Our Article

Our Article

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  CLINICAL ▼ 224 Journalof AESTHETIC NURSING ► June 2015 ► Volume 4 Issue 5 ©2015MAHealthcareLtd T o educate and advise patients about medical aesthetic treatments using radiofrequency (RF) devices, it is beneficial to be familiar with the mechanisms of tissue regeneration. RF energy procedures are a popular option for patients seeking non-surgical methods of reducing tissue laxity. These treatments initiate a process of dermal tissue remod- elling by stimulating fibroblasts to proliferate and produce new collagen and heat shock proteins (HSPs) (Touma and Gilchrest, 2003). When the first HSPs were discovered, they were found to be overexpressed by cells that had been exposed to heat (Ritossa, 1962). It is now accepted that there are several sizes of HSP that play many different roles in the cell, and researchers are still discovering all of the things HSPs can do. To date, it is known how HSPs repair dam- aged proteins, aid the cells to synthesise new proteins, help assemble proteins that are newly made, and pro- mote the survival and proliferation of cells under stress. Types of heat shock proteins HSPs are a family of proteins, classified according to their molecular size in kilodaltons (kDa), where one kDa is equivalent to 1000 g per mole. This article will discuss some of the sizes of HSP that are particularly relevant to dermal remodelling. The sizes range from HSP27, which is the smallest at 27 kDa, to HSP90, which is the largest at 90 kDa (Wagstaff et al, 2007). To put this into perspective, type 1 collagen is about 130 kDa (Silver and Trelstad, 1980). All members of the HSP family have a molecular chap- erone function—they help proteins to fold into their correct shape. HSP27 promotes cell survival and works to contract newly formed tissue scaffolding, which re- sults in a tightening and strengthening effect (Hirano et al, 2004). HSP47 is known as the collagen-specific chap- erone, as it stabilises procollagen filaments in the cor- rect conformation to make collagen chains (Nagata et al, 1988). HSP70 binds and folds a broad array of proteins, increases cell survival (Nonaka et al, 2004), and helps to determine whether a protein should be flagged for repair or sent to the ‘recycling bin’ (Wagstaff et al, 2007). Radiofrequency and the activation of heat shock proteins Aesthetic practitioners know that RF treatments can take several weeks to achieve their desired effect, and part of the reason for this is the timeline of the regenera- tive process taking place. To study the course of HSP ex- pression after RF therapy, Hantash et al (2009) recruited 22 patients undergoing an elective surgical facelift or abdominoplasty. After treatment with a bipolar RF de- vice, it was found that HSP70 expression peaked at an early time point and diminished rapidly after 2 days. Following this, the collagen-specific chaperone HSP47 increased progressively over the course of 10 weeks. Significant increases in connective tissue components including tropoelastin, fibrillin, and procollagen types I and III were observed as early as 28 days after treatment (Hantash et al, 2009). Exploring the role of heat shock proteins in radiofrequency energy therapies Abstract One of the most common questions asked by those considering radiofrequency treatment is ‘how do radiofrequency energy treatments work to tighten the skin?’. In this article, two industry experts explain the biological mechanism of how heat shock proteins revitalise skin following radiofrequency energy treatments. When tissue is heated or stressed, as occurs after radiofrequency energy treatments, cells naturally begin to produce tiny proteins that stabilise the cell. One of the roles of heat shock proteins is to help newly or improperly formed proteins to fold into their correct shape, as this is vital to their function. For example, collagen is strong because it is comprised of three strands of procollagen bound together—the helper protein that holds the strands in alignment as they bond is a heat shock protein. This paper discusses the various types of heat shock proteins and their roles in tissue regeneration following radiofrequency therapy. Key words ► Radiofrequency ► Heat shock proteins ► Collagen ► Tissue regeneration EMMA SOOS Aesthetic Nurse and Clinical Director, Medisico PLC, London. e: [email protected] MORGAN CLOND Research Director, Medisico PLC, London. e: [email protected] Journal of Aesthetic Nursing.Downloaded from magonlinelibrary.com by Emma Soos on June 25, 2015. For personal use only. No other uses without permission. . All rights reserved.
