Pharmacological activation of estrogen receptors-α and -β differentially modulates keratinocyte differentiation with functional impact on wound healing

Galectin-1 (Gal-1) and Galectin-3 (Gal-3) levels in seminal plasma and serum in azoospermic patients versus fertile men: A cross-sectional study

INTRODUCTION

Galectin-1 (Gal-1) and galectin-3 (Gal-3) are expressed by many immune cells and receive considerable attention in the context of immunity. We aimed to compare between seminal plasma and serum levels of Gal-1 and Gal-3 in azoospermic patients and fertile men.

MATERIALS AND METHODS

This cross-sectional study was conducted at the andrology outpatient clinic from January (2022) to September (2022). A total of 90 participants were enrolled and divided into two equal groups: azoospermic and normal group. Semen analysis was done for all participants. Hormonal profile including FSH, LH, serum prolactin, total testosterone and estradiol was performed as well as assessment of serum and seminal levels of Gal-1 and Gal-3 by ELISA commercial kits. Finally, scrotal Duplex was done in standing and supine position.

RESULTS

Serum and seminal levels of Gal-1 and Gal-3 were statistically significant higher in azoospermic patients compared with normal individuals (p < 0.001 for all). In addition, in healthy individuals there were statistically significant positive correlations between serum levels of Gal-1 and age, FSH, LH levels (r = 0.296, p = 0.005; r = 0.333, p = < 0.001; r = 0.312, p = 0.003, respectively) and serum levels of Gal-2 and FSH and LH (r = 0.436, p < 0.001; r = 0.350, p < 0.001, respectively), whereas serum Gal-3 showed a borderline positive correlation with age (r = 0.2, p = 0.059). Additionally, statistically significant positive correlations between seminal levels of Gal-1 and Gal-3 and free testosterone in healthy individuals were reported (r = 0.205, p = 0.053; r = 0.219, p = 0.038, respectively). On the other hand, there were negative correlations between serum and seminal levels of Gal-1 and Gal-3, total and progressive sperm motility, sperm count and abnormal sperm forms in healthy individuals (r = -0.382, p < 0.001; r = -0.405, p < 0.001; r = -0.376, p < 0.001; r = -0.364, p < 0.001) (r = -0.394, p < 0.001; r = -0.467, p < 0.001; r = -0.413, p < 0.001; r = -0.433, p < 0.001); (r = -0.372, p < 0.001; r = -0.377, p < 0.001; r = -0.317, p = 0.002; r = -0.311, p = 0.003)(r = -0.445, p < 0.001; r = -0.498, p < 0.001; r = -0.453, p < 0.001; r = -0.463, p < 0.001, respectively). Furthermore, statistically significant positive correlations between serum levels of Gal-1 and Gal-3 and age in azoospermic patients were reported (r = 0.511, p < 0.001; r = 0.390, p = 0.008, respectively). On the other hand, there were negative correlations between seminal Gal-1 and estradiol (E2) and seminal Gal-3 and FSH and LH in azoospermic patients (r= -0.318, p = 0.033; r = -0.322, p = 0.031; r = -0.477, p < 0.001, respectively). Also, negative correlations between serum Gal-3 and total and free testosterone in azoospermic patients were detected (r = -0.396, p = 0.007; r = -0.375, p = 0.011, respectively).

CONCLUSIONS

Elevated serum and seminal levels of Gal-1 and Gal-3 have detrimental effects on spermatogenesis. Furthermore, the current study demonstrated potential regulatory effects of reproductive hormones on Gal-1 and Gal-3. Thus, future studies are needed to confirm such findings.

