Modulation of collagen synthesis and its gene expression in human skin fibroblasts by tocotrienol-rich fraction

A Systematic Review on the Effectiveness and Safety of Combining Biostimulators with Botulinum Toxin, Dermal Fillers, and Energy-Based Devices

INTRODUCTION

Aesthetic medicine has evolved towards minimally invasive procedures, with biostimulators like Poly-L-Lactic Acid (PLLA), Calcium Hydroxylapatite (CaHA), and Polycaprolactone (PCL) gaining attention for their role in collagen induction, improving skin texture, elasticity, and volume. Combining these agents with other treatments-such as botulinum toxin, dermal fillers, and energy-based devices (e.g. laser and radiofrequency therapies)-is hypothesised to provide enhanced aesthetic outcomes. However, studies on the efficacy and safety of these combinations remain sparse and methodologically varied, posing challenges in establishing definitive recommendations.

METHODS

This systematic review adhered to PRISMA guidelines, involving a thorough literature search across PubMed, MEDLINE, Embase, and Cochrane databases. The search included terms related to biostimulators and combination treatments. Studies meeting inclusion criteria reported clinical outcomes of combined biostimulator treatments, including effectiveness, safety, patient satisfaction, and adverse effects. Key parameters extracted included treatment area, combination protocols, and outcomes. Data synthesis used a narrative approach due to variability in methodologies, treatment protocols, and outcome metrics.

RESULTS

Out of 1,237 studies initially identified, 29 met the inclusion criteria. These studies included various combinations of biostimulators with botulinum toxin, dermal fillers, and energy-based devices, with sample sizes ranging from 10 to 350 subjects. Treatments combining CaHA or PLLA with energy-based modalities like high-intensity focused ultrasound (HIFU), fractional lasers, and microneedling demonstrated notable improvements in skin texture, elasticity, and contouring, particularly in areas with ageing signs. Adverse events included erythema, bruising, and nodules in 15-30% of cases, with rare but severe complications such as granulomas and vascular occlusions. Management protocols for these events involved corticosteroids, hyaluronidase, or surgical intervention. The review also found a lack of molecular understanding of the synergistic mechanisms.

CONCLUSION

The review underscores the potential benefits of combined treatments in aesthetic outcomes, though limitations like heterogeneous methodologies, small sample sizes, and inconsistent protocols impact the reliability of findings. Current literature lacks a molecular understanding of the mechanisms underlying these combinations, limiting insights into the longevity and safety of results. Future studies with standardised protocols, objective outcome measures, and detailed molecular analyses are essential for developing evidence-based recommendations for combining biostimulators with other treatments in aesthetic practice.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Explicating the multifunctional roles of tocotrienol and squalene in promoting skin health

The skin is the largest organ in the integumentary system, protecting against various external threats, including ultraviolet exposure, heat, infections, dehydration and mechanical injuries. Skin disorders can arise from various causes, including allergic reactions or breaches in the skin barrier, which allow microorganisms or chemicals to penetrate the sweat ducts. These conditions encompass a wide range of issues, including acne, xerosis (dry skin), fungal infections, atopic dermatitis (eczema) and psoriasis. Collectively, these ailments affect a significant portion of the global population, impacting approximately one-third of people worldwide. Additionally, oxidative stress induced by ageing and prolonged exposure to ultraviolet rays can manifest in visible alterations such as pigmentation, wrinkling and dehydration. Recent investigations have underscored the potential of natural antioxidant compounds in safeguarding skin health and combating ageing-related changes. Tocotrienols, a subgroup of vitamin E, have garnered significant attention owing to their antioxidant and anti-inflammatory properties. Significant amounts of tocotrienols can be found in rice bran, olive, oats and hazelnuts. Similarly, squalene, predominantly sourced from fish liver oils such as those from sharks, has been used as an emollient in cosmetic formulations. This article offers a comprehensive review of existing literature elucidating the dermatological benefits associated with tocotrienols and squalene, emphasising their roles as antioxidants, anti-inflammatories, skin barrier protection and facilitators of wound healing. Moreover, it sheds light on contemporary research findings suggesting these compounds' therapeutic promise in managing and ameliorating various skin conditions.

