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CELL ADHESION MOLECULES AND MATRIX PROTEINS

BY

SHIHANA.S FIRST YEAR M.PHARM

DEPARTMENT OF PHARMACOLOGY

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CELL ADHESION Cell combines to form tissues.

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TYPES OF CELL ADHESION

• CELL-CELL ADHESION • CELL-MATRIX ADHESION

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CELL ADHESION MOLECULES (CAMs)

• Cell surface proteins• Cell-cell adhesion may be homophilic or heterophilic interaction• Specificity of cell-cell recognition• Functions-

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BIOLOGY OF CAMs

• An intracellular domain • A transmembrane domain• An extracellular domain

STRUCTURE OF CAMs

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CLASSIFICATION OF CAMs

1. Calcium-independent

• IgSF CAMs

• Lymophocyte homing receptors

2. Calcium-dependent

• Integrins

• Cadherins

• Selectins

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CALCIUM-INDEPENDENT CAMs

1. IgSF CAMs• Homophilic or heterophilic-70-110 amino acids.• Large group of cell surface molecules-VCAM, NCAM, ICAM,

Nectins and Necl.

2. Lymphocyte homing receptors • Addressins

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CALCIUM-DEPENDENT CAMs

• Integrinso Heterodimeric proteinso Structure o Physiological role

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• Cadherins o Homophilic interaction-150 aminoacids.o E,N,P o ECD

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• Selectins

o Heterophilic, bind with mucinso Members-E,L,Po PSGL-1

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ROLE OF CELL ADHESION MOLECULES IN VARIOUS DISEASES

• Inflammation• Ischemic stroke• Leukocyte adhesion deficiency• Alzheimer’s disease• Coronary artery disease• Cancer-metastasis,prostate cancer

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MATRIX PROTEINS

• Cell shapes, migration, proliferation, cell survival and metabolism.• Consists of protein-carbohydrate complexes.• Biology

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CLASSIFICATION

1. Proteoglycans

2. Glycoproteins

• Structural proteins- Collagen and Elastin

• Adhesive proteins- Fibronectin and laminin

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1. Proteoglycans • Core proteins-covalently attached to long non-branched chains of GAGs.• Hyaluronic acids, chondroitin sulfates, dermatan sulfates, heparin sulfate.• Polysaccharide content 95%.

2. Glycoproteins • Short branched oligosaccharides.• Carbohydrate content less than 10%.• Different types of glycoproteins.

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STRUCTURAL GLYCOPROTEINS

Collagen• 25% of total content, 29 types.• Stiff triple helix-3 peptide chains.• Monosaccharides and disaccharides.• Fibrillar collgens.

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Elastin

• Does not form stiff triple helix.• Consists of flexible polypeptides.• Microfibrils 10-20nm in diameter-fibrillins.

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ADHESIVE GLYCOPROTEINS

Fibronectinso Bind with other matrix proteins(strongest binding with collagen-III).o Guide cellular movement.o 20 types

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Laminin • Cross linked trimeric adhesive proteins.• Flexible-3 polypedtide chain(,,)-disulfide bond.

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ROLE OF MATRIX PROTEINS IN VARIOUS DISEASES

1. Endocrine diseases• Chronic pancreatitis- pancreatic fibrosis, chronic inflammatory

disease. • Renal hypertrophy

2. Collagenosis 3. Cancer4. COPD5. Infectious diseases

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REFERENCE

1. Harsh Mohan. Text book of Pathology. 5th edition: 31,137-138.

2. Robbins and Cortan. Pathologic Basis of Disease. 9th edition:72-77.

3. Cyrus C, Jones EY. The Molecular Structure of Cell Adhesion Molecules.

Annual Review of Biochemistry. 1997; 66: 823–62.

4. Alexandros D, Athanasios GP, Michael C, Eleni E, Meletios AD. The Role

of Cell Adhesion Molecules (integrins / cadherins) in Prostate Cancer.

International Brazilian Society of Urology. 2011; 37(3): 302-306.

5. Zerrin S University of Anatolia, Department of Pharmacology. Cellular

Adhesion and Adhesion Molecules. Turkish Journal of Biology. 2001; 25: 1-

15.

6. https://en.wikipedia.org/wiki/Cell_adhesion_molecule.

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THANK YOU