Natural killer cell activity and sex hormone levels in mastopathy

Sex-related Differences in Inflammatory Bowel Diseases: The Potential Role of Sex Hormones

Inflammatory bowel disease (IBD), characterized by chronic inflammation of the gastrointestinal tract, is a global health care problem. Compelling evidence shows sex differences regarding the prevalence, pathophysiology, clinical presentation, and treatment outcome of IBD. Sex hormones, including estrogen, progesterone, and androgen, have been proposed to have a role in the pathogenesis of sexual dimorphism in IBD. Clinical and experimental data support the modulatory effects of sex hormones on various clinical characteristics of the disease, including intestinal barrier dysfunction and mucosal immune activation. Additionally, the potential role of sex hormones in the modulation of gut microbiota is attracting increasing attention. Here, we discuss the sex dimorphic disease profile and address the potential mechanisms involved in the sex-specific pathogenesis of IBD. Improved understanding of these sex differences in the clinic could improve the knowledge of patients with IBD with heterogeneous disease profiles.

Effects of forest environment (Shinrin-yoku/Forest bathing) on health promotion and disease prevention -the Establishment of "Forest Medicine"

Humans have enjoyed forest environments for ages because of the quiet atmosphere, beautiful scenery, mild climate, pleasant aromas, and fresh, clean air. In Japan, since 2004, serial studies have been conducted to investigate the effects of forest environments (Forest bathing/Shinrin-yoku) on human health. My research team has established a new medical science called Forest Medicine. The Forest Medicine is a new interdisciplinary science, belonging to the categories of alternative medicine, environmental medicine and preventive medicine, which studies the effects of forest environments (Forest bathing/Shinrin-yoku) on human health. It has been reported that Forest bathing/Shinrin-yoku has the following beneficial effects on human health:1 Shinrin-yoku increases human natural killer (NK) activity, the number of NK cells, and the intracellular levels of anti-cancer proteins, suggesting a preventive effect on cancers. 2 Shinrin-yoku reduces blood pressure and heart rate showing preventive effect on hypertension and heart diseases. 3 Shinrin-yoku reduces stress hormones, such as urinary adrenaline and noradrenaline and salivary/serum cortisol contributing to stress management. 4 Shinrin-yoku increases the activity of parasympathetic nerves and reduces the activity of sympathetic nerves to stabilize the balance of autonomic nervous system. 5 Shinrin-yoku improve sleep. 6 Shinrin-yoku increases the levels of serum adiponectin and dehydroepiandrosterone sulfate. 7 In the Profile of Mood States (POMS) test, Shinrin-yoku reduces the scores for anxiety, depression, anger, fatigue, and confusion, and increases the score for vigor, showing preventive effects on depression. 8 Shinrin-yoku may apply to rehabilitation medicine 9 Shinrin-yoku in city parks also has benefits on human health. 10 Shinrin-yoku may have preventive effect on COVID-19 by boosting immune function and by reducing mental stress.Taken together, these findings suggest that Shinrin-yoku may have potential preventive effects on non-communicable diseases.

The role of estradiol in the immune response against COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen agent causing coronavirus disease (COVID)-19, which was declared a global pandemic in 2020. The spike protein of this virus and the angiotensin-converter enzyme (ACE)-2 in host cells in humans play a vital role in infection and in COVID-19 pathogenesis. Estradiol is known to modulate the actions of immune cells, and, therefore, the antiviral mechanisms of these cells could also be modified by this hormone stimulus. Even though estradiol is not considered a protective factor, evidence shows that women with high levels of this hormone have a lower risk of developing severe symptoms and an even a lower incidence of death. Understanding the mechanism of action of estradiol with regard to viral infections and COVID-19 is essential for the improvement of therapeutic strategies. This review aims to describe the effects that estradiol exerts on immune cells during viral infections and COVID-19.

THE ROLE OF E2/P RATIO IN THE ETIOLOGY OF FIBROCYSTIC BREAST DISEASE, MASTALGIA AND MASTODYNIA

- The aim of the study was to assess the role of the estradiol and progesterone relationship during the late luteal phase and the occurrence of fibrocystic breast disease (FBD). The concentration of estradiol/progesterone was measured in the group of women with FBD as study group (n=50) and control group of women without FBD (n=40). All women had regular ovulation cycles. Blood samples for estradiol (E2), progesterone (P) and prolactin determination were obtained in the morning at 8 am on days 21 and 24 of menstrual cycle. Significant mastalgia and mastodynia history in women with FBD was obtained with yes or no questionnaire. FBD diagnosis was confirmed with ultrasound (size and number of simple cysts). In the control group, a reduced E2/P ratio was noticed from day 21 to day 24 of the cycle (from 14.8±11.5 pg/mL to 9.1±6.1 pg/mL; p<0.05), which was not recorded in the group of women with FBD (study group). Even the slightest disturbance of the E2/P ratio may contribute to the occurrence of FBD with clinical manifestations of mastalgia and mastodynia.

