Relationship between sustained disability progression and functional system scores in relapsing-remitting multiple sclerosis: analysis of placebo data from four randomized clinical trials.

BACKGROUND: The Expanded Disability Status Scale (EDSS), based on different functional system scores (FSS), remains the most frequently used disability assessment in relapsing-remitting multiple sclerosis (RRMS). In this analysis, we evaluated the relationship between sustained disability progression, measured by EDSS, and simultaneous changes in individual FSS domains. METHODS: A post hoc analysis was performed on data from placebo-treated RRMS patients from four large, randomized, multicenter, phase 3 clinical trials. Sustained disability progression was defined as a ≥1.0-point EDSS score increase over a ≥3- or ≥6-month period. Simultaneous sustained disability progression and worsening of individual FSS domains was analyzed. RESULTS: The majority of patients experienced sustained disability progression and simultaneous worsening of ≥1 FSS domain, with ≥1-point worsening in the pyramidal domain being most frequently associated with sustained disability progression (in 31-51% of patients), followed by ≥1-point worsening in the cerebellar (35-41% of patients) and sensory (31-45% of patients) domains. CONCLUSION: The key FSS components correlating with sustained disability progression, measured by EDSS, appear to be pyramidal, cerebellar, and sensory. In this analysis, the simultaneous worsening of consistent FSS domains confirms the validity and reliability of the use of sustained EDSS progression as a measure of disability progression.

Direct suppression of CNS autoimmune inflammation via the cannabinoid receptor CB1 on neurons and CB2 on autoreactive T cells.

The cannabinoid system is immunomodulatory and has been targeted as a treatment for the central nervous system (CNS) autoimmune disease multiple sclerosis. Using an animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), we investigated the role of the CB(1) and CB(2) cannabinoid receptors in regulating CNS autoimmunity. We found that CB(1) receptor expression by neurons, but not T cells, was required for cannabinoid-mediated EAE suppression. In contrast, CB(2) receptor expression by encephalitogenic T cells was critical for controlling inflammation associated with EAE. CB(2)-deficient T cells in the CNS during EAE exhibited reduced levels of apoptosis, a higher rate of proliferation and increased production of inflammatory cytokines, resulting in severe clinical disease. Together, our results demonstrate that the cannabinoid system within the CNS plays a critical role in regulating autoimmune inflammation, with the CNS directly suppressing T-cell effector function via the CB(2) receptor.

A cyclin D1 intrinsically disordered domain accesses modified histone motifs to govern gene transcription.

The essential G1-cyclin, CCND1, is frequently overexpressed in cancer, contributing to tumorigenesis by driving cell-cycle progression. D-type cyclins are rate-limiting regulators of G1-S progression in mammalian cells via their ability to bind and activate CDK4 and CDK6. In addition, cyclin D1 conveys kinase-independent transcriptional functions of cyclin D1. Here we report that cyclin D1 associates with H2BS14 via an intrinsically disordered domain (IDD). The same region of cyclin D1 was necessary for the induction of aneuploidy, induction of the DNA damage response, cyclin D1-mediated recruitment into chromatin, and CIN gene transcription. In response to DNA damage H2BS14 phosphorylation occurs, resulting in co-localization with γH2AX in DNA damage foci. Cyclin D1 ChIP seq and γH2AX ChIP seq revealed ~14% overlap. As the cyclin D1 IDD functioned independently of the CDK activity to drive CIN, the IDD domain may provide a rationale new target to complement CDK-extinction strategies.

PELP1 oncogenic functions involve CARM1 regulation.

Estrogen receptor alpha (ERα) is implicated in the initiation and progression of breast cancer and its transcription depends on the modulation of epigenetic changes at target gene promoters via coregulators. There is a critical need to understand the molecular mechanism(s) by which deregulation of epigenetic changes occurs during breast cancer progression. The ERα coregulator PELP1 plays an important role in ERα signaling and is a proto-oncogene with aberrant expression in breast cancer. PELP1 interacts with histones and may be a reader of chromatin modifications. We profiled PELP1's epigenetic interactome using a histone peptide array. Our results show that PELP1 recognizes histones modified by arginine and lysine dimethylation. PELP1 functionally interacts with the arginine methyltransferase CARM1 and their interaction is enhanced by ERα. PELP1-CARM1 interactions synergistically enhance ERα transactivation. Chromatin immunoprecipitation assays revealed that PELP1 alters histone H3 arginine methylation status at ERα target gene promoters. Pharmacological inhibition or small interfering RNA knockdown of CARM1 substantially reduced PELP1 oncogenic functions. The critical role of PELP1 status in modulating arginine methylation status was also observed through in vivo studies where PELP1 knockdown mediated decreased tumorigenesis correlated with decreased arginine dimethylation. Further, immunohistochemical analysis of human breast tumor tissues revealed co-overexpression of PELP1 and CARM1 in a subset of ERα-positive breast tumors. Our findings show PELP1 is a reader of histone arginine methyl modifications and deregulation promotes tumor proliferation via epigenetic alterations at ERα target promoters. Targeting these epigenetic alterations through inhibition of PELP1 and the arginine methyltransferases could be a promising cancer therapeutic.