Exploring the Potential of Lapatinib, Fulvestrant, and Paclitaxel Conjugated with Glycidylated PAMAM G4 Dendrimers for Cancer and Parasite Treatment

Fulvestrant (F), lapatinib (L), and paclitaxel (P) are hydrophobic, anticancer drugs used in the treatment of estrogen receptor (ER) and epidermal growth factor receptor (EGFR)-positive breast cancer. In this study, glycidylated PAMAM G4 dendrimers, substituted with F, L, and/or P and targeting tumor cells, were synthesized and characterized, and their antitumor activity against glioma U-118 MG and non-small cell lung cancer A549 cells was tested comparatively with human non-tumorogenic keratinocytes (HaCaT). All cell lines were ER+ and EGFR+. In addition, the described drugs were tested in the context of antinematode therapy on C. elegans. The results show that the water-soluble conjugates of G4P, G4F, G4L, and G4PFL actively entered the tested cells via endocytosis due to the positive zeta potential (between 13.57-40.29 mV) and the nanoparticle diameter of 99-138 nm. The conjugates of G4P and G4PFL at nanomolar concentrations were the most active, and the least active conjugate was G4F. The tested conjugates inhibited the proliferation of HaCaT and A549 cells; in glioma cells, cytotoxicity was associated mainly with cell damage (mitochondria and membrane transport). The toxicity of the conjugates was proportional to the number of drug residues attached, with the exception of G4L; its action was two- and eight-fold stronger against glioma and keratinocytes, respectively, than the equivalent of lapatinib alone. Unfortunately, non-cancer HaCaT cells were the most sensitive to the tested constructs, which forced a change in the approach to the use of ER and EGFR receptors as a goal in cancer therapy. In vivo studies on C. elegans have shown that all compounds, most notably G4PFL, may be potentially useful in anthelmintic therapy.

Prediction of medication-related osteonecrosis of the jaws using machine learning methods from estrogen receptor 1 polymorphisms and clinical information

Objective

The purpose of this study was to evaluate the effect of estrogen receptor 1 (ESR1) polymorphisms on the development of medication-related osteonecrosis of the jaws (MRONJ) in women with osteoporosis.

Methods

A total of 125 patients taking bisphosphonates was evaluated the relationship between MRONJ occurrence and single nucleotide polymorphisms (SNPs) of ESR1. Clinical information was collected, including current age, treatment duration, and comorbidity. Univariate and Multivariable regression analyzes were performed to evaluate the independent predictive factors for MRONJ occurrence. Predictive models were constructed using machine learning methods such as Lasso regression, Random forest (RF), and Support vector machine (SVM). The area under the receiver-operating curve (AUROC) was used to evaluate the performance of a binary classifier.

Result

Two SNPs of ESR1 (rs4870056 and rs78177662) were significantly associated with MRONJ development. Patients with variant allele (A) of rs4870056 showed 2.45 times (95% CI, 1.03-5.87) the odds of MRONJ occurrence compared to those with wild-type homozygote (GG) after adjusting covariates. Additionally, carriers with variant allele (T) of rs78177662 had higher odds than those with wild-type homozygote (CC) (adjusted odds ratio (aOR), 2.64, 95% CI, 1.00-6.94). Among demographic variables, age ≥ 72 years (aOR, 3.98, 95% CI, 1.60-9.87) and bisphosphonate exposure ≥48 months (aOR, 3.16, 95% CI, 1.26-7.93) were also significant risk factors for MRONJ occurrence. AUROC values of machine learning methods ranged between 0.756-0.806 in the study.

Conclusion

Our study showed that the MRONJ occurrence was associated with ESR1 polymorphisms in osteoporotic women.

Menopause induces changes to the stratum corneum ceramide profile, which are prevented by hormone replacement therapy

The menopause can lead to epidermal changes that are alleviated by hormone replacement therapy (HRT). We hypothesise that these changes could relate to altered ceramide production, and that oestrogen may have a role in keratinocyte ceramide metabolism. White Caucasian women were recruited into three groups: pre-menopausal (n = 7), post-menopausal (n = 11) and post-menopausal taking HRT (n = 10). Blood samples were assessed for hormone levels, transepidermal water loss was measured to assess skin barrier function, and stratum corneum lipids were sampled from photoprotected buttock skin. Ceramides and sphingomyelins were analysed by ultraperformance liquid chromatography with electrospray ionisation and tandem mass spectrometry. Post-menopausal stratum corneum contained lower levels of ceramides, with shorter average length; changes that were not evident in the HRT group. Serum oestradiol correlated with ceramide abundance and length. Ceramides had shorter sphingoid bases, indicating altered de novo ceramide biosynthesis. Additionally, post-menopausal women had higher sphingomyelin levels, suggesting a possible effect on the hydrolysis pathway. Treatment of primary human keratinocytes with oestradiol (10 nM) increased production of CER[NS] and CER[NDS] ceramides, confirming an effect of oestrogen on cutaneous ceramide metabolism. Taken together, these data show perturbed stratum corneum lipids post-menopause, and a role for oestrogen in ceramide production.