Liquid collagen from freshwater fish skin ameliorates hydration, roughness and elasticity in photo-aged skin: a randomized, controlled, clinical study

BACKGROUND/OBJECTIVES

Collagen is commonly used in diverse forms as a functional component in skincare products. On the other hand, the effects of collagen on human skin are controversial. Dietary collagen hydrolysates from freshwater Pangasius hypophthalmus fish skin ameliorated photo-aged skin of hairless mice. This study conducted a randomized, double-blind, placebo-controlled clinical trial to determine if liquid fish collagen (Collagen-Tripep20™, Tripep20) as a drink strengthens skin health and quality.

SUBJECTS/METHODS

In this clinical trial, 85 subjects aged 35-60 yrs were diagnosed with photo-aged skin. Eighty-five subjects were randomized to receive either Tripep20 (n = 44) or placebo (n = 41). Seventy-eight subjects fully participating for a 12-week period consumed 1,000 mg of Tripep20 (n = 41) or placebo (n = 37) in a 50-mL bottle as a daily drink. The intend-to-treat and per-protocol populations were 85 and 78, respectively. Skin hydration, wrinkles, and elasticity were assessed at 0 (baseline), 6, and 12 weeks during the study period.

RESULTS

Skin hydration in the Tripep20 group was significantly higher from 6 weeks (P < 0.001) than the baseline. After 12 weeks, the Crow's-feet visual score and skin roughness (Ra, Rq, and Rmax) were significantly improved in the Tripep20 group than in the placebo group (P < 0.05). Consuming liquid collagen Tripep20 greatly enhanced skin elasticity (Gross R2, Net R5, and Biological elasticity R7) in 6 weeks compared to the placebo group. The Tripep20 group showed a significant increase in skin elasticity from the baseline after 6 and 12 weeks (P < 0.001). Neither abnormal symptoms nor adverse events were encountered during the study period in subjects ingesting Tripep20 or placebo. The changes in parameters related to hematology and clinical chemistry were within the normal ranges.

CONCLUSION

Oral consumption of liquid collagen Tripep20 was safe and well-tolerated. The results of this study show that freshwater fish-derived liquid collagen Tripep20 can be used as a healthy functional food ingredient to improve skin moisturizing, anti-wrinkling, and elasticity in an aging population.

Chondroitin Sulfate-Based Nanocapsules as Nanocarriers for Drugs and Nutraceutical Supplements

Oil-core nanocapsules (NCs, also known as nanoemulsions) are of great interest due to their application as efficient carriers of various lipophilic bioactives, such as drugs. Here, we reported for the first time the preparation and characterization of NCs consisting of chondroitin sulfate (CS)-based shells and liquid oil cores. For this purpose, two amphiphilic CS derivatives (AmCSs) were obtained by grafting the polysaccharide chain with octadecyl or oleyl groups. AmCS-based NCs were prepared by an ultrasound-assisted emulsification of an oil phase consisting of a mixture of triglyceride oil and vitamin E in a dispersion of AmCSs. Dynamic light scattering and cryo-transmission electron microscopy showed that the as-prepared core-shell NCs have typical diameters in the range of 30-250 nm and spherical morphology. Since CS is a strong polyanion, these particles have a very low surface potential, which promotes their stabilization. The cytotoxicity of the CS derivatives and CS-based NCs and their impact on cell proliferation were analyzed using human keratinocytes (HaCaTs) and primary human skin fibroblasts (HSFs). In vitro studies showed that AmCSs dispersed in an aqueous medium, exhibiting mild cytotoxicity against HaCaTs, while for HSFs, the harmful effect was observed only for the CS derivative with octadecyl side groups. However, the nanocapsules coated with AmCSs, especially those filled with vitamin E, show high biocompatibility with human skin cells. Due to their stability under physiological conditions, the high encapsulation efficiency of their hydrophobic compounds, and biocompatibility, AmCS-based NCs are promising carriers for the topical delivery of lipophilic bioactive compounds.

