ABSTRACT
IL-23 is central to psoriasis pathogenesis. Biologics targeting IL-23 are important therapies against psoriasis. IL-23 inhibitors risankizumab, tildrakizumab, and guselkumab bind the IL-23 p19 subunit, whereas ustekinumab binds p40; however, the structural composition of the IL-23-binding epitopes and how these molecular properties relate to clinical efficacy are not known. Utilizing epitope data derived from hydrogen-deuterium exchange or crystallographic experiments, we mapped inhibitor epitope locations, hydrophobicity, and surface charge onto the IL-23 surface. Molecular properties of each inhibitor epitope, including solvent-accessible surface area, were correlated to binding affinity, kinetic values, and clinical efficacy scores for plaque psoriasis through linear regression analysis. Each IL-23 inhibitor binds an epitope with a unique size, composition, and location except for a 10-residue overlap region outside of the IL-23 receptor epitope. We observed strong correlations between epitope surface area and KD and koff but not kon. Epitope surface area, KD, and koff were further associated with short-term (10-16 weeks) and long-term (44-60 weeks) clinical efficacy according to PASI-90 responses, with risankizumab demonstrating highest efficacy among IL-23 biologics. In contrast, kon, epitope hydrophobicity, polarity, and charge content did not correlate with efficacy. These data exemplify how molecular principles of medications within a therapeutic class can explain their differential clinical responses.
ABSTRACT
Increased de novo lipogenesis (DNL) in white adipose tissue is associated with insulin sensitivity. Under both Normal-Chow-Diet and High-Fat-Diet, mice expressing a kinase inactive Cyclin-dependent kinase 6 (Cdk6) allele (K43M) display an increase in DNL in visceral white adipose tissues (VAT) as compared to wild type mice (WT), accompanied by markedly increased lipogenic transcriptional factor Carbohydrate-responsive element-binding proteins (CHREBP) and lipogenic enzymes in VAT but not in the liver. Treatment of WT mice under HFD with a CDK6 inhibitor recapitulates the phenotypes observed in K43M mice. Mechanistically, CDK6 phosphorylates AMP-activated protein kinase, leading to phosphorylation and inactivation of acetyl-CoA carboxylase, a key enzyme in DNL. CDK6 also phosphorylates CHREBP thus preventing its entry into the nucleus. Ablation of runt related transcription factor 1 in K43M mature adipocytes reverses most of the phenotypes observed in K43M mice. These results demonstrate a role of CDK6 in DNL and a strategy to alleviate metabolic syndromes.
Subject(s)
Cyclin-Dependent Kinase 6 , Lipogenesis , Animals , Mice , Adipose Tissue, White/metabolism , Cyclin-Dependent Kinase 6/metabolism , Lipogenesis/genetics , Liver/metabolism , Transcription Factors/metabolismABSTRACT
Background: IL-23 is central to the pathogenesis of psoriasis, and is structurally comprised of p19 and p40 subunits. "Targeted" IL-23 inhibitors risankizumab, tildrakizumab, and guselkumab differ mechanistically from ustekinumab because they bind p19, whereas ustekinumab binds p40; however, a knowledge gap exists regarding the structural composition of their epitopes and how these molecular properties relate to their clinical efficacy. Objectives: To characterize and differentiate the structural epitopes of the IL-23 inhibitors risankizumab, guselkumab, tildrakinumab, and ustekinumab, and correlate their molecular characteristics with clinical response in plaque psoriasis therapy. Methods: We utilized epitope data derived from hydrogen-deuterium exchange studies for risankizumab, tildrakizumab, and guselkumab, and crystallographic data for ustekinumab to map drug epitope locations, hydrophobicity, and surface charge onto the IL-23 molecular surface (Protein Data Bank ID Code 3D87) using UCSF Chimera. PDBePISA was used to calculate solvent accessible surface area (SASA). Epitope composition was determined by classifying residues as acidic, basic, polar, or hydrophobic and calculating their contribution to epitope SASA. Linear regression and analysis of variance was performed. Results: All the p19-specific inhibitor epitopes differ in location and size, with risankizumab and guselkumab having large epitope surface areas (SA), and tildrakizumab and ustekinumab having smaller SA. The tildrakizumab epitope was mostly hydrophobic (56%), while guselkumab, risankizumab, and ustekinumab epitopes displayed >50% non-hydrophobic residues. Risankizumab and ustekinumab exhibited acidic surface charges, while tildrakizumab and guselkumab were net neutral. Each inhibitor binds an epitope with a unique size and composition, and with mostly distinct locations except for a 10-residue overlap region that lies outside of the IL-23 receptor epitope. We observed a strong correlation between epitope SA and PASI-90 rates (R2 = 0.9969, p = 0.0016), as well as between epitope SA and KD (R2 = 0.9772, p = 0.0115). In contrast, we found that total epitope hydrophobicity, polarity, and charge content do not correlate with clinical efficacy. Conclusions: Structural analysis of IL-23 inhibitor epitopes reveals strong association between epitope SA and early drug efficacy in plaque psoriasis therapy, exemplifying how molecular data can explain clinical observations, inform future innovation, and help clinicians in specific drug selection for patients.
