New drug for Sickle Cell Disease targets Leukocytes

Leukocytes adhere to blood vessels as a mechanism to enter tissue where there is inflammation. Inadvertently, they pile up sickle cell red blood cells.

Mutations in the hemoglobin gene can render a person to a lifetime of sickle cell disease (SCD). While otherwise healthy individuals with one allele (gene copy) of the sickle hemoglobin (HbS) gene are carriers, the disease is seen in those with two HbS alleles – one inherited from each carrier parent. A single HbS allele can also cause SCD in a person who inherits other defects in the second hemoglobin allele.

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3D monitoring of cell movement through Collagen I

The transition from non-invasive phenotype to invasive phenotype of tumor cells marks the switch from a benign tumor to a more malignant form of cancer. Understanding the mechanisms underlying this hallmark event, which enables tumor cells to invade through Extracellular matrix, is critical for discovering pathways and new targets to develop anti-metastatic strategies. In a previous post, A 96-well Invasion Assay Compatible with High Content Screening, I introduced a technology called Oris™ assays, which employs exclusion zone technology to facilitate unambiguous monitoring of cell migration from the periphery into a central circular detection zone. This assay is a high-throughput assay, but compatible with adherent cells only.  Today I’d like to introduce a new 3D Embedded Invasion Assay, compatible with both non-adherent and adherent cells.

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Enriched Tregs for a multitude of research applications

When it comes to the body’s natural defenses, is it possible to have “too much of a good thing”? Absolutely. To spare the host, the immune system needs to distinguish it from the real enemy –infectious agents. Autoimmune disorders occur when this recognition frays and the body’s own cells and tissues are damaged.

That’s where regulatory T cells, or Tregs, come in. [Read more…]

PBMCs & drug development

Use of human samples including peripheral blood mononuclear cells (PBMCs) in drug discovery is critical for increasing the chances of success for a small molecule screen hit. A review based on recent published data!

PBMCs DD 1Several theories try to explain why many drug discovery and development projects have a moderate success rate. Even with the advances made in methods (HTS, HCA, library managment, etc), there are many hurdles for a small molecule on the long road to FDA or EMA approval.

One way that may improve predicted efficacy and toxicity of drug leads is to use human samples, such as blood, early on in drug discovery programs. Peripheral blood mononuclear cells  (PBMCs) can be easily used in a variety of ways during the drug discovery process to gain a better understanding of the effects of a small molecule. [Read more…]

Biomimetic Chemistry, a new route for metabolite synthesis

In 2008, the FDA released guidance for drug metabolite safety testing (MIST), emphasizing the importance of metabolite toxicity testing in the drug development process. Indeed, drug toxicity, which accounts for roughly 40% of clinical drug failures, is a leading cause of the high drug attrition rates that have contributed to the skyrocketing drug development costs witnessed over the past few decades.

Traditionally, drug metabolites have been both difficult and hugely expensive to synthesize. Conventional methods of metabolite synthesis, such as those that employ the use of microsomes (while they have proven valuable as a predictive tool, their productive capabilities could be limited by NCE stability) or synthetic chemistry, can be extremely costly and time consuming. Consequently, drugmakers often choose to forego metabolite synthesis (and subsequent metabolite toxicity testing ) early on in the drug development process, opting instead to wait until lead compounds are further along in development before carrying out these essential functions. This decision, perceived to be a calculated risk, ultimately comes at huge price, as drug makers lose millions each year on investments in lead drug candidates that eventually turn out to be failures due to toxicity.

Biomimetic Chemistry, on the other hand, possesses the advantages of both chemistry and biology and is thus a much more efficient tool for metabolite synthesis. In fact, with biomimetic chemistry, large scale metabolite generation is enabled in one step, by mimicking and optimizing the same biotransformation reactions that occur in the liver. [Read more…]

Hyaluronic acid – size matters!

HA or Hyaluronan measurement | tebu-bio

Hyaluronan (HA) Competitive ELISA standard curve (cat. nr 117K-1200-1ea)

Hyaluronic acid (HA), or hyaluronan, is an ubiquitous, very high molecular mass polysaccharide that has applications in a variety of fields, including cosmetics, some types of surgery (e.g. opthalmic) and regenerative medicine. It can even be present as a contaminant in some bio-production processes. HA has also been suggested as a possible biomarker for Alzheimer’s disease (AD).

