Cytokeratin - An Overview

Introduction

Cytokeratins are keratin proteins that are present in the epithelial tissue's intracytoplasmic cytoskeleton. They play a crucial role in intermediate filaments, which support cells' ability to withstand mechanical stress. The expression of these cytokeratins in epithelial cells is mostly organ- or tissue-specific. As a result, they are employed clinically to identify the precursor cells of a variety of malignancies. The name "cytokeratin" was coined when the protein components of keratin intermediate filaments inside cells were initially discovered and described in the late 1970s. The proteins formerly known as cytokeratins are now simply referred to as keratins (human epithelial category) under a new, systematic nomenclature for mammalian keratins that was developed in 2006. For instance, keratin-4 (K4) has been used instead of cytokeratin-4 (CK-4). In clinical practice, they are still frequently referred to as cytokeratins.

What Are the Types of Cytokeratins?

Keratin is an essential protein for the development of hair, nails, the epidermis, and the outermost layer of skin. It also plays a critical role in wound healing, supporting skin integrity, and maintaining the health of nails and hair. There are 54 distinct keratin types in the body, divided into two primary categories.

• Type 1 Cytokeratin: Type I makes up 28 of the variants. Of the 54 kinds of keratin, type I comprises 11 hair keratins and 17 epithelial cell keratins. Type I keratins, or cytokeratins, are low-weight, acidic proteins that perform a variety of tasks, one of which is to protect cells from internal mechanical forces within the body.

• Type 2 Cytokeratin: The remaining 26 types of keratin are classified as type II, of which 20 are skin cell keratins and six are hair keratins. The high-weight, basic-neutral proteins make up these keratins, which maintain pH levels, control cell activity, and enhance the roles of type I keratins.

There are two forms of keratin: Alpha-keratin comprises type I and type II keratins and is present in the hair, epidermis, horns, and nails of mammals. Compared to its alpha-keratin counterparts, beta-keratin is different in composition and function and is found in the feathers, claws, beaks, and scales of birds and reptiles.

What Is the Function of Cytokeratins?

Keratin is a vital component of skin, hair, and nails as it gives the body the necessary support and protection. Keratin is also found in the body's glands and organs.

Keratin is a strong material that cannot dissolve easily in water, diluted acids, alkalines, and solvents. Many people believe that keratin treatments are beneficial for the health of their skin, hair, and nails since keratin is immune to the many chemicals found in the body. Use bullets to avoid numbering.

• Mechanical Support and Protection: The strength and tenacity of cytokeratins are well known. Because they are durable and resistant to a variety of environmental variables, they do not dissolve in dilute acids, alkalines, solvents, or water. This strength is essential for providing cells the mechanical support they need, particularly those that are subjected to external stresses, such as cells in the skin that experience mechanical stress.

• Cellular Organization and Differentiation: The function of certain keratin pairs in cellular organization and differentiation is demonstrated by the regular co-expression of these pairs in various kinds of epithelial cells. For example, Certain combinations of keratins are present only in simple epithelia, but others are common in stratified epithelia. The specific roles of these tissues are facilitated by this differential expression.

• pH Regulation and Balance: Cell activity is regulated by the balance between Type I and Type II keratins, which have acidic and basic-neutral characteristics, respectively. The maintenance of cellular homeostasis and the appropriate operation of epithelial tissues depend on this pH control.

• Wound Healing and Tissue Repair: The processes of tissue repair and wound healing are actively aided by cytokeratins. Their capacity to produce organized filaments and maintain structural integrity is essential for the regeneration of injured tissues. The cytokeratin-formed supramolecular network facilitates effective wound healing.

• Maintenance of Hair, Nails, and Skin Health: The condition of the skin, hair, and nails is directly impacted by the body's keratin levels. Because of its alleged ability to improve the condition and aesthetics of these tissues, keratin treatments are highly desired. The capacity of cytokeratins to withstand different substances found in the body contributes to their appropriateness for use in cosmetic applications.

What Are Conditions and Disorders That Affect Keratin?

Keratin is impacted by several illnesses and diseases, including:

• Epidermolysis Bullosa Simplex (EBS): The term epidermolysis bullosa simplex (EBS) refers to a class of conditions marked by fragile skin that is prone to blistering. Gene mutations related to keratin are frequently the main cause of EBS.

• Epidermal Inclusion Cysts, or Keratin cysts: Epidermal inclusion cysts, another name for keratin cysts, are often dome-shaped lumps packed with keratin.

• Keratosis Pilaris (KP): KP is a common skin ailment that causes little bumps to appear on the buttocks, arms, or legs. The disorder is caused by an overabundance of keratin clogging pores, which causes bumps to appear.

• Monilethrix: An uncommon condition called monilethrix is typified by easily broken, brittle hair. It usually appears within the first few months of infancy and might damage body hair, lashes, and eyebrows. A type II keratin gene mutation is the cause of monilethrix.

• PPK, or Palmoplantar Keratoderma: The thickening of the stratum corneum, or top layer of the epidermis, on the palms and soles of the hands and feet, is a characteristic of PPK. PPK is brought on by mutations in the keratin gene.

Conclusion

Cytokeratins are unique proteins that perform a variety of tasks in cells, from providing structural support to acting as regulators. The complexity of nature's design is reflected in its complex construction into filaments, protofilaments, and, eventually, supramolecular networks. Gaining knowledge about cytokeratin classification, structure, and functions will help one better understand how the body's epithelial tissues are maintained, wound healing, and general health. The complex functions of cytokeratins will probably become clearer as this field of study goes on, providing opportunities for medicinal treatments and aesthetic uses that maximize the potential of these intriguing proteins.