ABSTRACT
Acne vulgaris is one of the most common skin disorders worldwide. It typically affects skin areas with a high density of sebaceous glands such as the face, upper arms, chest, and/or back. Historically, the majority of research efforts have focused on facial acne vulgaris, even though approximately half of patients with facial lesions demonstrate truncal involvement. Truncal acne vulgaris is challenging to treat and poses a significant psychosocial burden on patients. Despite these characteristics, studies specifically examining truncal acne vulgaris are limited, with treatment guidelines largely derived from facial protocols. Therefore, truncal acne remains an understudied clinical problem. Here, we provide a clinically focused review on the epidemiology, evaluation, and available treatment options for truncal acne vulgaris. In doing so, we highlight knowledge gaps with the goal of spurring further investigation into the management of truncal acne vulgaris.
Subject(s)
Acne Vulgaris , Cicatrix , Humans , Cicatrix/pathology , Acne Vulgaris/drug therapy , Torso/pathology , Skin/pathology , Sebaceous GlandsABSTRACT
Dermatologists treating atopic dermatitis are interested in the safety profile of the recently available JAK inhibitors, upadacitinib and abrocitinib, especially after they received boxed safety warnings. Long-term clinical trial data using these JAK inhibitors for the treatment of atopic dermatitis suggest that they are associated with very low incidence rates of malignancy, major adverse cardiac events, and thromboembolic events. However, a knowledge gap exists regarding the incidence of adverse events for JAK inhibitors compared to traditional systemic therapies used to treat poorly controlled atopic dermatitis as well as baseline rates in both atopic dermatitis and reference control populations. To address this gap, we analyzed data regarding adverse events of special interest for methotrexate, cyclosporine, and systemic corticosteroids and calculated the incidence of adverse events per 100 patient-years for these drugs. We also examined data regarding baseline incidence of adverse events in atopic dermatitis and control patients. We found that compared to upadacitinib and abrocitinib, traditional systemic therapies for atopic dermatitis demonstrated equal or higher incidence rates for malignancy (excluding non-melanoma skin cancer), non-melanoma skin cancer, major adverse cardiac events, and venous thromboembolism. Moreover, the use of upadacitinib and abrocitinib also exhibited either comparable or lower incidence of malignancy (excluding non-melanoma skin cancer), major adverse cardiac events, and venous thromboembolism, but higher rates of non-melanoma skin cancer, in comparison to baseline rates in atopic dermatitis or control patients. These findings indicate that JAK inhibitors should be positioned, at least based on safety, ahead of traditional systemic therapies for atopic dermatitis treatment.J Drugs Dermatol. 2022;21(12):1298-1303. doi:10.36849/JDD.7187.