Effects of tocotrienol on aging skin: A systematic review

The skin is the largest organ of the body that protects from mechanical, thermal, and physical injury. However, the function and appearance of skin visibly degenerates with age due to its frequent exposure to harmful effects of the environment, including ultraviolet irradiation and hazardous substances, in addition to the progression of oxidative stress in aging. These factors result in phenotypic changes in the skin, including wrinkling, pigmentation, reduced elasticity, and hydration during aging. Many natural antioxidant compounds have been studied extensively to reverse the signs of aging skin. Tocotrienols are a subfamily of vitamin E with potent antioxidant activity. Therefore, supplementation with vitamin E in the form of tocotrienol may efficiently protect skin from aging. In this review, the effects of tocotrienol on skin health, including pigmentation, moisture, and wrinkles during aging and UV exposure, were systematically evaluated based on a literature search of the PubMed and Scopus databases. The present data showed that tocotrienols protect the skin from inflammation, UV radiation and melanin accumulation. As the therapeutic value of tocotrienols grows, the potential of these vitamin E analogs to the skin requires further investigation.

Puerarin protects fibroblasts against mechanical stretching injury through Nrf2/TGF-β1 signaling pathway

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most common form of urinary incontinence in women, which affects women's quality of life worldwide. Mechanical injury of the pelvic floor may disrupt the pelvic supportive tissues and connections via the remodeling of extracellular matrix (ECM), which is supposed to be one of the main pathological mechanisms of SUI.

METHODS

The SUI mouse model was established using vaginal distension (VD). Leak point pressure (LPP), maximum cystometric capacity (MCC), collagen, Nrf2 and TGF-β1 in the anterior vaginal wall were measured in either wild-type or Nrf2-knockout (Nrf2^-/^-) female C57BL/6 mice with or without puerarin treatment. Then, the mechanical stretching (MS) loaded on L929 cells was generated by a four-point bending device. mTGF-β1 or LY2109761 (an inhibitor of TGF-β1) was used to verify the protective effect of puerarin after Nrf2 knockdown or overexpression.

RESULTS

The collagen content of the anterior vaginal tissues in VD mice and LPP and MCC was decreased significantly. Besides, the expression levels of Nrf2, TGF-β1, collagen I and collagen III of MS group were downregulated in L929 cells. Puerarin pretreatment could reverse mechanical injury-induced collagen downregulation and Nrf2/TGF-β1 signaling inhibition. Moreover, both LY2109761 pretreatment and Nrf2 knockdown could attenuate the protective effect of puerarin in the mechanical injury-induced ECM remodeling, whereas exogenous TGF-β1 could counteract the effect of Nrf2 downregulation.

CONCLUSIONS

Puerarin protected fibroblasts from mechanical injury-induced ECM remodeling through the Nrf2/TGF-β1 signaling pathway. This might be a new strategy for the treatment of SUI.

In vitro safety evaluation of sunscreen formulation from nanostructured lipid carriers using human cells and skin model

There is a risk of toxicological reactions due to systemic absorption and photo-instability of sunscreens. The study aimed to investigate the safety profile (cytotoxicity, phototoxicity, photostability, UV filter release profile, and skin irritation properties) of sunscreen (NLC-TRF sunscreen) produced from nanostructured lipid carriers (NLCs) and tocotrienol-rich fraction (TRF). The cytotoxicity and phototoxicity of the sunscreen were evaluated on normal human dermal fibroblast (NHDF) and skin irritation properties was tested on skin model. Besides, the photoprotection in pre- and post-UV irradiation were analysed to determine the photostability. Additionally, the release profile for UV filters (diethylamino hydroxybenzoyl hexyl benzoate (DHHB) and ethylhexyl triazone (EHT)) were evaluated. The NLC-TRF sunscreen demonstrated no cytotoxicity and skin irritation to cause cell death. It showed no phototoxic effect and high photostability up to 10 Minimal Erythema Dose (MED) to ensure high SPF value above 50 and broad-spectrum of UV absorption. The NLC-TRF sunscreen implies its safety for topical application with sustainable release profile for UV filter (cumulative release of 28% for DHHB and 40% for EHT after 8 h) due to the application of NLCs. The results suggest that the NLC-TRF sunscreen is an advanced formulation with improved stability and is safe for topical delivery.

