Secretion of N- and O-linked Glycoproteins from 4T1 Murine Mammary Carcinoma Cells

Therapeutic Potential of Pigment Epithelium-derived Factor in Cancer

Pigment epithelium-derived factor (PEDF) is one of the serine protease inhibitors with multifunctional properties, which is produced by various types of organs and tissues. There is an accumulating body of evidence that PEDF plays an important role in the maintenance of tissue homeostasis. Indeed, PEDF not only works as an endogenous inhibitor of angiogenesis, but also suppresses oxidative stress, inflammatory and thrombotic reactions in cell culture systems, animal models, and humans. Furthermore, we, along with others, have found that PEDF inhibits proliferation of, and induces apoptotic cell death in, numerous kinds of tumors. In addition, circulating as well as tumor expression levels of PEDF have been inversely associated with tumor growth and metastasis. These observations suggest that supplementation of PEDF proteins and/or enhancement of endogenous PEDF expression could be a novel therapeutic strategy for the treatment of cancer. Therefore, in this paper, we review the effects of PEDF on diverse types of cancer, and discuss its therapeutic perspectives.

Structure-function and application of plant lectins in disease biology and immunity

Lectins are proteins with a high degree of stereospecificity to recognize various sugar structures and form reversible linkages upon interaction with glyco-conjugate complexes. These are abundantly found in plants, animals and many other species and are known to agglutinate various blood groups of erythrocytes. Further, due to the unique carbohydrate recognition property, lectins have been extensively used in many biological functions that make use of protein-carbohydrate recognition like detection, isolation and characterization of glycoconjugates, histochemistry of cells and tissues, tumor cell recognition and many more. In this review, we have summarized the immunomodulatory effects of plant lectins and their effects against diseases, including antimicrobial action. We found that many plant lectins mediate its microbicidal activity by triggering host immune responses that result in the release of several cytokines followed by activation of effector mechanism. Moreover, certain lectins also enhance the phagocytic activity of macrophages during microbial infections. Lectins along with heat killed microbes can act as vaccine to provide long term protection from deadly microbes. Hence, lectin based therapy can be used as a better substitute to fight microbial diseases efficiently in future.

Fatigue in primary Sjögren's syndrome: A proteomic pilot study of cerebrospinal fluid

Objectives:

Fatigue is a frequent and often disabling phenomenon that occurs in patients with chronic inflammatory and immunological diseases, and the underlying biological mechanisms are largely unknown. Because fatigue is generated in the brain, we aimed to investigate cerebrospinal fluid and search for molecules that participate in the pathophysiology of fatigue processes.

Methods:

A label-free shotgun proteomics approach was applied to analyze the cerebrospinal fluid proteome of 20 patients with primary Sjögren’s syndrome. Fatigue was measured with the fatigue visual analog scale.

Results:

A total of 828 proteins were identified and the 15 top discriminatory proteins between patients with high and low fatigue were selected. Among these were apolipoprotein A4, hemopexin, pigment epithelium-derived factor, secretogranin-1, secretogranin-3, selenium-binding protein 1, and complement factor B.

Conclusion:

Most of the discriminatory proteins have important roles in regulation of innate immunity, cellular stress defense, and/or functions in the central nervous system. These proteins and their interacting protein networks may therefore have central roles in the generation and regulation of fatigue, and the findings contribute with evidence to the concept of fatigue as a biological phenomenon signaled through specific molecular pathways.

Lectins: an effective tool for screening of potential cancer biomarkers

In recent years, the use of lectins for screening of potential biomarkers has gained increased importance in cancer research, given the development in glycobiology that highlights altered structural changes of glycans in cancer associated processes. Lectins, having the properties of recognizing specific carbohydrate moieties of glycoconjugates, have become an effective tool for detection of new cancer biomarkers in complex bodily fluids and tissues. The specificity of lectins provides an added advantage of selecting peptides that are differently glycosylated and aberrantly expressed in cancer patients, many of which are not possibly detected using conventional methods because of their low abundance in bodily fluids. When coupled with mass spectrometry, research utilizing lectins, which are mainly from plants and fungi, has led to identification of numerous potential cancer biomarkers that may be used in the future. This article reviews lectin-based methods that are commonly adopted in cancer biomarker discovery research.