Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or... – Involving nucleic acid
Reexamination Certificate
2001-09-06
2004-09-21
Whisenant, Ethan (Department: 1634)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Involving nucleic acid
C536S023100, C536S024300
Reexamination Certificate
active
06794137
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to the fields of molecular biology, cell biology and dermatology. More specifically, the invention relates to the molecular events underlying the response of a cell to exposure to ultraviolet radiation and, thereby, to the molecular processes contributing towards the development of premature tissue aging and cancer.
BACKGROUND OF THE INVENTION
Human skin is relatively simple tissue that performs varied and complex functions such as temperature regulation, the processing of vitamin D precursors, the excretion of urea, and the storage of carbohydrate and fat. The skin contains many unique cell types to effect its specialized functions. On a gross level, the skin consists of epidermis and a basement membrane zone overlying dermis and subcutaneous fat. Skin tissue arises embryologically from ectoderm, neuroectoderm, and mesoderm. The epidermis, hair and sebaceous glands (pilosebaceous units), sweat glands (eccrine units), and nails are all ectodermal derivatives. Neuroectodermal derivatives include melanocytes, nerves, and special neuroreceptors, while mesenchymal derivatives include collagen, reticulin and elastic fibers, blood vessels, muscle, and fat. Probably the most important function of the skin is that of protection; the skin produces a scaling surface impermeable to many substances, has an elaborate network of immunocompetent cells constantly monitoring for potentially harmful antigens, and produces pigment which filters out harmful rays of ultraviolet radiation from the sun.
Ultraviolet radiation is a major environmental damaging agent causing photodamage to the skin, including cutaneous malignancies and photoaging (see generally,
Fitzpatrick's Dermatology in Medicine,
Fifth Edition, I. M. Freedberg, et at, eds., McGraw-Hill (1999)). Clinical features of photoaging include wrinkles, skin laxity and coarseness, and pigmentation disorders. While histological manifestations of photoaging have been well known for some time, the molecular mechanisms that cause them have only recently become a focus of concerted studies.
Solar light contains a broad spectrum of energy wavelengths, and ultraviolet radiation which is among the relatively short wavelengths occurring at between 100 and 400 nanometers (in contrast to the visible light spectrum which occurs at between about 490 and 690 nanometers). Ultraviolet radiation is composed of three segments, designated as A, B, and C, Ultraviolet-C radiation (between 100 and 280 nanometers) is filtered out by the earth's ozone layer and is not known to pose a health threat. There is evidence, however, that exposure to both ultraviolet-A radiation (between 315 and 400 nanometers) and ultraviolet-B radiation (between 280 and 315 nanometers) can have adverse short-term and long-term effects on skin health and visual health. For example, ultraviolet radiation is known to play an important a role in both the development of skin cancers and premature aging of the skin.
The cell type most affected by ultraviolet radiation in humans is the keratinocyte. When illuminated by ultraviolet radiation, the keratinocyte reacts in three generally non-overlapping ways. First, it initiates a DNA repair response, which is activated by the DNA damage itself (Herrlick et al. (1994)
Adv. Enzyme Reg.
34:381-95). Second, it signals to the surrounding tissue by releasing pro-inflammatory cytokines, such as IL-1 and TNF&agr; (Ullrich et al. (2000)
J. Dermatol. Sci.
23:S10-2; Ouhtit et al. (2000)
Am. J. Pathol.
156:201-7; and Beissert et al. (1999)
J. Investig. Dermatol. Symp. Proc.
4:61-4). Third, the keratinocyte activates its inherent responses to ultraviolet radiation by changing its physiology, including regulation of gene expression, cytoskeletal rearrangements, and induction of apoptosis (Zhuang et al. (2000)
J. Interferon Cytokine Res.
20:445-54; and Assefa et al. (1997)
J. Invest. Dermatol.
108:886-891).