Targeting the PELP1-KDM1 axis as a potential therapeutic strategy for breast cancer.

INTRODUCTION: The estrogen receptor (ER) co-regulator proline glutamic acid and leucine-rich protein 1 (PELP1) is a proto-oncogene that modulates epigenetic changes on ER target gene promoters via interactions with lysine-specific histone demethylase 1 (KDM1). In this study, we assessed the therapeutic potential of targeting the PELP1-KDM1 axis in vivo using liposomal (1,2-dioleoyl-sn-glycero-3-phosphatidylcholine; DOPC) siRNA to downregulate PELP1 expression and KDM1 inhibitors, pargyline and N-((1S)-3-(3-(trans-2-aminocyclopropyl)phenoxy)-1-(benzylcarbamoyl)propyl)benzamide using preclinical models. METHODS: Preclinical xenograft models were used to test the efficacy of drugs in vivo. Ki-67 and terminal deoxynucleotidyl transferase dUTP nick end-labeling immunohistochemical analysis of epigenetic markers was performed on tumor tissues. The in vitro effect of PELP1-KDM axis blockers was tested using proliferation, reporter gene, chromatin immunoprecipitation and real-time RT-PCR assays. The efficacy of the KDM1 targeting drugs alone or in combination with letrozole and tamoxifen was tested using therapy-resistant model cells. RESULTS: Treatment of ER-positive xenograft-based breast tumors with PELP1-siRNA-DOPC or pargyline reduced tumor volume by 58.6% and 62%, respectively. In a postmenopausal model, in which tumor growth is stimulated solely by local estrogen synthesis, daily pargyline treatment reduced tumor volume by 78%. Immunohistochemical analysis of excised tumors revealed a combined decrease in cellular proliferation, induction of apoptosis and upregulation of inhibitory epigenetic modifications. Pharmacological inhibition of KDM1 in vitro increased inhibitory histone mark dimethylation of histone H3 at lysine 9 (H3K9me2) and decreased histone activation mark acetylation of H3K9 (H3K9Ac) on ER target gene promoters. Combining KDM1 targeting drugs with current endocrine therapies substantially impeded growth and restored sensitivity of therapy-resistant breast cancer cells to treatment. CONCLUSION: Our results suggest inhibition of PELP1-KDM1-mediated histone modifications as a potential therapeutic strategy for blocking breast cancer progression and therapy resistance.

A First-in-Class Inhibitor of ER Coregulator PELP1 Targets ER+ Breast Cancer.

Most patients with estrogen receptor alpha-positive (ER+) breast cancers initially respond to treatment but eventually develop therapy resistance with disease progression. Overexpression of oncogenic ER coregulators, including proline, glutamic acid, and leucine-rich protein 1 (PELP1), are implicated in breast cancer progression. The lack of small molecules that inhibits PELP1 represents a major knowledge gap. Here, using a yeast-two-hybrid screen, we identified novel peptide inhibitors of PELP1 (PIP). Biochemical assays demonstrated that one of these peptides, PIP1, directly interacted with PELP1 to block PELP1 oncogenic functions. Computational modeling of PIP1 revealed key residues contributing to its activity and facilitated the development of a small-molecule inhibitor of PELP1, SMIP34, and further analyses confirmed that SMIP34 directly bound to PELP1. In breast cancer cells, SMIP34 reduced cell growth in a dose-dependent manner. SMIP34 inhibited proliferation of not only wild-type (WT) but also mutant (MT) ER+ and therapy-resistant breast cancer cells, in part by inducing PELP1 degradation via the proteasome pathway. RNA sequencing analyses showed that SMIP34 treatment altered the expression of genes associated with estrogen response, cell cycle, and apoptosis pathways. In cell line-derived and patient-derived xenografts of both WT and MT ER+ breast cancer models, SMIP34 reduced proliferation and significantly suppressed tumor progression. Collectively, these results demonstrate SMIP34 as a first-in-class inhibitor of oncogenic PELP1 signaling in advanced breast cancer. SIGNIFICANCE: Development of a novel inhibitor of oncogenic PELP1 provides potential therapeutic avenues for treating therapy-resistant, advanced ER+ breast cancer.

Schizotypal, schizoid and paranoid characteristics in the biological parents of social anhedonics.

