Comparative Aspects of the Inner Root Sheath in Adult and Developing Hairs of Mammals in Relation to the Evolution of Hairs

September 2004 in “ Journal of Anatomy ”

Lorenzo Alibardi

inner root sheath trichohyalin cornification Henle layer epidermis hair morphogenesis

Studysummary This study suggests that the structure and function of the inner root sheath in mammalian hair may have evolved from simpler forms seen in monotremes, aiding in hair exit without damaging the epidermis.

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research Trichohyalin Mechanically Strengthens the Hair Follicle

108 citations , October 2003 in “Journal of biological chemistry/The Journal of biological chemistry”

This study documents that trichohyalin acts as a multi-functional cross-bridging protein in the inner root sheath of mouse hair follicles, enhancing mechanical strength by linking keratin filaments to the cell envelope.

research Distribution of Keratin and Associated Proteins in the Epidermis of Monotreme, Marsupial, and Placental Mammals

21 citations , June 2003 in “Journal of Morphology”

This study suggests that the epidermis of monotremes and marsupials exhibits a more primitive pattern of protein distribution compared to eutherian mammals, with differences in loricrin distribution and keratinocyte maturation.

research A Novel Epithelial Keratin, hK6irs1, Is Expressed Differentially in All Layers of the Inner Root Sheath, Including Specialized Huxley Cells of the Human Hair Follicle

86 citations , May 2002 in “Journal of Investigative Dermatology”

This study characterized a new human keratin, hK6irs1, specifically found in the inner root sheath of hair follicles, which suggests its role in the structural integrity and guidance of growing hair shafts.

research Molecular Mechanisms Regulating Hair Follicle Development

854 citations , February 2002 in “The journal of investigative dermatology/Journal of investigative dermatology”

This review summarizes recent advances in understanding the molecular mechanisms of hair follicle formation and discusses potential future clinical applications for treating hair loss and skin tumors, but it reports no new clinical results.

research The Catalog of Human Hair Keratins

272 citations , September 2001 in “Journal of Biological Chemistry”

This study cataloged human type II hair keratins, detailing their expression and differentiation roles in hair follicles and comparing them with type I keratins to explore keratin-pairing principles.

research A Unique Type I Keratin Intermediate Filament Gene Family Is Abundantly Expressed in the Inner Root Sheaths of Sheep and Human Hair Follicles

41 citations , January 2001 in “Journal of Investigative Dermatology”

research The Catalog of Human Hair Keratins

235 citations , July 1999 in “Journal of biological chemistry/The Journal of biological chemistry”

This study establishes a catalog of human type I hair keratins and identifies their specific roles and expression patterns during hair differentiation and growth in scalp follicles.

research A Novel Human Type II Cytokeratin, K6hf, Specifically Expressed in the Companion Layer of the Hair Follicle

139 citations , December 1998 in “The journal of investigative dermatology/Journal of investigative dermatology”

This study identified a new type II cytokeratin, named K6hf, exclusively expressed in the companion layer of the human hair follicle, distinguishing it from other keratins and suggesting a unique biochemical role.

research The Fate of Trichohyalin

135 citations , October 1997 in “Journal of biological chemistry/The Journal of biological chemistry”

This study suggests that trichohyalin is modified by peptidyl-arginine deiminase before being cross-linked by TGase 3, allowing the formation of rigid structures in hair follicle cells.

research Hair Follicle Companion Layer: Reacquainting an Old Friend

55 citations , May 1995 in “The journal of investigative dermatology/Journal of investigative dermatology”

research Existence of Trichohyalin-Keratohyalin Hybrid Granules: Co-Localization of Two Major Intermediate Filament-Associated Proteins in Non-Follicular Epithelia

54 citations , November 1994 in “Differentiation”

This study found that trichohyalin is expressed in various normal and pathological epithelia beyond hair follicle cells, where it is uniquely associated with filaggrin, suggesting a specific role in aggregating K6/K16-containing intermediate filaments.

research Analysis of the Sheep Trichohyalin Gene: Potential Structural and Calcium-Binding Roles of Trichohyalin in the Hair Follicle

72 citations , May 1993 in “The Journal of Cell Biology”

This study detailed the structure and amino acid composition of sheep trichohyalin, noting its presence in various tissues and suggesting a possible functional role beyond structural support in hair follicles.

research Changes in Fibronectin, Laminin, and Type IV Collagen Distribution Relate to Basement Membrane Restructuring During the Rat Vibrissa Follicle Hair Growth Cycle

45 citations , August 1992 in “PubMed”

In this study, researchers found that changes in the extracellular matrix components, particularly fibronectin, laminin, and type IV collagen, during the rat vibrissa follicle growth cycle, suggest dynamic remodeling related to dermal-epidermal signaling.

research The Secret Life of the Hair Follicle

745 citations , February 1992 in “Trends in genetics”

This article describes the potential role of various growth factors and molecules in regulating mammalian hair follicle development but does not present new experimental results.

research Trichohyalin: Presence in the Granular Layer and Stratum Corneum of Normal Human Epidermis

48 citations , May 1991 in “The journal of investigative dermatology/Journal of investigative dermatology”

This study found that trichohyalin, a protein previously thought to be restricted to hair and tongue, is also present in isolated cells within the granular layer and stratum corneum of normal human epidermis.

research Structure and Biochemistry of Mammalian Hard Keratin

252 citations , January 1991 in “Electron Microscopy Reviews”

research Trichohyalin, an Intermediate Filament-Associated Protein of the Hair Follicle

116 citations , April 1986 in “The journal of cell biology/The Journal of cell biology”

This study reports that a 190,000 molecular weight protein, identified as trichohyalin, may play a matrix role in the development of inner root sheaths in hair follicles.

research Genes for Hair and Avian Keratins

32 citations , October 1985 in “Annals of the New York Academy of Sciences”

This review discusses the current understanding of genes coding for hair and avian keratins, highlighting gene structure and protein sequences, but reports no new experimental findings.

research The Cytology and Cytochemistry of the Wool Follicle

90 citations , January 1979 in “International review of cytology”

This chapter reviews the complexity of hair and wool follicle formation, emphasizing the importance of cytological studies to understand the relationship between cellular components.