Exploring the impact of ovariectomy on hair growth: can ovariectomized mouse serve as a model for investigating female pattern hair loss in humans?

Female pattern hair loss (FPHL), a type of hair disease common in pre- and postmenopausal women, is characterized by thinning of hair to O-type, mainly at the crown. Although a mouse model of this disease has recently been established, its details are still unknown, and thus, warrants further analysis. In this study, 3 week-old and 7- to 8 week-old C57BL/6 female mice were divided into two groups: one group underwent ovariectomy (OVX), while the other underwent sham surgery. In the 3 week-old mice, the dorsal skin was collected at seven weeks of age, while in the 7- to 8 week-old mice, it was collected at 12 and 24 weeks of age. In the former group, both the pore size of the hair follicles (HFs) and diameter of the hair shaft of telogen HFs decreased upon OVX; while in the latter group, these factors increased significantly. Notably, the thickness of the dermis and subcutis increased significantly in the OVX group. It needs to be further elucidated whether OVX mouse could serve as an ideal mouse model for FPHL, but our results upon evaluation of skin thickness indicate that it could be used to establish a novel treatment for non-hair-related diseases, such as post-menopause-related skin condition.

Dual effects of bisphenol A on wound healing, involvement of estrogen receptor β

Bisphenol A (BPA) is a ubiquitous environmental pollutant that can specifically induce estrogen receptor β (ERβ) expression, and the latter plays a crucial role during wound healing. However, no study has investigated the association between BPA exposure and skin regeneration. This study aimed to explore the impacts of BPA on wound repair using mice models. C57BL/6 mice were administrated with BPA in two different ways during the process of wound healing-dietary intake (5 and 50 mg/kg) and wound application (1 and 100 nM). Mice primary fibroblasts were exposed to BPA to verify the role of BPA on the function of fibroblasts. We also applied BPA in diabetic mice to evaluate its therapy value. BPA showed dual effects on wound healing, which were dependent on the application routes. Dietary intake of BPA delayed wound healing by suppressing ovarian estrogen secretion, whereas wound application of BPA accelerated skin regeneration via up-regulating wound localized ERβ expression. Highly expressed ERβ enhanced the function of fibroblasts and promoted the transformation from fibroblasts to myofibroblasts. Impacts of BPA on wound healing were dismissed when ERβ was blocked. Moreover, wound application of BPA significantly accelerated wound repair in diabetic mice, but has no significant adverse effect on ovarian hormones levels. The current study indicates that although BPA disrupts the function of the endocrine system when administrated by diet, local application of BPA on wounds shows a superior role in promoting wound repair, and this may provide a novel approach for the therapy of pathologic wound healing.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Elucidating the cellular mechanism for E2-induced dermal fibrosis

BACKGROUND

Both TGFβ and estradiol (E2), a form of estrogen, are pro-fibrotic in the skin. In the connective tissue disease, systemic sclerosis (SSc), both TGFβ and E2 are likely pathogenic. Yet the regulation of TGFβ in E2-induced dermal fibrosis remains ill-defined. Elucidating those regulatory mechanisms will improve the understanding of fibrotic disease pathogenesis and set the stage for developing potential therapeutics. Using E2-stimulated primary human dermal fibroblasts in vitro and human skin tissue ex vivo, we identified the important regulatory proteins for TGFβ and investigated the extracellular matrix (ECM) components that are directly stimulated by E2-induced TGFβ signaling.

