Project description:Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system, representing the leading cause of non-traumatic neurologic disease in young adults. This disease is three times more common in women, yet more severe in men, but the mechanisms underlying these sex differences remain largely unknown. MS is initiated by autoreactive T helper cells, but CNS-resident and CNS-infiltrating myeloid cells are the key proximal effector cells regulating disease pathology. We have previously shown that genetic ablation of p38α MAP kinase broadly in the myeloid lineage is protective in the autoimmune model of MS, experimental autoimmune encephalomyelitis (EAE), but only in females, and not males. To precisely define the mechanisms responsible, we used multiple genetic approaches and bone marrow chimeras to ablate p38α in microglial cells, peripheral myeloid cells, or both. Deletion of p38α in both cell types recapitulated the previous sex difference, with reduced EAE severity in females. Unexpectedly, deletion of p38α in the periphery was protective in both sexes. In contrast, deletion of p38α in microglia exacerbated EAE in males only, revealing opposing roles of p38α in microglia vs. periphery. Bulk transcriptional profiling revealed that p38α regulated the expression of distinct gene modules in male vs. female microglia. Single-cell transcriptional analysis of WT and p38α-deficient microglia isolated from the inflamed CNS revealed a diversity of complex microglial states, connected by distinct convergent transcriptional trajectories. Microglial p38α deficiency in males resulted in enhanced transition from homeostatic to disease-associated microglial states, with the downregulation of regulatory genes such as Atf3, Rgs1, Socs3, and Btg2, and increased expression of inflammatory genes such as Cd74, Trem2, and MHC class I and II genes. Taken together, these results reveal the presence of a p38α-dependent male-specific molecular pathway in microglia that is protective in CNS autoimmunity, suggesting that autoimmunity in males and females is driven by distinct cellular and molecular pathways, thus informing the design of novel future sex-specific therapeutic approaches.

Project description:Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system, representing the leading cause of non-traumatic neurologic disease in young adults. This disease is three times more common in women, yet more severe in men, but the mechanisms underlying these sex differences remain largely unknown. MS is initiated by autoreactive T helper cells, but CNS-resident and CNS-infiltrating myeloid cells are the key proximal effector cells regulating disease pathology. We have previously shown that genetic ablation of p38α MAP kinase broadly in the myeloid lineage is protective in the autoimmune model of MS, experimental autoimmune encephalomyelitis (EAE), but only in females, and not males. To precisely define the mechanisms responsible, we used multiple genetic approaches and bone marrow chimeras to ablate p38α in microglial cells, peripheral myeloid cells, or both. Deletion of p38α in both cell types recapitulated the previous sex difference, with reduced EAE severity in females. Unexpectedly, deletion of p38α in the periphery was protective in both sexes. In contrast, deletion of p38α in microglia exacerbated EAE in males only, revealing opposing roles of p38α in microglia vs. periphery. Bulk transcriptional profiling revealed that p38α regulated the expression of distinct gene modules in male vs. female microglia. Single-cell transcriptional analysis of WT and p38α-deficient microglia isolated from the inflamed CNS revealed a diversity of complex microglial states, connected by distinct convergent transcriptional trajectories. Microglial p38α deficiency in males resulted in enhanced transition from homeostatic to disease-associated microglial states, with the downregulation of regulatory genes such as Atf3, Rgs1, Socs3, and Btg2, and increased expression of inflammatory genes such as Cd74, Trem2, and MHC class I and II genes. The effect of p38α deficiency was divergent in female microglia, with an upregulation of a small subset of inflammatory genes that overlapped with males, but mostly a unique transcriptional profile that also included an upregulation of potentially tissue reparative genes. Taken together, these results reveal the presence of a p38α-dependent sex-specific molecular pathway in microglia that is protective in CNS autoimmunity in males, suggesting that autoimmunity in males and females is driven by distinct cellular and molecular pathways, thus informing the design of novel future sex-specific therapeutic approaches.

Project description:PURPOSE: Estrogen receptor alpha (ERα, encoded by ESR1) is a well-characterized transcription factor expressed in more than 75% of breast tumors and is the key biomarker to direct endocrine therapies. On the other hand, much less is known about estrogen receptor beta (ERβ, encoded by ESR2) and its importance in cancer. Previous studies had some disagreement, however most reports suggested a more favorable prognosis for patients with high ESR2 expression. METHODS: To add further clarity to ESR2 in breast cancer, we interrogated a large population-based cohort of primary breast tumors (n=3207) from the SCAN-B study (Sweden Cancerome Analysis Network—Breast [SCAN-B], ClinicalTrials.gov identifier: NCT02306096). Spearman rank correlation was used to determine correlations between expression of ESR1 and ESR2. Kruskal-Wallis non-parametric test and Wilcoxon rank sum test were used to compare and plot expression of the ESR1 and ESR2 genes in various clinical groups such as PAM50 subtype and age groups in both the SCAN-B and TCGA cohorts. Transformed ESR2 expression data was divided into tertiles, with the first tertile defined as ESR2-high, and the bottom two tertiles at ESR2-low. Mann Whitney U test and Fisher’s exact test were used to evaluate significant differences in the clinicopathological variables for the ESR2-high and ESR2-low groups. Survival analysis was performed by Kaplan-Meier and Cox regression survival analyses that included a median follow-up of 6.2 years (IQR = 2.2). RESULTS: Using RNA-seq data, we found that ESR2 is expressed at low levels overall with a slight inverse correlation to ESR1 expression (Spearman R = -0.18, p = 2.2e-16), and highest ESR2 expression in the basal- and normal-like PAM50 subtypes. ESR2-high tumors had favorable overall survival (p=0.006), particularly in subgroups receiving endocrine therapy (p=0.03) and in triple-negative breast cancer (p=0.01). These results were generally robust in multivariable analyses accounting for patient age, size, node status, and grade. Gene modules consistent with immune response were associated to ESR2-high tumors. CONCLUSIONS: Taken together, our results indicate that ESR2 is generally expressed at low levels in breast cancer but associated with improved overall survival and may be related to immune response modulation.

Dataset Information

Expression data from BMDM

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets