Cells In Female Mice Research Articles

An antioxidant and anti-ER stress combination therapy elevates phosphorylation of α-Syn at serine 129 and alleviates post-TBI PD-like pathology in a sex-specific manner in mice

Clinical studies have shown that traumatic brain injury (TBI) increases the onset of Parkinson's disease (PD) in later life by >50%. Oxidative stress, endoplasmic reticulum (ER) stress, and inflammation are the major drivers of both TBI and PD pathologies. We presently evaluated if curtailing oxidative stress and ER stress concomitantly using a combination of apocynin and tert-butylhydroquinone and salubrinal during the acute stage after TBI in mice reduces the severity of late-onset PD-like pathology. The effect of multiple low doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on post-TBI neurodegeneration was also evaluated. The combo therapy elevated the level of phosphorylation at serine 129 (pS129) of α-Syn in the pericontusional cortex of male mice at 72 h post-TBI. Motor and cognitive deficits induced by TBI lasted at least 3 months and the combo therapy curtailed these deficits in both sexes. At 3 months post-TBI, male mice given combo therapy exhibited significantly lesser α-Syn aggregates in the SN and higher TH+ cells in the SNpc, compared to vehicle control. However, the aggregate number was not significantly different between groups of female mice. Moreover, TBI-induced loss of TH+ cells was negligible in female mice irrespective of treatment. The MPTP treatment aggravated PD-like pathology in male mice but had a negligible effect on the loss of TH+ cells in female mice. Thus, the present study indicates that mitigation of TBI-induced oxidative stress and ER stress at the acute stage could potentially reduce the risk of post-TBI PD-like pathology at least in male mice, plausibly by elevating pS129-α-Syn level.

Dietary restriction plus exercise change gene expression of Cxcl12 abundant reticular cells in female mice.

Low energy availability due to excessive exercise lowers bone mass and impairs various physiological functions, including immunity and hematopoiesis. We focused on Cxcl12 abundant reticular (CAR) cells, which are bone marrow mesenchymal stem cells and are essential for the maintenance of hematopoietic and immune cells in bone marrow. We examine the functional changes in CAR cells resulting from dietary restriction combined with exercise. Five-week-old wild-type female mice were divided into an ad libitum group (CON), a 60% dietary restriction group (DR), an ad libitum with exercise group (CON + ex), and a 60% dietary restriction with exercise group (DR + ex). Blood parameters, bone structure parameters, and bone marrow fat volume were evaluated after 5weeks. In addition, bone marrow CAR cells were isolated by cell sorting and analyzed for gene expression by RT-qPCR. Bone mineral density (BMD) was significantly decreased in DR and DR + ex compared to CON and CON + ex. Especially, cortical bone mass and thickness were significantly decreased in DR and DR + ex groups, whereas trabecular bone mass was significantly increased. Bone marrow fat volume was significantly increased in DR and DR + ex groups compared to CON and CON + ex. The number of leukocytes in the blood was significantly decreased in the DR + ex group compared to the other three groups. RT-qPCR showed a significant decrease in gene expression of both Foxc1 and Runx2 in CAR cells of the DR + ex group compared to CON. Dietary restriction combined with exercise promotes CAR cell differentiation into bone marrow adipocyte and suppresses osteoblast differentiation.

In vivo anticancer study of sodium 2‐[(4‐oxidobenzylidene)amino]‐6H‐1,3,4‐thiadiazine‐5‐olate against Ehrlich ascites carcinoma via targeting PI3K/mTOR pathway