The inherent responses of keratinocytes to ultraviolet radiation, by analogy with responses to other extracellular signals, can be separated into two phases, the immediate and delayed. The immediate phase contains the ultraviolet radiation-specific signal transduction cascades and results in activation of transcription factors. In the delayed phase one sees the changes in gene expression. The invention herein provides a characterization of the ultraviolet radiation-responsive induced and suppressed genes in human epidermal keratinocytes.
The histological signs of photoaging at the epidermal level include the following: (1) variation in the thickness of the epidermis (atrophy or hyperplasia according to the zones observed); (2) a cellular atypia (Kligman et al. (1986)
Photodermatol.
3:215-227); (3) a loss of cell polarity; (4) an unevenness of the horny layer; (5) a reduction in the number of Langerhans' cells (Lavker et al. (1987)
J. Invest. Dermatol.
88:44s-51s); (6) a pigmentation characterized by a mosaic appearance with hypo- or hyperpigmentation zones; and (7) a linearization of the dermo-epidermal junction (Lavker (1979)
J. Invest. Dermatol.
73:59). For a review of photoaging of the skin, see Gilchourest,
Skin and Aging Processes,
1989, CRC Press.
The biologic responses of cells exposed to ultraviolet radiation have been studied in a wide variety of systems, from
Esherichia coli
to man. In humans, the molecular effects of ultraviolet radiation include DNA damage, apoptosis and activation of the Jun N-terminal kinase (JNK) and the nuclear factor kappa-beta (NFkB). Both studied recently, although not extensively in epidermal keratinocytes, which are the primary target of ultraviolet radiation. A major impetus for studies of the molecular response to ultraviolet radiation came with the identification of the protein kinase that bound to and activated the c-Jun transcription factor in response to ultraviolet radiation (Derijard et al. (1994) Cell 76:1025-1037). The kinase was named “JNK” for Jun N-terminal kinase, or “SAPK” for stress activated protein kinase (Kyriakis et al. (1994)
Nature
369:156-160). Soon it was realized that JNK responds to several extracellular signals in addition to ultraviolet radiation, such as osmotic shock, arsenate, and pro-inflammatory cytokines (Rosette et al. (1996)
Science
274:1194-7; Cavigelli et al. (1996)
E.M.B.O. Journal
15:6269-79). JNK can phosphorylate additional transcription factors, including Elk1 and ATF2 (Kallunki et al. (1996)
Cell
87:929-39). JNK is itself activated by a small number of relatively specific kinases, designated “JNKKs.” Many kinases, designated JNKKKs, respond to a large variety of stimuli to phosphorylate and activate “JNKKs;” the ultraviolet radiation-responsive JNKKK has not yet been identified (Fanger et al. (1997)
Curr. Opin. Genet. Dev.
7:67-74).
Another clear molecular effect of ultraviolet radiation is the activation of the NFkB transcription factor (Devary et al. (1993)
Science
261:1442-5). The activation of NFkB by ultraviolet radiation is not associated with DNA damage and occurs even in cytoplasts devoid of nuclear DNA (Devary et al. (1993)
Science
261:1442-5; Simon et al. (1994)
J. Invest. Dermatol.
102:422-7). Inactive NFkB resides in the cytoplasm complexed with IkB protein. Upon activation by a very large and varied set of extracellular stimuli, IkB is phosphorylated and thus designated for proteolysis. This results in the release of NFkB, which is then free to enter the nucleus and activate gene transcription (Barnes et al. (1997)
NE J. Med.
336:1066-71). The ultraviolet radiation-responsive kinases that mark IkB for degradation have not yet been identified (Li et al. (1998)
Proc. Natl. Acad. Sci
(
USA
) 95:13012-13017).
Methods to evaluate photodamage to skin or to cells contained therein have been described in the art. For example, U.S. Pat. No. 6,079,415 provides methods and markers useful for establishing ultraviolet-A radiation damage to the dermis, and more specifically, to the production of collagen by fibroblasts of the dermis. Moreover, methods useful for the prevention
Hale and Dorr LLP
New York University
Whisenant Ethan
LandOfFree
Gene markers useful for detecting skin damage in response to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gene markers useful for detecting skin damage in response to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gene markers useful for detecting skin damage in response to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3186109