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  226 Journal ofAESTHETIC NURSING ► June 2015 ► Volume 4 Issue 5 CLINICAL ▼ ©2015MAHealthcareLtd Some heat shock proteins can increase cell survival and help to determine whether a protein should be flagged for repair or sent to the ‘recycling bin’ iStockPhoto/NatanaelGinting Heat shock proteins and fibroblast growth Fibroblasts are skin cells that maintain the structural framework of the skin by generating collagen and ex- tracellular matrix (Raghu et al, 1989). They also create HSPs when they are stressed and the presence of HSPs stimulates fibroblasts to replicate (Capon and Mordon, 2003). HSPs do this by causing the cell to produce a tis- sue growth factor called transforming growth factor beta (TGF-β) (Cao et al, 1999). TGF-β is also produced by inflammatory cells, such as neutrophils and macrophages (Steenfos, 1994), and in- fluences the proliferation, differentiation and motility of fibroblasts (Raghu et al, 1989). TGF-β typically activates HSP27 by phosphorylation, leading to further produc- tion of connective tissue growth factor and type 1 col- lagen (Lopes et al, 2009). It also ramps up the production of more HSPs (Sasaki et al, 2002). When TGF-β levels are reduced experimentally, this blocks the ability of fibrob- lasts to produce connective tissue (Mori et al, 2004). Heat shock proteins and cell survival promotion HSP70 and HSP27 are able to directly prevent pro- grammed cell death, or apoptosis. When a cell is suffi- ciently stressed, the cell may begin a process of breaking itself down before bursting. This autodigestion process makes it easier for phagocytotic cells to clear away the cell remnants, called apoptotic bodies (Kerr et al, 1972). HSP27 is normally found in the cell bound to actin, which forms part of the cytoskeletal scaffold and main- tains the shape of the cell (Hirano et al, 2004). During cell stress, HSP27 becomes available immediately by detaching from actin (Hirano et al, 2004). HSP70 and HSP27 both migrate from the cytoplasm and into the nucleus to stop cell death (Nahomi et al, 2014). HSP70 then binds to the caspase-binding domain of apoptotic protease activating factor 1 (APAF-1) to block cell death (Saleh et al, 2000). HSP27 phosphorylates Akt to down- regulate the apoptosis process (Qi et al, 2014). Heat shock proteins and tissue regeneration One study on the role of HSPs in collagen deposition focused on keloid scars (Totan et al, 2011). Keloid scars are an example of an unregulated collagen synthe- sis process that overproduces collagen, resulting in a hypertrophic growth of scar tissue. When normal and keloid tissue was collected from patients undergoing keloid scar revision, the tissue overexpressed HSP70, HSP47 and HSP27, compared to non-keloid tissue (To- tan et al, 2011). HSP60 and HSP90 were not increased in the keloid scar and are thought to have different roles in the cell unrelated to tissue matrix regeneration. HSP60 is responsible for mitochondrial processes and HSP90 works with cell-signalling molecules such as protein ki- nases and steroid receptors (Totan et al, 2011). Heat shock proteins and collagen synthesis To examine the role of HSP47 in collagen synthesis, Ohba et al (2003) studied rats undergoing wound heal- ing. HSP47 production was eliminated using an anti- sense oligonucleotide to bind HSP47 ribonucleic acid (RNA) and prevent it from being transcribed into pro- tein. When HSP47 was eliminated, western blot analysis determined that collagen precursor proteins (procolla- gen types I and III) were no longer synthesised for wound repair. Using reverse transcription polymerase chain re- action (RT-PCR), Obha et al (2003) determined that the messenger RNA (mRNA) for procollagen was still being manufactured, but the code was not being used to pro- duce a protein, thus, disrupting HSP47 prevented colla- gen production at the translation step in which proteins are built from mRNA. This finding indicated that HSP47 is required not just for assembly of collagen, but also in an earlier step during the translation of procollagen (Ohba et al, 2003). Heat shock proteins and tissue matrix contraction HSP27 is activated by TGF-β and, similar to HSP47, blocking HSP27 activation prevents the production of collagen and growth factors (Lopes et al, 2009). Follow- ing collagen deposition, contraction of the collagen ma- trix is another key process that occurs after RF treatment (Elsaie, 2009). When fibroblast cells were placed in an ar- tificial matrix of collagen and stimulated using platelet- Journal of Aesthetic Nursing.Downloaded from magonlinelibrary.com by Emma Soos on June 25, 2015. For personal use only. No other uses without permission. . All rights reserved.