Subject(s)
Dermatitis, Atopic , Janus Kinase Inhibitors , Skin Neoplasms , Venous Thromboembolism , Humans , Janus Kinase Inhibitors/adverse effects , Dermatitis, Atopic/drug therapy , Dermatitis, Atopic/epidemiology , Venous Thromboembolism/chemically induced , Venous Thromboembolism/epidemiology , Treatment Outcome , Immunosuppression Therapy , Skin Neoplasms/chemically inducedABSTRACT
After cessation of blood flow or similar ischaemic exposures, deleterious molecular cascades commence in mammalian cells, eventually leading to their death1,2. Yet with targeted interventions, these processes can be mitigated or reversed, even minutes or hours post mortem, as also reported in the isolated porcine brain using BrainEx technology3. To date, translating single-organ interventions to intact, whole-body applications remains hampered by circulatory and multisystem physiological challenges. Here we describe OrganEx, an adaptation of the BrainEx extracorporeal pulsatile-perfusion system and cytoprotective perfusate for porcine whole-body settings. After 1 h of warm ischaemia, OrganEx application preserved tissue integrity, decreased cell death and restored selected molecular and cellular processes across multiple vital organs. Commensurately, single-nucleus transcriptomic analysis revealed organ- and cell-type-specific gene expression patterns that are reflective of specific molecular and cellular repair processes. Our analysis comprises a comprehensive resource of cell-type-specific changes during defined ischaemic intervals and perfusion interventions spanning multiple organs, and it reveals an underappreciated potential for cellular recovery after prolonged whole-body warm ischaemia in a large mammal.
Subject(s)
Cell Survival , Cytoprotection , Perfusion , Swine , Warm Ischemia , Animals , Cell Death , Gene Expression Profiling , Ischemia/metabolism , Ischemia/pathology , Ischemia/prevention & control , Organ Specificity , Perfusion/methods , Swine/anatomy & histologyABSTRACT
The susceptibility of the brain to ischaemic injury dramatically limits its viability following interruptions in blood flow. However, data from studies of dissociated cells, tissue specimens, isolated organs and whole bodies have brought into question the temporal limits within which the brain is capable of tolerating prolonged circulatory arrest. This Review assesses cell type-specific mechanisms of global cerebral ischaemia, and examines the circumstances in which the brain exhibits heightened resilience to injury. We suggest strategies for expanding such discoveries to fuel translational research into novel cytoprotective therapies, and describe emerging technologies and experimental concepts. By doing so, we propose a new multimodal framework to investigate brain resuscitation following extended periods of circulatory arrest.
Subject(s)
Brain Ischemia/physiopathology , Brain/physiopathology , Cerebrovascular Circulation/physiology , Neuroprotection/physiology , Animals , HumansABSTRACT
The brains of humans and other mammals are highly vulnerable to interruptions in blood flow and decreases in oxygen levels. Here we describe the restoration and maintenance of microcirculation and molecular and cellular functions of the intact pig brain under ex vivo normothermic conditions up to four hours post-mortem. We have developed an extracorporeal pulsatile-perfusion system and a haemoglobin-based, acellular, non-coagulative, echogenic, and cytoprotective perfusate that promotes recovery from anoxia, reduces reperfusion injury, prevents oedema, and metabolically supports the energy requirements of the brain. With this system, we observed preservation of cytoarchitecture; attenuation of cell death; and restoration of vascular dilatory and glial inflammatory responses, spontaneous synaptic activity, and active cerebral metabolism in the absence of global electrocorticographic activity. These findings demonstrate that under appropriate conditions the isolated, intact large mammalian brain possesses an underappreciated capacity for restoration of microcirculation and molecular and cellular activity after a prolonged post-mortem interval.
Subject(s)
Autopsy , Brain/blood supply , Brain/cytology , Cerebrovascular Circulation , Microcirculation , Swine , Animals , Brain/metabolism , Brain/pathology , Brain Ischemia/metabolism , Brain Ischemia/pathology , Caspase 3/metabolism , Cell Survival , Cerebral Arteries/physiology , Disease Models, Animal , Hypoxia, Brain/metabolism , Hypoxia, Brain/pathology , Inflammation/metabolism , Inflammation/pathology , Neuroglia/cytology , Neurons/cytology , Neurons/metabolism , Neurons/pathology , Perfusion , Reperfusion Injury/prevention & control , Swine/blood , Synapses/metabolism , Synapses/pathology , Time Factors , VasodilationABSTRACT
Whereas white adipose tissue depots contribute to the development of metabolic diseases, brown and beige adipose tissue has beneficial metabolic effects. Here we show that CDK6 regulates beige adipocyte formation. We demonstrate that mice lacking the CDK6 protein or its kinase domain (K43M) exhibit significant increases beige cell formation, enhanced energy expenditure, better glucose tolerance, and improved insulin sensitivity, and are more resistant to high-fat diet-induced obesity. Re-expression of CDK6 in Cdk6 -/- mature or precursor cells, or ablation of RUNX1 in K43M mature or precursor cells, reverses these phenotypes. Furthermore, RUNX1 positively regulates the expression of Ucp-1 and Pgc1α by binding to proximal promoter regions. Our findings indicate that CDK6 kinase activity negatively regulates the conversion of fat-storing cells into fat-burning cells by suppressing RUNX1, and suggest that CDK6 may be a therapeutic target for the treatment of obesity and related metabolic diseases.
