Acute phase induction of mouse serum amyloid P component. Correlation with other parameters of inflammation

Hepatic mRNA levels of the mouse major acute phase proteins serum amyloid P component (SAP) and serum amyloid A component (SAA) were monitored at timed intervals after i.p. injection of thioglycollate or s.c. injection of azocasein. Both mRNA increased dramatically in response to either inflammatory stimulus. The increase in SAA mRNA levels accompanied an abrupt change in mRNA size from 650 to 750 bases. Peak SAA mRNA concentrations were observed 18 h after either stimulus; by 72 h concentrations had returned to preinflammatory levels. Peak SAP mRNA concentrations were observed 8 h after thioglycollate and 12 to 18 h after azocasein injection; by 36 h concentrations were close to preinflammatory levels. All mRNA species studied (SAP, SAA and the complement components C3, C5 and factor B) were induced more rapidly by the thioglycollate stimulus and reached higher peak concentrations. SAP mRNA levels were correlated with other parameters of inflammation: infiltration of peritoneal exudate cells (PEC) into the peritoneum after thioglycollate injection, and serum concentrations of SAP after azocasein injection. Serum SAP concentrations rose 20-fold in response to the latter stimulus by 36 h, i.e., 18 to 24 h after the peak SAP mRNA levels. The highest numbers of PEC were present 24 h after the thioglycollate stimulus, i.e. 16 h after the maximum SAP mRNA concentration, indicating the continuation of an active local inflammation many hours after one aspect of the systemic response has ceased.     

Binding of human C-reactive protein to mouse macrophages is mediated by distinct receptors

Human C-reactive protein (CRP) is known to activate mouse macrophages (M phi) to a tumoricidal state and to serve as an opsonin for M phi. Therefore, cell surface receptors for CRP on mouse M phi were characterized and their relationship to the IgG FcR determined. The specific binding of 125I-CRP to resident or elicited mouse M phi was saturable, reversible, and involved both a high and a low affinity receptor population. Binding of CRP to the mouse M phi cell lines PU5 1.8 and J774 was nearly identical to that observed with peritoneal M phi. The high affinity receptor population had a calculated K of 10 nM and a receptor density of approximately 10(5) sites per cell. Mouse Ig of the IgG2a, IgG2b, or IgG1 isotypes inhibited binding of 125I-CRP to PU5 1.8 cells at concentrations five-fold greater than that of the homologous ligand. In the converse experiment, unlabeled CRP failed to inhibit specific binding of 125I-labeled IgG2a, IgG2b or IgG1. Isolation of CRP binding proteins from surface iodinated PU5 1.8 cells by ligand-affinity chromatography or chemical cross-linking yielded a major protein band of 57 to 60 kDa which appeared to be distinct from the IgG1/IgG2b FcR (FcR-II) membrane proteins. Removal of radiolabeled IgG2b/IgG1 binding membrane proteins by affinity chromatography did not remove CRP-binding proteins. The rat mAb 2.4G2 which inhibits binding of radiolabeled mouse IgG2b, did not inhibit the binding of CRP. A rat polyclonal antiserum to CRP-binding membrane proteins of PU5 1.8 cells inhibited 125I-CRP binding, but not 125IgG2b binding. The rat polyclonal antibody reacted with two 57 to 60 kDa membrane proteins from PU5 1.8 cells that appear to be of a similar size on Western blots. The 125I-CRP was internalized via endosomes and intact CRP subunits could be detected intracellularly. The findings suggest that binding of CRP occurs through a receptor that is distinct from the IgG FcRs, but that CRP-R activity may be influenced by an association with an IgG FcR.     

Genome-wide analysis of key salinity-tolerance transporter (HKT1;5) in wheat and wild wheat relatives (A and D genomes)