Abstract1,3,4‐Thiadiazine‐based components have gained the attention as they afford significant intervention for cancer therapy. We aimed at assessing the in vivo antitumor activity of sodium 2‐[(4‐oxidobenzylidene) amino]‐6H‐1,3,4‐thiadiazine‐5‐c (SOTA) versus Ehrlich ascites carcinoma (EAC) cells in female mice's peritoneal cavity. An advantageous interaction of the test compound with the receptors p53 (2J1X), Caspase‐3 (3KJF), mTOR (3QAR), and PI3K (4JPS) was revealed by the docking study. The in vivo study of the test compound against EAC, equated with the EAC control mice, EAC bearing mice that received the test compound by i.p. injection proven a substantial decrease in the viability of tumor cell by 70%. Treatment with the tested compound increased total antioxidants capacity and decreasing malondialdehyde levels. Also, the apoptotic activity of the test compound was confirmed by up regulation of caspase‐3 and p53 and downregulation of PI3K and mTOR. Through the liver, kidney, and heart function assessments, the examined component has no adverse effects on either of the two organs, which were supported by a histological study. Significant positive and negative associations among variables were discovered, according to our research. Through the induction of apoptosis and antioxidant effects, the test compound show potential anticancer activity against EAC cells. The treatment with SOTA eliminated most of the pathological abnormalities brought on by EAC cells in mice, according to the results of tests on the liver, kidney, and heart as well as the histological investigation. Taking together, the tested compound SOTA is promising chemotherapeutic agent as supported by targeting PI3k/mTOR pathway.

FRI131 Abrogation Of Transglutaminase 2 In Myeloid Cells Ameliorates Angiotensin II Induced Vascular Stiffness In Female Mice

Abstract Disclosure: H. Naz: None. A.R. Aroor: None. A.T. Whaley-Connell: None. J. Guanghong: None. J.L. Hulse: None. C.M. Manrique Acevedo: None. G. Lastra: None. Introduction: Chronic low-grade inflammation and vascular stiffening contribute to cardiovascular disease (CVD) in obese and insulin-resistant women. Under these conditions, inappropriate activation of the renin angiotensin aldosterone system (RAAS) stimulates Transglutaminase 2 (TG2), a ubiquitously expressed enzyme that promotes vascular stiffening and remodeling. Additionally, Th17 cells contribute to CVD development in the setting of RAAS activation. However, it is unclear how TG2 activation mediates maladaptive immune responses associated with vascular stiffening in women. In this study, we hypothesize that TG2 abrogation inhibits Ang II-induced vascular stiffness in females by modulating Th17 immunity. Methods: 12-week-old female mice lacking TG2 expression (MyTG2KO) in myeloid cells, and control littermates (LM) were infused with Ang-II (1.4 mg/kg/day) for 2 weeks (n=4-8 per group). Prior to sacrifice, systolic blood pressure (SBP) was measured by tail-cuff method. Aortic stiffness was assessed by atomic force microscopy of thoracic aorta explants, and TG2 activity was examined by Alexa FluorTM 488 cadaverine. Analysis of Th17 cells in blood, spleen and epididymal fat (epi-fat) was done by flow cytometry. Cytokine bead array was used to measure cytokine levels in serum, RT-PCR was used to analyze cytokines in aortic tissue and TG2 knockdown efficiency in myeloid cells. Immunohistochemistry was used to examine fibrosis in aorta. Results: SBP was decreased in MyTG2KO-Ang-II as compared to LM-Ang-II cohort (129.6±5.6 vs 152.5 ±2 mmHg; p=0.04). TG2 mRNA expression in macrophages was lower in MyTG2KO mice as compared to LM (p=0.002). TG2 activity in aortic tissue increased in LM-Ang-II as compared to LM-saline (p=0.004) but was significantly lower in MyTG2KO-Ang-II mice (p=0.02). Aortic stiffness was lower in MyTG2KO-Ang-II mice relative to LM-Ang-II (4.0±0.6 vs 10.3±2.4 kPa; p=0.02). Compared to LM-Ang-II, MyTG2KO-Ang-II mice also had decreased Th17 lymphocytes (CD4+IL-17A+) in blood (3.5±0.2 vs 5.8 ±0.4 %; p=<0.0001), spleen (4.7±0.4 vs 7.1 ±0.5 %; p=0.004) and epi-fat (4.7±0.6 vs 6.8 ±0.5 %; p=0.02). MyTG2KO-Ang II mice also had significant lower levels of proinflammatory cytokines (TNF-a, IL6, IL17A, INF-g) in serum and mRNA expression of proinflammatory cytokines compared to LM-Ang-II mice and decreased total macrophage infiltration (CD68+) in the aorta. Ang-II treated MyTG2KO mice group also exhibited reduced fibrosis in the aorta relative to LM-Ang-II (p=0.003). Conclusion: The results demonstrate that abrogating TG2 in myeloid cells in female mice substantially reduces blood pressure, proinflammatory cytokines, and Th17 immune responses induced by Ang-II. Our findings have potential clinical implications for the prevention and management of CVD in women. Presentation: Friday, June 16, 2023

