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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.


Related in: MedlinePlus

PSA-induced anaphylaxis and serum histamine levels in female and male C57BL/6 mice. a Both male and female mice showed a decrease in body temperature after injection with IgE anti-DNP antibody (10 μg/mouse, i.p.), followed 24 h later with vehicle (PBS i.p., n = 4/sex) or DNP-HSA (500 μg/mouse, i.p., n = 8/sex). Female mice exhibited a trend (p < 0.06); Two-way ANOVA on repeated measures) (p < 0.05 with individual t-tests at each time point) of lower body temperature than male mice after anaphylaxis challenge along with females demonstrating more severe peak temperature drop (b). c Over the 120-min PSA challenge, females exhibited a trend of increased clinical scores of anaphylaxis, compared to males, a difference that was statistically significant around the peak of symptoms at 60 min. d Serum levels of histamine, as measured by ELISA 30 min after DNP (values represent results from one individual experiment with n = 4 animals/sex; results were replicated in three independent experiments) showed that both male and female mice had an increase in histamine, and the increase was greater for females. e Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in DNP-treated animals; original magnification, ×100, bar = 20 μM. f The number of mast cells was similar in female and male mice. Mast cells were counted in five randomly chosen fields per mouse. Values represent mean ± SE. †P < 0.10, *P < 0.05, #P < 0.0001
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Fig1: PSA-induced anaphylaxis and serum histamine levels in female and male C57BL/6 mice. a Both male and female mice showed a decrease in body temperature after injection with IgE anti-DNP antibody (10 μg/mouse, i.p.), followed 24 h later with vehicle (PBS i.p., n = 4/sex) or DNP-HSA (500 μg/mouse, i.p., n = 8/sex). Female mice exhibited a trend (p < 0.06); Two-way ANOVA on repeated measures) (p < 0.05 with individual t-tests at each time point) of lower body temperature than male mice after anaphylaxis challenge along with females demonstrating more severe peak temperature drop (b). c Over the 120-min PSA challenge, females exhibited a trend of increased clinical scores of anaphylaxis, compared to males, a difference that was statistically significant around the peak of symptoms at 60 min. d Serum levels of histamine, as measured by ELISA 30 min after DNP (values represent results from one individual experiment with n = 4 animals/sex; results were replicated in three independent experiments) showed that both male and female mice had an increase in histamine, and the increase was greater for females. e Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in DNP-treated animals; original magnification, ×100, bar = 20 μM. f The number of mast cells was similar in female and male mice. Mast cells were counted in five randomly chosen fields per mouse. Values represent mean ± SE. †P < 0.10, *P < 0.05, #P < 0.0001

Mentions: To investigate whether female and male mice exhibited differences in MC activation, we used a well-characterized MC-dependent model of PSA. Adult male and female mice were sensitized with mouse anti-DNP IgE monoclonal antibody, via i.p. injection and then challenged 24 h later with DNP to induce anaphylaxis. Body temperature, clinical scores, and serum histamine were measured as direct and indirect markers of MC activity. Compared with male mice, female mice exhibited a trend for more severe hypothermia when measured over the 120-min post-PSA induction (F(1,14) = 4.118, p = 0.0619 for sex effect; F(8.112) = 116.5, p < 0.0001 for time effect, interaction: F(8,112) = 5.05, p < 0.0001) while the peak drop in body temperature was significantly greater in females (Δ body temp = −4.53 ± 0.38 °C vs. −6.29 ± 0.45 °C in male and female mice, respectively; p < 0.05) (Fig. 1a, b). There was also a trend for female mice to exhibit more severe clinical symptoms of anaphylaxis, as indicated by increased clinical scores compared with male mice (F(1,14) = 3.239, p = 0.0935 for sex effect, F(13,182) = 29.11, p < 0.0001 for time effect; Fig. 1c). Serum levels of the MC granule mediator histamine, which is responsible for increased vascular permeability and symptoms of anaphylaxis including hyperemia, swelling, and hypothermia [33] were greater (by 1.8-fold) in female mice (2032 ± 64 ng/mL) compared with male mice (1121 ± 67 ng/mL) (F(1,12) = 96.8, p < 0.0001 for sex effect, F(1,12) = 1032, p < 0.0001 for treatment effect, interaction: F(1,12) = 93.7, p < 0.0001; Fig. 1d). To confirm tissue MC degranulation, we evaluated tissue MCs via toluidine blue staining in intestinal mesentery windows. While extensive degranulation was observed in response to PSA, there was no noticeable difference in MC activation patterns, such as extent of degranulation or percentage of MCs degranulated, between males and females (Fig. 1e). In addition, there were comparable numbers of MCs present in the intestinal mesentery of male and female mice, thus suggesting that heightened anaphylactic responses were not a result of increased MC numbers in female mice (Fig. 1f).Fig. 1


Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress
PSA-induced anaphylaxis and serum histamine levels in female and male C57BL/6 mice. a Both male and female mice showed a decrease in body temperature after injection with IgE anti-DNP antibody (10 μg/mouse, i.p.), followed 24 h later with vehicle (PBS i.p., n = 4/sex) or DNP-HSA (500 μg/mouse, i.p., n = 8/sex). Female mice exhibited a trend (p < 0.06); Two-way ANOVA on repeated measures) (p < 0.05 with individual t-tests at each time point) of lower body temperature than male mice after anaphylaxis challenge along with females demonstrating more severe peak temperature drop (b). c Over the 120-min PSA challenge, females exhibited a trend of increased clinical scores of anaphylaxis, compared to males, a difference that was statistically significant around the peak of symptoms at 60 min. d Serum levels of histamine, as measured by ELISA 30 min after DNP (values represent results from one individual experiment with n = 4 animals/sex; results were replicated in three independent experiments) showed that both male and female mice had an increase in histamine, and the increase was greater for females. e Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in DNP-treated animals; original magnification, ×100, bar = 20 μM. f The number of mast cells was similar in female and male mice. Mast cells were counted in five randomly chosen fields per mouse. Values represent mean ± SE. †P < 0.10, *P < 0.05, #P < 0.0001
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Fig1: PSA-induced anaphylaxis and serum histamine levels in female and male C57BL/6 mice. a Both male and female mice showed a decrease in body temperature after injection with IgE anti-DNP antibody (10 μg/mouse, i.p.), followed 24 h later with vehicle (PBS i.p., n = 4/sex) or DNP-HSA (500 μg/mouse, i.p., n = 8/sex). Female mice exhibited a trend (p < 0.06); Two-way ANOVA on repeated measures) (p < 0.05 with individual t-tests at each time point) of lower body temperature than male mice after anaphylaxis challenge along with females demonstrating more severe peak temperature drop (b). c Over the 120-min PSA challenge, females exhibited a trend of increased clinical scores of anaphylaxis, compared to males, a difference that was statistically significant around the peak of symptoms at 60 min. d Serum levels of histamine, as measured by ELISA 30 min after DNP (values represent results from one individual experiment with n = 4 animals/sex; results were replicated in three independent experiments) showed that both male and female mice had an increase in histamine, and the increase was greater for females. e Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in DNP-treated animals; original magnification, ×100, bar = 20 μM. f The number of mast cells was similar in female and male mice. Mast cells were counted in five randomly chosen fields per mouse. Values represent mean ± SE. †P < 0.10, *P < 0.05, #P < 0.0001
Mentions: To investigate whether female and male mice exhibited differences in MC activation, we used a well-characterized MC-dependent model of PSA. Adult male and female mice were sensitized with mouse anti-DNP IgE monoclonal antibody, via i.p. injection and then challenged 24 h later with DNP to induce anaphylaxis. Body temperature, clinical scores, and serum histamine were measured as direct and indirect markers of MC activity. Compared with male mice, female mice exhibited a trend for more severe hypothermia when measured over the 120-min post-PSA induction (F(1,14) = 4.118, p = 0.0619 for sex effect; F(8.112) = 116.5, p < 0.0001 for time effect, interaction: F(8,112) = 5.05, p < 0.0001) while the peak drop in body temperature was significantly greater in females (Δ body temp = −4.53 ± 0.38 °C vs. −6.29 ± 0.45 °C in male and female mice, respectively; p < 0.05) (Fig. 1a, b). There was also a trend for female mice to exhibit more severe clinical symptoms of anaphylaxis, as indicated by increased clinical scores compared with male mice (F(1,14) = 3.239, p = 0.0935 for sex effect, F(13,182) = 29.11, p < 0.0001 for time effect; Fig. 1c). Serum levels of the MC granule mediator histamine, which is responsible for increased vascular permeability and symptoms of anaphylaxis including hyperemia, swelling, and hypothermia [33] were greater (by 1.8-fold) in female mice (2032 ± 64 ng/mL) compared with male mice (1121 ± 67 ng/mL) (F(1,12) = 96.8, p < 0.0001 for sex effect, F(1,12) = 1032, p < 0.0001 for treatment effect, interaction: F(1,12) = 93.7, p < 0.0001; Fig. 1d). To confirm tissue MC degranulation, we evaluated tissue MCs via toluidine blue staining in intestinal mesentery windows. While extensive degranulation was observed in response to PSA, there was no noticeable difference in MC activation patterns, such as extent of degranulation or percentage of MCs degranulated, between males and females (Fig. 1e). In addition, there were comparable numbers of MCs present in the intestinal mesentery of male and female mice, thus suggesting that heightened anaphylactic responses were not a result of increased MC numbers in female mice (Fig. 1f).Fig. 1

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&nbsp;h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1&nbsp;h of restraint stress (RS)) and&nbsp;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 &beta;-hexosaminidase, histamine, tryptase, and TNF-&alpha; 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