METHODS

We used primary human dermal fibroblasts in vitro and human skin tissue ex vivo stimulated with E2 or vehicle (ethanol) to measure TGFβ1 and TGFβ2 levels using quantitative PCR (qPCR). To identify the necessary cell signaling proteins in E2-induced TGFβ1 and TGFβ2 transcription, human dermal fibroblasts were pre-treated with an inhibitor of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway, U0126. Finally, human skin tissue ex vivo was pre-treated with SB-431542, a TGFβ receptor inhibitor, and ICI 182,780, an estrogen receptor α (ERα) inhibitor, to establish the effects of TGFβ and ERα signaling on E2-induced collagen 22A1 (Col22A1) transcription.

RESULTS

We found that expression of TGFβ1, TGFβ2, and Col22A1, a TGFβ-responsive gene, is induced in response to E2 stimulation. Mechanistically, Col22A1 induction was blocked by SB-431542 and ICI 182,780 despite E2 stimulation. Additionally, inhibiting E2-induced ERK/MAPK activation and early growth response 1 (EGR1) transcription prevents the E2-induced increase in TGFβ1 and TGFβ2 transcription and translation.

CONCLUSIONS

We conclude that E2-induced dermal fibrosis occurs in part through induction of TGFβ1, 2, and Col22A1, which is regulated through EGR1 and the MAPK pathway. Thus, blocking estrogen signaling and/or production may be a novel therapeutic option in pro-fibrotic diseases.

Human galectin‑3: Molecular switch of gene expression in dermal fibroblasts in vitro and of skin collagen organization in open wounds and tensile strength in incisions in vivo

Understanding the molecular and cellular processes in skin wound healing can pave the way for devising innovative concepts by turning the identified natural effectors into therapeutic tools. Based on the concept of broad-scale engagement of members of the family of galactoside-binding lectins (galectins) in pathophysiological processes, such as cancer or tissue repair/regeneration, the present study investigated the potential of galectins-1 (Gal-1) and −3 (Gal-3) in wound healing. Human dermal fibroblasts, which are key cells involved in skin wound healing, responded to galectin exposure (Gal-1 at 300 or Gal-3 at 600 ng/ml) with selective changes in gene expression among a panel of 84 wound-healing-related genes, as well as remodeling of the extracellular matrix. In the case of Gal-3, positive expression of Ki67 and cell number increased when using a decellularized matrix produced by Gal-3-treated fibroblasts as substrate for culture of interfollicular keratinocytes. In vivo wounds were topically treated with 20 μg/ml Gal-1 or −3, and collagen score was found to be elevated in excisional wound repair in rats treated with Gal-3. The tensile strength measured in incisions was significantly increased from 79.5±17.5 g/mm² in controls to 103.1±21.4 g/mm² after 21 days of healing. These data warrant further testing mixtures of galectins and other types of compounds, for example a combination of galectins and TGF-β1.

Quercetin promotes human epidermal stem cell proliferation through the estrogen receptor/β-catenin/c-Myc/cyclin A2 signaling pathway

Skin epidermal stem cells (EpSCs) play an important role in wound healing. Quercetin is a phytoestrogen reported to accelerate skin wound healing, but its effect on EpSCs is unknown. In this study, we investigated the effect of quercetin on human EpSC proliferation and explored the underlying mechanisms. We found that quercetin at 0.1~1 μM significantly promoted EpSC proliferation and increased the number of cells in S phase. The pro-proliferative effect of quercetin on EpSCs was confirmed in cultured human skin tissue. Mechanistic studies showed that quercetin significantly upregulated the expressions of β-catenin, c-Myc, and cyclins A2 and E1. Inhibitor for β-catenin or c-Myc significantly inhibited quercetin-induced EpSC proliferation. The β-catenin inhibitor XAV-939 suppressed quercetin-induced expressions of β-catenin, c-Myc, and cyclins A2 and E1. The c-Myc inhibitor 10058-F4 inhibited the upregulation of c-Myc and cyclin A2 by quercetin. Pretreatment of EpSCs with estrogen receptor (ER) antagonist ICI182780, but not the G protein-coupled ER1 antagonist G15, reversed quercetin-induced cell proliferation and upregulation of β-catenin, c-Myc, and cyclin A2. Collectively, these results indicate that quercetin promotes EpSC proliferation through ER-mediated activation of β-catenin/c-Myc/cyclinA2 signaling pathway and ER-independent upregulation of cyclin E1 and that quercetin may accelerate skin wound healing through promoting EpSC proliferation. As EpSCs are used not only in clinic to treat skin wounds but also as seed cells in skin tissue engineering, quercetin is a useful reagent to expand EpSCs for basic research, skin wound treatment, and skin tissue engineering.