Coxsackievirus B3 elicits a sex-specific CD8+ T cell response which protects female mice.

Sex is a significant contributor to the outcome of human infections. Males are frequently more susceptible to viral, bacterial, and fungal infections, often attributed to weaker immune responses. In contrast, a heightened immune response in females enables better pathogen elimination but leaves females more predisposed to autoimmune diseases. Unfortunately, the underlying basis for sex-specific immune responses remains poorly understood. Here, we show a sex difference in the CD8+ T cell response to an enteric virus, Coxsackievirus B3 (CVB3). We found that CVB3 induced expansion of CD8+ T cells in female mice but not in male mice. CVB3 also increased the proportion and number of CD11ahiCD62Llo CD8+ T cells in female mice, indicative of activation. This response was independent of the inoculation route and type I interferon. Using a recombinant CVB3 virus expressing a model CD8+ T cell epitope, we found that the expansion of CD8+ T cells in females is viral-specific and not due to bystander activation. Finally, the depletion of CD8+ T cells, prior to infection, led to enhanced mortality, indicating that CD8+ T cells are protective against CVB3 in female mice. These data demonstrate that CVB3 induces a CD8+ T cell response in female mice and highlight the importance of sex-specific immune responses to viral pathogens.

Substituted Thiazole Derivatives Provide Corrective Anti-tumour and Anti-oxidant Activities against Ehrlich Ascites Carcinoma.

Novel and effective treatments are urgently needed for cancer, which is still the leading cause of death in the world. Biological characteristics linked to thiazole derivatives span a wide range. Thiazole derivatives are used in the creation of medications for therapy as well. The aim of current study is to evaluate the anticancer and antioxidant properties of the newly synthesized thiazole derivatives, compounds 1 and 2, on Ehrlich ascites carcinoma (EAC) cells in female mice. Our findings indicated that thiazole derivatives, compounds 1 and 2 have anticancer activity by elevating the p53 expression and cytochrome c levels in groups treated with compounds 1 and 2 compared to the positive control group. Furthermore, thiazole derivatives compounds 1 and 2 showed a potent antioxidant effect by increasing enzymatic antioxidants, catalase (CAT) activity, and non-enzymatic antioxidants, GSH, and lowering Malondialdehyde (MDA) in hepatic and renal tissues of treated groups. Additionally, the target compounds were capable of providing corrective effects against EAC-induced biochemical and histopathological changes without harmful side effects. CONCLUSION: The target studied thiazol derivatives compounds were capable of providing corrective effects against EAC-induced without harmful side effects.