Subject(s)
Adipose Tissue, Brown/physiology , Adipose Tissue, White/physiology , Core Binding Factor Alpha 2 Subunit/antagonists & inhibitors , Cyclin-Dependent Kinase 6/metabolism , Gene Expression Regulation , Adipocytes/cytology , Animals , Body Composition , Cell Differentiation , Core Binding Factor Alpha 2 Subunit/genetics , Core Binding Factor Alpha 2 Subunit/metabolism , Crosses, Genetic , Cyclin-Dependent Kinase 6/genetics , Diet, High-Fat , Female , Gene Expression Profiling , Glucose Tolerance Test , Male , Metabolic Diseases/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Obesity/genetics , Obesity/metabolism , Oxygen Consumption , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Phenotype , Uncoupling Protein 1/metabolismABSTRACT
BACKGROUND: Matrix metalloproteinases (MMPs) are a family of enzymes that are typically released from intracellular stores to act on specific extracellular substrates. MMP expression and activity can be increased in a neuronal activity-dependent manner, and further increased in response to tissue injury. MMP substrates include cell adhesion molecules (CAMs) that are abundantly expressed in the brain and well positioned for membrane proximal cleavage. Importantly, CAM integrity is important to synaptic structure and axon-myelin interactions, and shed ectodomains may themselves influence cellular function. METHODS: In the present study, we have examined proteolysis of N-cadherin (N-cdh) by MMP-7, a family member that has been implicated in disorders including HIV dementia, multiple sclerosis, and major depression. With in vitro digest assays, we tested N-cdh cleavage by increasing concentrations of recombinant enzyme. We also tested MMP-7 for its potential to stimulate N-cdh shedding from cultured neural cells. Since select CAM ectodomains may interact with cell surface receptors that are expressed on microglial cells, we subsequently tested the N-cdh ectodomain for its ability to stimulate activation of this cell type as determined by nuclear translocation of NF-κB, Iba-1 expression, and TNF-α release. RESULTS: We observed that soluble N-cdh increased Iba-1 levels in microglial lysates, and also increased microglial release of the cytokine TNF-α. Effects were associated with increased NF-κB immunoreactivity in microglial nuclei and diminished by an inhibitor of the toll-like receptor adaptor protein, MyD88. CONCLUSIONS: Together, these in vitro results suggest that soluble N-cdh may represent a novel effector of microglial activation, and that disorders with increased MMP levels may stimulate a cycle in which the products of excess proteolysis further exacerbate microglial-mediated tissue injury. Additional in vivo studies are warranted to address this issue.
Subject(s)
Cadherins/pharmacology , Matrix Metalloproteinases/metabolism , Microglia/drug effects , Microglia/metabolism , ADAM10 Protein/metabolism , ADAM10 Protein/pharmacology , Animals , Animals, Newborn , Calcium-Binding Proteins/metabolism , Cells, Cultured , Dose-Response Relationship, Drug , Enzyme-Linked Immunosorbent Assay , Mice , Mice, Inbred C57BL , Microfilament Proteins/metabolism , Myeloid Differentiation Factor 88/metabolism , NF-kappa B/metabolism , Oligopeptides/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Protein Transport/drug effects , Rats , Signal Transduction/drug effectsABSTRACT
Cytotoxic chemotherapies are used to treat breast cancer, but are limited by systemic toxicity. The key to addressing this important issue is the development of a nontoxic, tissue selective, and molecular specific delivery system. In order to potentially increase the therapeutic index of clinical reagents, we designed an Aminopeptidase P (APaseP) targeting tissue-specific construct conjugated to a homing peptide for selective binding to human breast-derived cancer cells. Homing peptides are short amino acid sequences derived from phage display libraries that have the unique property of localizing to specific organs. Our molecular construct allows for tissue-specific drug delivery, by binding to APaseP in the vascular endothelium. The breast homing peptide evaluated in our studies is a cyclic nine-amino-acid peptide with the sequence CPGPEGAGC, referred to as PEGA. We show by confocal microscopy that the PEGA peptide and similar peptide conjugates distribute to human breast tissue xenograft specifically and evaluate the interaction with the membrane-bound proline-specific APaseP (KD = 723 ± 3 nM) by binding studies. To achieve intracellular breast cancer cell delivery, the incorporation of the Tat sequence, a cell-penetrating motif derived from HIV, was conjugated with the fluorescently labeled PEGA peptide sequence. Ultimately, tissue specific peptides and their conjugates can enhance drug delivery and treatment by their ability to discriminate between tissue types. Tissue specific conjugates as we have designed may be valuable tools for drug delivery and visualization, including the potential to treat breast cancer, while simultaneously minimizing systemic toxicity.