Exclusion of sodium ions from cells is one of the key salinity tolerance mechanisms in plants. The high-affinity cation transporter (HKT1;5) is located in the plasma membrane of the xylem, excluding Na⁺ from the parenchyma cells to reduce Na⁺ concentration. The regulatory mechanism and exact functions of HKT genes from different genotypic backgrounds are relatively obscure. In this study, the expression patterns of HKT1;5 in A and D genomes of wheat were investigated in root and leaf tissues of wild and domesticated genotypes using real-time PCR. In parallel, the K⁺/Na⁺ ratio was measured in salt-tolerant and salt-sensitive cultivars. Promoter analysis were applied to shed light on underlying regulatory mechanism of the HKT1;5 expression. Gene isolation and qPCR confirmed the expression of HKT1;5 in the A and D genomes of wheat ancestors (Triticum boeoticum, AbAb and Aegilops crassa, MMDD, respectively). Interestingly, earlier expression of HKT1;5 was detected in leaves compared with roots in response to salt stress. In addition, the salt-tolerant genotypes expressed HKT1;5 before salt-sensitive genotypes. Our results suggest that HKT1;5 expression follows a tissue- and genotype-specific pattern. The highest level of HKT1;5 expression was observed in the leaves of Aegilops, 6 h after being subjected to high salt stress (200 mM). Overall, the D genome allele (HKT1;5-D) showed higher expression than the A genome (HKT1;5-A) allele when subjected to a high NaCl level. We suggest that the D genome is more effective regarding Na⁺ exclusion. Furthermore, in silico promoter analysis showed that TaHKT1;5 genes harbor jasmonic acid response elements.     

How the Nucleus and Mitochondria Communicate in Energy Production During Stress: Nuclear MtATP6, an Early-Stress Responsive Gene, Regulates the Mitochondrial F1F0-ATP Synthase Complex

A small number of stress-responsive genes, such as those of the mitochondrial F₁F₀-ATP synthase complex, are encoded by both the nucleus and mitochondria. The regulatory mechanism of these joint products is mysterious. The expression of 6-kDa subunit (MtATP6), a relatively uncharacterized nucleus-encoded subunit of F₀ part, was measured during salinity stress in salt-tolerant and salt-sensitive cultivated wheat genotypes, as well as in the wild wheat genotypes, Triticum and Aegilops using qRT-PCR. The MtATP6 expression was suddenly induced 3 h after NaCl treatment in all genotypes, indicating an early inducible stress-responsive behavior. Promoter analysis showed that the MtATP6 promoter includes cis-acting elements such as ABRE, MYC, MYB, GTLs, and W-boxes, suggesting a role for this gene in abscisic acid-mediated signaling, energy metabolism, and stress response. It seems that 6-kDa subunit, as an early response gene and nuclear regulatory factor, translocates to mitochondria and completes the F₁F₀-ATP synthase complex to enhance ATP production and maintain ion homeostasis under stress conditions. These communications between nucleus and mitochondria are required for inducing mitochondrial responses to stress pathways. Dual targeting of 6-kDa subunit may comprise as a mean of inter-organelle communication and save energy for the cell. Interestingly, MtATP6 showed higher and longer expression in the salt-tolerant wheat and the wild genotypes compared to the salt-sensitive genotype. Apparently, salt-sensitive genotypes have lower ATP production efficiency and weaker energy management than wild genotypes; a stress tolerance mechanism that has not been transferred to cultivated genotypes.     

Development of Novel Prime-Boost Strategies Based on a Tri-Gene Fusion Recombinant L. tarentolae Vaccine against Experimental Murine Visceral Leishmaniasis

Visceral leishmaniasis (VL) is a vector-borne disease affecting humans and domestic animals that constitutes a serious public health problem in many countries. Although many antigens have been examined so far as protein- or DNA-based vaccines, none of them conferred complete long-term protection. The use of the lizard non-pathogenic to humans Leishmania (L.) tarentolae species as a live vaccine vector to deliver specific Leishmania antigens is a recent approach that needs to be explored further. In this study, we evaluated the effectiveness of live vaccination in protecting BALB/c mice against L. infantum infection using prime-boost regimens, namely Live/Live and DNA/Live. As a live vaccine, we used recombinant L. tarentolae expressing the L. donovani A2 antigen along with cysteine proteinases (CPA and CPB without its unusual C-terminal extension (CPB^-CTE)) as a tri-fusion gene. For DNA priming, the tri-fusion gene was encoded in pcDNA formulated with cationic solid lipid nanoparticles (cSLN) acting as an adjuvant. At different time points post-challenge, parasite burden and histopathological changes as well as humoral and cellular immune responses were assessed. Our results showed that immunization with both prime-boost A2-CPA-CPB^-CTE-recombinant L. tarentolae protects BALB/c mice against L. infantum challenge. This protective immunity is associated with a Th1-type immune response due to high levels of IFN-γ production prior and after challenge and with lower levels of IL-10 production after challenge, leading to a significantly higher IFN-γ/IL-10 ratio compared to the control groups. Moreover, this immunization elicited high IgG1 and IgG2a humoral immune responses. Protection in mice was also correlated with a high nitric oxide production and low parasite burden. Altogether, these results indicate the promise of the A2-CPA-CPB^-CTE-recombinant L. tarentolae as a safe live vaccine candidate against VL.     