Comparing the wound healing effect of a controlled release wound dressing containing curcumin/ciprofloxacin and simvastatin/ciprofloxacin in a rat model: A preclinical study

Inflammation and infection are two main factors predisposing a wound to become a chronic one. Degradable wound dressings involving the controlled release of suitable drugs at the ulcer site are one of the solutions to make wounds healing progress smoothly and rapidly. In this research, biodegradable dressings made of polyglycerol sebacate/polycaprolactone (PGS/PCL) containing curcumin/ciprofloxacin (CUR/CIP) and simvastatin/ciprofloxacin (SIM/CIP) were prepared by using the coaxial electrospinning method. Transmission electron microscopy for uniform core/shell structure, swelling ratio, and drug release pattern of the wound dressings were evaluated. At the in vivo study, histometric, histopathologic, and collagen expression study was performed. The PGS/PCL samples containing SIM/CIP showed a burst release pattern of CIP with a delay in the release of SIM; meanwhile, in the samples containing CUR/CIP, both drugs showed a burst release behavior. No cytotoxicity response was observed in the study groups. The in vivo study showed that wound closure was almost completed only in the SIM/CIP group after 14 days. After 14 days, in the wound treated with SIM/CIP dressing, the amount of collagen deposition and angiogenesis was higher than that of the others. These results clearly showed the effect of SIM/CIP on the improvement of the wound healing efficiency in the long term (14 days) and the effect of CUR/CIP on wound contraction in the short term (4 day). It seems, therefore, that the use of SIM and CUR simultaneously in a wound dressing could cause a synergistic effect in the wound repair.

Isolation and Differentiation of Adipose-Derived Stem Cells into Odontoblast-Like Cells: A Preliminary In Vitro Study

Objective

The aim of present study was to isolate and differentiate human adipose-derived stem cells (ASCs) into odontoblast-like cells.

Materials and Methods

In this experimental study, human adipose tissues were taken from the buccal fat pad of three individuals (mean age: 24.6 ± 2.1 years). The tissues were transferred to a laboratory in a sterile culture medium, divided into small pieces and digested by collagenase I (2 mg/mL, 60-90 minutes). ASCs were isolated by passing the cell suspension through cell strainers (70 and 40 μm), followed by incubation at 37ºC and 5% CO₂ in Dulbecco's modified eagle medium (DMEM) supplemented with fetal bovine serum (FBS 5%) and penicillin/streptomycin (P/S). After three passages, the ASCs were harvested. Subsequently, flow cytometry and reverse transcriptase polymerase chain reaction (RT-PCR) were used to detect expression levels of NANOG and OCT4 to evaluate stemness. Then, a differentiation medium that included high-glucose DMEM supplemented with 10% FBS, dexamethasone (10 nM), sodium β-glycerophosphate (5 mM) and ascorbic acid (100 μM) was added. The cells were cultivated for four weeks, and the odontogenic medium was changed every two days. Cell differentiation was evaluated with Alizarin red staining and expressions of collagen I (COL1A1), dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP1).

Results

The ASCs were effectively and easily isolated. They were negative for CD45 and positive for the CD105 and CD73 markers. The ASCs expressed OCT4 and NANOG. Differentiated cells highly expressed DSPP, COL1A1 and DMP1. Alizarin red staining revealed a positive reaction for calcium deposition.

Conclusion

ASCs were isolated successfully in high numbers from the buccal fat pad of human volunteers and were differentiated into odontoblast-like cells. These ASCs could be considered a new source of cells for use in regenerative endodontic treatments.

Polymorphisms and alterations in gene expression associated with rotator cuff tear and healing following surgical repair: a systematic review

BACKGROUND

Rotator cuff tears (RCTs) are a common cause of shoulder disability, yet both conservative and surgical treatment strategies can lead to poor results in some patient populations. Enhanced understanding of the genetic processes associated with RCTs can assist in the development of more effective management options and help predict individual responses to surgical treatment. This systematic review analyzes the current literature on the genetic footprint associated with RCTs and interprets these findings to enhance the current understanding of RCT pathogenesis, potential treatment regimens, and prognostic biomarkers of outcomes after surgical repair.

METHODS

A systematic search of the Embase, PubMed, and Web of Science electronic databases was performed. Medical Subject Headings (MeSH) and Emtree index terms were formulated from the concept terms "rotator cuff tear," "genetics," and "human," and synonyms of these concepts were applied to the Web of Science search. Articles were screened against predefined inclusion and exclusion criteria. Eligible studies compared gene expression patterns and genetic polymorphisms between cases (with RCTs) and controls (without RCTs). Quality assessment was performed with studies being rated as high, moderate, or poor quality. A modified best-evidence synthesis was applied, and studies were determined to be of strong, moderate, or limited evidence.