Coxsackievirus B3 elicits a protective, sex-specific CD8 +T cell response in female mice

Abstract Sex is a significant contributor to the outcome of human infections. Males are frequently more susceptible to viral, bacterial, and fungal infections, often attributed to weaker immune responses. In contrast, a heightened immune response in females enables better pathogen elimination but leaves females more predisposed to autoimmune diseases. Unfortunately, the underlying basis for sex-specific immune responses remains poorly understood. Here, we show a sex difference in the CD8 +T cell response to an enteric virus, Coxsackievirus B3 (CVB3). We found that CVB3 induced expansion of CD8 +T cells in female Ifnar −/−mice but not in male Ifnar −/−mice. Using a recombinant CVB3 virus expressing a model CD8 +T cell epitope, we found that the expansion of CD8 +T cells is viral-specific and not due to bystander activation. CVB3 also increased the proportion and number of CD11a hiCD62L loCD8 +T cells in female mice, indicative of T cell activation. However, CD8 +T cell activation is dampened by the primary male sex hormone, testosterone, in male mice. Finally, using antibodies to deplete CD8 +T cells, we found that CD8 +T cells are required to limit CVB3-induced disease in female mice. These data demonstrate that CVB3 induces a sex-dependent CD8 +T cell response that is important for viral clearance in female mice and highlights the importance of sex differences in the immune response to viral pathogens. This work was funded by a K01 DK110216, R03 DK124749, and a Biomedical Research Grant from the Indiana Clinical and Translational Sciences Institute to CMR.

Profiling of innate and adaptive immune cells during influenza virus infection reveals sex bias in invariant natural killer T (iNKT) cells.

Influenza A virus (IAV) infection leads to significant morbidity and mortality. Biological sex influences the immune responses to IAV infection, resulting in higher mortality in women of reproductive age. Previous studies revealed increased activation of T and B cells in female mice after IAV infection, but extensive analysis of sex differences in both innate and adaptive immune cells over time is lacking. Invariant natural killer T (iNKT) cells are fast-reacting forces and modulators of immune responses that are important to IAV immunity, but it is not known if the presence and function of iNKT cells differ between females and males. The aim of this study was to determine immunological mechanisms that contribute to the increased disease severity in female mice during IAV infection. Female and male mice were infected with mouse-adapted IAV and monitored for weight loss and survival. Immune cell populations and cytokine expression in bronchoalveolar lavage fluid, lung, and mediastinal lymph node were determined at three time points after infection using flow cytometry and ELISA. The results reveal increased severity and mortality in adult female mice compared to age-matched males. Female mice show larger increases in innate and adaptive immune cell populations and cytokine production in lung compared to mock on Day 6 postinfection. On Day 9 postinfection, female mice express higher numbers of iNKT cells in lung and liver compared to males. This comprehensive analysis of immune cells and cytokines over time following IAV infection reveals increased leukocyte expansion and stronger proinflammatory cytokine responses in female mice during disease initiation. Furthermore, this is the first study to report a sex bias in iNKT cell populations after IAV infection. The data suggests that the process of recovery from IAV-induced airway inflammation is associated with increased expansion of several different iNKT cell subpopulations in female mice.

VMHvllCckar cells dynamically control female sexual behaviors over the reproductive cycle

Sexual behavior is fundamental for the survival of mammalian species and thus supported by dedicated neural substrates. The ventrolateral part of ventromedial hypothalamus (VMHvl) is an essential locus for controlling female sexual behaviors, but recent studies revealed the molecular complexity and functional heterogeneity of VMHvl cells. Here, we identify the cholecystokinin A receptor (Cckar)-expressing cells in the lateral VMHvl (VMHvllCckar) as the key controllers of female sexual behaviors. The inactivation of VMHvllCckar cells in female mice diminishes their interest in males and sexual receptivity, whereas activating these cells has the opposite effects. Female sexual behaviors vary drastically over the reproductive cycle. Invivo recordings reveal reproductive-state-dependent changes in VMHvllCckarcell spontaneous activity and responsivity, with the highest activity occurring during estrus. These invivo response changes coincide with robust alternation in VMHvllCckar cell excitability and synaptic inputs. Altogether, VMHvllCckar cells represent a key neural population dynamically controlling female sexual behaviors over the reproductive cycle.