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  Volume 4 Issue5 ► June 2015 ► Journal of AESTHETIC NURSING 227 ▼ CLINICAL ©2015MAHealthcareLtd (2009) Inhibition of HSP27 phosphorylation by a cell-permeant MAPKAP kinase 2 inhibitor. Biochem Biophys Res Commun 382(3): 535–9. doi:10.1016/j.bbrc.2009.03.056 Mori Y, Ishida W, Bhattacharyya S, Li Y, Platanias LC, Varga J (2004) Selective inhibition of activin receptor–like kinase 5 signaling blocks profibrotic transforming growth factor β responses in skin fibroblasts. Arthritis Rheum 50(12): 4008–21. doi:10.1002/art.20658 Nagata K, Hirayoshi K, Obara M, Saga S, Yamada KM (1988) Biosynthesis of a novel transformation-sensitive heat-shock protein that binds to collagen. Regulation by mRNA levels and in vitro synthesis of a functional precursor. J Biol Chem 263(17): 8344–9 Nahomi RB, DiMauro MA, Wang B, Nagaraj RH (2015) Identification of peptides in human Hsp20 and Hsp27 that possess molecular chaperone and anti-apoptotic activities. Biochem J 465(1): 115–25. doi:10.1042/BJ20140837 Nonaka M, Ikeda H, Inokuchi T (2004) Inhibitory effect of heat shock protein 70 on apoptosis induced by photodynamic therapy in vitro. Photochem Photobiol 79(1): 94–8 Ohba S, Wang ZL, Baba TT, Nemoto TK, Inokuchi T (2003) Antisense oligonucleotide against 47-kDa heat shock protein (Hsp47) inhibits wound-induced enhancement of collagen production. Arch Oral Biol 48(9): 627–33 Qi S, Xin Y, Qi Z et al (2014) HSP27 phosphorylation modulates TRAIL-induced activation of Src-Akt/ERK signaling through interaction with β-arrestin2. Cell Signal 26(3): 594–602. doi:10.1016/j.cellsig.2013.11.033 Raghu G, Masta S, Meyers D, Narayanan AS (1989) Collagen synthesis by normal and fibrotic human lung fibroblasts and the effect of transforming growth factor-β. Am Rev Respir Dis 140(1): 95–100 Ritossa F (1962) A new puffing pattern induced by temperature shock and DNP in drosophila. Experientia 18(12): 571–3 Saleh A, Srinivasula SM, Balkir L, Robbins PD, Alnemri ES (2000) Negative regulation of the Apaf-1 apoptosome by Hsp70. Nat Cell Biol 2(8): 476–83 Sasaki H, Sato T, Yamauchi N et al (2002) Induction of heat shock protein 47 synthesis by TGF-β and IL-1β via enhancement of the heat shock element binding activity of heat shock transcription factor 1. J Immunol 168(10): 5178–83 Silver FH, Trelstad RL (1980) Type I collagen in solution. Structure and properties of fibril fragments. J Biol Chem 255(19): 9427–33 Steenfos HH (1994) Growth factors and wound healing. Scand J Plast Reconstr Surg Hand Surg 28(2): 95–105 Totan S, Echo A, Yuksel E (2011) Heat shock proteins modulate keloid formation. Eplasty 11: e21 Touma DJ, Gilchrest BA (2003) Topical photodynamic therapy: a new tool in cosmetic dermatology. Semin Cutan Med Surg 22(2): 124–30 Wagstaff MJ, Shah M, McGrouther DA, Latchman DS (2007) The heat shock proteins and plastic surgery. J Plast Reconstr Aesthet Surg 60(9): 974–82 derived growth factor and lysophosphatidic acid, they began to contract the matrix to strengthen it (Hirano et al, 2004). Cells that had high levels of HSP27 contracted the matrix more than cells that expressed low levels of HSP27. Fibroblasts overexpressing HSP27 were also bet- ter at migration