Implication of microRNA regulation in para-phenylenediamine-induced cell death and senescence in normal human hair dermal papilla cells

Genotoxicity of oxidative hair dye precursors: A systematic review

This systematic review, conducted according to the PRISMA guidelines, focuses on genotoxicity of oxidative hair dye precursors. The search for original papers published from 2000 to 2021 was performed in Medline, Web of Science, Cochrane registry, Scientific Committee on Consumer Safety of the European Commission and German MAK Commission opinions. Nine publications on genotoxicity of p-phenylenediamine (PPD) and toluene-2,5-diamine (p-toluylenediamine; PTD) were included, reporting results of 17 assays covering main genotoxicity endpoints. PPD and PTD were positive in bacterial mutation in vitro assay, and PPD tested positive also for somatic cell mutations in the Rodent Pig-a assay in vivo. Clastogenicity of PPD and PTD was revealed by in vitro chromosomal aberration assay. The alkaline comet assay in vitro showed DNA damage after PPD exposure, which was not confirmed in vivo, where PTD exhibited positive results. PPD induced micronucleus formation in vitro, and increased micronucleus frequencies in mice erythrocytes following high dose oral exposure in vivo. Based on the results of a limited number of data from the classical genotoxicity assay battery, this systematic review indicates genotoxic potential of hair dye precursors PPD and PTD, which may present an important health concern for consumers and in particular for professional hairdressers.

Interactions of TiO2 Nanoparticles with Ingredients from Modern Lifestyle Products and Their Effects on Human Skin Cells

The number of consumer products containing nanoparticles (NPs) experienced a rapid increase during the past decades. However, most studies of nanosafety have been conducted using only pure NPs produced in the laboratory, while the interactions with other ingredients in consumer products have rarely been considered so far. In the present study, we investigated such interactions—with a special focus on modern lifestyle products (MLPs) used by adolescents. An extensive survey was undertaken at different high schools all over Austria to identify MLPs that either contain NPs or that could come easily in contact with NPs from other consumer products (such as TiO₂ from sunscreens). Based on the results from a survey among secondary schools students, we focused on ingredients from Henna tattoos (2-hydroxy-1,4-naphtoquinone, HNQ, and p-phenylenediamine, PPD), fragrances (butylphenyl methylpropional, known as Lilial), cosmetics and skin-care products (four different parabens). As a cellular model, we decided to use neonatal normal human dermal fibroblasts (nNHDF), since skin contact is the main route of exposure for these compounds. TiO₂ NPs interacted with these compounds as evidenced by alterations in their hydrodynamic diameter observed by nanoparticle tracking analysis. Combinations of TiO₂ NPs with the different MLP components did not show altered cytotoxicity profiles compared to MLP components without TiO₂ NPs. Nevertheless, altered cellular glutathione contents were detected after incubation of the cells with Lilial. This effect was independent of the presence of TiO₂ NPs. Testing mixtures of NPs with other compounds from consumer products is an important approach to achieve a more reliable safety assessment.

MicroRNA-30e inhibits adhesion, migration, invasion and cell cycle progression of prostate cancer cells via inhibition of the activation of the MAPK signaling pathway by downregulating CHRM3