Sexual dimorphism in atrophic effects of topical glucocorticoids is driven by differential regulation of atrophogene REDD1 in male and female skin

Topical glucocorticoids, well-known anti-inflammatory drugs, induce multiple adverse effects, including skin atrophy. The sex-specific effects of systemic glucocorticoids are known, but sexual dimorphism of therapeutic and side effects of topical steroids has not been studied. We report here that female and male mice were equally sensitive to the anti-inflammatory effect of glucocorticoid fluocinolone acetonide (FA) in ear edema test. At the same time, females were more sensitive to FA-induced skin atrophy. We recently reported that REDD1 (regulated in development and DNA damage 1) plays central role in steroid atrophy. We found that REDD1 was more efficiently activated by FA in females, and that REDD1 knockout significantly protected female but not male mice from skin atrophy. Studies using human keratinocytes revealed that both estradiol and FA induced REDD1 mRNA/protein expression, and cooperated when they were combined at low doses. Chromatin immunoprecipitation analysis confirmed that REDD1 is an estrogen receptor (ER) target gene with multiple estrogen response elements in its promoter. Moreover, experiments with GR and ER inhibitors suggested that REDD1 induction by these hormones was interdependent on functional activity of both receptors. Overall, our results are important for the development of safer GR-targeted therapies suited for female and male dermatological patients.

Acute body sodium depletion induces skin sodium mobilization in female Wistar rats

NEW FINDINGS

What is the central question of this study? Can Na⁺ depletion mobilize Na⁺ from the skin reservoir in ovariectomized rats? Does oestrogen replacement change the amount and the dynamics of skin Na⁺ storage? Is the reduced salt appetite after Na⁺ depletion in ovariectomized rats with oestrogen replacement related to changes in the skin Na⁺ ? What is the main finding and its importance? This work demonstrated that acute body Na⁺ depletion induced by frusemide mobilized the osmotically inactive skin Na⁺ reservoir to become osmotically active. Oestrogen treatment decreased the induced Na⁺ intake in ovariectomized rats but did not modulate the inactive Na⁺ reservoir in control conditions or its mobilization induced by Na⁺ depletion.

ABSTRACT

Oestradiol, which is an important hormone for water and electrolyte balance, also has a role in the inhibition of induced Na⁺ appetite. Sodium can be stored in the skin in osmotically active or inactive forms, and this skin Na⁺ reservoir may be involved in the control of body Na⁺ levels during physiopathological challenges. In this study, we investigated whether the effect of sodium depletion by frusemide can mobilize Na⁺ from the skin reservoir and whether oestradiol replacement changes or mobilizes the Na⁺ reserves in the skin. Ovariectomized Wistar rats were treated with vehicle or oestradiol for 7 days to evaluate the effects of oestrogen on the hydroelectrolyte balance, intake responses and skin Na⁺ and water content in basal conditions. Furthermore, the effects of oestrogen were evaluated after 24 h frusemide-induced whole-body Na⁺ depletion. Oestradiol-replaced rats exhibited reduced water intake without any significant changes in salt intake, Na⁺ excretion or water and Na⁺ skin content in basal conditions. After sodium depletion, both vehicle- and oestradiol-treated rats exhibited an increase in the osmotically active skin Na⁺ , which was associated with a decrease of the inactive skin Na⁺ reservoir. Oestrogen decreased the hypertonic saline intake induced by Na⁺ depletion, but it was not associated with any significant changes in the skin Na⁺ reservoir. Thus, sodium depletion is able to change the inactive-active skin Na⁺ reservoir balance. However, the oestrogenic modulation of sodium appetite after Na⁺ depletion is probably not related to the action of this hormone in the skin Na⁺ reservoir balance.

