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Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biological sex plays a prominent role in the prevalence and severity of a number of important stress-related gastrointestinal and immune-related diseases including IBS and allergy/anaphylaxis. Despite the establishment of sex differences in these diseases, the underlying mechanisms contributing to sex differences remain poorly understood. The objective of this study was to define the role of biological sex on mast cells (MCs), an innate immune cell central to the pathophysiology of many GI and allergic disorders.

Methods: Twelve-week-old C57BL/6 male and female mice were exposed to immunological stress (2 h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1 h of restraint stress (RS)) and temperature, clinical scores, serum histamine, and intestinal permeability (for RS) were measured. Primary bone marrow-derived MCs (BMMCs) were harvested from male and female mice and analyzed for MC degranulation, signaling pathways, mediator content, and RNA transcriptome analysis.

Results: Sexually dimorphic responses were observed in both models of PSA and RS and in primary MCs. Compared with male mice, female mice exhibited increased clinical scores, hypothermia, and serum histamine levels in response to PSA and had greater intestinal permeability and serum histamine responses to RS. Primary BMMCs from female mice exhibited increased release of β-hexosaminidase, histamine, tryptase, and TNF-α upon stimulation with IgE/DNP and A23187. Increased mediator release in female BMMCs was not associated with increased upstream phospho-tyrosine signaling pathways or downstream Ca2+ mobilization. Instead, increased mediator release in female MCs was associated with markedly increased capacity for synthesis and storage of MC granule-associated immune mediators as determined by MC mediator content and RNA transcriptome analysis.

Conclusions: These results provide a new understanding of sexual dimorphic responses in MCs and have direct implications for stress-related diseases associated with a female predominance and MC hyperactivity including irritable bowel syndrome, allergy, and anaphylaxis.

Electronic supplementary material: The online version of this article (doi:10.1186/s13293-016-0113-7) contains supplementary material, which is available to authorized users.

No MeSH data available.


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FcεRI-mediated p-tyrosine expression and Ca2+ mobilization in female and male murine BMMCs. After sensitization with anti-DNP IgE, BMMCs were stimulated with DNP-HSA (62 ng/ml) for 7 min. Results from female and male BMMCs showed no differences in a tyrosine phosphorylation of proteins after FcεRI engagement, b quantification of tyrosine-phosphorylated proteins (n = 4), or Ca2+ influx as indicated by Ca2+ tracings (c) and quantified as the d change in peak fluorescence (n = 3). Values represent mean ± SE
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Fig4: FcεRI-mediated p-tyrosine expression and Ca2+ mobilization in female and male murine BMMCs. After sensitization with anti-DNP IgE, BMMCs were stimulated with DNP-HSA (62 ng/ml) for 7 min. Results from female and male BMMCs showed no differences in a tyrosine phosphorylation of proteins after FcεRI engagement, b quantification of tyrosine-phosphorylated proteins (n = 4), or Ca2+ influx as indicated by Ca2+ tracings (c) and quantified as the d change in peak fluorescence (n = 3). Values represent mean ± SE

Mentions: To determine the mechanisms that led to increased MC degranulation responses in female MCs, we performed Western blotting to measure FcεR1-mediated tyrosine phosphorylation signaling, a critical upstream signaling event in IgE-mediated MC activation [14], in female and male BMMCs. As expected, IgE-FcεR1 cross-linking induced a robust tyrosine phosphorylation of numerous proteins that were increased in response to IgE-DNP treatment. However, P-tyrosine phosphorylation patterns were similar between female and male BMMCs (Fig. 4a, b). We next investigated whether differences existed in downstream MC degranulation signaling events. Specifically, we compared FcεRI-mediated intracellular Ca2+ mobilization responses in male and female BMMCs. Ca2+ release from intracellular endoplasmic reticulum stores and subsequent extracellular Ca2+ entry through store-operated Ca2+ entry (SOCE) channels are major downstream signaling events required for MC granule fusion with the plasma membrane and granule exocytosis [36]. Similar to P-tyrosine data, IgE/DNP induced a robust increase in intracellular Ca2+; however, no differences were observed between male and female BMMCs (Fig. 4c, d). Together, these data suggest that heightened MC degranulation responses in female MCs were not due to differences in upstream receptor-mediated signaling or downstream Ca2+ mobilization mechanisms.Fig. 4


Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress
FcεRI-mediated p-tyrosine expression and Ca2+ mobilization in female and male murine BMMCs. After sensitization with anti-DNP IgE, BMMCs were stimulated with DNP-HSA (62 ng/ml) for 7 min. Results from female and male BMMCs showed no differences in a tyrosine phosphorylation of proteins after FcεRI engagement, b quantification of tyrosine-phosphorylated proteins (n = 4), or Ca2+ influx as indicated by Ca2+ tracings (c) and quantified as the d change in peak fluorescence (n = 3). Values represent mean ± SE
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC5120457&req=5

Fig4: FcεRI-mediated p-tyrosine expression and Ca2+ mobilization in female and male murine BMMCs. After sensitization with anti-DNP IgE, BMMCs were stimulated with DNP-HSA (62 ng/ml) for 7 min. Results from female and male BMMCs showed no differences in a tyrosine phosphorylation of proteins after FcεRI engagement, b quantification of tyrosine-phosphorylated proteins (n = 4), or Ca2+ influx as indicated by Ca2+ tracings (c) and quantified as the d change in peak fluorescence (n = 3). Values represent mean ± SE
Mentions: To determine the mechanisms that led to increased MC degranulation responses in female MCs, we performed Western blotting to measure FcεR1-mediated tyrosine phosphorylation signaling, a critical upstream signaling event in IgE-mediated MC activation [14], in female and male BMMCs. As expected, IgE-FcεR1 cross-linking induced a robust tyrosine phosphorylation of numerous proteins that were increased in response to IgE-DNP treatment. However, P-tyrosine phosphorylation patterns were similar between female and male BMMCs (Fig. 4a, b). We next investigated whether differences existed in downstream MC degranulation signaling events. Specifically, we compared FcεRI-mediated intracellular Ca2+ mobilization responses in male and female BMMCs. Ca2+ release from intracellular endoplasmic reticulum stores and subsequent extracellular Ca2+ entry through store-operated Ca2+ entry (SOCE) channels are major downstream signaling events required for MC granule fusion with the plasma membrane and granule exocytosis [36]. Similar to P-tyrosine data, IgE/DNP induced a robust increase in intracellular Ca2+; however, no differences were observed between male and female BMMCs (Fig. 4c, d). Together, these data suggest that heightened MC degranulation responses in female MCs were not due to differences in upstream receptor-mediated signaling or downstream Ca2+ mobilization mechanisms.Fig. 4

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biological sex plays a prominent role in the prevalence and severity of a number of important stress-related gastrointestinal and immune-related diseases including IBS and allergy/anaphylaxis. Despite the establishment of sex differences in these diseases, the underlying mechanisms contributing to sex differences remain poorly understood. The objective of this study was to define the role of biological sex on mast cells (MCs), an innate immune cell central to the pathophysiology of many GI and allergic disorders.

Methods: Twelve-week-old C57BL/6 male and female mice were exposed to immunological stress (2 h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1 h of restraint stress (RS)) and temperature, clinical scores, serum histamine, and intestinal permeability (for RS) were measured. Primary bone marrow-derived MCs (BMMCs) were harvested from male and female mice and analyzed for MC degranulation, signaling pathways, mediator content, and RNA transcriptome analysis.

Results: Sexually dimorphic responses were observed in both models of PSA and RS and in primary MCs. Compared with male mice, female mice exhibited increased clinical scores, hypothermia, and serum histamine levels in response to PSA and had greater intestinal permeability and serum histamine responses to RS. Primary BMMCs from female mice exhibited increased release of β-hexosaminidase, histamine, tryptase, and TNF-α upon stimulation with IgE/DNP and A23187. Increased mediator release in female BMMCs was not associated with increased upstream phospho-tyrosine signaling pathways or downstream Ca2+ mobilization. Instead, increased mediator release in female MCs was associated with markedly increased capacity for synthesis and storage of MC granule-associated immune mediators as determined by MC mediator content and RNA transcriptome analysis.

Conclusions: These results provide a new understanding of sexual dimorphic responses in MCs and have direct implications for stress-related diseases associated with a female predominance and MC hyperactivity including irritable bowel syndrome, allergy, and anaphylaxis.

Electronic supplementary material: The online version of this article (doi:10.1186/s13293-016-0113-7) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus