Inhibition of Hippo Signaling Improves Skin Lesions in a Rosacea-Like Mouse Model.

The Hippo signaling pathway plays a key role in regulating organ size and tissue homeostasis. Hippo and two of its main effectors, yes-associated protein (YAP) and WWTR1 (WW domain-containing transcription regulator 1, commonly listed as TAZ), play critical roles in angiogenesis. This study investigated the role of the Hippo signaling pathway in the pathogenesis of rosacea. We performed immunohistochemical analyses to compare the expression levels of YAP and TAZ between rosacea skin and normal skin in humans. Furthermore, we used a rosacea-like BALB/c mouse model induced by LL-37 injections to determine the roles of YAP and TAZ in rosacea in vivo. We found that the expression levels of YAP and TAZ were upregulated in patients with rosacea. In the rosacea-like mouse model, we observed that the clinical features of rosacea, including telangiectasia and erythema, improved after the injection of a YAP/TAZ inhibitor. Additionally, treatment with a YAP/TAZ inhibitor reduced the expression levels of YAP and TAZ and diminished vascular endothelial growth factor (VEGF) immunoreactivity in the rosacea-like mouse model. Our findings suggest that YAP/TAZ inhibitors can attenuate angiogenesis associated with the pathogenesis of rosacea and that both YAP and TAZ are potential therapeutic targets for patients with rosacea.

Surtuin 1 as a potential prognostic biomarker in very elderly patients with colorectal cancer.

BACKGROUND/AIMS: Colorectal cancer (CRC) rate increases with aging. Aging-related proteins, such as sirtuins (SIRTs) may be a potential therapeutic target in the elderly patients with CRC. The clinical implications of SIRT1 and SIRT2 have not been reported for elderly patients with cancer. The aim of this study was to evaluate the impact of expression of SIRT1 and SIRT2 on clinical outcome in two extreme age groups of patients with CRC. METHODS: The expression of SIRT1 and SIRT2 were evaluated in CRC tissues of 101 patients aged ≥ 80 years and 29 patients aged ≤ 40 years by immunohistochemistry. We defined the patients aged ≥ 80 years as the very elderly and patients aged ≤ 40 years as the young patients. Correlations between the expression of these proteins and clinicopathological features were analyzed. RESULTS: The prognosis for the very elderly patients with high expressions of SIRT1 was significantly worse than that for patients showing low expression (median survival, 24.9 months vs. 38.6 months, p = 0.027) whereas high expression of SIRT2 better prognosis (median survival, 37.9 months vs. 17.3 months, p = 0.006). However, the young patients did not show any difference in prognosis according to expression of SIRT1 and SIRT2. In multivariate analysis, high SIRT1 expression retained statistical significance as a poor prognostic factor in the very elderly patients with CRC. CONCLUSION: The results suggest that high SIRT1 expression could be predictive of a poor outcome for very elderly patients with CRC.

Paracrine roles of hormone receptors in Riehl's melanosis: A quantitative analysis of oestrogen and progesterone receptor expression patterns.

The incidence of Riehl's melanosis (RM) is most common in the fifth or sixth decade of life with a female preponderance. As the skin is regarded a non-reproductive organ on which sex steroid hormones act, a possible relationship between the pathogenesis of RM and sex steroid hormone receptors can be inferred. This study intended to evaluate the expression profile of oestrogen receptor (ER)ß and progesterone receptor (PR) in RM. Twelve lesional and perilesional normal-appearing skin samples of RM patients and the skin of 12 healthy controls were retrieved for the analysis. Real-time PCR analysis and immunohistochemical studies were conducted for ERß and PR, respectively. The lesional and perilesional normal-appearing skin of 12 patients with RM and the skin of 12 healthy controls were retrieved for the analysis. Interestingly, the dermal ERß immunostaining intensity was increased more in lesional skin than in perilesional skin. When compared to healthy controls, increased expression of ERß and PR mRNAs was observed in the lesional skin of patients with RM. Of note, epidermal and dermal ERß and dermal PR expressions showed increased staining intensities in the lesional skin of RM patients compared with healthy controls. The altered expression of ERß and PR in RM supports the possible role of these hormone receptors in the pathogenesis of RM.

Melanogenic Properties and Expression Profiles of Melanogenic Paracrine Molecules in Riehl's Melanosis.

