Genome-wide analysis, expression profile of heat shock factor gene family (CaHsfs) and characterisation of CaHsfA2 in pepper (Capsicum annuum L.).

BACKGROUND: Heat shock factors (Hsfs) play crucial roles in plant developmental and defence processes. The production and quality of pepper (Capsicum annuum L.), an economically important vegetable crop, are severely reduced by adverse environmental stress conditions, such as heat, salt and osmotic stress. Although the pepper genome has been fully sequenced, the characterization of the Hsf gene family under abiotic stress conditions remains incomplete. RESULTS: A total of 25 CaHsf members were identified in the pepper genome by bioinformatics analysis and PCR assays. They were grouped into three classes, CaHsfA, B and C, based on highly conserved Hsf domains, were distributed over 11 of 12 chromosomes, with none found on chromosome 11, and all of them, except CaHsfA5, formed a protein-protein interaction network. According to the RNA-seq data of pepper cultivar CM334, most CaHsf members were expressed in at least one tissue among root, stem, leaf, pericarp and placenta. Quantitative real-time PCR assays showed that all of the CaHsfs responded to heat stress (40 °C for 2 h), except CaHsfC1 in thermotolerant line R9 leaves, and that the expression patterns were different from those in thermosensitive line B6. Many CaHsfs were also regulated by salt and osmotic stresses, as well as exogenous Ca(2+), putrescine, abscisic acid and methyl jasmonate. Additionally, CaHsfA2 was located in the nucleus and had transcriptional activity, consistent with the typical features of Hsfs. Time-course expression profiling of CaHsfA2 in response to heat stress revealed differences in its expression level and pattern between the pepper thermosensitive line B6 and thermotolerant line R9. CONCLUSIONS: Twenty-five Hsf genes were identified in the pepper genome and most of them responded to heat, salt, osmotic stress, and exogenous substances, which provided potential clues for further analyses of CaHsfs functions in various kinds of abiotic stresses and of corresponding signal transduction pathways in pepper.

Involvement of CaSR in hyperglycemia-induced macroangiopathy and related mechanism.

In order to clarify the potential role of calcium sensing receptor (CaSR), a typical G protein coupled receptor (GPCR), in hyperglacemia-induced macroangiopathy, experimental hyperglycemia models in vivo and in vitro were prepared. Firstly, SD rats were divided into control group (n=10) and diabetes group (n=10), and diabetic model was induced via high-fat diet feeding and streptozotocin (STZ, 30 mg/kg) injection. Hydroxyproline level, determined via Choramnie T oxidation method, in vessel wall in diabetic rats was 30% more than that in control group. The gene transcription and expression levels were detected by real-time PCR and Western blotting, respectively. Both of collagen I and III mRNA levels in diabetic aorta were nearly twice those in normal aorta. The cleaved caspase-3 and -9 were elevated 1.5 and 2.5 times respectively in diabetic vascular cells. As compared with controls, mRNA and protein levels of CaSR in aorta were increased by 3 and 1.5 times in diabetes group. The expression levels of Bax as well as pro-apoptotic kinases (phospho-p38 and phosphor-JNK) were also increased 2, 0.5 and 0.5 times respectively in diabetic rats. To further validate the involvement of CaSR in cell apoptosis and explore the potential mechanism, the endothelial cell line (human umbilical vascular endothelial cells, HUVECs) was stimulated with high concentration of glucose (33 mmol/L) to mimic hyperglycemia in vitro. Cell-based assays also showed that the CaSR level and key apoptotic proteins (cleaved caspase-3 and -9, Bax, phospho-p38 and phosphor-JNK) were elevated in response to stimulation, and inhibition of CaSR by using specific inhibitor (NPS-2143, 10 µmol/L) could protect cells against apoptosis. Our results demonstrated that CaSR might take important part in the development of diabetic macroangiopathy through promoting cell apoptosis induced by hyperglycemia.

Characterization of CaHsp70-1, a pepper heat-shock protein gene in response to heat stress and some regulation exogenous substances in Capsicum annuum L.

Pepper (Capsicum annuum L.) is sensitive to heat stress (HS). Heat shock proteins 70 (Hsp70s) play a crucial role in protecting plant cells against HS and control varies characters in different plants. However, CaHsp70-1 gene was not well characterized in pepper. In this study, CaHsp70-1 was cloned from the pepper thermotolerant line R9, which encoded a protein of 652 amino acids, with a molecular weight of 71.54 kDa and an isoelectric point of 5.20. CaHsp70-1 belongs to the cytosolic Hsp70 subgroup, and best matched with tomato SlHsp70. CaHsp70-1 was highly induced in root, stem, leaf and flower in R9 with HS treatment (40 °C for 2 h). In both thermosensitive line B6 and thermotolerant line R9, CaHsp70-1 significantly increased after 0.5 h of HS (40 °C), and maintained in a higher level after 4 h HS. The expression of CaHsp70-1 induced by CaCl2, H2O2 and putrescine (Put) under HS were difference between B6 and R9 lines. The different expression patterns may be related to the differences in promoters of CaHsp70-1 from the two lines. These results suggest that CaHsp70-1 as a member of cytosolic Hsp70 subgroup, may be involved in HS defense response via a signal transduction pathway contained Ca2+, H2O2 and Put.

