Disease relevance of TCHH

• Thus, in the absence of a clearly defined lymphoid origin, it is the detection of specific histiocytic markers that establishes a lymphoma as THL [1].
• For the present, it would appear that the treatment indicated for a patient with diffuse large cell lymphoma would also be appropriate for a comparable patient with THL [1].
• In follicular tumours, trichohyalin expression was positive in trichoepithelioma, keratotic basal cell epithelioma, proliferating trichilemmal tumour, trichilemmoma, pilomatricoma and keratoacanthoma [2].
• Similar trichohyalin expression was found in epidermal tumours, such as seborrheic keratosis, actinic keratosis, Bowen's disease and well-differentiated squamous cell carcinoma [2].
• In addition, trichohyalin is expressed in the epidermis in a number of hyperplastic skin diseases [3].

High impact information on TCHH

• Trichohyalin, an intermediate filament-associated protein of the hair follicle [4].
• The modified THH is thought to serve as a keratin intermediate filament matrix protein and/or as a constituent of the cell envelope [5].
• The fate of trichohyalin. Sequential post-translational modifications by peptidyl-arginine deiminase and transglutaminases [5].
• Protein unfolding by peptidylarginine deiminase. Substrate specificity and structural relationships of the natural substrates trichohyalin and filaggrin [6].
• We have determined the full-length sequence of human trichohyalin by use of RNA-mediated anchored polymerase chain reaction methods and from a genomic clone and analyzed its potential secondary structure [7].

Chemical compound and disease context of TCHH

• From comparative studies with filaggrin and involucrin, trichohyalin expression was co-localized with them in molluscum contagiosum, keratoacanthoma and pilomatricoma [2].

Biological context of TCHH

• Finally, trichohyalin possesses a pair of functional calcium-binding domains of the EF-hand type at its amino terminus that may be involved in its calcium-dependent postsynthetic processing during terminal differentiation [7].
• In hair follicles, trichohyalin expression was stable without change from 20 wk estimated gestational age [8].
• These findings suggest that fetal skin may have different sets of barriers from the second trimester; the immature cornified cell envelope is formed in the early second trimester and the mature cornified cell envelope is formed in the late second or early third trimester when filaggrin and trichohyalin appear [8].
• SIGNIFICANCE: The weak links in the dentin-adhesive resin-resin composite bonded joint may be the interphase regions between the THL and the adhesive resin and the BHL and dentin [9].
• The results demonstrated that THH alkaloids induced apoptosis of HL-60 cells though c-myc and NF-kappaB signaling pathways [10].

Anatomical context of TCHH

• Trichohyalin is an intermediate filament-associated protein that associates in regular arrays with keratin intermediate filaments (KIF) of the inner root sheath cells of the hair follicle and the granular layer of the epidermis and is a known substrate of transglutaminases [7].
• Trichohyalin is a major differentiation product of hard keratinizing tissues such as the inner root sheath and medullary cells of the hair follicle and the filiform papillae of the tongue, as well as terminally differentiating epidermal cells [11].
• Pig tongue epithelium yielded milligram quantities of pure trichohyalin from about 100 g of keratomed epithelium [12].
• Our data demonstrate that PAD3 is the enzyme that deiminates trichohyalin in the medulla and the Henle layer, indicate that PAD1 and 3 are involved in the hair follicle program of differentiation, and suggest a role for PAD1 and 2 in the physiology of sweat glands and arrector pili muscles [13].
• Another example of possible NO involvement in HF biology is the postsynthetic modification of trichohyalin in differentiating keratinocytes of the IRS [14].

Associations of TCHH with chemical compounds

• Mapping of the trichohyalin gene: co-localization with the profilaggrin, involucrin, and loricrin genes [15].
• In the course of studies of desmosomes, we found trichohyalin, a 200-kDa protein of the inner root sheath and medulla, in a citric acid-insoluble fraction ("desmosome preparation") from tongue epithelium [12].
• Our results indicate that repetin is indeed a member of the fused gene family similar to the prototypical members profilaggrin and trichohyalin [16].
• Degree of in vivo inhibition of human gastric and pancreatic lipases by Orlistat (Tetrahydrolipstatin, THL) in the stomach and small intestine [17].
• Similar regions are found in a variety of proteins including glutamic acid rich protein, trichohyalin, caldesmon, Tb-29 and several cytoskeleton-interacting proteins [18].

Regulatory relationships of TCHH

• Candidate autoantigens that have been identified include the 44/46 kDa hair-specific keratin (expressed in the precortical zone of anagen hair follicles) and trichohyalin (an important intermediate filament-associated protein) expressed in the inner root sheath of the growing hair follicle [19].

Other interactions of TCHH

• Similarly, in filiform papillae some cells contain granules that stain for both trichohyalin and filaggrin [12].
• While iNOS was only weakly expressed in the basal layer of the human epidermis, it was highly expressed in keratinocytes of the inner root sheath (IRS), where it colocalized with trichohyalin, a differentiation-associated protein of the IRS that requires enzyme-catalysed conversion of arginine to citrulline [14].
• Trichohyalin, hardly detectable in normal epidermis, was present in some granular and cornified cells in EH in association with keratin filaments, suggesting that it may function as an intermediate filament-associated protein [20].
• The "fused" gene family comprises profilaggrin, trichohyalin, repetin, hornerin, the profilaggrin-related protein and a protein encoded by c1orf10 [16].
• The distribution of keratins, trichohyalin, and transglutaminase in marsupial hairs was studied here for the first time by electron microscopy and immunocytochemistry [21].

Analytical, diagnostic and therapeutic context of TCHH

• Immunoblotting confirmed that trichohyalin is present in tongue and epidermis [12].
• The chromosomal location of the gene encoding the human hair follicle protein trichohyalin has been determined by in situ hybridization [15].
• Immunoelectron microscopy has located the Mr 190,000 protein to the trichohyalin granules but not to the newly synthesized filaments [4].
• Although long-term disease-free survival in THL is possible, there are presently inadequate data to estimate curability [1].
• The latter was identified as trichohyalin by selective immunoprecipitation [22].

References