RESULTS

The search identified 259 articles. Of these studies, 26 were eligible for review. Two studies were considered poor quality; 15 studies, moderate quality; and 9 studies, high quality. Analysis of these articles found that RCTs were associated with alterations in genes that code for the extracellular matrix, cell apoptosis, immune and inflammatory responses, and growth factor pathways. In particular, there was strong evidence of a significant association between RCTs and the genes MMP3, TNC, and ESRRB. Strong evidence of an association between BMP5 upregulation and successful healing after surgical repair was also found.

CONCLUSION

This review provides strong evidence of an genetic association with RCTs. The genotype and gene expression patterns detailed within this review can assist in deciphering the biological mechanisms resulting in RCTs, as well as predicting an individual's response to surgical repair. Future research could investigate whether manipulating these genes-or their associated signaling pathways-could assist in RCT healing and whether genetic biomarkers could be used clinically to predict patient outcomes after surgical repair of RCTs.

Achatina fulica mucous improves cell viability and increases collagen deposition in UVB-irradiated human fibroblast culture

Introduction: Ultraviolet radiation induces skin photoaging by increasing matrix metalloproteinase-1 (MMP-1). MMP-1 degrades type I and III collagen that comprise the dermal connective tissue. Achatina fulica mucous (AFM) is a natural remedy that has protective effects on fibroblasts and collagen. Objective: To investigate the effects of AFM on cell viability and collagen deposition in UVB-irradiated human fibroblast culture. Methods: The mucous was extracted from 50 Achatina fulica snails that were stimulated by a 5-10 Volt electricity shock for 30-60 seconds and converted into powder by the freeze-drying process. The human dermal fibroblast culture was divided into six groups: group 1 were normal fibroblasts without UVB irradiation as normal control, groups 2-5 consisted of 100 mJ/cm² UVB-irradiated fibroblasts. Group 2 had no treatment as negative control, group 3 was treated by PRP 10% as positive control group and groups 4-6 were treated by various concentrations of AFM (3.9; 15.625 and 62.5 μg/mL). At the end of the experiment, the proliferation was assessed with MTT assay, furthermore collagen deposition was measured by Sirius red assay. Real Time-PCR (RT-PCR) was performed to quantify Coll I, Coll III and MMP-1 mRNA expression, then to measured COL 1/COL III ratio. Results: UVB induced significant lower viability, upregulated MMP-1 and downregulated COL I and COL III mRNA expressions. Meanwhile AFM treated groups demonstrated higher cell viability with downregulation of MMP-1 and upregulation of COL I and COL III mRNA expressions. The ratio of COL I/ III expression was significantly (p<0.05) lower in the AFM treated groups compared to the UVB group. Among AFM treated groups, administration of 62.5 μg/mL AFM represented the best result. Conclusion: AFM may ameliorate viability of UVB-irradiated human fibroblast culture which associates with downregulating MMP-1, upregulating COL I and Col III, and reducing COL I/III ratio.

In vitro modulation of extracellular matrix genes by stingless bee honey in cellular aging of human dermal fibroblast cells

This study determined the antiaging effect of stingless bee honey on the expression of extracellular matrix genes. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was performed for determination of optimum concentration and incubation time of stingless bee honey. Gene expression of matrix metalloproteinase-1 (MMP-1) and collagen type Ⅰ (COL1A1) were analyzed using real time reverse transcriptase polymerase chain reaction technique. Incubation with stingless bee honey at concentration of 0.02% for 72 hr showed significant increase in the viability of human fibroblast cells. Stingless bee honey significantly downregulates metalloproteinase-1 gene expression in both pre-senescence and senescence fibroblast cells and upregulates collagen type Ⅰ gene expression in senescence fibroblast cells. In conclusion, stingless bee honey potentially delayed skin aging through modulation of extracellular matrix genes. PRACTICAL APPLICATIONS: Changes of the extracellular matrix regulation promote skin aging. Stingless bee honey is a good source of natural antioxidant which potentially delays skin aging. This study demonstrated that stingless bee honey beneficially increases collagen type Ⅰ expression and decreases MMP-1 expression during cellular aging of human dermal fibroblast cells.

