Pregnancy in postpartum estrus induces inflammatory milk production and catagen specific pup skin inflammation in interleukin-10 deficient mice

Immune modulation by curcumin: The role of interleukin-10

Cytokines are small secreted proteins released by different types of cells with specific effects on cellular signaling and communication via binding to their receptors on the cell surface. IL-10 is known to be a pleiotropic and potent anti-inflammatory and immunosuppressive cytokine that is produced by both innate and adaptive immunity cells including dendritic cells, macrophages, mast cells, natural killer cells, eosinophils, neutrophils, B cells, CD8⁺ T cells, and T_H1, T_H2, and T_H17 and regulatory T cells. Both direct and indirect activation of the stress axis promotes IL-10 secretion. IL-10 deregulation plays a role in the development of a large number of inflammatory diseases such as neuropathic pain, Parkinson's disease, Alzheimer's disease, osteoarthritis, rheumatoid arthritis, psoriasis, systemic lupus erythematosus, type 1 diabetes, inflammatory bowel disease, and allergy. Curcumin is a natural anti-inflammatory compound able to induce the expression and production of IL-10 and enhancing its action on a large number of tissues. In vitro and in pre-clinical models curcumin is able to modulate the disease pathophysiology of conditions such as pain and neurodegenerative diseases, bowel inflammation, and allergy, but also of infections and cancer through its effect on IL-10 secretion. In humans, at least one part of the positive effects of curcumin on health could be related to its ability to enhance IL-10 -mediated effects.

Regulator Versus Effector Paradigm: Interleukin-10 as Indicator of the Switching Response

The interleukin-10 (IL-10) is generally considered as the most important cytokine with anti-inflammatory properties and one of the key cytokines preventing inflammation-mediated tissue damage. In this respect, IL-10 producing cells play a crucial role in the outcome of infections, allergy, autoimmune reactions, tumor development, and transplant tolerance. Based on recent findings with regard to the mentioned clinical conditions, this review attempts to shed some light on the IL-10 functions, considering this cytokine as inherent inducer of the switching immunity. While acute infections and vaccinations are associated by IL-10 enhanced during few weeks, chronic parasitoses, tumor diseases, allergen-specific immunotherapy, transplants, and use of immune-suppressor drugs show an increased IL-10 level along months or years. With regard to autoimmune pathologies, the IL-10 increase is prevalently observed during early stages, whereas the successive stages are characterized by reaching of immune equilibrium independently to disease's activity. Together, these findings indicate that IL-10 is mainly produced during transient immune conditions and the persistent IL-10-related effect is the indication/prediction (and maybe effectuation) of the switching immunity. Actual knowledge emphasizes that any manipulation of the IL-10 response for treatment purposes should be considered very cautiously due to its potential hazards to the immune system. Probably, the IL-10 as potential switcher of immunity response should be used in association with co-stimulatory immune effectors that are necessary to determine the appropriate deviation during treatment of respective pathologies. Hopefully, further findings would open new avenues to study the biology of this "master switch" cytokine and its therapeutic potential.

5-Bromo-2'-deoxyuridine induced effluvium via p53-mediated CD326-positive keratinocyte apoptosis in C57BL/6 mice

Anagen effluvium develops because of disturbances in the hair follicle cycle, leading to acute and severe hair loss in humans. The objective of this study was to establish a mouse model of anagen effluvium by 5-bromo-2'-deoxyuridine (BrdU) treatment, and evaluate the pathological changes and underlying mechanisms. We treated 9-10-day-old pups and 3-7-week-old C57BL/6 mice with BrdU. After successfully inducing hair loss in the neonatal pups, microscopic, immunohistochemical and flow cytometry analyses were conducted. BrdU induced early onset alopecia in neonates and caused epidermal thickening and hair shaft breakage. BrdU appeared to incorporate the CD326-positive keratinocyte layer and induced p53-related apoptosis. Keratinocyte apoptosis caused immune cell infiltration in the dermal region; M2 macrophages and neutrophils were dominant. The BrdU-induced hair loss was dose-dependent, and alopecia was visible at a dose range of 25-200 μg/g bodyweight. The BrdU-induced anagen effluvium mouse model is novel and easily established by administrating four simple BrdU injections to pups; these mice showed synchronized onset of alopecia symptoms with little individual variation. Moreover, this model showed an alopecia phenotype similar to that of human anagen effluvium with acute, severe and widespread hair loss.

Premature mammary gland involution with repeated corticosterone injection in interleukin 10-deficient mice

Recently, we found that maternal stress could induce premature mammary gland involution in interleukin 10 knock out (IL-10^-/-) mice. To elucidate correlation between stress, IL-10, and mammary gland involution, corticosterone was injected into the lactating wild type and IL-10-deficient mice and assessed mammary gland phenotype. Repetitive corticosterone injection developed premature mammary gland involution only in B6.IL-10^-/- mice; moreover, it induced alopecia in nursing pups. Corticosterone injection induced several typical changes such as mammary gland epithelial cell apoptosis, macrophage infiltration, fat deposition in adipocyte, STAT3 phosphorylation, and upregulation of tyrosine hydroxylase gene in adrenal gland. Overall incidence of pup alopecia and mammary gland involution was relatively high in corticosterone than control B6.IL-10^-/- group (57% vs. 20%). Our finding demonstrates that IL-10 is important for stress modulation, and B6.Il-10^-/- with corticosterone has several advantage such as simple to establish, well-defined onset of mammary gland involution, high incidence, and inducing pup alopecia.