NFAT5 contributes to the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and decrease of T regulatory cells in female mice

Multiple sclerosis disproportionally affects women. The present study was undertaken to determine whether NFAT5 contributed to the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, and if it did, whether the impact was sex associated. NFAT5 haplodeficiency reduced the disease severity only in female mice. This effect was associated with significant increases in frequency of T regulatory (Treg) cells in the CNS (from 1.45 ± 0.39% to 3.73 ± 0.94%) and spleen from (0.31 ± 0.06% to 0.94 ± 0.29%) without significantly affecting the CNS CD4+ subsets frequency. NFAT5 haploinsufficiency also significantly reduced the frequency of CD11c+CD8α+ dendritic cells in the female CNS. However, increase of their frequency in the CNS via intraperitoneal Flt3L injection at peak EAE had no significant effect on the disease courses. We conclude that NFAT5 contributes to pathogenesis of EAE in female mice, possibly through decreasing tissue specific frequency of Treg cells.

Sex-specific differences in direct osteoclastic versus indirect osteoblastic effects underlay the low bone mass of Pannexin1 deletion in TRAP-expressing cells in mice

Pannexin1 (Panx1) is a hemichannel-forming protein that participates in the communication of cells with the extracellular space. To characterize the role of osteoclastic Panx1 on bone, Panx1fl/fl;TRAP-Cre (Panx1ΔOc) mice were generated, and compared to Panx1fl/fl littermates at 6 weeks of age. Total and femoral BMD was ~20% lower in females and males whereas spinal BMD was lower only in female Panx1ΔOc mice. μCT analyses showed that cortical bone of the femoral mid-diaphysis was not altered in Panx1ΔOc mice. In contrast, cancellous bone in the distal femur and lumbar vertebra was significantly decreased in both female and male Panx1ΔOc mice compared to Panx1fl/fl controls and was associated with higher osteoclast activity in female Panx1ΔOc mice, with no changes in the males. On the other hand, vertebral bone formation was decreased for both sexes, resulting from lower mineral apposition rate in the females and lower mineralizing surface in the males. Consistent with an osteoclastic effect in female Panx1ΔOc mice, osteoclast differentiation with RANKL/M-CSF and osteoclast bone resorbing activity in vitro were higher in female, but not male, Panx1ΔOc mice, compared to Panx1fl/fl littermates. Surprisingly, although Panx1 expression was normal in bone marrow stromal-derived osteoblasts from male and female Panx1ΔOc mice, mineral deposition by male (but not female) Panx1ΔOc osteoblasts was lower than controls, and it was reduced in male Panx1fl/fl osteoblasts when conditioned media prepared from male Panx1ΔOc osteoclast cultures was added to the cell culture media. Thus, deletion of Panx1 in TRAP-expressing cells in female mice leads to low bone mass primarily through a cell autonomous effect in osteoclast activity. In contrast, our evidence suggests that changes in the osteoclast secretome drive reduced osteoblast function in male Panx1ΔOc mice, resulting in low bone mass.

Polymorphic estrogen receptor binding site causes Cd2-dependent sex bias in the susceptibility to autoimmune diseases

Complex autoimmune diseases are sexually dimorphic. An interplay between predisposing genetics and sex-related factors probably controls the sex discrepancy in the immune response, but the underlying mechanisms are unclear. Here we positionally identify a polymorphic estrogen receptor binding site that regulates Cd2 expression, leading to female-specific differences in T cell-dependent mouse models of autoimmunity. Female mice with reduced Cd2 expression have impaired autoreactive T cell responses. T cells lacking Cd2 costimulation upregulate inhibitory Lag-3. These findings help explain sexual dimorphism in human autoimmunity, as we find that CD2 polymorphisms are associated with rheumatoid arthritis and 17-β-estradiol-regulation of CD2 is conserved in human T cells. Hormonal regulation of CD2 might have implications for CD2-targeted therapy, as anti-Cd2 treatment more potently affects T cells in female mice. These results demonstrate the relevance of sex-genotype interactions, providing strong evidence for CD2 as a sex-sensitive predisposing factor in autoimmunity.