Mounting evidence suggests that social anhedonia may be a marker of genetic liability for schizophrenia-spectrum pathology. To examine this hypothesis, we conducted a study of severity of schizotypal, schizoid and paranoid pathology (i.e., Cluster A personality disorders) in the biological parents of individuals with high levels of social anhedonia and healthy controls. Eighty-six individuals with social anhedonia, 89 healthy controls and their biological parents were recruited from a large community. Structured clinical interviews were conducted to obtain Cluster A diagnoses and symptom ratings for parents. The biological parents of socially anhedonic probands had elevated rates of Cluster A disorders (24%) compared with the parents of control probands (12%). Post hoc analyses revealed that these group differences were the result of elevated rates of diagnoses in the fathers of social anhedonic probands, but not the mothers. This finding was replicated when Cluster A symptoms were examined dimensionally. These findings are consistent with the hypothesis that social anhedonia is a promising indicator of the genetic vulnerability to schizophrenia-spectrum pathology. The unexpected findings of elevated pathology in fathers, but not mothers of socially anhedonic probands, require further exploration.

Effect of dimethyl fumarate on lymphocyte subsets in patients with relapsing multiple sclerosis.

BACKGROUND: In patients treated with dimethyl fumarate, absolute lymphocyte count decline typically occurs during the first year and then plateaus; early drops have been associated with the development of severe prolonged lymphopenia. OBJECTIVE: We investigated the effect of dimethyl fumarate on absolute lymphocyte counts and CD4+/CD8+ T cells in patients with relapsing-remitting multiple sclerosis treated with dimethyl fumarate in routine practice. METHODS: Lymphocyte data were collected via medical chart abstraction. Primary endpoint: change from baseline in absolute lymphocyte count and CD4+/CD8+ counts at 6-month intervals following dimethyl fumarate initiation. RESULTS: Charts of 483 patients were abstracted and 476 patients included in the analysis. Mean baseline absolute lymphocyte count (2.23 × 109/l) decreased by ∼39% (95% confidence interval: -41.1 to -37.2) by month 6 and 44% (95% confidence interval: -46.6 to -42.1) by month 12. CD4+ and CD8+ T-cell subsets strongly correlated with absolute lymphocyte count, with greater decreases from baseline to 6 months vs 6-12 months, and in CD8+ vs CD4+ T cells. Prior natalizumab was not a risk factor for lymphopenia. CONCLUSION: Dimethyl fumarate-associated decline in absolute lymphocyte count in the first 12 months correlated with decline in CD4+ and CD8+ T cells and was independent of prior natalizumab. Absolute lymphocyte count monitoring continues to be an effective strategy to identify patients at risk of prolonged lymphopenia.

Patients transitioning from non-pegylated to pegylated interferon beta-1a have a low risk of new flu-like symptoms: ALLOW phase 3b trial results.

BACKGROUND: Flu-like symptoms are common adverse events associated with interferon beta relapsing multiple sclerosis therapies. OBJECTIVES: To evaluate the incidence and severity of flu-like symptoms after transitioning from non-pegylated interferons to peginterferon beta-1a and assess flu-like symptom mitigation using naproxen. METHODS: ALLOW was a phase 3b open-label study in relapsing multiple sclerosis patients. Patients had received non-pegylated interferon for 4 or more months immediately before beginning a 4-week screening period. At baseline, patients switched to peginterferon beta-1a and were randomly assigned (1:1) to continue their current flu-like symptoms management regimen or start twice-daily naproxen 500 mg for 8 weeks. Patients then switched to their preferred regimen and were followed for 48 weeks in total. RESULTS: Of 201 patients, 89.6% did not experience new/worsening flu-like symptoms during their first 8 weeks on peginterferon beta-1a. Flu-like symptom severity remained low in current-regimen and naproxen patients, with no significant between-group differences. Median flu-like symptom duration per injection was 3.2 hours longer with peginterferon beta-1a versus prior interferon, but the 4-week cumulative duration was reduced 49-78%. No new safety signals were identified. CONCLUSION: Most patients who switched from non-pegylated interferon to peginterferon beta-1a did not experience new/worsening flu-like symptoms. Flu-like symptom duration per injection increased, but the cumulative duration significantly decreased. These data may inform flu-like symptom management guidance.

IL-13 induces the expression of the alternative activation marker Ym1 in a subset of testicular macrophages.

Macrophages are thought to play an important role in the maintenance of immune privilege in the testis, which functions to prevent immune responses to developing sperm. Two populations of macrophages are known to exist in the testis, one of which exhibits immunosuppressive activity. Macrophages that are alternatively activated with either IL-4 or IL-13 have been shown to be anti-inflammatory and promote wound healing. Expression of the Ym1 protein is an established marker of alternatively activated macrophages. Testicular macrophages were examined for expression of Ym1 protein, and it was found to be highly expressed in a subpopulation of CD11b(+) cells. Furthermore, we have shown that Ym1 protein expression in the testis is dependent upon IL-13R signaling, and that IL-13 is produced in the testis. These data suggest that IL-13 plays a role in testicular immune privilege by the maintenance of an alternatively activated macrophage population.