HA acts as a molecular shock-absorber and stabilizer for cells. Its visco-elastic properties, biologically speaking, are valuable for separating tissue and maintaining shape. It is a key in tissue lubrication, and it may play a role in wound repair. It is the ideal choice for some implants, as it does not usually cause an immune response (contrary to what may happen with some biomaterials). Size of the HA used in therapy has an impact on its success. Usually, higher weight forms usually render longer benefits. For bio-production, however, smaller HA forms are usually the main concern.

So, depending on the reason why you are studying this marker, keep size in mind in order to choose the best assay to measure the HA levels in your experimental model. It is of key importance that whatever product you use, analysis of the HA sizes detected with it are clearly mentioned in the technical documentation.

HA or Hyaluronan measurement | tebu-bio

Hyaluronic acid (HA) sandwich ELISA standard curve (direct assay cat. nr 117K-4800-1kit)

A post by my colleague Dr. Philippe Fixe is of great help for choosing the right assay!

It’s not that these assays will allow you to discriminate between high- and low-weight HA. What is intended here is that these assays will allow you to detect all or part of the HA forms depending on its weight. And that may be crucial, as you may be using the assay that does not detect the HA sizes relevant for your experiment.

It is also possible now to outsource HA measurements to an external lab performing regularly validated Hyaluronic acid-specific immuno-assays. As an example, Echelon’s Competitive or Sandwich HA ELISAs outsourcing by tebu-bio’s lab in cosmetology or drug discovery.

Any comments? Feel free to share them below!

 

Characterization & Applications of Human Cardiomyocytes

ReproCardio 2 Human iPSC-derived cardiomyocytes have been extensively characterized for their functional responsiveness to the known cardiotoxic compounds. In all our tests, including assays of cardiotoxic compounds not correctly identified by the hERG assay, ReproCardio has generated results in complete agreement with clinical findings.

In this post, we’ll highlight the characterisation of ReproCardio 2 cardiomyocytes and illustrate the applications they are used for. [Read more…]

Wealth of information in PBMC to predict therapeutic drug outcome

Single nucleotide polymorphism can alter liver enzyme interactions with drugs. PBMC samples provide genetic information predicting drug interaction outcome. Blood sampling is easy and a relatively painless means of obtaining myriads of information about one’s physiology. In the serum component of blood we have numerous tests for antibodies, other proteins, and metabolites that can tell tales about several internal organs. Then there is the peripheral blood mononuclear cell or PBMC component which can be used to unravel other mysteries.

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Epigenetics Writers – Readers – Erasers: Targeting Readers in Drug Discovery

DNA and Histone proteins are targets for epigenetic modifications. While DNA is only methylated, histones can be targets for diverse modifications such as methylation, acetylation, ubiquitination, phosphorylation and some more. One of the roles of Epigenetics is to drive cellular differentiation from totipotent Stem cells to fully differentiated cell types. This is made by regulating gene expression through modification patterns that differ according to cell types and cellular status. This means that these patterns may significantly differ between stem cells, germ cells, and differentiated cells.

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Writing – Erasing – Reading Epigenetics: Targeting Erasers in Drug Discovery

DNA and Histone proteins are targets for epigenetic modifications.

One of the roles of Epigenetics is to drive cellular differentiation from totipotent Stem cells to fully differentiated cell types, by regulating gene expression through patterns of modifications that differ according to the cell type and the cell status. This means that the patterns may significantly differ between stem cells, germ cells, and differentiated cells.

It has been found that cancer cells often differ in regard to specific Epigenetic modification sites too. Thus, epigenetic enzymes are considered as potential pharmaceutical drug targets or biomarkers, and quite some effort is made to define drugable targets.

In a previous post I focused on histone modifying enzmes (writers) . Today I will concentrate on those enzymes which erase modification from histones (erasers). Later on, in a further post we’ll be focusing on proteins which recognize specific modifications (readers). [Read more…]