Prostate cancer (PCa) testing is currently based on measurement of serum prostate‑specific antigen levels and digital rectal examination, which are limited by a low predictive value and the adverse effects associated with overdiagnosis and overtreatment. Recent studies have reported that the abnormal expression of microRNAs (miRNAs) is associated with the mechanism underlying the development of PCa. Thus, the aim of the present study was to investigate the effects of miR‑30e and its target gene, M3 muscarinic acetylcholine receptor (CHRM3), on the adhesion, migration, invasion and cell cycle distribution of PCa cells via the mitogen‑activated protein kinase (MAPK) signaling pathway. The differentially expressed genes were screened in the Gene Expression Omnibus database from a gene expression microarray (GSE55945) of PCa. PCa tissues and adjacent tissues were collected from patients with PCa. The PC‑3 and DU145 human PCa cell lines were treated with activator, inhibitor and siRNAs. The effects of miR‑30e on cell adhesion, migration, invasion and cell cycle distribution with the involvement of CHRM3 and the MAPK signaling pathway were investigated. The bioinformatics results demonstrated that the CHRM3 gene and the MAKP signaling pathway were involved in the progression of PCa, and has‑miR‑30e was selected for further study. The levels of miR‑30e were significantly downregulated, while the levels of CHRM3 were obviously upregulated in PCa. CHRM3 was verified as a target gene of miR‑30e. Upregulation of miR‑30e and downregulation of CHRM3 decreased the levels of p‑P38, p‑extracellular signal‑regulated kinase, p‑c‑Jun N‑terminal kinase, p‑c‑fos and p‑c‑JUN, cell adhesion, migration and invasion ability, and the number of cells in the S phase, while they increased the number of cells in the G0 and G1 phases. The findings of the present study suggest that miR‑30e inhibited the adhesion, migration, invasion and cell cycle entry of PCa cells by suppressing the activation of the MAPK signaling pathway and inhibiting CHRM3 expression. Thus, miR‑30e may serve as a candidate target for the treatment of PCa.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well-being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet-rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid-nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress-serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs' activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end-point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up-to-date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.

miR-30e* is overexpressed in prostate cancer and promotes NF-κB-mediated proliferation and tumor growth

According to the CDC prostate cancer (CaP) has the highest incidence and second highest mortality rate amongst cancers in American men. Constitutive NF-κB activation is a hallmark of CaP and this pathway drives many pro-tumorigenic characteristics of CaP cells, including cell proliferation and survival. An activated NF-κB gene signature is predictive of CaP progression and biochemical recurrence following therapeutic intervention. However, the mechanisms that perpetuate NF-κB activation are incompletely understood. Genes that control NF-κB activity are rarely mutated in CaP suggesting that epigenetic mechanisms may contribute to constitutive NF-κB activation. microRNAs (miRs) epigenetically regulate many genes involved with NF-κB activation. IκBα is a direct inhibitor of NF-κB; it binds to and sequesters NF-κB in the cytoplasm resulting in functional inhibition. IκBα is a target gene of miR-30e* yet the expression and oncological impact of miR-30e* in CaP is unknown. We report that miR-30e* expression is elevated in multiple murine models of CaP and is most pronounced in late stage disease. miR-30e* drives CaP proliferation and tumor growth through inhibition of IκBα, which results in chronic activation of NF-κB. Additionally, we show that inhibition of miR-30e* improves chemotherapeutic control of CaP. Thus, miR-30e* may prove to be a novel clinical target whose inhibition leads to decreased CaP cell proliferation and sensitization of CaP cells to chemotherapeutics.

Chemically induced strong cellular hypertrophy often reduces the accuracy of cytotoxicity measurements obtained using the ATP assay

The ATP assay is a highly sensitive and versatile method for measuring cytotoxicity. However, the correlation between the cell viability results obtained using the ATP assay and those obtained using direct cell counting has not been widely reported. Therefore, to evaluate the reliability and limitations of the ATP assay, we compared the results of ATP assay with those of automatic cell counter, which can measure the number and diameter of cells directly, by using 24 compounds and repeating individual experiments thrice. The correlation between the data was low for 7 of the 24 compounds (r² < 0.8, at least 2 out of 3 experiments). These were the top 7 of the 11 compounds that induced cell hypertrophy. These 7 compounds were also observed to increase the area of mitochondria. However, the last 4 of the 11 compounds increased the cell size but did not increase the mitochondrial area. For the remaining 13 compounds, which had no effect on cell size, a good correlation was observed between the results of the two methods (r² > 0.8, at least 2 out of 3 experiments), and the cell size was effectively the same as that of the controls. We concluded that the poor correlation between the two methods was attributable to an increase in the content of intracellular ATP because of the chemically induced cell and mitochondrial hypertrophy. We showed that the ATP assay is unsuitable for assessing the cytotoxicity of compounds that induce cell hypertrophy with increase in the mitochondrial area and ATP content.

