pi 6

SerpinB6, also known as Cytoplasmic antiproteinase, Peptidase inhibitor 6, Placental thrombin inhibitor, SERPINB6 and PI-6, is a cytoplasm protein that belongs to the serpin family and Ov-serpin subfamily. SerpinB6 / PI-6 is an inhibitor of cathepsin G, kallikrein-8 and thrombin. It may play an important role in the inner ear in the protection against leakage of lysosomal content during stress and loss of this protection results in cell death and sensorineural hearing loss. SerpinB6 / PI-6 is expressed in keratinocytes (at protein level). It is also found in placenta, cardiac muscle, lung, liver, kidney and pancreas. SerpinB6 / PI-6 is expressed in the inner ear hair cells. It’s expressed abundantly by normal mast cells in different tissues and by mast cells in mastocytoma lesions. SerpinB6 / PI-6 may be involved in the regulation of serine proteinases present in the brain or extravasated from the blood. Defects in SerpinB6 are the cause of deafness autosomal recessive type 91 which is a form of non-syndromic deafness characterized by progressive and age-dependent sensorineural hearing loss. Vestibular function is normal.

Serpin B6 belongs to the serpin family. Serpin B6 localizes to the cytoplasm. Serpin B6 is expressed in many tissues, abundantly by mast cells in different tissues and mastocytoma lesions. Serpin B6 may be involved in the regulation of serine proteinases present in the brain or extravasated from the blood. In addition, Serpin B6 may play an important role in the inner ear in the protection against leakage of lysosomal content during stress and loss of this protection results in cell death and sensorineural hearing loss.

Cardiotrophin-1, also known as CT-1 and CTF1, is a member of the IL-6 superfamily. It is a sreted cytokine that is expressed in heart, skeletal muscle, prostate and ovary, and to lower levels in lung, kidney, pancreas, thymus, testis and small intestine. The protein exerts its cellular effects by interacting with the glycoprotein 130 (gp130)/leukemia inhibitory factor receptor beta (LIFR) heterodimer. In addition, CT-1 activates phosphatidylinositol 3-kinase (PI-3 kinase) in cardiac myocytes and enhances transcription factor NF-κB DNA -binding activities.

SerpinB9, also known as Cytoplasmic antiproteinase 3, CAP-3, Peptidase inhibitor 9, SERPINB9 and PI-9, is a cytoplasm protein that belongs to the serpin family and Ov-serpin subfamily. Serpin-B9 ( CAP-3 / PI-9 ) is the only known human intracellular inhibitor of granzyme B (GrB), the effector molecule in immunity against cytomegalovirus (CMV) and in renal allograft rejection. Serpin-B9 and SPI-6 expression in immune-privileged cells, APCs, and CTLs protect these cells against the actions of granzyme B, and when expressed in tumor cells or virally infected hepatocytes, confers resistance to killing by CTL and NK cells. Expression of increasing levels of Serpin-B9 ( CAP-3 / PI-9 ) in target cells may progressively inhibit immune surveillance by blocking NK and CTL-induced cytotoxicity through the perforin / granzyme pathway and then through the Fas / FasL pathway. Serpin-B9 ( CAP-3 / PI-9 ) is selectively up-regulated in hepatocytes in response to infiltration of the liver by NK cells that express perforin and enzymatically active granzyme B. Upregulated expression of Serpin-B9 ( CAP-3 / PI-9 ) in NSCLC cells may serve to protect them from apoptosis induced by GrB.