Retinoic acid and/or progesterone differentiate mouse induced pluripotent stem cells into male germ cells in vitro

Numerous reagents were employed for differentiating induced pluripotent stem cells (iPSCs) into male germ cells; however, the induction procedure was ineffective. The aim of this study was to improve the in vitro differentiation of mice iPSCs (miPSCs) into male germ cells with retinoic acid (RA) and progesterone (P). miPSCs were differentiated to embryoid bodies (EBs) in suspension with RA with or without progesterone for 0, 4, and 7 days. Then, the expression of certain genes at different stages of male germ cell development including Ddx4 (pre meiosis), Stra8 (meiosis), AKAP3 (post meiosis), and Mvh protein was examined in RNA and/or protein levels by real-time polymerase chain reaction or flow cytometry, respectively. The Stra8 gene expression increased in the RA groups on all days. But, expression of this gene declined in RA + P groups. In addition, an increased expression of Ddx4 gene was observed on day 0 in the P group. Also, a significant upregulation was observed in the expression of AKAP3 gene in the RA + P group on days 0 and 4. However, gene expression decreased in P and RA groups on day 7. The expression of Mvh protein significantly increased in the RA group on day 7. The Mvh expression was also enhanced in the P group on day 4, but it decreased on day 7, while this protein upregulated on day 0 and 7 in the RA + P group. The miPSCs have the capacity for in vitro differentiation into male germ cells by RA and/or progesterone. However, the effects of these inducers depend on the type of combination and an effective time.     

Modulatory effects of statins on the autophagy: A therapeutic perspective

Autophagy is considered as an important mechanism for maintaining homeostasis and responsible for the degradation of superfluous or potentially toxic components and organelles. Autophagy impairment is associated with a number of pathological conditions, such as aging, neurological disorders, cancer, and infection. Autophagy also plays a significant role in cancer chemotherapy. The multiple cancer drugs have been notably developed with the strategy of autophagy modulation. Statins, 3-hydroxy-3-methyl-glutaryl-CoA inhibitors, are known due to their efficacy in decreasing low-density lipoprotein and extensively used for the management of cardiovascular diseases. Statins have other therapeutic and biological activities, such as antioxidant, anti-inflammatory, antitumor, and neuroprotective known as pleiotropic effects. It seems that statins are capable of targeting various signaling pathways in the induction of their great pharmacological effects. At the present study, we demonstrate the therapeutic effects of statins mediated via autophagy regulation.     

The survivin molecule as a double-edged sword in cellular physiologic and pathologic conditions and its role as a potential biomarker and therapeutic target in cancer

Survivin is a member of the family of apoptosis inhibitory proteins with increased expression level in most cancerous tissues. Evidence shows that survivin plays regulatory roles in proliferation or survival of normal adult cells, principally vascular endothelial cells, T lymphocytes, primitive hematopoietic cells, and polymorphonuclear neutrophils. Survivin antiapoptotic role is, directly and indirectly, related to caspase proteins and shows its role in cell division through the chromosomal passenger complex. Survivin contains many genetic polymorphisms that the role of some variations has been proven in several cancers. The −31G/C polymorphism is one of the most important survivin mutations which is located in the promoter region on a CDE/CHR motif. This polymorphism can upregulate the survivin messenger RNA. In addition, its allele C can increase the risk of cancers in 1.27-fold than allele G. Considering the fundamental role of survivin in different cancers, this protein could be considered as a new therapeutic target in cancer treatment. For this purpose, various strategies have been designed including the prevention of survivin expression through inhibition of mRNA translation using antagonistic molecules, inhibition of survivin gene function through small inhibitory molecules, gene therapy, and immunotherapy. In this study, we describe the structure, played roles in physiological and pathological states and genetic polymorphisms of survivin. Finally, the role of survivin as a potential target in cancer therapy given challenges ahead has been discussed.