Using proteomic analysis, an investigation aimed at a better understanding of the molecular adaptation mechanisms of cold stress was carried out in rice (Oryza sativa). The seedlings were exposed to a progressively low temperature stress treatment from normal temperature to 15, 10, and 5 degrees C. Proteins were extracted from the leaves collected from both control and stressed seedlings. By fractionation, approximately 1700 protein spots were separated and visualized on CBB-stained 2-D gels. Sixty protein spots were found to be up-regulated in responding to the progressively low temperature stress and displayed different dynamic patterns. As an initial work, 41 of these proteins were identified using MALDI-TOF MS or ESI/MS/MS. These cold responsive proteins, besides two proteins of unknown function, include four factors of protein biosynthesis, four molecular chaperones, two proteases, and eight enzymes involved in biosynthesis of cell wall components, seven antioxidative/detoxifying enzymes, and proteins linked to energy pathway, as well as a protein involved in signal transduction. The functional proteomes illuminate the facts, at least in plant cell, that protein quality control mediated by chaperones and proteases and enhancement of cell wall components play important roles in tolerance to cold stress. Using TargetP program, the subcellular localization of the identified proteins was analyzed. Proteins (43.9%) were predicted to be located in the chloroplasts, implying that chloroplast proteome is virtually subjective to cold stress. The physiological implications, revealed from the experimental data, are discussed in context of a complex metabolic network in plant cells responsive to cold stress.

Recent studies suggest that mRNAs may be differentially expressed between males and females. This study aimed to perform expression analysis of mRNA and its main regulatory molecule, microRNA (miRNA), to discuss the potential sex-specific expression patterns using abnormal expression profiles from The Cancer Genome Atlas database. Generally, deregulated miRNAs and mRNAs had consistent expression between males and females, but some miRNAs may be oppositely expressed in specific diseases: up-regulated in one group and down-regulated in another. Studies of miRNA gene families and clusters further confirmed that these sequence or location related miRNAs might have opposing expression between sexes. The specific miRNA might have greater expression divergence across different groups, suggesting flexible expression across different individuals, especially in tumor samples. The typical analysis regardless of the sex will ignore or balance these sex-specific deregulated miRNAs. Compared with flexible miRNAs, their targets of mRNAs showed relative stable expression between males and females. These relevant results provide new insights into miRNA-mRNA interaction and sex difference.

An invasive green alga, Caulerpa racemosa, collected from the South China Sea was tested for its antiviral properties. Hot water extracts and the n-butanol fraction obtained showed potent inhibition of herpes simplex virus type 1 (HSV-1) and Coxsackie virus B3 (Cox B3). A sulfoquinovosyldiacylglycerol (SQDG) compound was isolated and purified from the n-butanol fraction following further antiviral-guided fractionation. The SQDG compound exhibited an excellent antiviral effect against HSV-2, with a 50% inhibitory concentration (IC50) of 15.6 μg ml-1 against both standard and clinical strains of HSV-2, but showed only moderate antiviral effects against HSV-1 and Cox B3. The SQDG compound was chemically characterized using spectroscopic methods as (2S)-1,2-di-O-palmitoyl-3-O-(6′-sulfo-α-D-quinovopyranosyl) glycerol. This is the first isolation from C. racemosa of this SQDG compound with notable selective antiviral activity against HSV-2.

No abstract

Rabies virus (RABV) invades the central nervous system and nearly always causes fatal disease in humans. RABV enters cells via clathrin-mediated endocytosis upon receptor binding. The detailed mechanism of this process and how it is regulated are not fully understood. Here, we carried out a high-through-put RNAi analysis and identified AP2-associated kinase 1 (AAK1), a serine/threonine kinase, as an important cellular component in regulating the entry of RABV. AAK1 knock-down greatly inhibits RABV infection of cells, and AAK1-induced phosphorylation of threonine 156 of the μ subunit of adaptor protein 2 (AP2M1) is found to be required for RABV entry. Inhibition of AAK1 kinase activity by sunitinib blocked AP2M1 phosphorylation, significantly inhibiting RABV infection and preventing RABV from entering early endosomes. In vivo studies revealed that sunitinib prolongs the survival of mice challenged with RABV street virus. Our findings indicate that AAK1 is a potential drug target for postexposure prophylaxis against rabies.

Pro-pregnancy hormone progesterone (P4) helps to maintain a quiescent status of uterine tissues during gestation. However, P4’s functional role in maintaining fetal membrane (amniochorion) integrity remains unclear. P4 functions through its membrane receptors (PGRMCs) as fetal membrane cells lack nuclear receptors. This study screened the differential expression of PGRMCs in the fetal membranes and tested P4-PGRMC interactions under normal and oxidative stress (OS) conditions expected that can disrupt P4-PGRMC interactions impacting fetal membrane stability resulting in parturition. Human fetal membranes were collected from term and preterm deliveries (N = 5). Immunohistochemistry and western blot localized and determined differential expression of P4 receptors. Primary amnion epithelial (AEC), mesenchymal (AMCs), and chorion cell were treated with P4 alone or cotreat (P4 + OS induced by cigarette smoke extract [CSE]). Proximity ligation assay (PLA) documented P4-receptor binding, while P4 ELISA documented culture supernatant levels. Immunohistology confirmed lack of nuclear PRs; however, confirmed expressions of PGRMC 1 and 2. Term labor (P = 0.01) and preterm rupture (P = 0.01) are associated with significant downregulation of PGRMC2. OS induced differential downregulation of PGRMCs in both amnion and chorion cells (all P < 0.05) and downregulates P4 release (AMCs; P = 0.01). The PLA showed preferential receptor-ligand binding in amnion and chorion cells. Co-treatment of P4 + CSE did not reverse CSE-induced effects. In conclusion, P4-PGRMCs interaction maintains fetal membranes’ functional integrity throughout pregnancy. Increased OS reduces endogenous P4 production and cell type-dependent downregulation of PGRMCs. These changes can lead to fetal membrane-specific ‘functional progesterone withdrawal’, contributing to the dysfunctional fetal membrane status seen at term and preterm conditions.

Inter-simple Sequence Repeat (ISSR) molecular markers were used to detect the genetic diversity among 50 materials of Dactylis glomerata collected from China and other countries. Twelve primers produced 101 polymorphic bands, averaged 8.41 bands each primer pair. The average percentage of polymorpgic bands was 86.3.8%, and the range of GS (define) was 0.6116-0.9290, indicating a rich genetic diversity of D. glomerata. Based on the cluster and principal component analyses on the genetic characteristics, D. glomerata could be divided into 5 groups according to the nearest phylogenetic relationship. In most cases, accessions from the same continent were classified into the same group, the accessions from China and the United States belong to the different groups, respectively, indicating the geographical distribution of genetic diversity of D. glomerata. The present paper also discussed collection and conservation of germplasm resources in D. glomerata.

No abstract