Regulation of Cutaneous Immunity In Vivo by Calcitonin Gene-Related Peptide Signaling through Endothelial Cells.

Calcitonin gene-related peptide (CGRP) can bias the outcome of Ag presentation to responsive T cells in vitro away from Th1-type immunity and toward the Th2 and Th17 poles through actions on endothelial cells (ECs). To test the in vivo significance of this observation, we engineered a mouse lacking functional CGRP receptors on ECs (EC receptor activity modifying protein 1 [RAMP1] knockout mice). On percutaneous immunization to 1-fluoro-2,4-dinitrobenzene, stimulated CD4+ T cells from draining lymph nodes showed significantly reduced IL-17A expression with significantly increased IFN-γ, IL-4, and IL-22 expression at the protein and mRNA levels compared with control mice. Retinoic acid receptor-related orphan receptor γ t mRNA was significantly reduced, while mRNAs for T-box expressed in T cells and GATA binding protein 3 were significantly increased. In addition, EC RAMP1 knockout mice had significantly reduced contact hypersensitivity responses, and systemic administration of a CGRP receptor antagonist similarly inhibited contact hypersensitivity in wild-type mice. These observations provide compelling evidence that CGRP is a key regulator of cutaneous immunity through effects on ECs and suggest a novel pathway for potential therapeutic manipulation.

Inhibition of UVB radiation-induced tissue swelling and immune suppression by nicotinamide riboside and pterostilbene.

BACKGROUND: Environmental ultraviolet radiation has deleterious effects on humans, including sunburn and immune perturbations. These immune changes are involved in skin carcinogenesis. OBJECTIVES: To determine whether nicotinamide riboside and/or pterostilbene administered systemically inhibits inflammatory and immune effects of exposure to mid-range ultraviolet radiation. METHODS: To examine UVB radiation-induced inflammatory effects, mice were fed standard chow/water, 0.04% pterostilbene in chow and 0.2% nicotinamide riboside in drinking water, diet with nicotinamide riboside alone, or diet with pterostilbene alone. After 4 weeks, mice were exposed to UVB radiation (3500 J/m2), and 24-/48-h ear swelling was assessed. We also asked if each agent or the combination inhibits UVB radiation suppression of contact hypersensitivity in two models. Mice were fed standard diet/water or chow containing 0.08% pterostilbene, water with 0.4% nicotinamide riboside, or both for 4 weeks. Low-dose: Half the mice in each group were exposed on the depilated dorsum to UVB radiation (1700 J/m2) daily for 4 days, whereas half were mock-irradiated. Mice were immunized on the exposed dorsum to dinitrofluorobenzene 4 h after the last irradiation, challenged 7 days later on the ears with dinitrofluorobenzene, and 24-h ear swelling assessed. High dose: Mice were treated similarly except that a single dose of 10,000 J/m2 of radiation was administered and immunization was performed on the unirradiated shaved abdomen 3 days later. RESULTS: Nicotinamide riboside and pterostilbene together inhibited UVB-induced skin swelling more than either alone. Pterostilbene alone and both given together could inhibit UVB-induced immune suppression in both the low-dose and high-dose models while nicotinamide riboside alone was more effective in the low-dose model than the high-dose model. CONCLUSION: Nicotinamide riboside and pterostilbene have protective effects against UVB radiation-induced tissue swelling and immune suppression.

Soluble adenylyl cyclase contributes to imiquimod-mediated inflammation and is a potential therapeutic target in psoriasis.