Low-level laser treatment promotes skin wound healing by activating hair follicle stem cells in female mice.

The aim of the study was to explore the effect and mechanism of a low-level laser on hair follicle stem cells in full-thickness skin wound healing in mice. Full-thickness skin defects were generated by a 5-mm punch biopsy tool on the backs of depilated C57/BL6N mice, which were randomly divided thereafter into a low-dose laser treatment group (LLLT-Low), a high-dose laser treatment group (LLLT-High), and a control group (control). From the day of modeling to the day before the skin samples were taken, the wound area and wound edge of the mice in the LLLT-Low and LLLT-High groups were irradiated with a laser comb every 24h, and the energy density was 1J/cm2 and 10J/cm2, respectively. The control group was irradiated with an ordinary fluorescent lamp. At 0, 3, 5, 10, and 14days after modeling, pictures of each wound were taken, and the percent wound closure was analyzed. At 3, 5, 10, and 14days after modeling, the samples were observed by hematoxylin and eosin (HE) and immunofluorescence (IF) staining. Whole transcriptome sequencing (RNA-Seq) was performed on the samples on day 10. Gene Ontology (GO) analysis was performed, and the results were validated by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). The analysis of the percent of wound closure showed that healing was accelerated (significantly from 5 to 10days) in the LLLT-Low group, but there was no clear change in the LLLT-High group. HE staining showed that the LLLT-Low group had an increasing number of hair follicles and a tendency to migrate to the center of the wound. There was no significant increase in the number of hair follicles and no obvious migration in the LLLT-High group. Immunofluorescence staining showed that the total number of CK15 + hair follicle stem cells in the LLLT-Low group was higher than that in the control group and LLLT-High group at all time points. The number and farthest migration distance of CK15 + hair follicle stem cells increased significantly with time, and after 5days, they were significantly higher than those in the control group and LLLT-High group. RNA-Seq and Western blot analysis showed that the expression of related genes in hair follicle stem cells, including CK15, in the LLLT-Low group was upregulated. GO analysis and ELISA showed that the expression of many cytokines, represented by IL34, in the LLLT-Low group was upregulated. Low-level laser treatment can promote the proliferation, differentiation, and migration of CK15 + hair follicle stem cells by upregulating the cytokine IL34, thereby promoting skin wound healing in mice.

Content of apoptosis factors and self-organization processes in the mitochondria of heart cells in female mice C57BL/6 under growth of melanoma B16 / F10 linked with comorbid pathology

The aim is to study some mechanisms of regulation of apoptosis and self-organization in the mitochondria in the heart cells in female mice during the growth of experimental melanoma B16/ F10 linked with chronic neurogenic pain as comorbid pathology.

The state of apoptosis factor system in mitochondria of skin and tumor cells in standard and stimulated growth of B16/F10 melanoma in female C57BL/6 mice

