2015-04-15

What’s the Role of Microglia Cells in the Aged Brain?

Microglia cells are the primary immune cells of the central neuron system(CNS). They are the brain counterpart of macrophages and are known as the defender of the brain. Although they are neuroprotective in the young brain, microglia cells have also been found to react abnormally to stimuli in the aged brain and to become neurotoxic and destructive during neurodegeneration.


Aging-induced immune senescence with microglia senescence in the brain causes microglia to function abnormally and promote neurodegeneration. Microglia senescence includes morphological changes and alterations in immunophenotypic expression and inflammatory profile, usually caused by microinvironmental factors. The hypothesis of microglia senescence during aging give a novel perspective on their roles in aging-related neurodegeneration.


Many scientists believe that aberrant inflammatory responses play a role in the etiology of several neurodegenerative diseases, such as Parkinson's disease or Alzheimer's disease, in which aging is the most important risk factor. The CNS is relatively immune-privileged and major immune-cell antigens can be detected on microglia. Therefore, microglia cells have been considered to represent the brain's internal immune system. It is concluded that any changes in microglial activities during aging are key components in influencing the pathogenesis of neurodegeneration.


Microglia normally keep in a quiescent state, thus sometimes called resting microglia, with ramified morphology and weak expression of function-associated antigens. When triggered by appropriate stimulation, microglia rapidly become activated with deramified shape and enhanced antigen presentation. As an active sensor and monitor in the brain, microglia are neuroprotective. However, uncontrolled response of microglia may be dangerous to the survival of injured neurons or even cause damage to healthy neurons. In the normal aged monkey brain, microglial expression of MHC class II increases with age, and the phagocytic activity of microglia increases age-dependently. Immunohistochemical studies also reveal that microglial activation is age-related. Additionally, from activated microglia explanted from aged mice model, the increased pro-inflammatory cytokines and decreased anti-inflammatory cytokines have been demonstrated, which also suggests the abnormal immune state of microglia in the aged brain.


All of the facts suggests that the inflammatory state of microglia in the aged brain primes them to be over-responsive to small stimuli and so the activation of microglia in the aged brain loses control. However, it still remain uncertain what triggers the microglial activation in the healthy aged brain.
Creative Bioarray is the world’s largest primary cells supplier. The company offers 35 human cell systems with over 160 different cell types and also provide primary cells from over 13 types of other animals. We offer both rat microglia cells and human microglia cells for research use.

Purchase high quality microglia cells at http://www.creative-bioarray.com/Human-Microglia-CSC-C1527-item-39336.htm

Stem Cells

Generally, stem cells are cells that have the capability to become any type of cell in the body. They have the ability to self-renew or multiply while retaining the ability to develop into other types of cells, such as cells of the blood, heart, bones, skin, muscles, brain etc. Though there are different sources of stem cells, all types of stem cells share the same capacity to develop into multiple types of cells. Stem cells are categorized by their potential to differentiate into other types of cells.

Embryonic stem cells are the most powerful stem cells because they can become every type of cell in the body.

Totipotent stem cell

These cells have the ability to differentiate into all possible cell types. Examples are the zygote formed at egg fertilization and the first few cells that result from the division of the zygote.

Pluripotent stem cell

Pluripotent stem cells can differentiate into almost all cell types. Examples include embryonic stem cells and cells that are derived from the mesoderm, endoderm, and ectoderm germ layers that are formed in the beginning stages of embryonic stem cell differentiation.

Multipotent stem cell

Multipotent stem cell have the ability to differentiate into a closely related family of cells. Examples include hematopoietic (adult) stem cells that can become red and white blood cells or platelets.

Oligopotent stem cell

This kind of stem cells can differentiate into a few cells. Examples include (adult) lymphoid or myeloid stem cells.

Unipotent stem cell

This type of cells can only produce cells of their own type, but have the property of self-renewal required to be labeled a stem cell. Examples include (adult) muscle stem cells. Stem cells have become the very common research topic in labs.

Scientists and researchers are interested in stem cells for several reasons. Although stem cells do not serve any one function, but when instructed to specialize, they can serve almost any function. World Leading

Commercial Stem Cells Suppliers 

1. Creative Bioarray

Creative Bioarray offers over 1,000 stem cell products including adult stem cells, tumor stem cells, embryonic stem cells, iPS cells and other stem cells.
http://www.creative-bioarray.com/

2. Advanced Cell Technology

Working to produce embryonic stem cells that are immunologically compatible with patients; stem-cell therapeutic development
http://www.advancedcell.com

3. StemCell 

Media, reagents and kits for the propagation and differentiation of human and mouse embryonic stem cells and human adult stem cells
http://www.stemcell.com

4. ScienCell

ScienCell provides quality products of culture medium, growth factors, mesenchymal stem cells, characterization tools etc. for your stem cells research.
www.sciencellonline.com

2015-04-09

Immunohistochemistry Introduction

Immunohistochemistry is based on the principle of antibodies binding specifically to antigens in biological tissues to detect the antigens in cells of a tissue section. It is a process used to diagnose some types of cancer including mesothelioma. The procedure involves locating antigens in biopsy tissue through the use of a visual marker. The cellular events associated with cancerous tumors will be highlighted by the stained tissue sample. Besides, immunohistochemistry can also distinguish whether or not a tumor is benign or malignant.

The principle of IHC was uncovered in the 1930s and about ten years later the first IHC study was reported. Since then, with improvement and development of protein conjugation, enzyme labels have been introduced, such as peroxidase and alkaline phosphatase. Later colloidal gold label, radioactive elements were introduced and the immunoreaction could be visualized by autoradiography. Now immunohistochemistry has become a routine and essential tool in diagnostic and research laboratories.

Immunohistochemistry (IHC) analysis

Immunohistochemistry (IHC) analysis is a method for demonstrating the presence and location of proteins in tissue sections. This method is believed less sensitive quantitatively than immunoassays such as western blotting or ELISA, but it has advantage that it enables the observation of processes in the context of intact tissue. This is especially useful for assessing the progression and treatment of diseases such as cancer.

Immunohistochemical staining is accomplished with antibodies that recognize the target protein. The antibody-antigen interaction will be visualized using either chromogenic detection or fluorescent detection.

Immunohistochemical Methods

Direct Method:Direct method is one step staining method, and involves a labeled antibody (i.e. FITC conjugated antiserum) reacting directly with the antigen in tissue sections.

Indirect Method:Indirect method involves an unlabeled primary antibody (first layer) which react with tissue antigen, and a labeled secondary antibody (second layer) react with primary antibody.

PAP Method (peroxidase anti-peroxidase method): PAP method is a further development of the indirect technique and it involves a third layer which is a rabbit antibody to peroxidase, coupled with peroxidase to make a very stable peroxidase anti-peroxidase complex.

Avidin-Biotin Complex (ABC) Method: ABC method is standard IHC method and one of widely used technique for immunhistochemical.

Labeled StreptAvidin Biotin (LSAB) Method:A recent report suggests that LSAB method is about 5 to 10 times more sensitive than standard ABC method.

More information at:http://www.creative-bioarray.com/Services/Immunohistochemistry-IHC.htm