Potential role of estrogens in wound healing

Morphological and Molecular Peculiarities of Healing of Uterine Incision when Using Conditioned Media of Bone Marrow Stromal Cells Cultivated under Hypoxic Condition

We studied the effect of conditioned media (CM) from cultivated bone marrow stromal cells grown at 10% O2 on extracellular matrix and vascular component in the healing zone after surgical incision of the uterine wall in Sprague-Dawley rats (n=17). Control group (n=10) received no treatment. On days 5 and 15 after the surgery, the expression of CoL1a1, CoL4a, MMP9, TIMP1, and FGF2 genes was evaluated and a morphological study was carried out. On day 5, CoL1a1 expression, CD34+ cell content, and the area of newly formed tissue were lower in the experimental group. On day 15, the expression of MMP9, TIMP1, FGF2, and CoL1a1 genes in the control group was lower, while CD34+ cell content and area of healing zone were higher. Thus, the application of CM reduced the damage area and accelerated the recovery process after surgical full-thickness incision of the uterine wall.

Regulation of Joint Tissues and Joint Function: Is There Potential for Lessons to Be Learned Regarding Regulatory Control from Joint Hypermobility Syndromes?

Normal development of joints starts in utero with the establishment of a cellular and extracellular matrix template. Following birth, individual joint tissues grow and mature in response to biochemical and mechanical signals, leading to a coordinated pattern of further maturation resulting in a joint that functions as an organ system. Each joint develops and matures as an organ system defined by the biomechanical environment in which it will function. For those with joint hypermobility syndromes, either defined by specific genetic mutations or not (i.e., Ehlers-Danlos syndrome, Marfan syndrome, Loey-Dietz syndrome, hypermobility-type Ehlers-Danlos syndrome), this process is partially compromised, but many aspects of joint tissue maturation and resulting joint function is retained such that the organs form and retain partial function, but it is compromised. Comparing the characteristics of what is known regarding development, growth, maturation, and response to stressors such as puberty, pregnancy, and aging in joints of those without and with joint hypermobility leads to the conclusion that in those that have hypermobility syndromes, the joint systems may be compromised via a failure to undergo mechanical maturation, possibly via defective mechanotransduction. Given the breadth of the mutations involved in such hypermobility syndromes, further characterization of this concept may reveal commonalities in their impact on tissue maturation, which will further inform regulatory aspects of normal tissue and functional integrity. This review/perspective piece will attempt to detail such comparisons and summarize how further study will aid in further understanding.

Effect of Reproductive Tract Microbiota on Vaginal Fibroblasts in Pelvic Organ Prolapse

IMPORTANCE

The effect of vaginal bacteria on wound healing is an evolving area of study. Bacterial vaginosis (BV), characterized by an overgrowth of anaerobic bacteria, is linked to increased surgical site infections after pelvic surgery. While BV-associated microbes are known to impair epithelial repair, their effects on fibroblasts, which are crucial for wound healing and prolapse recurrence after pelvic organ prolapsesurgery, are unclear. Understanding these interactions can deepen knowledge of vaginal tissue remodeling.

OBJECTIVE

This study aimed to compare the effects of BV-associated bacteria and commensal lactobacilli on fibroblast cell number and function, using estradiol as a positive control.

STUDY DESIGN

Fibroblasts were isolated from vaginal wall biopsies of 9 participants undergoing pelvic organ prolapse surgery. Cells were co-cultured in media alone, media containing estradiol, and media with cell-free supernatants (CFS) from Lactobacillus crispatus, Lactobacillus iners, and Gardnerella vaginalis. Intact cell number was assessed using an lactate dehydrogenase assay at 0, 24, and 48 hours, and ELISA measured IL-6, type I collagen, and fibronectin levels.

RESULTS

Fibroblasts exposed to G vaginalis CFS showed significantly reduced cell number and type I collagen production, with increased fibronectin levels. Cell-free supernatants from L crispatus and L iners did not affect fibroblast proliferation. While some donor cells showed an increase in cell number with estradiol, the change was inconsistent and not statistically significant. IL-6 levels showed a nonsignificant increase with any bacterial CFS.

CONCLUSIONS

G vaginalis significantly impairs fibroblast cell number and type I collagen production, suggesting BV-associated microbes may alter fibroblast function, emphasizing the vaginal microbiome's role in outcomes.

Treatment of menopausal skin - A narrative review of existing treatments, controversies, and future perspectives

Menopause is a state of estrogen deficiency that affects numerous estrogen-dependent tissues in the female body. Skin is one of the most affected organs. Many consider menopausal skin changes to be merely an aesthetic problem; however, they can significantly affect women's quality of life. Currently, there are no approved effective treatments to prevent or alleviate skin changes associated with estrogen deficiency. Standard systemic hormone replacement therapy used to treat menopausal symptoms may be effective to some degree for skin treatment. In addition, compounded bioidentical hormone replacement therapy, selective estrogen receptor modulators, and phytoestrogens could also be used for skin treatment, although this is only hypothetical due to lack of data. Many questions therefore remain unanswered. On the other hand, topical, low-dose estrogen that would act only on the skin without systemic effects could be a possible option, as could be skin-only acting topical phytoestrogens. Such topical products without systemic effects could play a role in the treatment of menopausal skin. However, they are not currently approved because there is insufficient data on their safety and efficacy. A healthy lifestyle could have a positive effect on the menopausal skin. In this review, we provide an overview of the characteristics of menopausal skin, an outlook on the future treatment of menopausal skin with estrogens and other approaches, and the associated controversies and speculations. Overall, the importance of menopausal skin changes should not be neglected, and high-quality research is needed to gain new insights into the treatment of menopausal skin.

The Potential of Exercise on Lifestyle and Skin Function: Narrative Review

BACKGROUND

The skin is an important organ of the human body and has moisturizing and barrier functions. Factors such as sunlight and lifestyle significantly affect these skin functions, with sunlight being extremely damaging. The effects of lifestyle habits such as smoking, diet, and sleep have been studied extensively. It has been found that smoking increases the risk of wrinkles, while excessive fat and sugar intake leads to skin aging. Lack of sleep and stress are also dangerous for the skin's barrier function. In recent years, the impact of exercise habits on skin function has been a focus of study. Regular exercise is associated with increased blood flow to the skin, elevated skin temperature, and improved skin moisture. Furthermore, it has been shown to improve skin structure and rejuvenate its appearance, possibly through promoting mitochondrial biosynthesis and affecting hormone secretion. Further research is needed to understand the effects of different amounts and content of exercise on the skin.

OBJECTIVE

This study aims to briefly summarize the relationship between lifestyle and skin function and the mechanisms that have been elucidated so far and introduce the expected effects of exercise on skin function.

METHODS

We conducted a review of the literature using PubMed and Google Scholar repositories for relevant literature published between 2000 and 2022 with the following keywords: exercise, skin, and life habits.

RESULTS

Exercise augments the total spectrum power density of cutaneous blood perfusion by a factor of approximately 8, and vasodilation demonstrates an enhancement of approximately 1.5-fold. Regular exercise can also mitigate age-related skin changes by promoting mitochondrial biosynthesis. However, not all exercise impacts are positive; for instance, swimming in chlorinated pools may harm the skin barrier function. Hence, the exercise environment should be considered for its potential effects on the skin.