Riehl's melanosis is a hyperpigmentary disorder that occurs predominantly on the face and neck. To date, the pathogenesis of Riehl's melanosis with regards to the melanogenic properties and paracrine melanogenic molecules has not well been studied. This study was aimed to provide a novel perspective on the pathogenesis of Riehl's melanosis by identifying the relevant paracrine melanogenic molecules in Riehl's melanosis. Skin biopsies were performed on lesional and normal-appearing perilesional skin of 12 patients with Riehl's melanosis and 12 age- and sex-matched healthy controls. Histopathological and immunohistochemical staining for paracrine melanogenic molecules was analyzed. The major histopathological findings of Riehl's melanosis were basal hyperpigmentation, melanocyte proliferation, interface change, dermal pigmentary incontinence, vascular proliferation, and dermal inflammation. Dermal expression intensities of stem cell factor (SCF) and c-kit were increased in the lesional skin of Riehl's melanosis. In addition, increased expression of epidermal and dermal ET-1 was also observed in the lesional skin of Riehl's melanosis. Increased tissue expressions of SCF, c-kit, and ET-1 in Riehl's melanosis support the role of these paracrine melanogenic molecules in the pathogenesis of Riehl's melanosis. The findings from this study might present useful information on the pathogenetic mechanism of Riehl's melanosis.

The effect of prolonged rhBMP-2 treatment on telomerase activity, replicative capacity and senescence of human nucleus pulposus cells.

We investigated the effect of prolonged rhBMP-2 treatment on telomerase activity, replicative capacity and senescence of nucleus pulposus cells (NPCs) during long term culture. We obtained intervertebral disc (IVD) tissues with grade III degeneration from four patients. NPCs were isolated and passaged serially in three groups: control group, low-dose rhBMP-2 group and high-dose rhBMP-2 group until the cells reached the end of their replicative lifespan. Cumulative population doubling level (CPDL), telomerase activity and senescence markers, senescence-associated ß-galactosidase (SA-ß-gal), p53, p21, and p16, were assessed. The replicative capacity of NPCs in the high-dose rhBMP-2 group was decreased significantly compared to the control and low-dose rhBMP-2 groups. Mean telomerase activity was significantly greater in the high-dose rhBMP-2 group compared to the control and low-dose rhBMP-2 groups. The percentage of SA-ß-gal-positive NPCs increased more rapidly in the high-dose rhBMP-2 group with passaging compared to the control and low-dose rhBMP-2 groups. The expression of p53, p21, and p16 in both low and high dose rhBMP-2 groups increased in all passages compared to the control group. We found that prolonged high-dose rhBMP-2 treatment increased telomerase activity of human NPCs, but decreased replicative capacity and lifespan in long term culture. We also found that excessive growth stimulation by prolonged high-dose rhBMP-2 treatment can promote NPCs senescence and result in growth arrest.

Long-pulsed 1064-nm Nd: YAG laser ameliorates LL-37-induced rosacea-like skin lesions through promoting collagen remodeling in BALB/c mice.

Long-pulsed 1064-nm neodymium: yttrium-aluminum-garnet laser (LPND) effectively treats rosacea, although the underlying mechanism is unclear, to evaluate the histological effects and molecular mechanism of LPND on LL-37-induced rosacea-like skin lesions in mice. Intradermal injection of LL-37 was performed into the dorsal skin of BALB/c mice (n = 30) twice a day for 2 days. Fifteen mice were treated with LPND. After 48 h, the excised skin sample was stained for histology and type I collagen; transforming growth factor (TGF)-ß, matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase (TIMP)-1, tumor necrosis factor (TNF)-α, and interleukin (IL)-1α mRNA levels were determined by real-time RT-PCR. Intradermal injection of LL-37 induced rosacea-like clinical features. LPND treatment significantly reduced erythema and increased dermal collagen production. Levels of Type I collagen, TGF-ß, and MMP-1 mRNA were significantly higher in LPND-treated mice than in untreated mice. LPND may improve rosacea by ameliorating dermal connective tissue disorganization and elastosis through MMP-mediated dermal collagen remodeling.

Inhibition of mast cell infiltration in an LL-37-induced rosacea mouse model using topical brimonidine tartrate 0.33% gel.

Brimonidine is a highly selective α2-adrenergic receptor agonist approved by the FDA for the treatment of rosacea. Rosacea is a major clinical disease with vasodilatation and rash on the centre of the face, and that brimonidine as a vasoconstrictor can act as a remedy for rosacea. However, there is no study of how brimonidine has an effect on rosacea-related immune cells or mechanisms in the skin to improve rosacea. In this study, we observed that clinical features of rosacea induced by LL-37 in Balb/c mice were improved after the application of brimonidine gel, and we also showed a marked decrease in the number of inflammatory cells, especially mast cells (MCs) histologically. Furthermore, we confirmed that mRNA levels of MC enzymes increased by LL-37 were reduced by brimonidine gel. To our knowledge, we first found that brimonidine has a mechanism of treating rosacea by reducing the number and mRNA levels of MC-specific enzymes, an important immune cell in the pathogenesis of rosacea.