Cyclic AMP (cAMP) has a key role in psoriasis pathogenesis, as indicated by the therapeutic efficacy of phosphodiesterase inhibitors that prevent the degradation of cAMP. However, whether soluble adenylate cyclase (sAC) (encoded by the ADCY10 gene), which is an important source for cAMP, is involved in Th17 cell-mediated inflammation or could be an alternative therapeutic target in psoriasis is unknown. We have utilized the imiquimod model of murine psoriasiform dermatitis to address this question. Adcy10-/- mice had reduced erythema, scaling and swelling in the skin and reduced CD4+ IL17+ cell numbers in the draining lymph nodes, compared with wild-type mice after induction of psoriasiform dermatitis with imiquimod. Keratinocyte-specific knock out of Adcy10 had no effect on imiquimod-induced ear swelling suggesting keratinocyte sAC has no role in imiquimod-induced inflammation. During Th17 polarization in vitro, naive T cells from Adcy10-/- mice exhibited reduced IL17 secretion and IL-17+ T-cell proliferation suggesting that differentiation into Th17 cells is suppressed without sAC activity. Interestingly, loss of sAC did not impact the expression of Th17 lineage-defining transcription factors (such as Rorc and cMaf) but rather was required for CREB-dependent gene expression, which is known to support Th17 cell gene expression. Finally, topical application of small molecule sAC inhibitors (sACi) reduced imiquimod-induced psoriasiform dermatitis and Il17 gene expression in the skin. Collectively, these findings demonstrate that sAC is important for psoriasiform dermatitis in mouse skin. sACi may provide an alternative class of topical therapeutics for Th17-mediated skin diseases.

Standard management options for rosacea: The 2019 update by the National Rosacea Society Expert Committee.

In 2017, a National Rosacea Society Expert Committee developed and published an updated classification of rosacea to reflect current insights into rosacea pathogenesis, pathophysiology, and management. These developments suggest that a multivariate disease process underlies the various clinical manifestations of the disorder. The new system is consequently based on phenotypes that link to this process, providing clear parameters for research and diagnosis as well as encouraging clinicians to assess and treat the disorder as it may occur in each individual. Meanwhile, a range of therapies has become available for rosacea, and their roles have been increasingly defined in clinical practice as the disorder has become more widely recognized. This update is intended to provide a comprehensive summary of management options, including expert evaluations, to serve as a guide for tailoring treatment and care on an individual basis to achieve optimal patient outcomes.

Immunoregulatory Effects of Neuropeptides on Endothelial Cells: Relevance to Dermatological Disorders.

Many skin diseases, including psoriasis and atopic dermatitis, have a neurogenic component. In this regard, bidirectional interactions between components of the nervous system and multiple target cells in the skin and elsewhere have been receiving increasing attention. Neuropeptides released by sensory nerves that innervate the skin can directly modulate functions of keratinocytes, Langerhans cells, dermal dendritic cells, mast cells, dermal microvascular endothelial cells and infiltrating immune cells. As a result, neuropeptides and neuropeptide receptors participate in a complex, interdependent network of mediators that modulate the skin immune system, skin inflammation, and wound healing. In this review, we will focus on recent studies demonstrating the roles of α-melanocyte-stimulating hormone, calcitonin gene-related peptide, substance P, somatostatin, vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide, and nerve growth factor in modulating inflammation and immunity in the skin through their effects on dermal microvascular endothelial cells.

Regulation of T helper cell responses during antigen presentation by norepinephrine-exposed endothelial cells.

Dermal blood vessels and regional lymph nodes are innervated by sympathetic nerves and, under stress, sympathetic nerves release norepinephrine (NE). Exposure of primary murine dermal microvascular endothelial cells (pDMECs) to NE followed by co-culture with Langerhans cells (LCs), responsive CD4+ T-cells and antigen resulted in modulation of CD4+ T-cell responses. NE-treatment of pDMECs induced increased production of interleukin (IL)-6 and IL-17A while down-regulating interferon (IFN)-γ and IL-22 release. This effect did not require contact between pDMECs and LCs or T-cells and depended upon pDMEC production of IL-6. The presence of NE-treated pDMECs increased the proportion of CD4+ T-cells expressing intracellular IL-17A and increased IL-17A mRNA while decreasing the proportion of IFN-γ- or IL-22-expressing CD4+ T-cells and mRNA levels for those cytokines. Retinoic acid receptor-related orphan receptor gamma (ROR-γt) mRNA was significantly increased in CD4+ T-cells while T-box transcription factor (T-bet) mRNA was decreased. Intradermal administration of NE prior to hapten immunization at the injection site produced a similar bias in draining lymph node CD4+ T-cells towards IL-17A and away from IFN-γ and IL-22 production. Under stress, release of NE may have significant regulatory effects on the outcome of antigen presentation through actions on ECs with enhancement of inflammatory skin disorders involving IL-17/T helper type 17 (Th17) cells.