Purpose of the study. Studying the dynamics of factors of apoptosis in mitochondria of skin and tumors cells in female mice with melanoma growth stimulated by chronic neurogenic pain. Material and methods. The study included female С57ВL/6 mice (n=56) with a model of chronic neurogenic pain (CNP) produced by the bilateral sciatic nerve ligation and with transplanted B16/F10 melanoma. After 1–3 weeks of the tumor growth, levels of cytochrome C, caspase‑9 (Bioscience, Austria), Bcl‑2 (Thermo Fisher Scientific, Austria), and AIF (RayBiotech, USA) were determined by ELISA, and levels of calcium (Са2+) were determined by the Arsenazo III method (Abris+, Russia) in mitochondria of tumors cells and skin not affected by the tumor growth. Results. In the CNP state, mitochondria of the skin cells showed a significant increase in Са2+ by 96.7 times, AIF by 1.4 times and Bcl‑2 by 5.9 times, while caspase‑9 decreased by 2.6 times, compared to the levels in intact mice. In the CNP‑stimulated melanoma growth, mitochondria of cells of the skin not affected by the tumor growth demonstrated a decrease in all studied indices, except caspase‑9 – its levels increased by 4.6 times after 3 weeks of the tumor growth. In mitochondria of the tumor cells within 1–3 weeks, levels of Са2+ decreased over time by 37.2–96.1 times, respectively, AIF by 49.4–2.0 times, Bcl‑2 by 3.0–1.5 times, cytochrome C by 15.3–8.8 times, and caspase‑9 increased by 1.7–4.4 times compared with the level in animals with pain. Conclusions. In general, the growth of melanoma stimulated by chronic pain and the standard melanoma growth were characterized by the opposite dynamics of levels of apoptosis factor both in mitochondria of skin cells and in mitochondria of tumor cells, with the exception of cytochrome C. Mitochondria of melanoma cells and of the unchanged skin have a similar tendency to change the levels of apoptosis factors, which may indicate their functioning in the conditions of the mitochondrial network at the level of one organ. Mitochondria of tumor cells provide the anti‑apoptotic state of the tumor itself and of the skin not affected by the malignant process, probably due to the stress state of the skin.

Biological sex, not reproductive cycle, influences peripheral blood immune cell prevalence in mice.

Traditionally the female sex, compared with the male sex, has been perceived as having greater variability in many physiological traits, including within the immune system. We investigated effects of biological sex and the female reproductive cycle on numbers of circulating leukocytes in C57BL/6J mice. We show that biological sex, but not female reproductive cyclicity, has a significant effect on peripheral blood immune cell prevalence and variability, and that sex differences were not consistent amongst common inbred laboratory mouse strains. We found that male C57BL/6J mice, compared with female mice, have greater variability in peripheral blood immunophenotype, and that this was influenced by body weight. We created summary tables for researchers to facilitate experiment planning and sample size calculations for peripheral immune cells that consider the effects of biological sex. Immunophenotyping (i.e. quantifying the number and types of circulating leukocytes) is used to characterize immune changes during health and disease, and in response to pharmacological and other interventions. Despite the importance of biological sex in immune function, there is considerable uncertainty amongst researchers as to the extent to which biological sex or the female reproductive cycle influence blood immunophenotype. We quantified circulating leukocytes by multicolour flow cytometry in young C57BL/6J mice and assessed the effects of the reproductive cycle, biological sex, and other experimental and biological factors on data variability. We found that there are no significant effects of the female reproductive cycle on the prevalence of peripheral blood B cells, NK cells, CD4+ T cells, CD8+ T cells, monocytes, or neutrophils. Immunophenotype composition and variability do not significantly change between stages of the female reproductive cycle. There are, however, sex-specific differences in immune cell prevalence, with fewer monocytes, neutrophils, and NK cells in female mice. Surprisingly, immunophenotype is more variable in male mice, and weight is a significant contributing factor. We provide tools for researchers to perform a priori sample size calculations for two-group and factorial analyses. We show that immunophenotype varies between inbred mouse strains, and that using equal sample sizes of male and female mice is not always appropriate for within-sex evaluations of immune cell populations in peripheral blood.

In utero exposure to diesel exhaust particles, but not silica, alters post-natal immune development and function