Effect of forest bathing trips on human immune function

In Japan, a forest bathing trip, called "Shinrinyoku" in Japanese, is a short, leisurely visit to a forest; it is regarded as being similar to natural aromatherapy. This review focuses on the effects of forest bathing trips on human immune function. Beginning in 2005, adult Japanese individuals, both male and female, participated in a series of studies aimed at investigating the effect of forest bathing trips on human immune function. The subjects experienced a 3-day/2-night trip to forest areas, and blood and urine were sampled on days 2 (the first sampling during each trip) and 3 (the second sampling during each trip), and on days 7 and 30 after the trips. Natural killer (NK) activity, the numbers of NK, granulysin-, perforin-, and granzymes A/B-expressing lymphocytes in the blood, and the concentration of urinary adrenaline were measured. The same measurements were made before the trips on a normal working day as a control. The mean values of NK activity and the numbers of NK, granulysin-, perforin-, and granzymes A/B-expressing cells on forest bathing days were significantly higher than those on the control days, whereas the mean values of the concentration of urinary adrenaline on forest bathing days were significantly lower than that on the control days in both male and female subjects. The increased NK activity lasted for more than 30 days after the trip, suggesting that a forest bathing trip once a month would enable individuals to maintain a higher level of NK activity. In contrast, a visit to the city as a tourist did not increase NK activity, the numbers of NK cells, or the level of intracellular granulysin, perforin, and granzymes A/B. These findings indicate that forest bathing trips resulted in an increase in NK activity, which was mediated by increases in the number of NK cells and the levels of intracellular granulysin, perforin, and granzymes A/B.

Effect of estrogen/progesterone hormone replacement therapy on natural killer cell cytotoxicity and immunoregulatory cytokine release by peripheral blood mononuclear cells of postmenopausal women

Sex steroids are known to affect immune responses; however, information on immunomodulatory effects of estrogen/progesterone hormone replacement therapy (HRT) is still limited. Therefore, the present study aimed to investigate the effect of estrogen/medroxyprogesterone HRT on natural killer (NK) cell cytotoxicity and immunoregulatory cytokine (IL-2, IL-4 and IFN-gamma) release by phytohemaglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) from 15 selected healthy postmenopausal women. NK cell cytotoxicity, cytokine production and serum levels of 17beta-estradiol (E2), progesterone (P) and FSH were tested in each patient before and after 90-days HRT. NK cell cytotoxicity was tested by (51)Cr-release assay using K562 erythroleukemic cells as target. Specific cytokine production and serum hormone levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and immunochemiluminescent assays, respectively. HRT resulted in a significant decrease of Kupperman index, an increase of E2 and a decrease of FSH levels. These changes were associated with a significant decrease of NK cell cytotoxicity, IL-2 and IFN-gamma production. The levels of IL-4 production remained unchanged. Changes of NK cell cytotoxicity and cytokine release in individual patients did not correlate with changes of serum sex hormone levels. Nevertheless, the present results imply strongly that estrogen/progesterone HRT may affect cell-mediated immunity, thus being a potential factor influencing development and course of autoimmune disorders and neoplastic diseases.

Trafficking of peripheral blood CD56(bright) cells to the decidualizing uterus--new tricks for old dogmas?

CD56(bright) lymphocytes become abundant in the human uterus during every menstrual cycle, following the surge in pituitary-derived luteinizing hormone (LH), which initiates final oocyte maturation. While the uterus is host to some CD56(bright) cells prior to ovulation, the rapid increase is thought to be due to proliferation of the resident population, accompanied by recruitment of CD56(bright) lymphocytes from the circulation. The rapid increase in CD56(bright) cells is concurrent with the onset of decidualization, the transformation of uterine stromal cells into secretory decidual cells. Uterine CD56(bright) cells proliferate and differentiate to become the predominant lymphocytes of the post-ovulatory uterus. These distinct, tissue-specific natural killer (NK) cells either die prior to menses or increase in number during early pregnancy, and then decline toward the end of the first trimester. Since lymphocytes home to tissues from the circulation, we investigated mechanisms of NK cell traffic over the course of natural menstrual cycles by measuring functional interactions between CD56+ cells from blood and endothelial cells using the Stamper-Woodruff assay of lymphocyte adhesion to frozen tissue sections. While a baseline level of adhesion was maintained throughout the cycle, elevated l-selectin-dependent adhesion of peripheral blood CD56(bright) cells occurred during a peri-ovulatory window. However, there were no significant menstrual cycle-induced changes in the transcription of l-selectin, alpha 4 integrin or LFA-1, or in expression of these proteins by NK cells, suggesting that the enhanced adhesion was due to post-translational modifications of these molecules. Quantitative RT-PCR failed to amplify the message for LH receptor or the alpha or beta forms of progesterone or estrogen receptors from blood NK cell subsets. Thus, we conclude that the actions of LH, E(2,) and P(4) on NK cells that promote interactions with endothelium and potential uterine homing are indirectly mediated through the responsiveness of other cell types.

Sex-associated hormones and immunity to protozoan parasites

Numerous epidemiological and clinical studies have noted differences in the incidence and severity of parasitic diseases between males and females. Although in some instances this may be due to gender-associated differences in behavior, there is overwhelming evidence that sex-associated hormones can also modulate immune responses and consequently directly influence the outcome of parasitic infection. Animal models of disease can often recreate the gender-dependent differences observed in humans, and the role of sex-associated hormones can be confirmed by experimentally altering their levels. Under normal circumstances, levels of sex hormones not only differ between males and females but vary according to age. Furthermore, not only are females of reproductive age subject to the regular hormonal cycles which control ovulation, they are also exposed to dramatically altered levels during pregnancy. It is thus not surprising that the severity of many diseases, including those caused by parasites, has been shown to be affected by one or more of these circumstances. In addition, infection with many pathogens has been shown to have an adverse influence on pregnancy. In this article we review the impact of sex-associated hormones on the immune system and the development and maintenance of immunity to the intracellular protozoan parasites Toxoplasma gondii, Plasmodium spp., and Leishmania spp.