Vitamin E preconditioning alleviates in vitro thermal stress in cultured human epidermal keratinocytes

AIMS

Thermal burns are the most common type of skin injuries. Clinically, the deteriorating thermal wounds have been successfully treated with skin cell sheets, suspensions or bioengineered skin substitutes. After thermal injury, oxidative microenvironment prevalent in the burnt tissue due to imbalance between production of free radicals and antioxidants defense aiding to destruction of cellular or tissue components. However, depleted antioxidant content particularly vitamin E after heat injury challenges efficient regenerative and healing capacity of transplanted cells. Thus, aim of current study was to pretreat human epidermal keratinocytes with vitamin E in order to enhance their survival rate and therapeutic ability under oxidative microenvironment induced by in vitro heat stress.

MAIN METHODS

Keratinocytes were treated with 100 μM vitamin E at 37 °C for 24 h followed by thermal stress at 51 °C for 10 min. Cell viability and cytotoxicity assays, gene expression analysis and paracrine release analysis were performed.

KEY FINDINGS

Vitamin E preconditioning resulted in significantly improved cell morphology, enhanced viability and reduced lactate dehydrogenase release. Furthermore, Vitamin E preconditioned cells exposed to thermal stress showed significant down-regulated expression of BAX and up-regulated expression of PCNA, BCL-XL, vascular endothelial growth factor (VEGF), involucrin, transglutaminase 1 (TGM1) and filaggrin (FLG) escorted by increased paracrine release of VEGF, basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF).

SIGNIFICANCE

Results of the current study suggest that clinical transplantation of vitamin E preconditioned keratinocytes alone or in combination with dermal fibroblasts in skin substitutes for the treatment of thermally injured skin.

Protective Effects of Kuding Tea (Ilex kudingcha C. J. Tseng) Polyphenols on UVB-Induced Skin Aging in SKH1 Hairless Mice

In this study, the protective effects of Kuding tea polyphenols (KTPs) on ultraviolet B (UVB)-induced skin injury of SKH1 hairless mice were studied. The ion precipitation method was used for extraction of polyphenols from Kuding tea. High-performance liquid chromatography showed that KTPs contains chlorogenic acid, cryptochlorogenic acid, isochlorogenic acid B, isochlorogenic acid A, and isochlorogenic acid C. SKH1 hairless mice were induced skin aging using 2.0 mW/s intensity of 90 mJ/cm² UV light once a day for seven weeks. The 2.5% and 5% KTPs solution was smeared on 2 cm² of back skin of skin aging mice twice a day. Mouse experiments showed that KTP strongly increased the serum levels of total superoxide dismutase (T-SOD) and catalase (CAT) and reduced those of malondialdehyde, interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) in mice with UVB-induced skin damage. KTP also increased the levels of type 1 collagen (Col I), hydroxyproline, and hyaluronic acid and reduced those of Col III and hydrogen peroxide in the damaged skin tissues of mice. Pathological observations of tissues stained with H & E, Masson’s trichrome, Verhoeff, and toluidine blue showed that KTPs could protect skin cells, collagen, and elastin and decrease the number of mast cells, thus inhibiting skin damage. Quantitative PCR and western blot assays showed that KTP upregulated the mRNA and protein expression of tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, copper/zinc-SOD, manganese-SOD, CAT, and glutathione peroxidase and downregulated the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. In addition, the same concentration of KTP had stronger protective effects than vitamin C. The results of this study demonstrate that KTPs have good skin protective effects, as they are able to inhibit UVB-induced skin damage.

Modulation of Oxidative Status by Normoxia and Hypoxia on Cultures of Human Dermal Fibroblasts: How Does It Affect Cell Aging?