Analysis of apoptosis-associated molecules Erythroid differentiation regulator 1, bcl-2 and p53 in actinic keratosis after treatment with ingenol mebutate.

Actinic keratosis (AK) is the most common cutaneous premalignant neoplasm precursor of malignant skin tumors. The aberrant apoptotic pathway is thought to be associated with pathogenesis of AK. Ingenol mebutate has been shown to be effective and safe for treatment of AK. However, the effect of ingenol mebutate on apoptosis-related molecules using human skin samples has not been studied well. Erythroid differentiation regulator 1 (Erdr1) was recently reported to play a crucial role in malignant skin cancers like malignant melanoma. The role of Erdr1 in premalignant actinic keratosis (AK) has not been explored. The purpose of this study was to investigate whether the expression of apoptosis-associated molecules such as Erdr1, p53 and bcl-2 was affected by the treatment of ingenol mebutate in AK. Nine patients with AK underwent skin biopsy at baseline and 8 weeks after treatment with ingenol mebutate for immunohistochemical evaluation with Erdr1, p53 and bcl-2. In addition, skin samples from five control subjects were retrieved. Upregulation of Erdr1 and a significant decrease in expression of p53 and bcl-2 were observed after treatment with ingenol mebutate. Ingenol mebutate treatment for AK resulted in the modulation of apoptosis-associated molecules with an increase in the expression of Erdr1 and a decrease in the expression of p53 and bcl-2.

Erythroid Differentiation Regulator 1 as a Novel Biomarker for Hair Loss Disorders.

Erythroid differentiation regulator 1 (Erdr1) is known to be involved in the inflammatory process via regulating the immune system in many cutaneous disorders, such as psoriasis and rosacea. However, the role of Erdr1 in various hair loss disorders remains unclear. The aim of this study was to investigate the putative role of Erdr1 in alopecias. Skin samples from 21 patients with hair loss disorders and five control subjects were retrieved, in order to assess their expression levels of Erdr1. Results revealed that expression of Erdr1 was significantly downregulated in the epidermis and hair follicles of patients with hair loss disorders, when compared to that in the control group. In particular, the expression of Erdr1 was significantly decreased in patients with alopecia areata. We propose that Erdr1 downregulation might be involved in the pathogenesis of hair loss, and could be considered as a novel biomarker for hair loss disorders.

Effects of the Ultra-High-Frequency Electrical Field Radiofrequency Device on Mouse Skin: A Histologic and Molecular Study.

BACKGROUND: Radiofrequency technology is one of the most recently developed methods for noninvasive skin tightening and facial contouring, and works by generating thermal energy in the deep dermis. Although clinical improvements have been reported using radiofrequency devices, there are few histologic and molecular studies about the mechanisms of dermal collagen remodeling. The authors investigated the histologic effects of an ultra-high-frequency electrical field (40.68 MHz) radiofrequency device (Polargen) on collagen remodeling in hairless mouse skin and evaluated its relative molecular mechanism. METHODS: The radiofrequency was applied to the dorsal skin of hairless mice three times per week for 2 weeks. At 21 days after initial treatment, treated skin and nontreated control skin samples were excised for semiquantitative analysis of histologic features, including collagen. The authors also checked the mRNA expression levels of collagen type 1, transforming growth factor (TGF)-ß, matrix metalloproteinase-1, vascular endothelial growth factor, tumor necrosis factor-α, and interleukin-1. RESULTS: Histologic examination revealed epidermal hyperplasia, increased collagen staining, and fat atrophy in treated skin area compared with the nontreated skin area. In addition, mRNA expression of collagen type І, TGF-ß, and vascular endothelial growth factor in radiofrequency-treated areas was significantly increased compared with that in untreated control areas (p < 0.05, p < 0.05, and p < 0.01, respectively). CONCLUSIONS: These results suggest that the device may facilitate replacement of subcutaneous fat tissue with new collagen in association with the increased mRNA levels in TGF-ß and vascular endothelial growth factor. Therefore, this device may effectively reduce adipose tissue and achieve facial contouring in addition to skin tightening.

Relationship between Initial Telomere Length, Initial Telomerase Activity, Age, and Replicative Capacity of Nucleus Pulposus Chondrocytes in Human Intervertebral Discs: What Is a Predictor of Replicative Potential?

