Franco Gasparri

Paracrine crosstalk between human hair follicle dermal papilla cells and microvascular endothelial cells

Human follicle dermal papilla cells (FDPC) are a specialized population of mesenchymal cells located in the skin. They regulate hair follicle (HF) development and growth, and represent a reservoir of multipotent stem cells. Growing evidence supports the hypothesis that HF cycling is associated with vascular remodeling. Follicular keratinocytes release vascular endothelial growth factor (VEGF) that sustains perifollicular angiogenesis leading to an increase of follicle and hair size. Furthermore, several human diseases characterized by hair loss, including Androgenetic Alopecia, exhibit alterations of skin vasculature. However, the molecular mechanisms underlying HF vascularization remain largely unknown. In vitro coculture approaches can be successfully employed to greatly improve our knowledge and shed more light on this issue. Here we used Transwell‐based co‐cultures to show that FDPC promote survival, proliferation and tubulogenesis of human microvascular endothelial cells (HMVEC) more efficiently than fibroblasts. Accordingly, FDPC enhance the endothelial release of VEGF and IGF‐1, two well‐known proangiogenic growth factors. Collectively, our data suggest a key role of papilla cells in vascular remodeling of the hair follicle.

A Comparative Analysis of the Photo-Protective Effects of Soy Isoflavones in Their Aglycone and Glucoside Forms

Isoflavones exist in nature predominantly as glucosides such as daidzin or genistin and are rarely found in their corresponding aglycone forms daidzein and genistein. The metabolism and absorption of isoflavones ingested with food is well documented, but little is known about their use as topical photo-protective agents. The aim of this study was to investigate in a comparative analysis the photo-protective effects of isoflavones in both their aglycone and glucoside forms. In human skin fibroblasts irradiated with 60 mJ/cm2 ultraviolet B (UVB), we measured the expression levels of COX-2 and Gadd45, which are involved in inflammation and DNA repair, respectively. We also determined the cellular response to UVB-induced DNA damage using the comet assay. Our findings suggest that both the isoflavone glucosides at a specific concentration and combination with an aglycone mixture exerted an anti-inflammatory and photo-protective effect that prevented 41% and 71% of UVB-induced DNA damage, respectively. The advantages of using either isoflavone glucosides or an aglycone mixture in applications in the field of dermatology will depend on their properties and their different potential uses.

Effects of flavonoid derivatives on human microvascular endothelial cells

Abstract Some natural compounds, including flavonoids, are active in vasculature re-growth during hair follicle disruption, but their effects have not been yet evaluated directly on microvascular endothelial cells. Skin vascularisation regulates the physiological blood supply required for hair growth and its dysregulation is the basis of several human diseases. Follicle-derived vascular endothelial growth factor (VEGF) release from follicular keratinocytes promotes perifollicular vascularisation and increases follicle and hair size, while blockade of VEGF-mediated angiogenesis leads to impaired hair growth. Here, we tested three flavonoids, namely visnadin (VSD), hesperidin (HSP) and baicalin (BC), on cultured human microvascular endothelial cells (HMEC), comparing their effects with minoxidil (MXD), a synthetic drug broadly used in the treatment of androgenetic alopecia. The response to these compounds was assayed in terms of endothelial survival, proliferation, tubulogenesis and proangiogenic signalling. We show that BC promotes HMEC proliferation, while both VSD and MXD enhance tubulogenesis. Interestingly, only HSP increases VEGFR-2 phosphorylation.

Submicrometric hypromellose acetate succinate particles as carrier for soy isoflavones extract with improved skin penetration performance

In this study, hypromellose acetate succinate (HPMCAS) stable submicronic particles loaded with a soy isoflavones extract have been obtained by nano spray drying technology. HPMCAS has been used as excipient able to increase both stability and supersaturation levels of the active ingredients hence able to enhance skin penetration performance of genistein and daidzein. The influence of polymer/extract ratio as other process variables, on particle size, morphology and permeation performance, have been investigated. Particles in submicronic range (mean size around 550nm) and narrow size distribution with high encapsulation efficiency (up to 86%) were obtained. HPMCAS was able to improve amorphization of genistein during the atomization process and avoid recrystallization during storage, even in harsh environmental condition. Moreover, the enhanced affinity of the optimized formulations with aqueous media, strongly increased isoflavones penetration through membrane with diffusive properties well-correlated to human skin, up to 10-fold higher than pure soy isoflavones extract raw material.