Reactive oxygen species (ROS) production in the skin is among the highest compared to other organs, and a clear correlation exists between ROS production and skin aging. Many attempts are underway to reduce oxidative stress in the skin by topical treatment or supplementation with antioxidants/cosmeceuticals, and cultures of human dermal fibroblasts (HDF) are widely used for these studies. Here, we examined the influence of oxygen tension on cell aging in HDF and how this impacted ROS production, the enzymatic and nonenzymatic antioxidant response system, and the efficacy of this defense system in limiting DNA damage and in modulating gene expression of proteins involved in the extracellular matrix, linked to skin aging. We investigated a selection of parameters that represent and reflect the behavior of cellular responses to aging and oxygen tension. Serial passaging of HDF under normoxia (21%) and hypoxia (5%) leads to cell aging as confirmed by β-galactosidase activity, p16 expression, and proliferation rate. However, in HDF under 21% O₂, markers of aging were significantly increased compared to those under 5% O₂ at matched cell passages despite having lower levels of intracellular ROS and higher levels of CoQ₁₀, total GSH, SOD1, SOD3, and mitochondrial superoxide anion. miRNA-181a, which is known to be upregulated in HDF senescence, was also analyzed, and indeed, its expression was significantly increased in old cells at 21% O₂ compared to those at 5% O₂. Upregulation of MMP1 and downregulation of COL1A1 along with increased DNA damage were also observed under 21% O₂ vs 5% O₂. The data highlight that chronic exposure to atmospheric 21% O₂ is able to trigger hormetic adaptive responses in HDF that however fail, in the long term, to prevent cellular aging. This information could be useful in further investigating molecular mechanisms involved in adaptation of skin fibroblasts to oxidative stress and may provide useful hints in addressing antiaging strategies.

Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study

Collagen-peptide supplementation could be an effective remedy to improve hydration, elasticity, and wrinkling in human skin. The aim of this study was to conduct a double-blind, randomized, placebo-controlled trial to clinically evaluate the effect on human skin hydration, wrinkling, and elasticity of Low-molecular-weight Collagen peptide (LMWCP) with a tripetide (Gly-X-Y) content >15% including 3% Gly-Pro-Hyp. Individuals (n = 64) were randomly assigned to receive either placebo or 1000 mg of LMWCP once daily for 12 weeks. Parameters of skin hydration, wrinkling, and elasticity were assessed at baseline and after 6 weeks and 12 weeks. Compared with the placebo group, skin-hydration values were significantly higher in the LMWCP group after 6 weeks and 12 weeks. After 12 weeks in the LMWCP group, visual assessment score and three parameters of skin wrinkling were significantly improved compared with the placebo group. In case of skin elasticity, one parameter out of three was significantly improved in the LMWCP group from the baseline after 12 weeks, while, compared with the placebo group, two parameters out of three in the LMWCP group were higher with significance after 12 weeks. In terms of the safety of LMWCP, none of the subjects presented adverse symptoms related to the test material during the study period. These results suggest that LMWCP can be used as a health functional food ingredient to improve human skin hydration, elasticity, and wrinkling.

Protective role of vitamin E preconditioning of human dermal fibroblasts against thermal stress in vitro

AIMS

Oxidative microenvironment of burnt skin restricts the outcome of cell based therapies of thermal skin injuries. The aim of this study was to precondition human dermal fibroblasts with an antioxidant such as vitamin E to improve their survival and therapeutic abilities in heat induced oxidative in vitro environment.

MAIN METHODS

Fibroblasts were treated with 100μM vitamin E for 24h at 37°C followed by heat shock for 10min at 51°C in fresh serum free medium.

KEY FINDINGS

Preconditioning with vitamin E reduced cell injury as demonstrated by decreased expression of annexin-V, cytochrome p450 (CYP450) mediated oxidative reactions, senescence and release of lactate dehydrogenase (LDH) accomplished by down-regulated expression of pro-apoptotic BAX gene. Vitamin E preconditioned cells exhibited remarkable improvement in cell viability, release of paracrine factors such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), stromal derived factor-1alpha (SDF-1α) and also showed significantly up-regulated levels of PCNA, VEGF, BCL-XL, FGF7, FGF23, FLNβ and Col7α genes presumably through activation of phosphatidylinositol 3-kinase (PI3-K)/Akt pathway.

SIGNIFICANCE

The results suggest that pretreatment of fibroblasts with vitamin E prior to transplantation in burnt skin speeds up the wound healing process by improving the antioxidant scavenging responses in oxidative environment of transplanted burn wounds.