CONCLUSIONS

This review demonstrates that exercise can potentially enhance skin function retention.

Biotransformed soybean cream as a new nutraceutical for skin care: collagen stimulation in vitro and ex vivo

Treatments that attenuate the effects of hypoestrogenism in menopausal women have been gaining visibility. This study investigated the skin response to a phytoestrogen-enriched cosmetic formulation created by incorporating a biotransformed soybean extract (BE) into a cream-like matrix. Collagen-I expression was analyzed both in vitro (fibroblast cells) and ex vivo (skin explants). The results revealed an increased amount of collagen-I both in fibroblasts and human skin when treated with BE and BE-incorporated cream. Also, this collagen-I overexpression was inhibited by PHTPP, indicating a dependence on estrogen hormone receptor beta (ERβ) signaling. Moreover, BE was not harmful to skin microbiota, showing a promising nutricosmetic potential. Thus, this work presented a fully functional cream-like formulation that was shown to be safe and effectively increase collagen-I levels both in vitro and ex vivo.

Conditional deletion of CD25 in the corneal epithelium reveals sex differences in barrier disruption

PURPOSE

IL-2 promotes activation, clonal expansion, and deletion of T cells. IL-2 signals through its heterotrimeric receptor (IL-2R) consisting of the CD25, CD122 and CD132 chains. CD25 knockout (KO) mice develop Sjögren Syndrome-like disease. This study investigates whether corneal CD25/IL-2 signaling is critical for ocular health.

METHODS

Eyes from C57BL/6 mice were collected and prepared for immunostaining or in-situ hybridization. Bulk RNA sequencing was performed on the corneal epithelium from wild-type and CD25KO mice. We generated a conditional corneal-specific deletion of CD25 in the corneal epithelium (CD25Δ/ΔCEpi). Corneal barrier function was evaluated based on the uptake of a fluorescent dye. Mice were subjected to unilateral corneal debridement, followed by epithelial closure over time.

RESULTS

In C57BL/6 mice, CD25 mRNA was expressed in ocular tissues. Protein expression of CD25, CD122, and CD132 was confirmed in the corneal epithelium. Delayed corneal re-epithelization was seen in female but not male CD25KO mice. There were 771 differentially expressed genes in the corneal epithelium of CD25KO compared to wild-type mice. While barrier function is disrupted in CD25Δ/ΔCEpi mice, re-epithelialization rates are not delayed.

CONCLUSIONS

All three chains of the IL-2R are expressed in the corneal epithelium. Our results indicate for the first time, deleting CD25 systemically in all tissues in the mouse and deleting CD25 locally in just the corneal epithelium compromises corneal epithelial barrier function, leading to dry eye disease in female mice. Future studies are needed to delineate the pathways used by IL-2 signaling to influence cornea homeostasis.

Recent trends in diabetic wound healing with nanofibrous scaffolds

There is an emphasis in this review on nanofibrous scaffolds (NFSs) in diabetic wound healing, as well as their mechanisms and recent advancements. Diabetes-related complex wounds pose an important problem to humanity, due to the fact that their chronic nature can lead to serious complications including sepsis and amputations. Despite the fact that there are certain therapy options available for diabetic wound healing, these options are either ineffective or intrusive, making clinical intervention difficult. Clinical research is also challenged by the emergence of bacterial resistance to standard antibiotics. However, research into nanotechnology, in particular NFSs, is growing swiftly and has a positive impact on the treatment of diabetic wounds. For instance, SpinCare™, developed by Nanomedic Technologies Ltd, has successfully finished clinical testing and can re-epithelialize second-degree burns and chronic diabetic wounds in 7 and 14 days, respectively. In this review, we discussed homologous studies as well as other recent research studies on diabetic wound healing using NFSs.

Estradiol-17β [E2] stimulates wound healing in a 3D in vitro tissue-engineered vaginal wound model

Childbirth contributes to common pelvic floor problems requiring reconstructive surgery in postmenopausal women. Our aim was to develop a tissue-engineered vaginal wound model to investigate wound healing and the contribution of estradiol to pelvic tissue repair. Partial thickness scalpel wounds were made in tissue models based on decellularized sheep vaginal matrices cultured with primary sheep vaginal epithelial cells and fibroblasts. Models were cultured at an airliquid interface (ALI) for 3 weeks with and without estradiol-17β [E₂]. Results showed that E₂ significantly increased wound healing and epithelial maturation. Also, E₂ led to collagen reorganization after only 14 days with collagen fibers more regularly aligned and compactly arranged Additionally, E₂ significantly downregulated α-SMA expression which is involved in fibrotic tissue formation. This model allows one to investigate multiple steps in vaginal wound healing and could be a useful tool in developing therapies for improved tissue healing after reconstructive pelvic floor surgery.

Behavioral alterations, brain oxidative stress, and elevated levels of corticosterone associated with a pressure injury model in male mice

OBJECTIVES

Sustained stress can cause physiological disruption in crucial systems like the endocrine, autonomic, and central nervous system. In general, skin damages are physical stress present in hospitalized patients. Also, these pressure injuries lead to pathophysiological mechanisms involved in the neurobiology of mood disorders. Here, we aimed to investigate the behavioral alterations, oxidative stress, and corticosterone levels in the brain areas of mice submitted to the model of pressure injury (PI).

METHODS

The male mice behaviors were assessed in the open field test (OFT), elevated plus maze test (EPM), tail suspension test (TST), and sucrose preference test (SPT). Then, we isolated the prefrontal cortex (PFC), hippocampus (HP), and striatum (ST) by brain dissection. The nonprotein sulfhydryl groups (NP-SH) and malondialdehyde (MDA) were measured in the brain, and also the plasma corticosterone levels were verified.

RESULTS

PI model decreased the locomotor activity of animals (p<0.05). Considering the EPM test, the PI group showed a decrease in the open arm activity (p<0.01), and an increase in the closed arm activity (p<0.05). PI group showed an increment in the immobility time (p<0.001), and reduced sucrose consumption (p<0.0001) compared to the control groups. Regarding the oxidative/nitrosative profile, all brain areas from the PI group exhibited a reduction in the NP-SH levels (p<0.0001-p<0.01), and an increase in the MDA level (p<0.001-p<0.01). Moreover, the PI male mice presented increased levels of plasma corticosterone (p<0.05).

CONCLUSIONS

Our findings suggest that the PI model induces depressive and anxiety-like behaviors. Furthermore, it induces pathophysiological mechanisms like the neurobiology of depression.

