Malarial pigment does not induce MMP-2 and TIMP-2 protein release by human monocytes

Dear editor, In the recent years growing evidence on the involvement of human matrix metalloproteinases(MMPs) and tissue inhibitors of metalloproteinases(TIMPs) in cerebral malaria (CM) has been reported[1]and a role for malarial pigment haemozoin(HZ) has been proposed[2,3].In a recent work my group showed that in human microvascular endothelial

Simultaneous Cell Disruption and Aqueous Two-Phase Extraction for Isolation of Intracellular Recombinant Proteins

A new technique was developed for the integrated processing of cell disruption and aqueous two-phase extraction in a high-speed bead mill to separate intracellular proteins from microbial cells. The process was named as simultaneous cell disruption and aqueous two-phase extraction (SDATE). Advantages, such as high cell disruption efficiency, biochemical activities preservation of proteins, cell debris elimination, and prelimiary purification of the target protein were being claimed. When this technique was employed for isolating recombinant Tumor Necrosis Factor (TNF) from E. coli, overall protein concentration and TNF activity were found to have been increased. More than 95% of TNF was partitioned into the top phase and all cell debris were in the bottom phase. The partition coefficient was greater than 3 and the TNF purification factor was greater than 6. It is shown that less separation steps were being utilized in the new technique, meaning a reduction in separation time and less process extractors required.

Extracellular nucleoprotein exacerbates influenza viruspathogenesis by activating Toll-like receptor 4 and the NLRP3inflammasome

Host immune responses, such as those initiated by pattern recognition receptor (PRR) activation, are important for viralclearance and pathogenesis. However, little is known about the interactions of viral proteins with surface PRRs or, moreimportantly, the association of innate immune activation with viral pathogenesis. In this study, we showed that internalinfluenza virus proteins were released from infected cells. Among these proteins, nucleoprotein (NP) played a critical role inviral pathogenesis by stimulating neighboring cells through toll-like receptor (TLR)2, TLR4, and the NLR family pyrin domaincontaining 3 (NLRP3) inflammasome. Through the activation of these PRRs, NP induced the production of interleukin (IL)-1β andIL-6, which subsequently led to the induction of trypsin. Trypsin induced by NP increased the infectivity of influenza virus,leading to increases in viral replication and pathology upon subsequent viral infection. These results reveal the role of releasedNP in influenza pathogenesis and highlight the importance of the interactions of internal viral proteins with PRRs in theextracellular compartment during viral pathogenesis.

Release of the Oxygen-Evolving Complex Subunits from Photosystem II Membranes in Phosphorylation Condition under Light Stress

So far it is unclear whether the release of oxygen-evolving complex （OEC） subunits including PsbO, PsbP, and PsbQ proteins is affected by the phosphorylation of photosystem II （PSII） membranes under light stress. In this work, different phosphorylated PSII membranes were obtained from spinach. Phosphorylation partially suppressed the release of PsbO, PsbP, and PsbQ proteins from PSII membranes under light stress. Reactive oxygen species including superoxide anion, hydrogen peroxide and hydroxyl radical, were involved in the release of a small part of PsbO protein, but not in the release of PsbP and PsbQ proteins in the non-phosphorylated and phosphorylated PSII membranes. All of the results suggested that the release of PsbO, PsbP, and PsbQ proteins was partially regulated by phosphorylation in PSII membranes, and the role of reactive oxygen species in the release of OEC subunits in non-phosphorylated PSII membranes was the same as in phosphorylated PSII membranes.

The cAMP-mediated protein kinase signal transduction pathway is involved in the pyrogenic effect of CRH in rats

To determine whether the cyclic adenosine monophosphate (cAMP) mediated protein kinase signal transduction pathway is involved in the pyrogenic action of corticotropin releasing hormone (CRH) in rats.Methods Corticotropin releasing hormone, 2', 3 '-dideoxyadenosine (DDA) and adenosine-3', 5'(cyclic) monophosphorothionate, Rp-lsomer (Rp-cAMPS), were administered intracerebroventricularly (i.c.v.). The colonic temperature was measured using a thermistor, and the content of cAMP in the hypothalamus was determined by radioimmunoassay. Hypethalemic incubation was used to assess the effects of CRH on the content of cAMP in the hypothalamus in vitro.Results Microinjection (i.c.v.) of CRH (2.5 μg, 5.0 μg and 10 μg) caused increases in colonic temperature and the hypothalemus cAMP level in conscious rats. CRH increased hypothalemus cAMP level in vitro. The pyrogenic effects of CRH were abolished or markedly inhibited by prior injection (i. c. v. ) of an adenylate cyclase inhibitor, DDA (30 μg), or an inhibitor of cAMP-dependent protein kinase, Rp-cAMPS (15 μg).Conclusion cAMP mediates the pyrogenic action of centrally administered of CRH in rats, and protein kinase A may play an important role in the central CRH-induced fever. The cAMP-dependent protein kinase signal transduction pathway may be involved in the central mechanisms of the pyrogenic action of CRH in rats.