Progress in Histochemistry and Cytochemistry最新文献

Articular cartilage guarantees for an optimal functioning of diarthrodial joints by providing a gliding surface for smooth articulation, weight distribution, and shock absorbing while the subchondral bone plays a crucial role in its biomechanical and nutritive support. Both tissues together form the osteochondral unit. The structural assessment of the osteochondral unit is now considered the key standard procedure for evaluating articular cartilage repair in translational animal models. The aim of this review is to give a detailed overview of the different methods for a comprehensive evaluation of osteochondral repair. The main focus is on the histological assessment as the gold standard, together with immunohistochemistry, and polarized light microscopy. Additionally, standards of macroscopic, non-destructive imaging such as high resolution MRI and micro-CT, biochemical, and molecular biological evaluations are addressed. Potential pitfalls of analysis are outlined. A second focus is to suggest recommendations for osteochondral evaluation.

Low voltage transmission electron microscopy (LVTEM) was employed to examine biological tissues with accelerating voltages as low as 5 kV. Tissue preparation was modified to take advantage of the low-voltage techniques. Treatments with heavy metals, such as post-fixation with osmium tetroxide, on block and counterstaining were omitted. Sections (40 nm) were thinner than usual and generated highly contrasted images. General appearance of the cells remains similar to that of conventional TEM. New features were however revealed. The matrix of the pancreatic granules displays heterogeneity with partitions that may correspond to the inner-segregation of their secretory proteins. Mitochondria revealed the presence of the ATP synthase granules along their cristea. The nuclear dense chromatin displayed a honeycomb organization while distinct beads, nucleosomes, aligned along thin threads were seen in the dispersed chromatin. Nuclear pore protein complexes revealed their globular nature. The intercalated disks in cardiac muscle displayed their fine structural organization. These features correlate well with data described or predicted by cell and molecular biology. These new aspects are not revealed when thicker and conventionally osmicated tissue sections were examined by LVTEM, indicating that major masking effects are associated with standard TEM techniques. Immunogold was adapted to LVTEM further enhancing its potential in cell biology.

Mas-related genes (Mrgs) belong to a large family of G protein-coupled receptor genes found in rodents. Human MRGX proteins are G protein-coupled 7-transmembrane proteins sharing 41-52% amino acid identity with each other, but have no orthologs in rodents. MrgX2 is a member of the MrgX family. MRGX2 is expressed in the small neurons of sensory ganglia and mast cells. It can interact with a series of factors and genes such as the peptides substance P, vasoactive intestinal peptide, cortistatin (CST), proadrenomedullin N-terminal peptide (PAMP), LL-37, PMX-53 and β-defensins. MRGX2 is related to nociception, adrenal gland secretion and mast cell degranulation. Recent research on MrgX2 provides insights into its role in nociception and anti-microbial activities. This article reviewed the origin, expression and function of MrgX2, and discussed possible future research focus.

The metastatic cascade comprises the following steps in sequential manner: the future metastatic cell has to leave the primary tumor mass, degrade the surrounding extracellular matrix, extravasate and circulate within in the bloodstream. Thereafter it has to attach to the endothelium of a target organ, intravasate into the connective tissue and has to proliferate to form a clinically detectable metastasis. We overview the in vitro microfluidic platforms modelling the metastatic cascade and the evolution towards systems capable of recapitulating all the steps by a single comprehensive model.

The c-KIT, a tyrosine kinase receptor, and its ligand the stem cell factor (SCF) play an important role in the production of male and female gametes. The interaction of SCF with c-KIT is required for germ cell survival and growth, and abnormalities in the activity of the SCF/c-KIT system have been associated with human infertility. Recently, it was demonstrated that gonadotropic and sex steroid hormones, among others, regulate the expression of SCF and c-KIT in testicular and ovarian cells. Therefore, the hormonal (de)regulation of SCF/c-KIT system in the testis and ovary may be a cause underpinning infertility. In the present review, we will discuss the effects of hormones modulating the expression levels of SCF and c-KIT in the human gonads. In addition, the implications of hormonal regulation of SCF/c-KIT system for germ cell development and fertility will be highlighted.