Dermal‐Epidermal Cross‐Talk: Differential Interactions With Microvascular Endothelial Cells

The biological importance of circulatory blood supply and angiogenesis for hair growth is now well recognized, but the their regulatory mechanisms require more mechanistic investigation. In vitro cocultures and tricultures can be successfully employed to greatly improve our knowledge on paracrine crosstalk between cell types that populate the dermal‐epidermal interface and cutaneous vasculature. Here we report that human dermal fibroblasts (NHDF) promote viability and proliferation of microvascular endothelial cells (HMVEC), while HMVEC are not mitogenic for NHDF. In triculture setup, conditioned media (CM) obtained by cocultures (HMVEC/NHDF or HMVEC/follicle fibroblasts) differently modulate growth and proliferation of keratinocytes and alter the expression of metabolic and pro‐inflammatory markers. In conclusion, tricultures were successfully employed to characterize in vitro dermal‐epithelial and endothelial interactions and could integrate ex vivo and in vivo approaches by the use of high‐throughput and standardized protocols in controlled conditions. J. Cell. Physiol. 232: 897–903, 2017.

Effects of the biomimetic peptide Sh‐Polypeptide 9 (CG‐VEGF) on cocultures of human hair follicle dermal papilla cells and microvascular endothelial cells

in keratinocytes of healthy human epidermis and suggest that mRAGE could monitor and respond to acute reactions and cellular responses, including inflammation and apoptosis, rather than to long-term alterations during ageing to maintain homoeostasis of the skin. Author contributions MI, YY, HY, TH and KH conceived and designed the experiments. MI and KH performed the experiments. MI, YK and KH analysed the data and provided reagents/materials/analysis tools. MI, YY and TF wrote the manuscript. Conflict of interest The authors declare no conflict of interest. Supporting Information

Pleiotropic Effects of White Willow Bark and 1,2-Decanediol on Human Adult Keratinocytes

Background: Acne vulgaris is a common skin defect, usually occurring during adolescence, but often it can persist in adults leaving permanent face scarring. Acne is usually treated with topical drugs, oral antibiotics, retinoids, and hormonal therapies, but medicinal plants are increasingly employed. Objective: To investigate the protective role of white willow bark (WWB) and 1,2-decanediol (DD) on the damage caused by lipopolysaccharides (LPS) on human adult keratinocytes (HaCaT). Methods: HaCaT were exposed to LPS alone or in association with WWB and DD. Epidermal viability, metabolic modulation, inflammatory activity, and cell migration were assessed with both common standardized protocols or high-throughput screening systems. Results: The preincubation of HaCaT with WWB and DD (used separately or in combination) differently prevented the alterations induced by LPS on HaCaT in terms of growth factor release (IGF, EGF, VEGF), cytokine production (IL-1α, IL-6, IL-8), or expression of the transcription factor FOXO-I. Moreover, they partially restore wound repair lowered by LPS. Conclusions: These results suggest that both natural compounds were able to differently affect several functions of LPS-stressed keratinocytes suggesting their potential role for the prevention of acne vulgaris, without adverse effects.

Application of Spray Drying Particle Engineering to a High-Functionality/Low-Solubility Milk Thistle Extract: Powders Production and Characterization

Many natural compounds having antioxidant and anti-inflammatory activity are a potential target for new therapies against chronic inflammatory syndromes. The oral administration of functional herbal supplements may become a prevention strategy or therapy adjuvant for susceptible patients. A case study is our milk thistle (Silybum marianum) extract rich in silymarin complex. A water-soluble microencapsulated powder system was developed by a spray drying technique to improve the poor silymarin bioactivity after oral administration. Sodium carboxymethylcellulose (NaCMC) was employed as coating/swelling polymer matrix and sodium lauryl sulfate (SLS) as the surfactant (1:1:0.05 w/w/w). A H2O/EtOH/acetone (50/15/35 v/v/v) solvent system was used as liquid feed. The microsystems were capable of improving the in vitro dissolution and permeation rates, suggesting an enhancement of bioactivity after oral administration. The microsystems protect the antioxidant activity of silymarin after harsh storage conditions period and do not affect the anti-inflammatory properties of the raw extract (efficient already at lower concentrations of 0.312 mg/mL) to reduce dendritic cells (DCs) inflammatory cytokine secretion after lipopolysaccharide administration. This approach allows managing particle size, surface properties and release of bioactive agents improving the bioactivity of a herbal supplement and is also possibly applicable to many other similar natural products.