Red light interferes in UVA-induced photoaging of human skin fibroblast cells

The possible regulation mechanism of red light was determined to discover how to retard UVA-induced skin photoaging. Human skin fibroblasts were cultured and irradiated with different doses of UVA, thus creating a photoaging model. Fibroblasts were also exposed to a subtoxic dose of UVA combined with a red light-emitting diode (LED) for five continuous days. Three groups were examined: control, UVA and UVA plus red light. Cumulative exposure doses of UVA were 25 J cm(-2), and the total doses of red light were 0.18 J cm(-2). Various indicators were measured before and after irradiation, including cell morphology, viability, β-galactosidase staining, apoptosis, cycle phase, the length of telomeres and the protein levels of photoaging-related genes. Red light irradiation retarded the cumulative low-dose UVA irradiation-induced skin photoaging, decreased the expression of senescence-associated β-galactosidase, upregulated SIRT1 expression, decreased matrix metalloproteinase MMP-1 and the acetylation of p53 expression, reduced the horizon of cell apoptosis and enhanced cell viability. Furthermore, the telomeres in UVA-treated cells were shortened compared to those of cells in the red light groups. These results suggest that red light plays a key role in the antiphotoaging of human skin fibroblasts by acting on different signaling transduction pathways.

Effects of cigarette smoke extracts on the growth and senescence of skin fibroblasts in vitro

Epidemiological studies have shown that cigarette smoke (CS), a very common environmental factor, plays an important role in skin aging. Although some in vivo studies have suggested that CS affects skin aging, the detailed effects of CS on skin cells in vitro remain largely unknown. In this study, we investigated the effects of cigarette smoke extract (CSE) on the growth, proliferation, and senescene of skin fibroblasts and the possible mechanism underlying these effects. Primary cultured human fibroblasts were exposed to a range of concentrations of CSE. Cell viability and cell proliferation after CSE exposure were analyzed with the methyl thiazolyl tetrazolium (MTT) assay and bromodeoxyuridine incorporation assay, respectively. Growth curves of fibroblasts exposed to different concentrations of CSE were developed and prolonged CSE-exposed cells were observed. Morphological and ultrastructural changes in fibroblasts were assessed by inverted light microscopy and transmission electron microscopy (TEM). Dying cells were stained with senescence-associated β-galactosidase (SA β-gal). Intracellular reactive oxygen species (ROS) levels, superoxide dismutase (SOD) activity, and glutathione peroxidase (GSH-Px) activity were determined by a colorimetric method. We found that proliferative capacity and growth were inhibited by CSE exposure in a dose- and time-dependent manner. Fibroblasts exposed to even low concentrations of CSE for a long period of time (5 passages) showed significantly increased SA β-gal activity and typical features of aging cells. Meanwhile, CSE inhibited superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and augmented ROS levels. Our observations suggest that CSE exposure impairs fibroblast growth and proliferation and leads to features similar to those seen in senescent cells. Oxidative stress injury and inhibition of antioxidant defense activity may be involved in CSE-induced fibroblast senescence.

Telomere shortening in cultured human dermal fibroblasts is associated with acute photodamage induced by UVA irradiation

Introduction

Photoaging is the superposition of chronic ultraviolet (UV)-induced damage on intrinsic aging. Telomere length is a molecular marker of cell aging, and genomic instability due to telomere shortening has been linked to several aging-related diseases.

Aim

To explore the effects of different doses of ultraviolet A (UVA) on the length of telomeres in human skin fibroblasts and partly reveal the mechanism of skin photoaging initiated by UVA irradiation.

Material and methods

Primary cultured human skin fibroblasts were irradiated with different doses of UVA light. Cell viability, cell cycle phase, β-galactosidase, and the length of telomeres were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, cytochemical staining, and real-time polymerase chain reactions, respectively.

Results

After UVA irradiation, inhibited proliferation, S phase accumulation and increased expression of senescence-associated β-galactosidase were observed in cultured fibroblasts. Moreover, the length of telomeres in UVA-treated cells was shortened in a dose-dependent manner as compared to controls (p < 0.05).

Conclusions

These results suggest that telomere length in human dermal fibroblasts can be shortened by a single high dosage of UVA radiation, and that acute photodamage might contribute to early photoaging in human skin via rapid telomere shortening. This study potentially provides the basis for better understanding of the molecular mechanism of photoaging.