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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.


Psychological RS-induced intestinal permeability and serum histamine levels in female and male C57BL/6 mice. a After experiencing 15 min (n = 6/sex), 30 min (n = 6/male, n = 12/female), and 1 h (n = 5/sex) of restraint stress (RS), females exhibited a statistically significant increase in serum histamine (t-test; p<0.05), as measured by ELISA, compared to males. b Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in RS animals; original magnification, ×20, bar = 100 μM, inset; ×100, bar = 20 μM. c Distal ileum harvested after RS demonstrated increased permeability for both females and males, compared to baseline (n = 3–4/sex). After RS, female intestinal permeability was 0.0223 ng cm2/h and male intestinal permeability was 0.0137 ng cm2/h. d Serum corticosterone increased similarly in male and female mice after 30 min RS (n = 6/male, n = 12/female). e Serum estradiol decreased in female mice after 30 min of RS (n = 6/male, n = 12/female). f Serum testosterone levels were similar in males before and after RS (n = 6). Values represent mean ± SE, *P < 0.05, **P<0.01 vs. other treatments
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Fig2: Psychological RS-induced intestinal permeability and serum histamine levels in female and male C57BL/6 mice. a After experiencing 15 min (n = 6/sex), 30 min (n = 6/male, n = 12/female), and 1 h (n = 5/sex) of restraint stress (RS), females exhibited a statistically significant increase in serum histamine (t-test; p<0.05), as measured by ELISA, compared to males. b Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in RS animals; original magnification, ×20, bar = 100 μM, inset; ×100, bar = 20 μM. c Distal ileum harvested after RS demonstrated increased permeability for both females and males, compared to baseline (n = 3–4/sex). After RS, female intestinal permeability was 0.0223 ng cm2/h and male intestinal permeability was 0.0137 ng cm2/h. d Serum corticosterone increased similarly in male and female mice after 30 min RS (n = 6/male, n = 12/female). e Serum estradiol decreased in female mice after 30 min of RS (n = 6/male, n = 12/female). f Serum testosterone levels were similar in males before and after RS (n = 6). Values represent mean ± SE, *P < 0.05, **P<0.01 vs. other treatments

Mentions: To determine if the heightened MC responses and pathophysiology exhibited in female mice was specific to the IgE-dependent PSA model, we also measured MC responses (through serum histamine levels) between males and females in a non-IgE-dependent model of psychological RS. Female and male mice were subjected to short periods (15 min, 30 min, 1 h) of RS, after which serum histamine was measured. Restraint stress induced an elevation in serum histamine that was greater in female mice as compared to male mice, most notably at the 15-min time point (101.6 ± 9.906 vs. 52.39 ± 3.086, F(1,44) = 10.62, p =0.0022 for sex effect, F(3,44) = 13.1, p < 0.0001 for time effect) (Fig. 2a). Toluidine blue staining of intestinal mesentery confirmed that RS led to MC degranulation in both male and female mice (Fig. 2b). Intestinal permeability, a MC-dependent pathophysiologic response to RS, was measured on Ussing chambers following 1 h of RS and revealed similar findings to serum histamine in that female mice exhibited greater RS-induced intestinal permeability compared with males (F(1,9) = 6.563, p = 0.0306 for sex effect, F(1,9) = 57.03, p < 0.0001 for stress effect; Fig. 2c). Corticosterone, the main glucocorticoid involved in stress responses in rodents, was similarly elevated in male and female mice after RS demonstrating a similar activation of the hypothalamic-pituitary-adrenal axis (HPA) response induced by RS in both sexes (F(1,30) = 61.5, p < 0.0001 for stress effect; Fig. 2d). Because previous studies have shown that stress can alter the secretion of sex steroids by interfering with the hypothalamic pituitary-gonadal axis, we determined whether serum concentrations of estradiol or testosterone differed between male and female mice in response to RS. As expected, serum estradiol was higher in female mice compared with male mice under control, non-stressed conditions (Fig. 2e). However, restraint stress reduced serum estradiol in female mice which was in line with previously published work [34]. However, serum estradiol levels remained unaltered when measured at 1 h after RS in male mice (F(1,28) = 4.629, p = 0.0402 for interaction; Fig. 2e). Also comparable to previous studies [35], testosterone levels were not reduced in males in response to restraint stress (Fig. 2f). Serum testosterone measurements were below the limit of detection for female mice in our experiments (data not shown). Together, results from the PSA and RS models indicate that female mice display heightened MC activation in response to diverse immunological and psychological stressors which was associated with more severe MC-associated clinical and tissue pathophysiology.Fig. 2


Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress
Psychological RS-induced intestinal permeability and serum histamine levels in female and male C57BL/6 mice. a After experiencing 15 min (n = 6/sex), 30 min (n = 6/male, n = 12/female), and 1 h (n = 5/sex) of restraint stress (RS), females exhibited a statistically significant increase in serum histamine (t-test; p<0.05), as measured by ELISA, compared to males. b Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in RS animals; original magnification, ×20, bar = 100 μM, inset; ×100, bar = 20 μM. c Distal ileum harvested after RS demonstrated increased permeability for both females and males, compared to baseline (n = 3–4/sex). After RS, female intestinal permeability was 0.0223 ng cm2/h and male intestinal permeability was 0.0137 ng cm2/h. d Serum corticosterone increased similarly in male and female mice after 30 min RS (n = 6/male, n = 12/female). e Serum estradiol decreased in female mice after 30 min of RS (n = 6/male, n = 12/female). f Serum testosterone levels were similar in males before and after RS (n = 6). Values represent mean ± SE, *P < 0.05, **P<0.01 vs. other treatments
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Fig2: Psychological RS-induced intestinal permeability and serum histamine levels in female and male C57BL/6 mice. a After experiencing 15 min (n = 6/sex), 30 min (n = 6/male, n = 12/female), and 1 h (n = 5/sex) of restraint stress (RS), females exhibited a statistically significant increase in serum histamine (t-test; p<0.05), as measured by ELISA, compared to males. b Representative photomicrographs of intestinal mesentery from male and female mice stained with toluidine blue showing increased degranulation in RS animals; original magnification, ×20, bar = 100 μM, inset; ×100, bar = 20 μM. c Distal ileum harvested after RS demonstrated increased permeability for both females and males, compared to baseline (n = 3–4/sex). After RS, female intestinal permeability was 0.0223 ng cm2/h and male intestinal permeability was 0.0137 ng cm2/h. d Serum corticosterone increased similarly in male and female mice after 30 min RS (n = 6/male, n = 12/female). e Serum estradiol decreased in female mice after 30 min of RS (n = 6/male, n = 12/female). f Serum testosterone levels were similar in males before and after RS (n = 6). Values represent mean ± SE, *P < 0.05, **P<0.01 vs. other treatments
Mentions: To determine if the heightened MC responses and pathophysiology exhibited in female mice was specific to the IgE-dependent PSA model, we also measured MC responses (through serum histamine levels) between males and females in a non-IgE-dependent model of psychological RS. Female and male mice were subjected to short periods (15 min, 30 min, 1 h) of RS, after which serum histamine was measured. Restraint stress induced an elevation in serum histamine that was greater in female mice as compared to male mice, most notably at the 15-min time point (101.6 ± 9.906 vs. 52.39 ± 3.086, F(1,44) = 10.62, p =0.0022 for sex effect, F(3,44) = 13.1, p < 0.0001 for time effect) (Fig. 2a). Toluidine blue staining of intestinal mesentery confirmed that RS led to MC degranulation in both male and female mice (Fig. 2b). Intestinal permeability, a MC-dependent pathophysiologic response to RS, was measured on Ussing chambers following 1 h of RS and revealed similar findings to serum histamine in that female mice exhibited greater RS-induced intestinal permeability compared with males (F(1,9) = 6.563, p = 0.0306 for sex effect, F(1,9) = 57.03, p < 0.0001 for stress effect; Fig. 2c). Corticosterone, the main glucocorticoid involved in stress responses in rodents, was similarly elevated in male and female mice after RS demonstrating a similar activation of the hypothalamic-pituitary-adrenal axis (HPA) response induced by RS in both sexes (F(1,30) = 61.5, p < 0.0001 for stress effect; Fig. 2d). Because previous studies have shown that stress can alter the secretion of sex steroids by interfering with the hypothalamic pituitary-gonadal axis, we determined whether serum concentrations of estradiol or testosterone differed between male and female mice in response to RS. As expected, serum estradiol was higher in female mice compared with male mice under control, non-stressed conditions (Fig. 2e). However, restraint stress reduced serum estradiol in female mice which was in line with previously published work [34]. However, serum estradiol levels remained unaltered when measured at 1 h after RS in male mice (F(1,28) = 4.629, p = 0.0402 for interaction; Fig. 2e). Also comparable to previous studies [35], testosterone levels were not reduced in males in response to restraint stress (Fig. 2f). Serum testosterone measurements were below the limit of detection for female mice in our experiments (data not shown). Together, results from the PSA and RS models indicate that female mice display heightened MC activation in response to diverse immunological and psychological stressors which was associated with more severe MC-associated clinical and tissue pathophysiology.Fig. 2

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.