Genistein Improves Skin Flap Viability in Rats: A Preliminary In Vivo and In Vitro Investigation

Selective estrogen receptor modulators (SERMs) have been developed to achieve beneficial effects of estrogens while minimizing their side effects. In this context, we decided to evaluate the protective effect of genistein, a natural SERM, on skin flap viability in rats and in a series of in vitro experiments on endothelial cells (migration, proliferation, antioxidant properties, and gene expression profiling following genistein treatment). Our results showed that administration of genistein increased skin flap viability, but importantly, the difference is only significant when treatment is started 3 days prior the flap surgery. Based on our in vitro experiments, it may be hypothesized that the underlying mechanism may rather by mediated by increasing SOD activity and Bcl-2 expression. The gene expression profiling further revealed 9 up-regulated genes (angiogenesis/inflammation promoting: CTGF, CXCL5, IL-6, ITGB3, MMP-14, and VEGF-A; angiogenesis inhibiting: COL18A1, TIMP-2, and TIMP-3). In conclusion, we observed a protective effect of genistein on skin flap viability which could be potentially applied in plastic surgery to women undergoing a reconstructive and/or plastic intervention. Nevertheless, further research is needed to explain the exact underlying mechanism and to find the optimal treatment protocol.

[Effects of local anesthetics on wound healing]

INTRODUCTION

Local anesthetic infiltration is used widely for post-operative analgesia in many situations. However the effects of local anesthetics on wound healing are not demonstrated clearly. This study planned to evaluate the effects of lidocaine, prilocaine, bupivacaine and levobupivacaine on wound healing, primarily on wound tensile strength and on collagen ultrastructure.

METHODS

This study was conducted on male Sprague Dawley rats. On days 0, 8th, 15th, and 21st, all animals were weighed and received a preincisional subcutaneous infiltration of 3mL of a solution according the group. Control saline (C), lidocaine (L) 7mg.kg^-1, prilocaine (P) 2mg.kg^-1, bupivacaine (B) 2mg.kg^-1 and levobupivacaine (LVB) 2.5mg.kg^-1. The infiltrations were done at the back region 1.5cm where incision would be performed at the upper, middle and lower part along the midline, under general anesthesia. Wound tensile strengths were measured after 0.7cm×2cm of cutaneous and subcutaneous tissue samples were obtained vertical to incision from infiltrated regions. Tissue samples were also obtained for electron microscopic examination. Evaluations were on the 8th, 15th and 21st days after infiltration.

RESULTS

There was no difference between groups in the weights of the rats at the 0th, 8th, 15th and 21st days. The collagen maturation was no statistically different between groups at the 8th and 15th days. The maturation scores of the B and L groups at the 21st day was significantly lower than the Group C (1.40, 1.64 and 3.56; respectively). The wound tensile strength was no statistically different between groups at the 8th and 15th days but at the 21st day the Groups B and LVB had significantly lower value than Group C (5.42, 5.54 and 6.75; respectively).

CONCLUSION

Lidocaine and prilocaine do not affect wound healing and, bupivacaine and levobupivacaine affect negatively especially at the late period.

