Methods and Protocol for Single-Cell Motility Assays under Topological Constraints.

The extracellular environment plays a crucial role in many physiological and pathological processes involving cell motility, such as metastatic invasion in cancer development, by heavily impacting the migration strategies adopted by the cells. The study of how mechanical constraints affect the dynamics of cell migration may be relevant to gain more insight into such processes, and it may prove to be a powerful tool in the hands of biologists. In this chapter, we describe the methods used to investigate the ability of neoplastic cells to migrate through narrowing, rigid microstructures upon chemoattractant stimulation.

[Research progress of chemerin in polycystic ovary syndrome].

As a multifunctional adipokine, chemerin plays a crucial role in various pathophysiological processes through endocrine and paracrine manner. It can bind to three known receptors (ChemR23, GPR1 and CCRL2) and participate in energy metabolism, glucose and lipid metabolism, and inflammation, especially in metabolic diseases. Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases, which seriously affects the normal life of women of childbearing age. Patients with PCOS have significantly increased serum levels of chemerin and high expression of chemerin in their ovaries. More and more studies have shown that chemerin is involved in the occurrence and development of PCOS by affecting obesity, insulin resistance, hyperandrogenism, oxidative stress and inflammatory response. This article mainly reviews the production, subtypes, function and receptors of chemerin protein, summarizes and discusses the research status of chemerin protein in PCOS from the perspectives of metabolism, reproduction and inflammation, and provides theoretical basis and reference for the clinical diagnosis and treatment of PCOS.

Biophysical characterization of the CXC chemokine receptor 2 ligands.

The chemokines of the immune system act as first responders by operating as chemoattractants, directing immune cells to specific locations of inflamed tissues. This promiscuous network is comprised of 50 ligands and 18 receptors where the ligands may interact with the receptors in various oligomeric states i.e., monomers, homodimers, and heterodimers. Chemokine receptors are G-protein coupled receptors (GPCRs) present in the membrane of immune cells. The migration of immune cells occurs in response to a concentration gradient of the ligands. Chemotaxis of neutrophils is directed by CXC-ligand (CXCL) activation of the membrane bound CXC chemokine receptor 2 (CXCR2). CXCR2 plays an important role in human health and is linked to disorders such as autoimmune disorders, inflammation, and cancer. Yet, despite their important role, little is known about the biophysical characteristics controlling ligand:ligand and ligand:receptor interaction essential for biological activity. In this work, we study the homodimers of three of the CXCR2 cognate ligands, CXCL1, CXCL5, and CXCL8. The ligands share high structural integrity but a low sequence identity. We show that the sequence diversity has evolved different binding affinities and stabilities for the CXC-ligands resulting in diverse agonist/antagonist behavior. Furthermore, CXC-ligands fold through a three-state mechanism, populating a folded monomeric state before associating into an active dimer.

Inflamación y asma bronquial / Inflammation and bronchial asthma

En la reacción asmática inmediata, la liberación de mediadores del mastocito, produce una alteración tisular limitada de corta duración (2 horas), controlable con Beta2 adrenérgicos o Teofilina y prevenible con cromoglicato o similares. Más de la mitad de los asmáticos tienen una respuesta tardía al factor provocador de la reacción, que alcanza su máxima intensidad unas ocho horas después y puede mantenerse durante varios días. A nivel de los tejidos se ha producido una infiltración celular, de neutrófilos y eosinófilos primero y células mononucleares luego. Este proceso se produce por acción de alergenos, infección viral o sustancias químicas y determina manifiesta hiperirritabilidad bronquial, siendo más afectada la pequeña vía aérea. Están involucrados en la inflamación del bronquio, mastocitos, basófilos, neutrófilos, eosinófilos, linfocitos, plaquetas y macrófagos-monocitos. Se liberan mediadores de origen celular, plasmático o neurógeno que provocan edema, contracción del músculo bronquial, hipersecreción mucosa con discrinia y quimiotaxis. PAF parece ocupar un lugar central entre los mediadores, su efecto es potente y prolongado y recluta plaquetas, neurotrófilos y eosinófilos en el pulmón. Todo esto contribuye al daño epitelial con pérdida de colgajos. Fibras nerviosas aferentes liberan SP y otros neuropéptidos localmente, contribuyen a la inflamación e interactúan con los otros mediadores. La terapéutica implica evitar la exposición a alergenos, inmunoterapia, esteroides, teofilina y cromoglicato o similares