Role of microRNA-130a in the pathogeneses of obstructive sleep apnea hypopnea syndrome-associated pulmonary hypertension by targeting the GAX gene

OBJECTIVE

The purpose of this study was to elucidate the role of microRNA-130a (miR-130a) in obstructive sleep apnea hypopnea syndrome (OSAHS)-associated pulmonary hypertension (PHT) by targeting the growth arrest-specific homeobox (GAX) gene.

METHODS

A total of 108 patients with OSAHS-associated PHT were recruited as the OSAHS-associated PHT group and 110 healthy individuals were randomly selected as the normal control group. Human umbilical vein endothelial cells (HUVECs) were selected and divided into the control, miR-130a mimic, mimic negative control (NC), miR-130a inhibitor, and inhibitor-NC groups. The dual luciferase reporter gene assay was used to identify the relationship between miR-130a and the GAX gene. The quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were applied for the relative expressions of miR-130a and the mRNA and protein expressions of GAX. Serum levels of endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), nitric oxide (NO), and super oxide dismutase (SOD) were detected. Cell apoptosis and angiogenic activity were analyzed by flow cytometry and cell tube formation assay.

RESULTS

GAX was a target gene of miR-130a. Compared with the normal control group, the relative expression of miR-130a and the serum levels of ET-1 and VEGF were increased, whereas the mRNA expression of GAX and the serum levels of NO and SOD were decreased in the OSAHS-associated PHT group. Compared with the control, mimic-NC, and inhibitor-NC groups, the relative expressions of miR-130a in the miR-130a mimic group were enhanced, whereas the expression of miR-130a in the miR-130a inhibitor group was reduced. However, the mRNA and protein expressions of GAX showed an opposite trend in the miR-130a mimic and miR-130a inhibitor groups. In comparison to the control, mimic-NC, and inhibitor-NC groups, the miR-130a mimic group had an increase of ET-1 and VEGF expressions, whereas the expressions of NO and SOD were reduced. However, the miR-130a inhibitor group exhibited an opposite trend. The apoptosis rate and tube formation number in the miR-130a mimic group were obviously increased, whereas the miR-130a inhibitor group showed an obvious decrease.

CONCLUSION

These data provided strong evidence that miR-130a may be involved in the progression of OSAHS-associated PHT by down-regulating GAX gene.

Clinical potential of miR-3651 as a novel prognostic biomarker for esophageal squamous cell cancer

Accumulating evidence indicates that dysregulated microRNA-3651(miR-3651) is involved in tumorigenesis and cancer progression. In this study, we investigated the expression of miR-3651 in esophageal squamous cell cancer(ESCC) and its relationship with tumor progression and clinical prognosis. The expression level of miR-3651 was examined by quantitative Real-time PCR (qRT-PCR) in fresh ESCC tissues and FFPE tissues. The correlation between miR-3651 expression and clinical features and prognosis were statistically analyzed. The results showed that the miR-3651 expression was significantly down-regulated in tumor tissues compared with the paracancerous tissues. Moreover, miR-3651 expression was negatively correlated with T stage of ESCC (P = 0.022) and tumor length (P = 0.015). Kaplan-Meier analysis demonstrated that low miR-3651 expression level was associated with poorer overall survival (OS) (P = 0.004) and disease-free survival (DFS) (P = 0.001). Multivariate analysis identified miR-3651 expression as independent prognostic factor for OS and DFS (P = 0.001 and P = 0.001, resp.). Further stratified analysis revealed the significant association between low miR-3651 expression and worse survival in early patients, but not in the advanced patients. Taken together, miR-3651 was down-regulated in cancerous tissues of ESCC. It may play an important role in cancer progression and could be used as an independent prognostic biomarker for ESCC patients.