Subject(s)
Aminopeptidases/metabolism , Breast/metabolism , Drug Carriers/chemistry , Drug Carriers/metabolism , Animals , Breast/pathology , Cell Transformation, Neoplastic , Fluorescent Dyes/chemistry , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells , Mice , Oligopeptides/chemistry , Oligopeptides/metabolism , Organ SpecificityABSTRACT
Synucleinopathies, such as Parkinson's disease and diffuse Lewy body disease, are progressive neurodegenerative disorders characterized by selective neuronal death, abnormal accumulation of misfolded α-synuclein, and sustained microglial activation. In addition to inducing neuronal toxicity, higher-ordered oligomeric α-synuclein causes proinflammatory responses in the brain parenchyma by triggering microglial activation, which may exacerbate pathogenic processes by establishing a chronic neuroinflammatory milieu. We found that higher-ordered oligomeric α-synuclein induced a proinflammatory microglial phenotype by directly engaging the heterodimer TLR1/2 (Toll-like receptor 1 and 2) at the cell membrane, leading to the nuclear translocation of NF-κB (nuclear factor κB) and the increased production of the proinflammatory cytokines TNF-α (tumor necrosis factor-α) and IL-1ß (interleukin-1ß) in a MyD88-dependent manner. Blocking signaling through the TLR1/2 heterodimer with the small-molecule inhibitor CU-CPT22 reduced the nuclear translocation of NF-κB and secretion of TNF-α from cultured primary mouse microglia. Candesartan cilexetil, a drug approved for treating hypertension and that inhibits the expression of TLR2, reversed the activated proinflammatory phenotype of primary microglia exposed to oligomeric α-synuclein, supporting the possibility of repurposing this drug for synucleinopathies.
Subject(s)
Myeloid Differentiation Factor 88/metabolism , Protein Folding , Signal Transduction , Toll-Like Receptor 1/metabolism , Toll-Like Receptor 2/metabolism , alpha-Synuclein/metabolism , Animals , HEK293 Cells , Humans , Lewy Body Disease/genetics , Lewy Body Disease/metabolism , Mice , Myeloid Differentiation Factor 88/genetics , Parkinson Disease/genetics , Parkinson Disease/metabolism , Proteostasis Deficiencies/genetics , Proteostasis Deficiencies/metabolism , Toll-Like Receptor 1/genetics , Toll-Like Receptor 2/genetics , alpha-Synuclein/geneticsABSTRACT
Isolation of microglia from CNS tissue is a powerful investigative tool used to study microglial biology ex vivo. The present method details a procedure for isolation of microglia from neonatal murine cortices by mechanical agitation with a rotary shaker. This microglia isolation method yields highly pure cortical microglia that exhibit morphological and functional characteristics indicative of quiescent microglia in normal, nonpathological conditions in vivo. This procedure also preserves the microglial immunophenotype and biochemical functionality as demonstrated by the induction of morphological changes, nuclear translocation of the p65 subunit of NF-κB (p65), and secretion of the hallmark proinflammatory cytokine, tumor necrosis factor-α (TNF-α), upon lipopolysaccharide (LPS) and Pam3CSK4 (Pam) challenges. Therefore, the present isolation procedure preserves the immunophenotype of both quiescent and activated microglia, providing an experimental method of investigating microglia biology in ex vivo conditions.