Creating an Optimal In Vivo Environment to Enhance Outcomes Using Cell Therapy to Repair/Regenerate Injured Tissues of the Musculoskeletal System

Following most injuries to a musculoskeletal tissue which function in unique mechanical environments, an inflammatory response occurs to facilitate endogenous repair. This is a process that usually yields functionally inferior scar tissue. In the case of such injuries occurring in adults, the injury environment no longer expresses the anabolic processes that contributed to growth and maturation. An injury can also contribute to the development of a degenerative process, such as osteoarthritis. Over the past several years, researchers have attempted to use cellular therapies to enhance the repair and regeneration of injured tissues, including Platelet-rich Plasma and mesenchymal stem/medicinal signaling cells (MSC) from a variety of tissue sources, either as free MSC or incorporated into tissue engineered constructs, to facilitate regeneration of such damaged tissues. The use of free MSC can sometimes affect pain symptoms associated with conditions such as OA, but regeneration of damaged tissues has been challenging, particularly as some of these tissues have very complex structures. Therefore, implanting MSC or engineered constructs into an inflammatory environment in an adult may compromise the potential of the cells to facilitate regeneration, and neutralizing the inflammatory environment and enhancing the anabolic environment may be required for MSC-based interventions to fulfill their potential. Thus, success may depend on first eliminating negative influences (e.g., inflammation) in an environment, and secondly, implanting optimally cultured MSC or tissue engineered constructs into an anabolic environment to achieve the best outcomes. Furthermore, such interventions should be considered early rather than later on in a disease process, at a time when sufficient endogenous cells remain to serve as a template for repair and regeneration. This review discusses how the interface between inflammation and cell-based regeneration of damaged tissues may be at odds, and outlines approaches to improve outcomes. In addition, other variables that could contribute to the success of cell therapies are discussed. Thus, there may be a need to adopt a Precision Medicine approach to optimize tissue repair and regeneration following injury to these important tissues.

Cost-Effectiveness of perioperative Vaginally Administered estrogen in postmenopausal women undergoing prolapse surgery (EVA trial): study protocol for a multicenter double-blind randomized placebo-controlled trial

BACKGROUND

Surgery for pelvic organ prolapse (POP) is associated with high recurrence rates. The costs associated with the treatment of recurrent POP are huge, and the burden from women who encounter recurrent POP, negatively impacts their quality of life. Estrogen therapy might improve surgical outcome for POP due to its potential beneficial effects. It is thought that vaginal estrogen therapy improves healing and long-term maintenance of connective tissue integrity. Hence, this study aims to evaluate the cost-effectiveness of perioperative vaginal estrogen therapy in postmenopausal women undergoing POP surgery.

METHODS

The EVA trial is a multi-center double-blind randomized placebo-controlled trial conducted in the Netherlands comparing the effectiveness and costs-effectiveness of vaginal estrogen therapy. This will be studied in 300 postmenopausal women undergoing primary POP surgery, with a POP-Q stage of ≥ 2. After randomization, participants administer vaginal estrogen cream or placebo cream from 4 to 6 weeks preoperative until 12 months postoperative. The primary outcome is subjective improvement of POP symptoms at 1 year follow-up, measured with the Patient Global Impression of Improvement (PGI-I) scale. Secondary outcomes are POP-Q anatomy in all compartments, re-interventions, surgery related complications, general and disease specific quality of life, sexual function, signs and complaints of vaginal atrophy, vaginal pH, adverse events, costs, and adherence to treatment. Follow up is scheduled at 6 weeks, 6 months and 12 months postoperative. Data will be collected using validated questionnaires and out-patient visits including gynecological examination performed by an independent gynecologist.

DISCUSSION

This study investigates whether perioperative vaginal estrogen will be cost-effective in the surgical treatment of POP in postmenopausal women. It is hypothesized that estrogen therapy will show a reduction in recurrent POP symptoms and a reduction in reoperations for POP, with subsequent improved quality of life among women and cost savings. Trial registrationNetherlands Trial Registry: NL6853; registered 19-02-2018, https://www.trialregister.nl/trial/6853 . EudraCT: 2017-003144-21; registered: 24-07-2017.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

Gender differences in UV-induced skin inflammation, skin carcinogenesis and systemic damage

Ultraviolet (UV) radiation-induced chronic inflammation contributes to all stages of skin tumor development. In addition, gender plays an important role in inflammatory diseases or cancer. In this study, histopathology changes, hematology, oxidative stress and inflammatory response were used to evaluate sex differences in UV-induced chronic inflammation-associated cancer development. The results showed that the male and female mice had photoaging damage at the 9th week. However, skin tumors only appeared in male mice at 31st week. Furthermore, UV increased ROS production, p65, p-p65, IL-6 and TNF-α protein expressions in skin, and these factors elevated more in male mouse model. Hematology results showed that the parameters of blood systemic inflammation were changed in different degrees in model groups, while the pathological results showed inflammatory cell infiltration in the internal organs of both model groups in varying degrees. These results indicate that there are gender differences in UV-induced skin inflammation, carcinogenesis and systemic damage. Moreover, male mice are more sensitive to UV irradiation, which may be responsible to greater oxidative stress and inflammatory damage.

Lung Surfactant Accelerates Skin Wound Healing: A Translational Study with a Randomized Clinical Phase I Study

Lung surfactants are used for reducing alveolar surface tension in preterm infants to ease breathing. Phospholipid films with surfactant proteins regulate the activity of alveolar macrophages and reduce inflammation. Aberrant skin wound healing is characterized by persistent inflammation. The aim of the study was to investigate if lung surfactant can promote wound healing. Preclinical wound models, e.g. cell scratch assays and full-thickness excisional wounds in mice, and a randomized, phase I clinical trial in healthy human volunteers using a suction blister model were used to study the effect of the commercially available bovine lung surfactant on skin wound repair. Lung surfactant increased migration of keratinocytes in a concentration-dependent manner with no effect on fibroblasts. Significantly reduced expression levels were found for pro-inflammatory and pro-fibrotic genes in murine wounds. Because of these beneficial effects in preclinical experiments, a clinical phase I study was initiated to monitor safety and tolerability of surfactant when applied topically onto human wounds and normal skin. No adverse effects were observed. Subepidermal wounds healed significantly faster with surfactant compared to control. Our study provides lung surfactant as a strong candidate for innovative treatment of chronic skin wounds and as additive for treatment of burn wounds to reduce inflammation and prevent excessive scarring.

Endometriosis-Associated Pain - Do Preclinical Rodent Models Provide a Good Platform for Translation?

Pelvic pain is a common symptom of endometriosis. Our understanding of its etiology remains incomplete and medical management is limited by poor translation from preclinical models to clinical trials. In this review, we briefly consider the evidence, or lack thereof, that different subtypes of lesion, extra-uterine bleeding, and neuropathic pathways add to the complex and heterogeneous pain experience of women with the condition. We summarize the studies in rodent models of endometriosis that have used behavioral endpoints (evoked and non-evoked) to explore mechanisms of endometriosis-associated pain. Lesion innervation, activation of nerves by pronociceptive molecules released by immune cells, and a role for estrogen in modulating hyperalgesia are key endometriosis-associated pain mechanisms replicated in preclinical rodent models. The presence of ectopic (full thickness uterus or endometrial) tissue may be associated with changes in the spinal cord and brain, which appear to model changes reported in patients. While preclinical models using rats and mice have yielded insights that appear relevant to mechanisms responsible for the development of endometriosis-associated pain, they are limited in scope. Specifically, most studies are based on models that only resulted in the formation of superficial lesions and use induced (evoked) behavioral 'pain' tests. We suggest that translation for patient benefit will be improved by new approaches including models of ovarian and deep infiltrating disease and measurement of spontaneous pain behaviors. Future studies must also capitalize on new advances in the wider field of pain medicine to identify more effective treatments for endometriosis-associated pain.

Is sex a biological variable in corneal wound healing?

