). To elucidate the function of D-aspartate, we generated mice with targeted deletion of Ddo (Ddo(-/-)) and observe massive but selective augmentations of D-aspartate in various tissues. The pituitary intermediate lobe, normally devoid of D-aspartate from endogenous Ddo expression, manifests pronounced increases of immunoreactive D-aspartate in Ddo(-/-) mice. Ddo(-/-) mice show markedly diminished synthesis and levels of pituitary proopiomelanocortin/alpha-MSH, associated with decreased melanocortin-dependent behaviors. Therefore, Ddo is the endogenous enzyme that degrades D-aspartate, and Ddo-enriched organs, low in D-aspartate, may represent areas of high turnover where D-aspartate may be physiologically important.

Behavioural alterations in male mice lacking the gene for D-aspartate oxidase.

D-serine and D-aspartate are important regulators of mammalian physiology. D-aspartate is found in nervous and endocrine tissue, specifically in hypothalamic supraoptic and paraventricular nuclei, pituitary, and adrenal medullary cells. Endogenous D-aspartate is selectively degraded by D-aspartate oxidase. We previously reported that adult male mice lacking the gene for D-aspartate oxidase (Ddo(-/-) mice) display elevated concentrations of D-aspartate in several neuronal and neuroendocrine tissues as well as impaired sexual performance and altered autogrooming behaviour. In the present study, we analyzed behaviours relevant to affect, cognition, and motor control in Ddo(-/-) mice. Ddo(-/-) mice display deficits in sensorimotor gating and motor coordination as well as reduced immobility in the forced swim test. Basal corticosterone concentrations are elevated. The Ddo(-/-) mice have D-aspartate immunoreactive cells in the cerebellum and adrenal glands that are not observed in the wild-type mice. However, no differences in anxiety-like behaviour are detected in open field or light-dark preference tests. Also, Ddo(-/-) mice do not differ from wild-type mice in either passive avoidance or spontaneous alternation tasks. Although many of these behavioural deficits may be due to the lack of Ddo during development, our results are consistent with the widespread distribution of D-aspartate and the hypothesis that endogenous D-aspartate serves diverse behavioural functions.

Photoelectrochemical Cells Utilizing Tunable Corroles.

Organic dyes with their wide range of molecular structures and spectroscopic features show great promise for solar energy applications. Corroles, structural analogues to porphyrins, are highly fluorescent molecules with tunable properties. We have synthesized a series of structurally similar corroles chelating gallium and phosphorus, along with a ß-chlorinated phosphorus corrole, and determined their photophysical and electrochemical properties. The electrochemical potentials to oxidize the corroles range from 0.78 V vs NHE for the gallium corrole to 1.42 V for the ß-octachlorinated phosphorus corrole. We are interested in developing photosensitizers for water oxidation on a metal oxide-based photoanode, so the corroles were modified to contain a meso-phenyl-COOH substituent for binding to metal oxide surfaces. The ability of these corrole dyes to act as photosensitizers was assessed by comparing the corroles in a model dye sensitized solar cell design. Transient absorption spectroscopy was utilized to analyze recombination dynamics and determine the kinetics of iodide oxidation. The most efficient photoelectrochemical cell was achieved for the phosphorus corrole P-2 with electrochemical properties and kinetics suitable for both photoinduced electron injection into TiO2 and oxidation of iodide. This structure-function study highlights the wide window for tuning corrole electrochemical potentials while still maintaining desirable photophysical properties, important variables when designing dyes for applications in photoelectrochemical water-oxidation cells.

Serine racemase: activation by glutamate neurotransmission via glutamate receptor interacting protein and mediation of neuronal migration.

Serine racemase (SR), localized to astrocytic glia that ensheathe synapses, converts L-serine to D-serine, an endogenous ligand of the NMDA receptor. We report the activation of SR by glutamate neurotransmission involving alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors via glutamate receptor interacting protein (GRIP) and the physiologic regulation of cerebellar granule cell migration by SR. GRIP physiologically binds SR, augmenting SR activity and D-serine release. GRIP infection of neonatal mouse cerebellum in vivo enhances granule cell migration. Selective degradation of D-serine by D-amino acid oxidase and pharmacologic inhibition of SR impede migration, whereas D-serine activates the process. Thus, in neuronal migration, glutamate stimulates Bergmann glia to form and release D-serine, which, together with glutamate, activates NMDA receptors on granule neurons, chemokinetically enhancing migration.