There is evidence that telomere length (TL), telomerase activity (TA), and age are related to the replicative potential of human nucleus pulposus chondrocytes (NPCs). However, it has not yet been established if any of these factors can serve as predictors of the replicative potential of NPCs. To establish predictors of the replicative potential of NPCs, we evaluated potential relationships between replicative capacity of NPCs, initial TL (telomere length at the first passage), initial TA (telomerase activity at the first passage), and age. Nucleus pulposus specimens were obtained from 14 patients of various ages undergoing discectomy. NPCs were serially cultivated until the end of their replicative lifespans. Relationships among cumulative population doubling level (PDL), initial TL, initial TA, and age were analyzed. Initial TA was negatively correlated with age (r = -0.674, P = 0.008). However, no correlation between initial TL and age was observed. Cumulative PDL was also negatively correlated with age (r = -0.585, P = 0.028). Although the cumulative PDL appeared to increase with initial TL or initial TA, this trend was not statistically significant. In conclusion, age is the sole predictor of the replicative potential of human NPCs, and replicative potential decreases with age. Initial TL and initial TA are not predictors of replicative potential, and can serve only as reference values.

Recombinant erythroid differentiation regulator 1 inhibits both inflammation and angiogenesis in a mouse model of rosacea.

The erythroid differentiation regulator 1 (Erdr1), which is a novel and highly conserved factor, was recently reported to be negatively regulated by IL-18 and to play a crucial role as an antimetastatic factor. IL-18 is a proinflammatory cytokine that functions as an angiogenic mediator in inflammation. Rosacea is a chronic inflammatory skin disorder that is characterized by abnormal inflammation and vascular hyperactivity of the facial skin. To determine whether Erdr1 contributes to the regulation of the chronic inflammatory process in the development of rosacea, an immunohistochemical analysis was performed in healthy donors and patients with rosacea. In this study, we showed that Erdr1 was downregulated, whereas IL-18 was upregulated, in patients with rosacea, which led us to question the role of Erdr1 in this disorder. Moreover, a rosacea-like BALB/c mouse model was used to determine the role of Erdr1 in rosacea in vivo. LL-37 injection induced typical rosacea features, including erythema, telangiectasia and inflammation. Treatment with recombinant Erdr1 (rErdr1) resulted in a significant reduction of erythema, inflammatory cell infiltration (including CD4(+) and CD8(+) T cells), and microvessel density with vascular endothelial growth factor (VEGF). Taken together, our findings suggest that rErdr1 may be involved in attenuating the inflammation and angiogenesis associated with the pathogenesis of rosacea. Thus, these results provide new insight into the mechanism involved in this condition and indicate that rErdr1 could be a potential target for therapeutic intervention of rosacea.

In vitro lifespan and senescence mechanisms of human nucleus pulposus chondrocytes.

BACKGROUND CONTEXT: Our previous in vivo study demonstrated that human nucleus pulposus chondrocytes (NPCs) in aging discs exhibited characteristic senescent features such as an increased senescence-associated ß-galactosidase (SA-ß-gal) expression, shortened telomere, and decreased telomerase activity. The replicative p53-p21-pRB pathway, rather than the stress-induced p16-pRB pathway, played a more important role in the senescence of NPCs in an in vivo condition, although there is a situation in which both the pathways can be activated simultaneously. However, the in vitro lifespan and senescence mechanisms of human NPCs remain unclear. PURPOSE: To evaluate the underlying mechanisms of in vitro lifespan and in vitro senescence of the human NPCs and to verify whether the in vitro senescence mechanisms of the human NPC can represent the in vivo aging mechanisms of the cell. STUDY DESIGN/SETTING: An in vitro study. METHODS: We serially cultivated human NPCs from patients of different ages (35, 42, 55, 66, and 76 years) until the cells reached the end of their in vitro lifespan. During each subcultivation, we calculated NPCs cumulative population doubling level (PDL) and examined senescence markers (SA-ß-gal, telomere length, telomerase activity, and p53, p21, pRB, and p16 expressions). RESULTS: The cumulative PDLs of the NPCs from patients aged 35, 42 55, 66, and 76 years were 32, 29, 11, 9, and 11, respectively. The younger patients (35 and 42 years) had a higher mean of cumulative PDLs than the elderly patients did (55, 66, and 76 years; 30.5 vs. 10.3; p=.001). In addition, there was a significant, negative correlation between the cumulative PDLs and patient's age (r=-0.89; p=.04). With advancing culture passages, the NPCs irrespective of patient's age exhibited characteristic senescent features, such as an increase in SA-ß-gal expression, shortening of telomeres, decrease in telomerase activity, and activation of both replicative p53-p21-pRB and stress-induced p16-pRB pathways. However, all the senescent features occurred at the earlier passages in elderly compared with younger patients. CONCLUSIONS: The present study demonstrated that the human NPCs had a finite in vitro lifespan, which declined with host aging. The in vitro lifespan was determined by both replicative and stress-induced senescence mechanisms. The similarity in the in vitro senescent features with those apparent in the previous in vivo study suggests a possibility of the in vitro senescence mechanisms of the human NPC as a model of the in vivo aging mechanisms of the cell for future studies.