Standard classification and pathophysiology of rosacea: The 2017 update by the National Rosacea Society Expert Committee.

In 2002, the National Rosacea Society assembled an expert committee to develop the first standard classification of rosacea. This original classification was intended to be updated as scientific knowledge and clinical experience increased. Over the last 15 years, significant new insights into rosacea's pathogenesis and pathophysiology have emerged, and the disorder is now widely addressed in clinical practice. Growing knowledge of rosacea's pathophysiology has established that a consistent multivariate disease process underlies the various clinical manifestations of this disorder, and the clinical significance of each of these elements is increasing as more is understood. This review proposes an updated standard classification of rosacea that is based on phenotypes linked to our increased understanding of disease pathophysiology. This updated classification is intended to provide clearer parameters to conduct investigations, guide diagnosis, and improve treatment.

Calcitonin Gene-Related Peptide-Exposed Endothelial Cells Bias Antigen Presentation to CD4+ T Cells toward a Th17 Response.

Calcitonin gene-related peptide (CGRP) is a neuropeptide with well-established immunomodulatory functions. CGRP-containing nerves innervate dermal blood vessels and lymph nodes. We examined whether CGRP regulates the outcome of Ag presentation by Langerhans cells (LCs) to T cells through actions on microvascular endothelial cells (ECs). Exposure of primary murine dermal microvascular ECs (pDMECs) to CGRP followed by coculture with LCs, responsive CD4(+) T cells and Ag resulted in increased production of IL-6 and IL-17A accompanied by inhibition of IFN-γ, IL-4, and IL-22 compared with wells containing pDMECs treated with medium alone. Physical contact between ECs and LCs or T cells was not required for this effect and, except for IL-4, we demonstrated that IL-6 production by CGRP-treated pDMECs was involved in these effects. CD4(+) cells expressing cytoplasmic IL-17A were increased, whereas cells expressing cytoplasmic IFN-γ or IL-4 were decreased by the presence of CGRP-treated pDMECs. In addition, the level of retinoic acid receptor-related orphan receptor γt mRNA was significantly increased, whereas T-bet and GATA3 expression was inhibited. Immunization at the site of intradermally administered CGRP led to a similar bias in CD4(+) T cells from draining lymph node cells toward IL-17A and away from IFN-γ. Actions of nerve-derived CGRP on ECs may have important regulatory effects on the outcome of Ag presentation with consequences for the expression of inflammatory skin disorders involving Th17 cells.

Pachydermodactyly: A Case Report Including Histopathology.

Pachydermodactyly (PDD) is a rare form of digital fibromatosis characterized by painless soft tissue swelling, primarily about the proximal interphalangeal joints. The skin at the metacarpophalangeal joints, the palm, and the dorsum of the hand may also be involved. Because swelling can occur over the proximal interphalangeal and metacarpophalangeal joints, PDD may be confused with juvenile inflammatory arthropathy and may even occur concurrently. We present the clinical and histopathologic findings of a case of PDD characterized by bilateral proximal phalangeal involvement of the index through little fingers.

Teledermatology: from historical perspective to emerging techniques of the modern era: part I: History, rationale, and current practice.

Telemedicine is the use of telecommunications technology to support health care at a distance. Technological advances have progressively increased the ability of clinicians to care for diverse patient populations in need of skin expertise. Dermatology relies on visual cues that are easily captured by imaging technologies, making it ideally suited for this care model. Moreover, there is a shortage of medical dermatologists in the United States, where skin disorders account for 1 in 8 primary care visits and specialists tend to congregate in urban areas. Even in regions where dermatologic expertise is readily accessible, teledermatology may serve as an alternative that streamlines health care delivery by triaging chief complaints and reducing unnecessary in-person visits. In addition, many patients in the developing world have no access to dermatologic expertise, rendering it possible for teledermatologists to make a significant contribution to patient health outcomes. Teledermatology also affords educational benefits to primary care providers and dermatologists, and enables patients to play a more active role in the health care process by promoting direct communication with dermatologists.