Wound healing differs significantly between men and women in a tissue-dependent manner. Dermal wounds heal faster in women whereas mucosal wounds heal faster in men. However, the effect of sex as a variable in corneal wound healing is largely unknown. The primary objective of this study was to test whether sex is a biological variable in corneal wound healing activated by the trauma or injury using an established in vivo rabbit model with male and female New Zealand White rabbits. Corneal wounds in rabbits were produced by a single topical alkali (0.5N Sodium hydroxide) application. Serial slit-lamp, stereo biomicroscopy, and applanation tonometry evaluated corneal opacity, anterior segment ocular health, and intraocular pressure (IOP), respectively, at various times during the study. Fourteen days after alkali-wound, corneal tissues were collected after humane euthanasia to examine cellular and molecular wound healing parameters. Quantitative PCR (qPCR) and immunofluorescence were used to quantify changes in the extracellular modeling protein levels of alpha-smooth muscle actin (α-SMA), Fibronectin (FN), Collagen-I (Col-I), and Transforming growth factor beta 1 (TGFβ1) involved in corneal healing. Hematoxylin and Eosin (H&E) staining was used to study histopathological changes in morphology and TUNEL assay to evaluate levels of apoptotic cell death. Male and female rabbits showed no significant differences in corneal opacity (Fantes score) or intraocular pressure (IOP) values (9.5 ± 0.5 mm Hg) in live animals. Likewise, no statistically significant sex-based differences in the mRNA levels of α-SMA (male = 5.95 ± 0.21 fold vs. female = 5.32 ± 0.043), FN (male = 3.02 ± 0.24 fold vs. female = 3.23 ± 0.27), Col-I (male = 3.12 ± 0.37 fold vs. female = 3.31 ± 0.24), TGFβ1 (male = 1.65 ± 0.06 fold vs. female = 1.59 ± 0.053); and protein levels of α-SMA (male = 74.16 ± 4.6 vs. female = 71.58 ± 7.1), FN (male = 60.11 ± 4.6 vs. female = 57.41 ± 8.3), Col-I (male = 84.11 ± 2.8 vs. female = 84.55 ± 3.6), TGFβ1 (male = 11.61 ± 2.8 vs. female = 9.5 ± 3.04) were observed. Furthermore, H&E and TUNEL analyses found no statistically significant differences in cellular structures and apoptosis, respectively, in male vs. female corneas. Consistent with earlier reports, wounded corneas showed significantly increased levels of these parameters compared to the unwounded corneas. Our data suggest that sex is not a major biological variable during active early stages of corneal wound healing in rabbits in vivo.

Transcriptomic analysis of the impacts of ethinylestradiol (EE2) and its consequences for proliferative kidney disease outcome in rainbow trout (Oncorhynchus mykiss)

Freshwater fish are threatened by the cumulative impact of multiple stressors. The purpose of this study was to unravel the molecular and organism level reactions of rainbow trout, Oncorhynchus mykiss, to the combined impact of two such stressors that occur in the natural habitat of salmonids. Fish were infected with either the myxozoan parasite, Tetracapsuloides bryosalmonae, which causes proliferative kidney disease (PKD), or exposed to ethinylestradiol (EE2) an estrogenic endocrine disrupting compound, or to a combination of both (PKD × EE2). PKD is a slow progressive chronic disease here we focused on a later time point (130-day post-infection (d.p.i.)) when parasite intensity in the fish kidney has already started to decrease. At 130 d.p.i., RNA-seq technology was applied to the posterior kidney, the main target organ for parasite development. This resulted with 280 (PKD), 14 (EE2) and 444 (PKD × EE2) differentially expressed genes (DEGs) observed in the experimental groups. In fish exposed to the combination of stressors (PKD × EE2), a number of pathways were regulated that were neither observed in the single stressor groups. Parasite infection, alone and in combination with EE2, only resulted in a low intensity immune response that negatively correlated with an upregulation of genes involved in a variety of metabolic and inflammation resolution processes. This could indicate a trade-off whereby the host increases investment in recovery/resolution processes over immune responses at a later stage of disease. When PKD infection took place under simultaneous exposure to EE2 (PKD × EE2), parasite intensity decreased and pathological alterations in the posterior kidney were reduced in comparison to the PKD only condition. These findings suggest that EE2 modulated these response profiles in PKD infected fish, attenuating the disease impact on the fish.

Topical estradiol increases epidermal thickness and dermal collagen of foreskin prior to hypospadia surgery - Randomized double blinded controlled trial

INTRODUCTION

The use of preoperative topical testosterone stimulation prior to hypospadias correction aims to increase penile size and achieve better surgical results. Topical estradiol has been shown to improve the quality of skin in other sites, but its use in boys with hypospadia has not yet been elucidated.

OBJECTIVE

This study aims to evaluate the primary effects in epidermal thickness and collagen distribution of estradiol compared to testosterone and placebo in skin of prepuce before hypospadia surgery.

MATHERIALS AND METHODS

Patients were randomized into three groups according to the topical hormone used: TG: Testosterone ointment; EG: Estradiol ointment; CG: Neutral base ointment. Fragments of foreskin were excised, fixed and then sectioned for histology. For each sample, epidermal thickness and dermal collagen expression was measured by specific computer analysis, P-values of <0.05.

RESULTS

Thirty-three patients with a mean age of 4.01 ± 2.92 years were included. Hypospadia classification was similar in all three groups. Mean epidermal thickness and collagen type I expression in EG were greater than those of the other groups. Collagen type III expression was similar in all groups.

DISCUSSION

Foreskin has a fundamental role in many techniques of hypospadias surgery and can be used either as a graft or a flap in the correction of the penile defect. Increase of epidermal thickness and dermal collagen observed in the present study has already been related to use of estradiol in other skin sites, but not yet in foreskin. Further studies are needed to evaluate the real significance of these findings in boys with hypospadias.

CONCLUSION

Use of topical estradiol before hypospadias surgery lead to greater epidermal thickness and increases dermal collagen expression in foreskin.

Scarless wound healing: From development to senescence

An essential element of tissue homeostasis is the response to injuries, cutaneous wound healing being the most studied example. In the adults, wound healing aims at quickly restoring the barrier function of the skin, leading however to scar, a dysfunctional fibrotic tissue. On the other hand, in fetuses a scarless tissue regeneration takes place. During ageing, the wound healing capacity declines; however, in the absence of comorbidities a higher quality in tissue repair is observed. Senescent cells have been found to accumulate in chronic unhealed wounds, but more recent reports indicate that their transient presence may be beneficial for tissue repair. In this review data on skin wound healing and scarring are presented, covering the whole spectrum from early embryonic development to adulthood, and furthermore until ageing of the organism.

Temporal progression of gene regulation of peripheral white blood cells explains gender dimorphism of critically ill patients after trauma

BACKGROUND

The immune response of the critically ill after severe trauma is sex-specific and may explain the different progression of the disease. This may be explained by a different gene regulatory program of their peripheral immune cells. We investigated the progression of the transcription profiles of peripheral immune cells of the patients to elucidate their distinct physiological response and clinical course.

METHODS

We compared transcription profiles of whole blood of male and female patients from a larger longitudinal study of critically ill patients after trauma. We developed a statistical analysis pipeline that synchronized the time lapse of the profiles based on the temporal severity score of each patient.