and adhesion (Hirano et al, 2004). This finding implicates HSP27 to be extremely important to the desired skin-tightening effect of aesthetic RF therapy (Hirano et al, 2004). Conclusion All RF energy devices designed to tighten tissue by heat- ing the skin rely on HSPs to achieve this outcome. In particular, HSP27, HSP47 and HSP70 are the sizes of HSP involved in collagen matrix regeneration. HSPs promote the survival and replication of skin fibroblasts, and support the production and assembly of structural components such as collagen. HSP27 can detach from actin and begin working within minutes to stabilise cell proteins and prevent cell death. The peak of HSP27 expression has not been determined, but many studies have measured increased levels several weeks after the initial tissue damage while it works to contract newly formed tissue matrix. HSP70 increases within the first 2 days to prevent cells from undergoing programmed cell death and stimulates fibroblasts to produce more HSPs. HSP70 triages cellular proteins affected by the heat treatment and helps to de- termine what to repair and recycle. HSP47 is the collagen assembly protein; its levels rise within 2 days and contin- ue to increase over the course of 10 weeks. The timeframe of HSP expression after RF treatment explains why clini- cal results first become apparent within 2–4 weeks and then increase in the following months. Conflict of interest: The authors of this article are employees and stockholders of Medisico PLC and have no conflict of interest with the research reported in this review. References Cao Y, Ohwatari N, Matsumoto T, Kosaka M, Ohtsuru A, Yamashita S (1999) TGF-beta1 mediates 70-kDa heat shock protein induction due to ultraviolet irradiation in human skin fibroblasts. Pflugers Arch 438(3): 239–44 Capon A, Mordon S (2003) Can thermal lasers promote skin wound healing? Am J Clin Dermatol 4(1): 1–12 Elsaie ML (2009) Cutaneous remodeling and photorejuvenation using radiofrequency devices. Indian J Dermatol 54(3): 201–5. doi: 10.4103/0019-5154.55625 Hantash BM, Ubeid AA, Chang H, Kafi R, Renton B (2009) Bipolar fractional radiofrequency treatment induces neoelastogenesis and neocollagenesis. Lasers Surg Med 41(1): 1–9. doi:10.1002/ lsm.20731 Hirano S, Shelden EA, Gilmont RR (2004) HSP27 regulates fibroblast adhesion, motility, and matrix contraction. Cell Stress Chaperones 9(1): 29–37 Kerr JF, Wyllie AH, Currie AR (1972) Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer 26(4): 239–57 Lopes LB, Flynn C, Komalavilas P, Panitch A, Brophy CM, Seal BL Key points ►► Heat shock proteins (HSPs) play a variety of roles in tissue rejuvenation after radiofrequency treatments ►► HSPs promote fibroblast proliferation through the growth factor TGF-β ►► HSP47 is the collagen-specific protein and helps to assemble collagen from three individual strands of procollagen ►► HSP47 and HSP27 are required for the formation of new collagen ►► HSP27 increases for several weeks after treatment, and helps the newly formed tissue matrix to tighten Journal of Aesthetic Nursing.Downloaded from magonlinelibrary.com by Emma Soos on June 25, 2015. For personal use only. No other uses without permission. . All rights reserved.