Teledermatology: from historical perspective to emerging techniques of the modern era: part II: Emerging technologies in teledermatology, limitations and future directions.

Telemedicine is the use of telecommunications technology to support health care at a distance. Dermatology relies on visual cues that are easily captured by imaging technologies, making it ideally suited for this care model. Advances in telecommunications technology have made it possible to deliver high-quality skin care when patient and provider are separated by both time and space. Most recently, mobile devices that connect users through cellular data networks have enabled teledermatologists to instantly communicate with primary care providers throughout the world. The availability of teledermoscopy provides an additional layer of visual information to enhance the quality of teleconsultations. Teledermatopathology has become increasingly feasible because of advances in digitization of entire microscopic slides and robot-assisted microscopy. Barriers to additional expansion of these services include underdeveloped infrastructure in remote regions, fragmented electronic medical records, and varying degrees of reimbursement. Teleconsultants also confront special legal and ethical challenges as they work toward building a global network of practicing physicians.

Collection of biospecimens from the inspiration4 mission establishes the standards for the space omics and medical atlas (SOMA).

The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from four crew members longitudinally before (Launch: L-92, L-44, L-3 days), during (Flight Day: FD1, FD2, FD3), and after (Return: R + 1, R + 45, R + 82, R + 194 days) spaceflight, spanning a total of 289 days across 2021-2022. The collection process included venous whole blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies. Venous whole blood was further processed to obtain aliquots of serum, plasma, extracellular vesicles and particles, and peripheral blood mononuclear cells. In total, 2,911 sample aliquots were shipped to our central lab at Weill Cornell Medicine for downstream assays and biobanking. This paper provides an overview of the extensive biospecimen collection and highlights their processing procedures and long-term biobanking techniques, facilitating future molecular tests and evaluations.As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can aid future human spaceflight and space biology experiments.

Pituitary adenylate cyclase-activating peptide and vasoactive intestinal polypeptide bias Langerhans cell Ag presentation toward Th17 cells.

Epidermal Langerhans cells (LCs) are dendritic APCs that play an important role in cutaneous immune responses. LCs are associated with epidermal nerves and the neuropeptides vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) inhibit LC Ag presentation for Th1-type immune responses. Here, we examined whether PACAP or VIP modulates LC Ag presentation for induction of IL-17A-producing CD4(+) T cells. Treatment with VIP or PACAP prior to in vitro LC Ag presentation to CD4(+) T cells enhanced IL-17A, IL-6, and IL-4 production, decreased interferon (IFN)-γ and interleukin (IL)-22 release, and increased RORγt and Gata3 mRNA expression while decreasing T-bet expression. The CD4(+) T-cell population was increased in IL-17A- and IL-4-expressing cells and decreased in IFN-γ-expressing cells. Addition of anti-IL-6 mAb blocked the enhanced IL-17A production seen with LC preexposure to VIP or PACAP. Intradermal administration of VIP or PACAP prior to application of a contact sensitizer at the injection site, followed by harvesting of draining lymph node CD4(+) T cells and stimulation with anti-CD3/anti-CD28 mAbs, enhanced IL-17A and IL-4 production but reduced production of IL-22 and IFN-γ. PACAP and VIP are endogenous mediators that likely regulate immunity and immune-mediated diseases within the skin.

Norepinephrine and adenosine-5'-triphosphate synergize in inducing IL-6 production by human dermal microvascular endothelial cells.