RESULTS

This enabled to categorize the temporal progression of the disease into two pre-acute, an acute and two post-acute phases. Comparing gene regulation of male and female patients at each phase, we identified distinctively regulated molecular processes mainly in the immune response, but also in the regulation of metabolism allowing to cluster these discriminative gene sets into sets of highly related cellular processes. Compared to male patients and healthy controls, female patients showed upregulation of gene sets of innate immunity in the early phase, upregulation of wound healing processes during the acute phase and upregulation of adaptive immunity in the late phase indicating early recovery. In turn, during the pre-acute and acute phase, male patients showed less suppression of gene sets coding for enzymes of energy metabolism and anabolism, most prominently the tricarboxylic acid cycle and β-oxidation, and cellular maintenance, such as cell cycle, DNA replication and damage response, and RNA metabolism.

CONCLUSIONS

A stronger innate immune response at the very early phase of the disease may support early clearance of the pathogen and its associated molecular patterns. Upregulation of wound healing processes may explain reduced multiple organ failure during the acute phase. Down regulated energy metabolism during the acute phase may make female patients less susceptible to oxidative stress, the upregulated adaptive immune system reflects an earlier recovery and rebuilding of the adaptive immune system that may protect them from secondary infections. Follow up studies need to be performed confirming these observations experimentally.

The Effect of C-Reactive Protein Isoforms on Nitric Oxide Production by U937 Monocytes/Macrophages

Inflammation is regulated by many endogenous factors including estrogen, a steroid hormone that declines with increasing age, leading to excessive inflammation in the elderly. C-reactive protein (CRP) is an acute phase inflammatory protein that exists in two forms, native CRP (nCRP) and monomeric CRP (mCRP), which mediate distinct biological activities. It is unclear how each CRP isoform mediates nitric oxide (NO), a signaling molecule generated by NO synthase (NOS). This study investigated whether CRP isoforms have distinct effects on NO production by unstimulated and lipopolysaccharide (LPS)-activated monocytes/macrophages and whether estrogen mediates CRP-induced NO production in an in vitro model of aging. NO and inducible NOS (iNOS) were measured (n = 12) by the Griess assay and an enzyme-linked immunosorbent assay, respectively following incubation (24 h) of human-derived U937 monocytes/macrophages with CRP isoforms [(nCRP) = 500 and 1,000 µg/ml; (mCRP) = 100 and 250 µg/ml] in the absence or presence of 17 beta-estradiol (1 × 10-7, 1 × 10-8, and 1 × 10-9 M). The response to each CRP isoform and estrogen was dependent on the differentiation and activation status of cells. Monocytes with or without prior LPS-activation significantly increased (P < 0.01) NO/iNOS production when treated with mCRP. The mCRP isoform had no effect (P > 0.05) on NO/iNOS production by unactivated or LPS-activated macrophages, whereas nCRP significantly (P < 0.05) reduced NO/iNOS production by macrophages, with or without prior LPS-activation. The nCRP isoform had opposing actions on monocytes, significantly (P < 0.01) increasing and reducing NO/iNOS by unactivated and LPS-activated monocytes, respectively. Estrogen significantly (P < 0.01) reversed nCRP-mediated NO inhibition by unactivated macrophages but decreased CRP-induced NO by unactivated monocytes treated with nCRP or mCRP and LPS-activated monocytes treated with mCRP. NO was differentially mediated by CRP isoforms in a cell-type/state-specific manner, with production corresponding to concomitant changes in iNOS levels. Collectively, the findings indicate nCRP and estrogen predominantly reduce NO production, whereas mCRP increases NO production. This supports growing evidence that mCRP exacerbates inflammation while nCRP and estrogen dampen the overall inflammatory response. Therapeutic strategies that restore estrogen levels to those found in youth and promote the stability of nCRP or/and prevent the formation of mCRP may reduce NO production in age-related inflammatory conditions.

A preliminary study of uterine scar tissue following cesarean section

AIM

To compare smooth muscle cells, type I collagen, and apoptosis of the lower uterine segment of women who had/without a prior cesarean delivery.

METHODS

Alpha smooth muscle actin (α-SMA), type I collagen, and nuclear apoptosis were compared between the groups from lower uterine segment. Twenty-eight controls and 82 with one prior cesarean delivery were included. The women with a prior cesarean section were classified by time since the surgery: ≤3 years, >3 and ≤5 years, >5 and ≤7 years, >7 and ≤9 years, and >9 years.

RESULTS

Smooth muscle volume density (VD) % was significantly lower in women who had cesarean sections in first three groups than in the controls (all, P<0.01). Type I collagen VD% was similar among all groups and the controls. The number of apoptotic nuclei in the lower uterine segment of the scarred group was greater up to 3 years after surgery and less than in the control at 7-9 years. The number of non-apoptotic nuclei in the scarred group was greater than controls up to 7 years after surgery.

CONCLUSION

The lower uterine segment scar becomes stable at 3 years after cesarean delivery, and by 9 years, the scar is mature.

Trauma and endometriosis. A review. May we explain surgical phenotypes and natural history of the disease?

OBJECTIVE

The study was performed to evaluate whether trauma is an initial event of development of endometriosis.

METHOD

Using Medline database from January 1960 up to December 2014, a systematic review was made of all published studies using the keywords trauma, healing, injury, infection, hyperperistaltism, stretch and endometriosis, adenomyosis and trauma. Studies and review articles written in French and/or in English related to the topic were included and reviewed independently by two authors.

RESULTS

The role of trauma is well-established for endometriotic lesions diagnosed in surgical scars. Various traumas including delivery, uterine curettage or incision, intraperitoneal hemorrhage, or occult pelvic inflammatory diseases could be involved to explain other localizations of the disease. Many data suggested that the healing process, particularly growth factors and the associated estrogen production, may facilitate the implantation and the growth of ectopic endometrial cells. After the initial, a traumatic event, the phenotype of the disease would depend on the tissue in which the endometriotic lesion grows.

CONCLUSIONS

The present literature review may support a potential role of a trauma as an initial event of endometriosis.

Mean echogenicity and area of puborectalis muscle in women with stress urinary incontinence during pregnancy and after delivery

Introduction and hypothesis

Pregnancy and childbirth are risk factors for the development of stress urinary incontinence (SUI). Urinary continence depends on normal urethral support, which is provided by normal levator ani muscle function. Our objective was to compare mean echogenicity and the area of the puborectalis muscle between women with and those without SUI during and after their first pregnancy.

Methods

We examined 280 nulliparous women at a gestational age of 12 weeks, 36 weeks, and 6 months after delivery. They filled out the validated Urogenital Distress Inventory and underwent perineal ultrasounds. SUI was considered present if the woman answered positively to the question “do you experience urine leakage related to physical activity, coughing, or sneezing?” Mean echogenicity of the puborectalis muscle (MEP) and puborectalis muscle area (PMA) were calculated. The MEP and PMA during pregnancy and after delivery in women with and without SUI were compared using independent Student’s t test.

Results

After delivery the MEP was higher in women with SUI if the pelvic floor was at rest or in contraction, with effect sizes of 0.30 and 0.31 respectively. No difference was found in the area of the puborectalis muscle between women with and those without SUI.