Our understanding of the impact of in utero exposure to PM on post-natal immune function and the subsequent response to PM exposure is limited. Similarly, very few studies have considered the effect of exposure to PM from different sources. Thus, the aim of this study was to examine how in utero exposure to PM from different sources effects the post-natal response to pro-inflammatory and immune stimuli. C56BL/6J pregnant mice were exposed intranasally on gestational day (E)7.5, E12.5 and E17.5–50 μg of diesel exhaust particles (DEP), silica or saline. At 4-weeks post-natal age, sub-groups of male and female mice were exposed intranasally to 50 μg of DEP or saline. Lung inflammatory responses were assessed 6 h later by quantifying inflammatory cells and cytokine production (MCP-1, MIP-2, IL-6). In separate groups of mice, the spleen was harvested to quantify B and T cell populations. Splenocytes were isolated and exposed to lipopolysaccharide or poly I:C for assessment of cytokine production. Exposure to DEP in utero decreased %CD1dhighCD5+ B cells in female mice and IFN-γ production by splenocytes in both sexes. Male mice had elevations in macrophage and lymphocyte numbers in response to DEP whereas female mice only had elevated IL-6, MCP-1 and MIP-2 levels. In utero exposure to silica had no effect on these measures. These data suggest that in utero exposure to PM alters immune development and post-natal immune function. This response is dependent on the source of PM, which has implications for understanding the community health effects of exposure to air pollution.

Genotoxic effects of drospirenone and ethinylestradiol in human breast cells (in vitro) and bone marrow cells of female mice (in vivo)

Estrogen and progesterone congeners as found in various oral contraceptive formulations have been implicated as the cause of cancer in sex and tissue-specific targets. The mechanism of carcinogenesis by sex steroids is still debatable. In this study, we evaluated the genotoxicity induced by two components of one of the commonly used oral contraceptive formulation; drospirenone and ethinylestradiol in human breast cells (MCF-7) in vitro and in bone marrow cells of female mice in vivo. DNA damage was assessed by alkaline comet assay. Both of the drugs produced DNA damage in human breast cells at exposure concentrations which are about 100-fold and above than normally found in human blood after their lowest recommended doses. The DNA damage was produced only after metabolic activation by mice liver S-9 fraction in both cases. The co-exposure with both the compounds at median exposure levels resulted in potentiation of DNA damage. In bone marrow cells of adult female mice, both the compounds produced DNA damage at human equivalent doses after exposure was carried out repeatedly for approximately one estrus cycle (5 days). The co-administration with the compounds resulted in potentiation of DNA damage as indicated by percent tail DNA in comet assay. Thus it is concluded that drospirenone and ethinylestradiol cause DNA damage in certain target specific tissue (mammary epithelial cells) and in female bone marrow cells. The co-exposure with drospirenone and ethinylestradiol results in potentiation of genotoxicity which may pose a threat of cancer development in women taking these drugs for long periods.

Research Highlights

Research Highlights

Acute Psychosocial Stress Inhibits LH Pulsatility and Kiss1 Neuronal Activation in Female Mice.

Psychosocial stress, such as isolation and restraint, disrupts reproductive neuroendocrine activity. Here we investigate the impact of psychosocial stress on luteinizing hormone (LH) pulses and gene expression and neuronal activation within Rfrp and Kiss1 cells in female mice. Mice were ovariectomized (OVX) and handled daily to habituate to the tail-tip blood collection procedure. Blood was collected every 5 minutes for 180 minutes for measurement of LH. After 90 minutes, stress animals were placed into restraint devices and isolated to new cages. No-stress control animals remained in their home cages. LH pulses occurred at regular intervals during the entire 180-minute sampling period in controls. In contrast, stress induced a rapid and robust suppression of pulsatile LH secretion. Stress reduced the frequency of pulses by 60% and diminished basal LH levels by 40%; pulse amplitude was unaffected. In a separate cohort of OVX females, brains were collected after 45, 90, or 180 minutes of stress or in no-stress controls. At all time points, stress induced a potent decrease in arcuate Kiss1 neuronal activation, using cfos induction as a marker, with a 50% to 60% suppression vs control levels, whereas Rfrp and cfos coexpression in the dorsal-medial nucleus was elevated after 45 minutes of stress. Although arcuate Kiss1 gene expression remained stable, Rfrp expression was elevated 20% after 180 minutes of stress. These findings demonstrate rapid suppression of LH pulsatile secretion by psychosocial stress, associated with reduced cfos induction in Kiss1 neurons and time-dependent increases in Rfrp neuronal activation and messenger RNA.