α-Tocopherol promotes HaCaT keratinocyte wound repair through the regulation of polarity proteins leading to the polarized cell migration

In many developed countries including Japan, how to care the bedridden elderly people with chronic wounds such as decubitus becomes one of the most concerned issues. Although antioxidant micronutrients including vitamin E, especially α-tocopherol (α-Toc), are reported to shorten a period of wound closure, the promoting effect of α-Toc on wound healing independent of its antioxidant activity remains to be fully elucidated. The aim of this study was to examine whether α-Toc affects wound-mediated HaCaT keratinocyte polarization process including the recruitment of polarity regulating proteins, leading to wound repair independently of its antioxidant activity. We investigated the effects of α-Toc and other antioxidants such as Trolox, a cell-permeable α-Toc analog on the migration, proliferation, and cell polarization of HaCaT keratinocytes after wounding. We analyzed the localization and complex formation of polarity proteins, partitioning defective 3 (Par3), and atypical protein kinase C (aPKC), and aPKC activity by immunohistochemistry, immunoprecipitation analyses, and in vitro kinase assays, respectively. α-Toc but not other antioxidants enhanced the wound closure and cell polarization in HaCaT keratinocytes after wounding. α-Toc regulated the localization and complex formation of Par3 and aPKC during wound healing. Knockdown of aPKC or Par3 abrogated α-Toc-mediated promotion of the wound closure and cell polarization in HaCaT keratinocytes. Furthermore, aPKC kinase activity was significantly increased in α-Toc-treated cells through activation of phosphatidylinositol 3-kinase/Akt signaling pathway. These results suggest that α-Toc promotes HaCaT keratinocyte wound repair by regulating the aPKC kinase activity and the formation of aPKC-Par3 complex. © 2017 BioFactors, 44(2):180-191, 2018.

Estrogen Effects on Wound Healing

Wound healing is a physiological process, involving three successive and overlapping phases—hemostasis/inflammation, proliferation, and remodeling—to maintain the integrity of skin after trauma, either by accident or by procedure. Any disruption or unbalanced distribution of these processes might result in abnormal wound healing. Many molecular and clinical data support the effects of estrogen on normal skin homeostasis and wound healing. Estrogen deficiency, for example in postmenopausal women, is detrimental to wound healing processes, notably inflammation and re-granulation, while exogenous estrogen treatment may reverse these effects. Understanding the role of estrogen on skin might provide further opportunities to develop estrogen-related therapy for assistance in wound healing.

A thermal gradient modulates the oxidative metabolism and growth of human keratinocytes

During their spatial and differentiative progression, keratinocytes face a thermal gradient, from 37 °C in the proliferating basal layer to 32 °C found in skin surface. In our study, we hypothesized that this difference in temperature must be balanced by increasing the heat produced during respiratory activity. We demonstrated that at 33 °C human primary keratinocytes and HaCaT cells raised mitochondrial energy metabolism, but not glycolytic activity. At 33 °C, the increased mitochondrial ATP synthesis was associated with a strong induction of the modulator of the respiratory chain estrogen receptor β, whereas uncoupling protein 1 expression was not changed. The enhanced mitochondrial oxidative metabolism was accompanied by a remarkable reduction in proliferation. These results suggest that environmental temperature can modulate the energy metabolism and proliferation of human keratinocytes.

Roles of ERα during mouse trophectoderm lineage differentiation: revealed by antagonist and agonist of ERα

During mouse early embryogenesis, blastomeres increase in number by the morula stage. Among them, the outer cells are polarized and differentiated into trophectoderm (TE), while the inner cells remain unpolarized and give rise to inner cell mass (ICM). TE provides an important liquid environment for ICM development. In spite of extensive research, the molecular mechanisms underlying TE formation are still obscure. In order to investigate the roles of estrogen receptor α (ERα) in this course, mouse 8-cell embryos were collected and cultured in media containing ERα specific antagonist MPP and/or agonist PPT. The results indicated that MPP treatment inhibits blastocyst formation in a dose-dependent manner, while PPT, at proper concentration, promotes the cavitation ratio of mouse embryos. Immunofluorescence staining results showed that MPP significantly decreased the nuclear expression of CDX2 in morula, but no significant changes of OCT4 were observed. Moreover, after MPP treatment, the expression levels of the genes related to TE specification, Tead4, Gata3 and Cdx2, were significantly reduced. Overall, these results indicated that ERα might affect mouse embryo cavitation by regulating TE lineage differentiation.