8 criteria for selecting your ELISA kits

Biomarkers specialists are often asked to select an ELISA kit for researchers: with thousands of ELISA references available on the market, the choice can be tricky regarding proteins for which several kits available.

When researchers have to choose a new ELISA kit, the price is regularly the first parameter of selection. But my experience with long term projects shows that it should in fact be the very last one…

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Unraveling the protective role of the stroma

Research performed by David García-Molleví and his team at ICO (Barcelona, Spain), in cooperation with tebu-11018152_928445027176257_6580852836315207360_nbio laboratories, is being presented at the AACR congress in Philadelphia these days.

The poster describes how cytokine profiling of drug-disrupted tumour cell / fibroblast crosstalk provides insights to understand the protective role of the stroma. Briefly, an array including 174 cytokines was performed on tumour cell / fibroblast co-cultures. Results determine that IL1b and TGFb1 secreted by tumor cells trigger the activation of normal colonic fibroblasts (NCF) to become CAFs. The role of IL1b is not as well known as TGFb1 in a cancer context.

Cytokine arrays were used in order to determine:

i) cytokine profiling of IL1b-treated NCF
ii) profiling of tumor cell-NCF cocultures in the presence of inhibitors of IL1b and TGFb1 signaling, main triggers of NCFactivation.

This poster shows how cytokine profiling can be useful as a complementary approach for microenvironment studies in assessing reciprocal activation of tumour cells and stroma, mediators of such interplay, treatment effectiveness and new target interventions.

Would you like to have a copy of this poster? Contact us!

5 best selling Human cytokines in 2014….

The start of a new year is a good opportunity to take stock of the previous one… Today, let’s take a look at our best selling human cytokines in 2014.

First of all, a little reminder… Cytokines are signaling molecules that control the activities of cells through intercellular communication. Numerous families of diverse molecules are categorized as cytokines and/or growth factors.

So, which were our 5 most popular human cytokines in 2014? [Read more…]

Growth factors in cartilage biology and osteoarthritis

Cartilage is a flexible connective tissue which can rapidly grow and which is specialized to absorb and resist compression. The perichondrium, a vascularized layer, surrounds the tissue which does not contain any blood vessels of its own. Therefore nutrients and waste material have to be able to diffuse through the cartilage tissue. A thin layer of smooth hyaline cartilage (the so called articular cartilage) covering the joint surfaces of the bone, does not have any perichondrium though. Articular cartilage is protected by synovial fluid, a nutritive and lubricating medium. [Read more…]

Tumour microenvironment – inflammation and immunity

Following our series of posts on tumour microenvironment (TME) and the role of Cox-2/PGE2 signaling, I’d like today to focus on inflammation and immunity.

TME is a dynamic milieu influenced by numerous changes favoring the emergence of a tumour-promoting inflammatory environment (eg. tissue remodeling, metabolic alterations, recruitment of stromal cells (including immune cells)…). Extracellular matrix (ECM) also participate in this inflammatory environment by promoting pro-inflammatory cytokines expression (CCL2, GM-CSF). Tumour cell progression seems to be mediated by adaptative and immune cells, where differential cytokine and chemokine expression changes the balance between Th1 (anti-tumour) and Th2 (pro-tumour) phenotypes. Microbiota also influences cancer progression by regulating the inflammatory components of TME, though how this is done needs further investigation (1).

[Read more…]

Cytokines and growth factors in Angiogenesis

Angiogenesis is the growth process of new blood vessels from pre-existing one’s. It’s a normal physiological process, observed during embryonic development. But it’s also a pathological process, essentially in the growth of malignant tumors and metastasis development.

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Cytokines and growth factors in Bone biology

Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support and protect the various organs of the body, produce red and white blood cells and store minerals.

The rigid bone, the flexible cartilage, and the elastic tendon illustrate the remarkable capacity of connective tissue to assume a wide range of physiological states.

The three major cell types found in bone are osteoblasts, osteocytes and osteoclasts.

Bone modeling and structure

 

Osteoblasts

Osteoblasts, or bone forming cells, originate from pluripotent mesenchymal stem cells that can also differentiate into muscle, fat, and blood cells. Mature osteoblasts synthesize and extrude the necessary proteins for bone construction, including type I collagen, osteocalcin, osteonectin and alkaline phosphatase. Osteocalcin is a 6 kDa calcium binding protein, capable of capturing calcium from circulation. Osteonectin is a 32 kDa protein that serves as glue between the collagenous matrix and hydroxyapatite. Alkaline phosphatase is an enzyme that facilitates proper bone mineralization.

Osteocytes

Once entrapped within the mineralized bone, the osteoblast loses its synthetic activity and becomes a resting osteocyte. The metabolic activity of osteocytes helps to maintain the calcified bone as a living tissue.

