1、The skin and Skin Regenerative Medicine再生医学,Lujun YangBurns and Plastic suregeryCenter for Translational medicine2nd Hospital of Shantou University,Kayi,Name?,Aging skin,skin,the largest organ in the bodyprotectsenseregulate temperatureProduction of Vitamin D,Clininians,Dermatology-dermatologistPlas
2、tic and esthetic surgery-plastic surgeon,Keratinocytefibroblast,OBJECTIVE,Master skin structure and function epidermis-keratinization 角化作用:proliferation增殖/differentiation分化,Acquaitance Anomalies异常现象 of skin- common skin diseases,AdvanceSkin regenerative medicine皮肤再生医学,INTRODUCTION,epidermis,dermis,h
3、ypodermis,Dermis真皮,Papillary layer乳头层+,Reticular layer网状层,第二节真皮,epidermis,hypodermis,dermis,skin,dermis真皮,papillary layer 乳头层,reticular layer 网织层,appendages附属器,hair 毛,sebaceous gland 皮脂腺,sweat gland 汗腺,THE STRUCTURE OF SKIN,epidermis表皮,nail 指(趾)甲,EPIDERMIS,主要细胞组成keratinocyte(角质形成细胞 ) non-keratinocyt
4、e(非角质形成细胞),differentiation,stratum corneum角质层,（一）Epidermal stratification and differentiation,PSORIASIS 银屑病,red and white hues of scaly patches appearing on the top first layer of the epidermis (skin).,Langerhans cell(郞格汉斯细胞),Langerhans cells are dendritic cells (antigen-presenting immune cells) of
5、the skin and mucosa, and contain large granules called Birbeck granules. They are present in all layers of the epidermis, but are most prominent in the stratum spinosum.,In skin infections, the local Langerhans cells take up and process microbial antigens to become fully functional antigen-presentin
6、g cells.,Langerhans cells derive from the cellular differentiation of monocytes with the marker Gr-1 (also known as Ly-6G/Ly-6C). This differentiation requires stimulation by colony stimulating factor (CSF)-1.6 They are similar in morphology and function to macrophages.,Albinos lack an enzyme called
7、 tyrosinase络氨酸酶. Tyrosinase is required for melanocytes to produce melanin from the amino acid tyrosine,melanocyte(黑素细胞 ),Melanocytes are melanin-producing cells located in the bottom layer (the stratum basale) of the skins epidermis, the middle layer of the eye (the uvea), the inner ear, meninges,M
8、elanin is a pigment色素 that is responsible primarily for the color of skin.,No difference in melanocyte number between species.The distribution and tyrosinase activity !,Vitiligo,Melanoma(黑色素瘤):,4% of all diagnosed skin cancers, melanoma begins in the melanocytes, cells within the epidermis that give
9、 skin its color. Melanoma has been coined “the most lethal form of skin cancer” because it can rapidly spread to the lymph system and internal organs. With early detection and proper treatment, the cure rate for melanoma is about 95%. Once its spreads, the prognosis is poor. Melanoma most often deve
10、lops in a pre-existing mole or looks like a new mole, which is why it is important for people to know what their moles look like and be able to detect changes to existing moles and spot new moles.,The Hair Sebaceous Glands 皮脂腺Sweat Glands The Nails,The Accessary Structures of the Skin,Acne vulgaris寻
11、常痤疮 普通粉刺 (or cystic acne) is a common disease, characterized by areas of skin with scaly鳞状的 red skin, blackheads黑头粉刺 and whiteheads, pinheads针头, pimples丘疹, nodules小瘤 and possibly scarring结疤. Acne affects mostly skin with the denset密集 population of sebaceous follicles皮脂腺; these areas include the face
12、, the upper part of the chest, and the back. Severe acne is inflammatory炎症性的, but acne can also manifest显现 in noninflammatory forms.2 The lesions损伤 are caused by changes in pilosebaceous毛囊皮脂腺 units, skin structures consisting of a hair follicle and its associated sebaceous gland, changes that requir
13、e androgen雄性激素 stimulation. Acne occurs most commonly during adolescence, and often continues into adulthood. In adolescence, acne is usually caused by an increase in testosterone睾丸素, which people of both genders性别 accrue during puberty青春期.,Alopecia Totalis(全頭脱毛症）,Alopecia means loss of hair from th