Endothelial cells (ECs) play important roles in cutaneous inflammation, in part, by release of inflammatory chemokines/cytokines. Because dermal blood vessels are innervated by sympathetic nerves, the sympathetic neurotransmitter norepinephrine (NE) and the co-transmitter adenosine-5'-triphosphate (ATP) may regulate expression of EC inflammatory factors. We focused on IL-6 regulation because it has many inflammatory and immune functions, including participation in Th17 cell differentiation. Strikingly, NE and ATP synergistically induced release of IL-6 by a human dermal microvascular endothelial cell line (HMEC-1). Adrenergic antagonist and agonist studies indicated that the effect of NE on induced IL-6 release is primarily mediated by ß2-adrenergic receptors (ARs). By real-time PCR IL-6 mRNA was also synergistically induced in HMEC-1 cells. This synergistic effect of NE and ATP was reproduced in primary human dermal endothelial cells (pHDMECs) and is also primarily mediated by ß2-ARs. Under conditions of stress, activation of the symphathetic nervous system may lead to release of ATP and NE by sympathetic nerves surrounding dermal blood vessels with induction of IL-6 production by ECs. IL-6 may then participate in immune and inflammatory processes including generation of Th17 cells. Production of IL-6 in this manner might explain stress-induced exacerbation of psoriasis, and perhaps, other skin disorders involving Th17-type immunity.

Nerve-derived transmitters including peptides influence cutaneous immunology.

Clinical observations suggest that the nervous and immune systems are closely related. For example, inflammatory skin disorders; such as psoriasis, atopic dermatitis, rosacea and acne; are widely believed to be exacerbated by stress. A growing body of research now suggests that neuropeptides and neurotransmitters serve as a link between these two systems. Neuropeptides and neurotransmitters are released by nerves innervating the skin to influence important actors of the immune system, such as Langerhans cells and mast cells, which are located within close anatomic proximity. Catecholamines and other sympathetic transmitters that are released in response to activation of the sympathetic nervous system are also able to reach the skin and affect immune cells. Neuropeptides appear to direct the outcome of Langerhans cell antigen presentation with regard to the subtypes of Th cells generated and neuropeptides induce the degranulation of mast cells, among other effects. Additionally, endothelial cells, which release many inflammatory mediators and express cell surface molecules that allow leukocytes to exit the bloodstream, appear to be regulated by certain neuropeptides and transmitters. This review focuses on the evidence that products of nerves have important regulatory activities on antigen presentation, mast cell function and endothelial cell biology. These activities are highly likely to have clinical and therapeutic relevance.

Muramyl dipeptide induces Th17 polarization through activation of endothelial cells.

Endothelial cells (ECs) express the nucleotide-binding oligomerization domain (Nod) receptor 2, which recognizes the bacterial derivate muramyl dipeptide (MDP). MDP stimulation of these cells enhances their IL-6 production and may thus contribute to the immune and inflammatory activities in the skin. However, whether ECs are capable of influencing the development of T cell priming and its polarization remains unknown. We report that in vitro the murine bEnd.3 EC line induces, following MDP stimulation, a Th17 polarization at the expense of Th1 and Th2 polarization in the setting of Langerhans cell (LC) Ag presentation to responsive T cells as assessed by IL-17, IL-6, IFN-γ, and IL-4 production. Interestingly, IL-22 production, which has been associated with Th17 priming, was not influenced by MDP-treated bEnd.3 cells, illustrating differential regulation of this cytokine from IL-17. Additional analysis confirmed a significantly increased percentage of IL-17(+)CD4(+) T cells by flow cytometry and an increased mRNA level of the specific Th17 transcription factor retinoic acid-related orphan receptor γt in cocultures of LCs and responsive T cells in the presence of activated bEnd.3 cells. Experiments using the RNA interference technique to knockdown IL-6 in bEnd.3 cells confirmed that IL-6 produced by bEnd.3 cells stimulated by MDP is at least partially involved in Th17 polarization. Our data suggest that activated ECs are capable of influencing LC Ag processing and presentation to T cells and induce a Th17 polarization. These results are important for the understanding of Th17-related disorders of the skin such as psoriasis.

Collection of Biospecimens from the Inspiration4 Mission Establishes the Standards for the Space Omics and Medical Atlas (SOMA).