Osteoclasts

The osteoclast is a giant multinucleated cell derived from fusion of several precursor cells of the monocyte/macrophage lineage. The primary function of osteoclasts is bone resorption, a process that involves both extraction of calcium and destruction of matrix. Normally, bone resorption occurs concomitantly with new bone formation.

The coupling of these processes, known as bone remodeling, enables continuous renewal of bone mass throughout the life of the organism. It also provides bone with the capacity to heal itself from breaks and cracks.

Ossification, or the conversion of tissue to bone, involves destruction and removal of tissue and formation of bone in the space formally occupied by it. It normally occurs in either membranous fibrous tissue or in cartilage, as in the formation of the cranial and long bones, respectively.

Growth factors and cytokines involved in bone biology

It was in 1965 that Urist discovered that acellular, devitalized and demineralized bone matrix (DBM) could induce cartilage and bone formation when implanted under the skin or into the muscle of adult rodents (Urist M.R., Science 150, 893-899 (1965)). Later, the osteoinductivity, or bone inducing activity of DBM was attributed to a proteinacious component that received the name bone morphogenetic protein (BMP) (Urist M.R., et. al., Proc. Natl. Acad. Sci. USA 76, 1828-1832 (1979)). Protein purification followed by amino acid sequencing of several BMP-derived tryptic fragments, led to the cloning and expression of the first group of BMPs (5-7). Today, these proteins constitute a family of more than 30 known members, 15 of which are of mammalian origin. Members of the BMP family are also known by other names such as osteogenin (BMP-3), osteogenic protein-1 or OP-1 (BMP-7), and cartilage-derived morphogenetic protein-1 or CDMP-1 (BMP-14). As implied by their name, BMPs initiate, promote, and regulate bone development, growth, remodeling and repair.

With the exception of BMP-1, which mistakenly was called BMP, but is in fact a type I procollagen C-proteinase, the BMPs belong to the TGF-ß superfamily of structurally related signaling proteins. Members of this superfamily are widely represented throughout the animal kingdom, and have been implicated in a variety of developmental processes.

The potential clinical uses of BMPs in treating bone and cartilage defects have stimulated extensive research. During the past decade, the osteogenic activities of these proteins have been tested in combination with a variety of osteoconductive carriers both in human and animal models. These studies have demonstrated the efficacy of some of these proteins, for example BMP-2 and BMP-7, in bone-repair experiments.

Find yours!

  • BMP-2  : a potent osteoinductive cytokine, capable of inducing bone and cartilage formation in association with osteoconductive carriers such as collagen and synthetic hydroxyapatite
  • BMP-4  : involved in the development and maintenance of bone and cartilage
  • BMP-5  : expressed in the nervous system, lung and liver. It is a known regulator for dendritic growth in sympathetic neurons
  • BMP-6: abnormally expressed in breast cancer cell lines; however, its function in promoting breast cancer development is unknown
  • BMP-7/OP-1: a potent bone inducing agent, which in the presence of appropriate osteoconductive carrier can be used in the treatment of bone defects.
  • BMP-10 :  plays a crucial role in the development of the embryonic heart by acting to stimulate and maintain cardiomyocyte proliferation
  • BMP-13/CDMP2: expressed in hypertrophic chondrocytes during embryonic development of long bones
  • GDF-5 (BMP-14/CDMP1): expressed in long bones during embryonic development and postnatally in articular cartilage
  • Myostatin: a TGF-β family member that acts as an inhibitor of skeletal muscle growth
  • SPARC/Osteonectin: a TGF-β family member that acts as an inhibitor of skeletal muscle growth
  • TGF-beta 2: multifunctional cytokines that regulate cell proliferation, growth, differentiation and motility as well as synthesis and deposition of the extracellular matrix

Any doubts about the best factors for your research?

Finding the tools optimally suited to your needs helps to boost research. Some expert advice in identifying and using the best factors may be welcome!

Specific cytokines & growth factors in… apoptosis!

Apoptosis is the process of programmed cell death. Upon induction of apoptotic processes, cell undergo characteristic morphological changes (blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation) and finally die.

Apoptosis has to be clearly separated from necrotic processes, which occur due to cellular injury thus being a kind of traumatic cell death. Apoptosis on the other side is a process which is necessary during the life cycle of organisms.

In a human adult, 50 – 70 billion cells die per day due to apoptosis.

Defective apoptotic processes have been linked to a number of diseases such as cancer (insufficient apoptosis) and atrophy (excessive apoptosis).

[Read more…]

Specific cytokines & growth factors in… hematology!

Hematology is the study of blood, blood-forming organs and blood diseases. The formation of blood cells is referred to as hematopoiesis. All cellular components of the blood are derived from hematopoietic stem cells.

[Read more…]

tebu-bio sponsors Pasteur Institute’s Advances in Stem Cell Biology Course 2014

Pasteur Institut LogoFor the second year running,  tebu-bio is proud to be partner of the Pasteur Institute during the “2nd Advances in stem cell biology (ASCBC )” course (June 30 – July 12, 2014).

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