14、e head or body. baldness,Hemidesmosomes (HD) are very small stud- or rivet-like structures on the inner basal surface of keratinocytes in the epidermis of skin. They are similar in form to desmosomes when visualized by electron microscopy. While desmosomes link two cells together, hemidesmosomes att
15、ach one cell to the extracellular matrix.,Desmosomes细胞桥粒 are molecular complexes of cell adhesion黏着蛋白 proteins and linking proteins that attach the cell surface adhesion proteins to intracellular keratin 角蛋白cytoskeletal细胞支架细胞 filaments细丝.The cell adhesion proteins of the desmosome, desmoglein桥粒芯蛋白 a
16、nd desmocollin桥粒胶蛋白, are members of the cadherin钙粘蛋白 family of cell adhesion molecules. They are transmembrane proteins that bridge the space between adjacent epithelial cells by way of homophilic binding of their extracellular domains to other desmosomal cadherins on the adjacent cell. Both have fi
17、ve extracellular domains, and have calcium-binding motifs.,Age-associated skin changes include thinning, skin laxity松弛, fragility脆弱, and wrinkles皱纹. Sun-exposed areas demonstrate additional aging changes, including dyspigmentation, premature wrinkling, telangiectasia, and actinic elastosis.,The sun
18、emits ultraviolet radiation in the UVA, UVB, and UVC bands. The Earths ozone layer blocks 9799% of this UV radiation from penetrating through the atmosphere. Of the ultraviolet radiation that reaches the Earths surface, 98.7% is UVA,Photoaging光老化,UV and molecular and genetic changesUVB ray is consid
19、ered as a primary mutagen that can only penetrate through the epidermal or outermost layer of the skin, resulting in DNA mutations. The epidermal layer does not contain any blood vessels or nerve endings but melanocytes and basal cells are embedded in this layer. Upon exposure to UVB rays, melanocyt
20、es will produce melanin, a pigment that gives the skin its color tone. However, UVB will cause the formation of freckles and dark spots, both of which are symptoms of photoaging. With constant exposure to UVB rays, signs of photoaging might appear and precancerous lesions or skin cancer may develop.
21、UVA rays are able to penetrate deeper into the skin as compared to UVB rays. Hence, in addition to the epidermal layer, the dermal layer will also be damaged. The dermis is the second major layer of the skin and it comprises collagen, elastin, and extrafibrillar matrix which provides structural supp
22、ort to the skin. However, with constant UVA exposure, the size of the dermis layer will be reduced, thereby causing the epidermis to start drooping off the body. Due to the presence of blood vessels in the dermis, UVA rays could lead to dilated or broken blood vessels most commonly visible on the no
23、se and cheeks.,Photoaging: telangiectasia, pigmentation,Laser and Photon skin treatment,Sunscreen,SPF: ratio of the minimal erythema dose (MED) of sunscreen-protected skin over the MED of unprotected skin.,Currently available products offer excellent protection from UVB and, to a more variable exten
24、t, from UVA; therefore, the regular use of sunscreens should offer protection against sunburn as well as photoaging,A water-resistant product maintains the SPF level after 40 minutes of water immersion, whereas a very water-resistant (formerly waterproof) product maintains the SPF level after 80 min
25、utes of water immersion.,The UV exposure would be the strongest between 10am and 4pm and sun avoidance between this period of time is highly encouraged. If one cannot avoid exposure to the sun, clothing, hats and sunglasses that protects one from sun exposure should be fully utilized. Wide spectrum sun screens that have a sun protection factor (SPF) of at least 30 should be used when one gets frequent sun exposure.,chemicals, electricity, radiation, and heat,Burns,(Sulfuric acid, sodium hydroxide),