Conclusions

Women with SUI after delivery had a statistically significant higher mean echogenicity of the puborectalis muscle compared with non-SUI women when the pelvic floor was at rest and in contraction; the effect sizes were small. This higher MEP is indicative of a relatively higher intramuscular extracellular matrix component and could represent diminished contractile function.

Estrogen accelerates the resolution of inflammation in macrophagic cells

Although 17β-estradiol (E₂) anti-inflammatory activity has been well described, very little is known about the effects of this hormone on the resolution phase of the inflammatory process. Here, we identified a previously unreported ERα-mediated effect of E₂ on the inflammatory machinery. The study showed that the activation of the intracellular estrogen receptor shortens the LPS-induced pro-inflammatory phase and, by influencing the intrinsic and extrinsic programs, triggers the resolution of inflammation in RAW 264.7 cells. Through the regulation of the SOCS3 and STAT3 signaling pathways, E₂ facilitates the progression of the inflammatory process toward the IL10-dependent “acquired deactivation” phenotype, which is responsible for tissue remodeling and the restoration of homeostatic conditions. The present study may provide an explanation for increased susceptibility to chronic inflammatory diseases in women after menopause, and it suggests novel anti-inflammatory treatments for such disorders.

A new concept of endometriosis and adenomyosis: tissue injury and repair (TIAR)

Pelvic endometriosis, deeply infiltrating endometriosis and uterine adenomyosis share a common pathophysiology and may be integrated into the physiological mechanism and new nosological concept of 'tissue injury and repair' (TIAR) and may, in this context, just represent the extreme of a basically physiological, estrogen-related mechanism that is pathologically exaggerated in an extremely estrogen-sensitive reproductive organ. The acronym TIAR describes a fundamental and apparently ubiquitous biological system that becomes operative in mesenchymal tissues following tissue injury and, upon activation, results in the local production of estradiol. Endometriosis and adenomyosis are caused by trauma. In the spontaneously developing disease, chronic uterine peristaltic activity or phases of hyperperistalsis induce, at the endometrial-myometrial interface near the fundo-cornual raphe, microtraumatisations, with activation of the TIAR mechanism. With ongoing traumatisations, such sites of inflammation might accumulate and the increasingly produced estrogens interfere in a paracrine fashion with ovarian control over uterine peristaltic activity, resulting in permanent hyperperistalsis and a self-perpetuation of the disease process. Overt autotraumatisation of the uterus with dislocation of fragments of basal endometrium into the peritoneal cavity and infiltration of basal endometrium into the depth of the myometrial wall ensues. In most cases of endometriosis/adenomyosis a causal event early in the reproductive period of life must be postulated, rapidly leading to archimetral hyperestrogenism and uterine hyperperistalsis. In late premenopausal adenomyosis such an event might not have occurred. However, as indicated by the high prevalence of the disease, it appears to be unavoidable that, with time, chronic normoperistalsis throughout the reproductive period of life accumulates to the same extent of microtraumatisation. With activation of the TIAR mechanism followed by chronic inflammation and infiltrative growth, endometriosis/adenomyosis of the younger woman and premenopausal adenomyosis share in principal the same pathophysiology.

Estrogens induce rapid cytoskeleton re-organization in human dermal fibroblasts via the non-classical receptor GPR30

The post-menopausal decrease in estrogen circulating levels results in rapid skin deterioration pointing out to a protective effect exerted by these hormones. The identity of the skin cell type responding to estrogens is unclear as are the cellular and molecular processes they elicit. Here, we reported that lack of estrogens induces rapid re-organization of the human dermal fibroblast cytoskeleton resulting in striking cell shape change. This morphological change was accompanied by a spatial re-organization of focal adhesion and a substantial reduction of their number as evidenced by vinculin and actin co-staining. Cell morphology and cytoskeleton organization was fully restored upon 17β-estradiol (E2) addition. Treatment with specific ER antagonists and cycloheximide respectively showed that the E2 acts independently of the classical Estrogen Receptors and that cell shape change is mediated by non-genomic mechanisms. E2 treatment resulted in a rapid and transient activation of ERK1/2 but not Src or PI3K. We show that human fibroblasts express the non-classical E2 receptor GPR30 and that its agonist G-1 phenocopies the effect of E2. Inhibiting GPR30 through treatment with the G-15 antagonist or specific shRNA impaired E2 effects. Altogether, our data reveal a novel mechanism by which estrogens act on skin fibroblast by regulating cell shape through the non-classical G protein-coupled receptor GPR30 and ERK1/2 activation.

The role of nuclear hormone receptors in cutaneous wound repair

The cutaneous wound repair process involves balancing a dynamic series of events ranging from inflammation, oxidative stress, cell migration, proliferation, survival and differentiation. A complex series of secreted trophic factors, cytokines, surface and intracellular proteins are expressed in a temporospatial manner to restore skin integrity after wounding. Impaired initiation, maintenance or termination of the tissue repair processes can lead to perturbed healing, necrosis, fibrosis or even cancer. Nuclear hormone receptors (NHRs) in the cutaneous environment regulate tissue repair processes such as fibroplasia and angiogenesis. Defects in functional NHRs and their ligands are associated with the clinical phenotypes of chronic non-healing wounds and skin endocrine disorders. The functional relationship between NHRs and skin niche cells such as epidermal keratinocytes and dermal fibroblasts is pivotal for successful wound closure and permanent repair. The aim of this review is to delineate the cutaneous effects and cross-talk of various nuclear receptors upon injury towards functional tissue restoration.

Modeling the effects of systemic mediators on the inflammatory phase of wound healing

The normal wound healing response is characterized by a progression from clot formation, to an inflammatory phase, to a repair phase, and finally, to remodeling. In many chronic wounds there is an extended inflammatory phase that stops this progression. In order to understand the inflammatory phase in more detail, we developed an ordinary differential equation model that accounts for two systemic mediators that are known to modulate this phase, estrogen (a protective hormone during wound healing) and cortisol (a hormone elevated after trauma that slows healing). This model describes the interactions in the wound between wound debris, pathogens, neutrophils and macrophages and the modulation of these interactions by estrogen and cortisol. A collection of parameter sets, which qualitatively match published data on the dynamics of wound healing, was chosen using Latin Hypercube Sampling. This collection of parameter sets represents normal healing in the population as a whole better than one single parameter set. Including the effects of estrogen and cortisol is a necessary step to creating a patient specific model that accounts for gender and trauma. Utilization of math modeling techniques to better understand the wound healing inflammatory phase could lead to new therapeutic strategies for the treatment of chronic wounds. This inflammatory phase model will later become the inflammatory subsystem of our full wound healing model, which includes fibroblast activity, collagen accumulation and remodeling.