The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from the crew at different stages of the mission, including before (L-92, L-44, L-3 days), during (FD1, FD2, FD3), and after (R+1, R+45, R+82, R+194 days) spaceflight, creating a longitudinal sample set. The collection process included samples such as venous blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies, which were processed to obtain aliquots of serum, plasma, extracellular vesicles, and peripheral blood mononuclear cells. All samples were then processed in clinical and research laboratories for optimal isolation and testing of DNA, RNA, proteins, metabolites, and other biomolecules. This paper describes the complete set of collected biospecimens, their processing steps, and long-term biobanking methods, which enable future molecular assays and testing. As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can also aid future experiments in human spaceflight and space biology.

N-acetyl-S-farnesyl-l-cysteine suppresses chemokine production by human dermal microvascular endothelial cells.

Isoprenylcysteine (IPC) molecules modulate G-protein-coupled receptor signalling. The archetype of this class is N-acetyl-S-farnesyl-l-cysteine (AFC). Topical application of AFC locally inhibits skin inflammation and elicitation of contact hypersensitivity in vivo. However, the mechanism of these anti-inflammatory effects is not well understood. Dermal microvascular endothelial cells (ECs) are involved in inflammation, in part, by secreting cytokines that recruit inflammatory cells. We have previously shown that the sympathetic nerve cotransmitter adenosine-5'-triphosphate (ATP) and adenosine-5'-O-(3-thio) triphosphate (ATPγS), an ATP analogue that is resistant to hydrolysis, increase secretion of the chemokines CXCL8 (interleukin-8), CCL2 (monocyte chemotactic protein-1) and CXCL1 (growth-regulated oncogene α) by dermal microvascular ECs. Production of these chemokines can also be induced by the exposure to the proinflammatory cytokine TNFα. We have now demonstrated that AFC dose-dependently inhibits ATP-, ATPγS- and TNFα-induced production of CXCL1, CXCL8 and CCL2 by a human dermal microvascular EC line (HMEC-1) in vitro under conditions that do not affect cell viability. Inhibition of ATPγS- or TNFα-stimulated release of these chemokines was associated with reduced mRNA levels. N-acetyl-S-geranyl-l-cysteine, an IPC analogue that is inactive in inhibiting G-protein-coupled signalling, had greatly reduced ability to suppress stimulated chemokine production. AFC may exert its anti-inflammatory effects through the inhibition of chemokine production by stimulated ECs.

ß2-Adrenergic agonists bias TLR-2 and NOD2 activated dendritic cells towards inducing an IL-17 immune response.

This study tested the hypothesis that activation of ß2-adrenoceptors on DCs influences NOD2 signaling along with its cross-talk with Toll-like receptor-2 resulting in altered Th cell priming ability. Th17 cells are a newly discovered lineage of CD4(+) T cells involved in defense against extracellular bacteria and also implicated in autoimmune disorders. Initiation and polarization of the adaptive immune response is controlled by innate immune recognition mediated by DCs. Previous studies demonstrated that adrenergic receptors modulate cytokine production by DCs and affect their Th cell priming ability. We show that the ß2-adrenoceptor agonist salbutamol enhanced IL-6 production in murine bone marrow-derived DCs stimulated with the nucleotide-binding oligomerization domain 2 ligand muramyl dipeptide. However, when the Toll-like receptor-2 ligand Pam3CysSK4 was added, salbutamol inhibited IL-12 but did not alter IL-6 and IL-23 expression. Gene expression analysis showed that salbutamol inhibited the p40 subunit as well as IL-12p35, while IL-23p19 and IL-6 were stimulated. Therefore, ß2-adrenoceptors modulated cytokine production resulting in a Th17 cell priming cytokine pattern. Indeed, when antigen-pulsed DCs stimulated by muramyl dipeptide or Pam3CysSK4+muramyl dipeptide in the presence of salbutamol were used for in vivo immunization, the resulting Th17/Th1 cell ratio was increased as evaluated by IL-17 and IFN-γ production. In addition, intradermal injection of norepinephrine along with Pam3CysSK4+muramyl dipeptide increased the Th17 response to an immunogenic protein and this effect was reversed by a ß2-adrenoceptor antagonist. Thus, ß2-adrenoceptors may be involved in the regulation of defense against extracellular bacteria and the pathogenesis of inflammatory diseases.