Clinical aspects and molecular diagnostics of skin aging

This contribution will address the effect of aging on skin functions, with a particular focus on skin permeability, wound healing, angiogenesis, lipogenesis, sweat production, immune function, and vitamin D synthesis. With accelerating age, skin functions deteriorate due to structural and morphologic changes. Skin is prone to the development of several diseases, varying from benign to malignant. Because the number of persons aged 80 and older is expected to rise in the next decades, disease prevention will become an important issue. Screening examinations and prevention through public education starting at an early age regarding sun avoidance, the use of sunscreens and the importance of a balanced nutrition are the first steps for successful healthy aging. Although the fundamental mechanisms in the pathogenesis of aged skin are still poorly understood, a growing body of evidence points toward the involvement of multiple pathways. Recent data obtained by expression profiling studies and studies of progeroid syndromes illustrate that among the most important biologic processes involved in skin aging are alterations in DNA repair and stability, mitochondrial function, cell cycle and apoptosis, extracellular matrix, lipid synthesis, ubiquitin-induced proteolysis and cellular metabolism. Among others, a major factor that has been implicated in the initiation of aging is the physiologic decline of hormones occurring with age. However, hormones at age-specific levels may regulate not only age-associated mechanisms but also tumor suppressor pathways that influence carcinogenesis. Understanding the molecular mechanisms of aging may open new strategies to deal with the various diseases accompanying high age, including cancer.

[Dermatoendocrinology. Skin aging]

Hormones and their imbalances have significant effects on the morphology and physiology of the skin and influence various skin functions, especially wound healing and lipogenesis. With increasing age, the concentrations of important circulating hormones, including growth hormone and sex-related steroids, decrease continuously. As a result, physiologic processes are negatively influenced and various age-associated disorders may develop. As the population aged 80 and over is expected to rise in the next decades, the understanding of the molecular mechanisms accompanying skin aging and disease prevention will become even more important and play a role in preventing disease.

Skin wrinkles and rigidity in early postmenopausal women vary by race/ethnicity: baseline characteristics of the skin ancillary study of the KEEPS trial

OBJECTIVE

To characterize skin wrinkles and rigidity in recently menopausal women.

DESIGN

Baseline assessment of participants before randomization to study drug.

SETTING

Multicenter trial, university medical centers.

PATIENT(S)

Recently menopausal participants enrolled in the Kronos Early Estrogen Prevention Study (KEEPS).

INTERVENTION(S)

Skin wrinkles were assessed at 11 locations on the face and neck using the Lemperle wrinkle scale. Skin rigidity was assessed at the forehead and cheek using a durometer.

MAIN OUTCOME MEASURE(S)

Skin wrinkles and rigidity were compared among race/ethnic groups. Skin wrinkles and rigidity were correlated with age, time since menopause, weight, and body mass index (BMI).

RESULT(S)

In early menopausal women, wrinkles, but not skin rigidity, vary significantly among races, where black women have the lowest wrinkle scores. In white women, chronological age was significantly correlated with worsening skin wrinkles, but not with rigidity. Skin rigidity correlated with increasing length of time since menopause, however, only in the white subgroup. In the combined study group, increasing weight was associated with less skin wrinkling.

CONCLUSION(S)

Skin characteristics of recently menopausal women are not well studied. Ethnic differences in skin characteristics are widely accepted, but poorly described. In recently menopausal women not using hormone therapy (HT), significant racial differences in skin wrinkling and rigidity exist. Continued study of the KEEPS population will provide evidence of the effects of HT on the skin aging process in early menopausal women.

Genistein aglycone improves skin repair in an incisional model of wound healing: a comparison with raloxifene and oestradiol in ovariectomized rats

BACKGROUND AND PURPOSE

Oestrogen loss at menopause is frequently related to poor wound healing. Genistein has been tested in anti-ageing cosmetic preparations with interesting results on skin health. Here, we investigated the effects of the genistein aglycones, given systemically, in an incisional model of wound healing, compared to systemic oestradiol and raloxifene.

EXPERIMENTAL APPROACH

Six months after ovariectomy (OVX), rats were randomly assigned to groups of 12 animals each and treated daily with genistein aglycone (1 and 10 mg kg(-1) s.c.), raloxifene hydrochloride (0.05 and 0.5 mg kg(-1) s.c.) or 17-alpha-ethinyl oestradiol (0.003 and 0.03 mg kg(-1) s.c.) for 12 weeks. Untreated OVX and sham OVX rats were used as controls. Then, 14 or 7 days before the end of the experiment, an incisional wound healing procedure was performed and skin specimens were collected to evaluate molecular, histological and functional measurements.

KEY RESULTS

Seven and fourteen days after wounding, samples from OVX rats showed a decrease in transforming growth factor-beta1, tissue transglutaminase 2 and vascular endothelial growth factor compared to samples from sham OVX rats. Oestradiol, raloxifene and genistein all significantly modified this decrease, but the lowest genistein dose exerted a greater effect than the other treatments. Moreover, the lowest dose of genistein was the most effective in improving skin healing and wound tensile strength.

CONCLUSIONS AND IMPLICATIONS

Genistein aglycone might be an alternative therapy for the management of skin wound healing.

Detection of RXFP1 receptors in skin biopsies from children with congenital adrenal hyperplasia: a preliminary report

OBJECTIVE

Relaxin may potentiate the effect of topical estrogen treatment to eradicate post-incisional scarring in congenital adrenal hyperplasia (CAH) patients undergoing genitoplasty. The aim of this study was to determine whether CAH skin is capable of responding to relaxin.

PATIENTS AND METHODS

Skin biopsies were obtained from four female CAH patients (aged 2-9 years; Prader 4-5, salt-wasting, 21-hydroxylase deficiency, Caucasian) during routine genitoplasty surgery and screened for relaxin receptors. All received corticosteroid and mineralocorticoid replacement therapy. Specimens were sectioned, mounted and screened for the presence of the putative H2 relaxin receptor using conventional two-antibody immunohistochemistry. Tissue controls were processed concurrently.

RESULTS

Tissue controls evidenced appropriate staining. Biopsies from CAH patients stained positively for RXFP1 expression while some variation between specimens was evident. Staining occurred adjacent to the basement membrane of the epithelium, localized to germinative basal keratinocytes.

CONCLUSION

Based on a limited patient sample, germinative keratinocytes in CAH patients appear competent to respond to relaxin perhaps topically applied. Given that relaxin downregulates collagen accretion and upregulates collagenases, its use may potentiate the effects of estradiol and abrogate post-incisional wound scarring. More research is needed to confirm or refute this thesis.

Estrogens and the skin

OBJECTIVE

A review of the medical literature concerning the effect of the menopause and its hormonal treatment on the skin.

METHODS

An extensive Medline and Pubmed internet search utilizing the key words: collagen, elastin, estrogen, hormone replacement therapy, skin and aging.

RESULTS

The literature review demonstrated a wide array of research ranging from basic science work to clinical implications of the effects of the menopause and its treatment on the skin.

CONCLUSION

Estrogen loss at menopause has a profound influence on skin. Estrogen treatment in postmenopausal women has been repeatedly shown to increase collagen content, dermal thickness and elasticity, and data on the effect of estrogen on skin water content are also promising. Further, physiologic studies on estrogen and wound healing suggest that hormone replacement therapy (HRT) may play a beneficial role in cutaneous injury repair. Results on the effect of HRT on other physiologic characteristics of skin, such as elastin content, sebaceous secretions, wrinkling and blood flow, are discordant. Given the responsiveness of skin to estrogen, the effects of HRT on aging skin require further examination, and careful molecular studies will likely clarify estrogen's effects at the cellular level.

Estrogen deficiency and tobacco smoke exposure promote matrix metalloproteinase-13 activation in skin of aging B6 mice

Estrogen deficiency may contribute to extracellular matrix turnover in skin. This has led previous authors to postulate that aged skin heals less efficiently when compared to younger skin. Also, cigarette smokers have been shown to heal less efficiently than nonsmokers. Matrix metalloproteinase (MMP)-13, an enzyme that participates in the degradation of the extracellular matrix, has been implicated in physiologic aging and wound healing. This study investigates the effects of smoke exposure and estrogen deficiency on MMP-13 in young and aged female mouse skin. Young and aged female C57Bl/6J mice were ovariectomized. They were then randomly administered either 17beta-estradiol (E2) or placebo pellets. Half the animals in each age group were further randomized to exposure to cigarette smoke for a period of 6 months. Smoking and estrogen deficiency increased MMP-13 protein and activity in aged skin. The tissue inhibitors of metalloproteinases, which inhibit MMPs, activity was unchanged across all groups. E2 replacement decreased the actual level of MMP-13 protein and activity. We also found an increased collagen content and decreased ER receptor protein level in aged, smoke-exposed female mice. Our experimental data show that tobacco smoke exposure and estrogen deficiency are additive risk factors for promoting increased activity of MMP-13 in aged skin. These findings suggest that MMP-13 functions as a mediator of smoke-induced skin injury in susceptible, aged experimental female mice.

Androstenediol reverses steroid-inhibited wound healing

It is well recognized that stress of any nature will cause a delay in the wound healing response. This delayed healing response appears closely associated with immune regulators. In this study, CD-1 mice were injected with a long acting form of methyl prednisolone to cause a steroid-induced immune suppression. After 24 hours, two 6-mm full thickness wounds were placed on the animals' backs and one group of animals received the immune-regulating hormone, androstenediol. Wound contraction was quantified by planimetry for the subsequent 14 days. Animals that were stressed with methyl prednisolone but receiving androstenediol contracted their open wounds at faster rates compared with methyl prednisolone-stressed animals treated with the vehicle alone. These findings suggest that restoration of immune regulation by androstenediol can reverse the delayed open wound contraction secondary to steroid stress.

The pathophysiology of endometriosis and adenomyosis: tissue injury and repair

INTRODUCTION

This study presents a unifying concept of the pathophysiology of endometriosis and adenomyosis. In particular, a physiological model is proposed that provides a comprehensive explanation of the local production of estrogen at the level of ectopic endometrial lesions and the endometrium of women affected with the disease.

METHODS

In women suffering from endometriosis and adenomyosis and in normal controls, a critical analysis of uterine morphology and function was performed using immunohistochemistry, MRI, hysterosalpingoscintigraphy, videohysterosonography, molecular biology as well as clinical aspects. The relevant molecular biologic aspects were compared to those of tissue injury and repair (TIAR) mechanisms reported in literature.

RESULTS AND CONCLUSIONS

Circumstantial evidence suggests that endometriosis and adenomyosis are caused by trauma. In the spontaneously developing disease, chronic uterine peristaltic activity or phases of hyperperistalsis induce, at the endometrial-myometrial interface near the fundo-cornual raphe, microtraumatizations with the activation of the mechanism of 'tissue injury and repair' (TIAR). This results in the local production of estrogen. With ongoing peristaltic activity, such sites might increase and the increasingly produced estrogens interfere in a paracrine fashion with the ovarian control over uterine peristaltic activity, resulting in permanent hyperperistalsis and a self-perpetuation of the disease process. Overt auto-traumatization of the uterus with dislocation of fragments of basal endometrium into the peritoneal cavity and infiltration of basal endometrium into the depth of the myometrial wall ensues. In most cases of endometriosis/adenomyosis, a causal event early in the reproductive period of life must be postulated leading rapidly to uterine hyperperistalsis. In late premenopausal adenomyosis, such an event might not have occurred. However, as indicated by the high prevalence of the disease, it appears to be unavoidable that, with time, chronic normoperistalsis throughout the reproductive period of life leads to the same extent of microtraumatization. With the activation of the TIAR mechanism followed by infiltrative growth and chronic inflammation, endometriosis/adenomyosis of the younger woman and premenopausal adenomyosis share in principle the same pathophysiology. In conclusion, endometriosis and adenomyosis result from the physiological mechanism of 'tissue injury and repair' (TIAR) involving local estrogen production in an estrogen-sensitive environment normally controlled by the ovary.

Sex hormones and mucosal wound healing

Wound healing studies, which have chiefly examined dermal tissues, have reported a female advantage in healing rates. In contrast, our laboratory recently demonstrated women heal mucosal wounds more slowly than men. We hypothesized sex hormones influence wound healing rates, possibly through their modulating effects on inflammation. This study involved 329 younger subjects aged 18-43 (165 women, 164 men) and 93 older subjects aged 50-88 (60 women, 33 men). A 3.5mm diameter wound was created on the hard oral palate and videographed daily to assess wound closure. Blood collected at the time of wounding was used to assess circulating testosterone, progesterone and estradiol levels, and in vitro cytokine production in response to LPS. No strong associations were observed between healing times and estradiol or progesterone levels. However, in younger subjects, lower testosterone levels related to faster wound closure. Conversely, in older women higher testosterone levels related to (1) lower inflammatory responses; and (2) faster healing times. No such relationships were seen in older men, or in women taking oral contraceptives or hormone replacement therapy [HRT]. Older women (50-54 years) not yet experiencing menopause healed similarly to younger women and dissimilarly from age-matched post-menopausal women. This suggests that the deleterious effects of aging on wound healing occur secondary to the effects of menopause. Supporting this, there was evidence in post-menopausal women that HRT augmented wound closure. Overall, this study suggests that human mucosal healing rates are modulated by testosterone levels. Based upon when between-group differences were observed, testosterone may impact upon the proliferative phase of healing which involves immune processes such as re-epithelialization and angiogenesis.

Local Effects of Vaginally Administered Estrogen Therapy: A Review

The results of the Women's Health Initiative (WHI) led to a distinct decline in the routine use of estrogen as preventive therapy for vasomotor symptoms, osteoporosis, and cardiovascular disease in postmenopausal women. Without estrogen replacement, one third of women experience symptoms of atrophic vaginitis including dryness, irritation, itching and or dyspareunia. Local application of estrogen has been shown to relieve these symptoms and improve quality of life for these women. In addition, local estrogen therapy may have a favorable effect on sexuality, urinary tract infections, vaginal surgery, and incontinence. This review examines the effects of vaginally applied estrogen on the vaginal epithelium, urethra and endometrium. An accompanying review examines the systemic effects of vaginally applied estrogen.

Suitability of Excised Rabbit Ear Skin—Fresh and Frozen—for Evaluating Transdermal Permeation of Estradiol

Estradiol transdermal application still represents a relevant topic due to the recent controversies about hormone replacement therapy, its increasing potential in the treatment of skin aging and wound healing, and the new use of its derivatives in the transdermal contraceptive treatment. The aim of our work was to verify if fresh or frozen rabbit ear skin can be a suitable skin model to study in vitro estradiol transdermal absorption. Fresh rabbit ear skin demonstrated a reasonable model of human epidermis in the investigation of estradiol permeation starting from both solutions and commercial patches.