Endoplasmic reticulum stress-mediated aldosterone-induced apoptosis in vascular endothelial cells.

The aim of this study was to examine the effects of endoplasmic reticulum (ER) stress on aldosterone (Aldo)-induced apoptosis of endothelial cells. Glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP, a hallmark of ER-associated apoptosis) were used to evaluate ER stress. Western blotting and real-time PCR were used to analyze indicators of ER molecule. Apoptosis was detected by annexin V/propidium iodide staining and flow cytometry. Human umbilical vein endothelial cells (HUVECs) were stimulated with different concentrations of Aldo for different durations. Aldo promoted apoptosis of HUVECs and induced ER stress, as evidenced by increased expression of GRP78 and CHOP. siRNA knockdown of CHOP attenuated Aldo-mediated apoptosis. These results indicate that ER stress may be involved in Aldo-induced apoptosis of HUVECs.

Investigation and Analysis of 108 Cases of Home Isolated Patients With Mild COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) began to spread across Wuhan, China, by the end of 2019, and patients were unable to be hospitalized because medical resources were limited. METHODS: A questionnaire survey was conducted among 108 participants with mild COVID-19 who have isolated at home under the guidance of doctors. The results of the questionnaire and outpatient data were integrated to evaluate participants' compliance with various epidemic prevention measures. RESULTS: During isolation, most participants were able to follow epidemic prevention measures under the guidance of doctors. After 14 d from the start of isolation, 45.37% of the participants recovered. Approximately half of the participants were relieved of symptoms, and most of them were transferred to mobile cabin hospitals to continue isolation. Three participants with worsening symptoms were transferred to the designated hospitals. There were no deaths of the participants, but there were 7 family members that were infected. CONCLUSIONS: During a period of home isolation under the guidance of a doctor, individuals can comply with epidemic prevention measures and symptoms can be improved. Scientific home isolation may be an effective way to relieve the strain of medical and social resources during the epidemic of COVID-19.

[Erythrocyte oxidative stress in children with left to right shunt congenital heart disease].

OBJECTIVE: To study erythrocyte oxidative stress status and its association with left to right shunt congenital heart disease (CHD) in children. METHODS: A total of 31 children with left to right shunt CHD were enrolled, including 7 cases of atrial septal defect (ASD), 12 ventricular septal defect (VSD), 4 patent ductus arteriosus (PDA), 6 patent foramen ovale (PFO), and 2 complete endocardial cushion defect. Twenty healthy age-matched (1 month to 3 years old) children severed as the control group. The contents of superoxide dismutase (SOD) and malonaldehyde (MDA) in erythrocytes were determined using ELISA. ESR was measured by Westergen. PaO(2) and PaCO(2) were measured by Blood Gas Analyzer (GEM Premier 3000). RESULTS: The MDA content in erythrocytes in the CHD group was significantly higher, in contrast, SOD content was significantly lower than that in the control group (P<0.05). The CHD children with heart failure had more decreased SOD and more increased MDA contents compared with the control group (P<0.01). The SOD level was the highest in the PFO group and was the lowest in the complete endocardial cushion defect group. The SOD level in the PFO group was significantly higher than that in the ASD, VSD and complete endocardial cushion defect groups (P<0.05). The MDA level was the highest in the VSD group and was the lowest in the complete endocardial cushion defect group. There were significant differences in the MDA level among CHD subgroups (P<0.05). The ESR was negatively correlated to the SOD level (r=-0.191, P<0.05), while positively correlated to PaO(2) level in CHD children (r=0.216, P<0.05). There was a negative correlation between SOD and MDA levels (r=-0.312, P<0.05). CONCLUSIONS: Oxidative stress exists in children with left to right shunt CHD. The SOD and MDA contents in erythrocytes can be used as markers for the assessment of severity of the disease.

Genome-wide analysis of the CaHsp20 gene family in pepper: comprehensive sequence and expression profile analysis under heat stress.

The Hsp20 genes are present in all plant species and play important roles in alleviating heat stress and enhancing plant thermotolerance by preventing the irreversible aggregation of denaturing proteins. However, very little is known about the CaHsp20 gene family in pepper (Capsicum annuum L.), an important vegetable crop with character of temperate but thermosensitive. In this study, a total of 35 putative pepper Hsp20 genes (CaHsp20s) were identified and renamed on the basis of their molecular weight, and then their gene structure, genome location, gene duplication, phylogenetic relationship, and interaction network were also analyzed. The expression patterns of CaHsp20 genes in four different tissues (root, stem, leaf, and flower) from the thermotolerant line R9 under heat stress condition were measured using semi-quantitative RT-PCR. The transcripts of most CaHsp20 genes maintained a low level in all of the four tissues under normal temperature condition, but were highly induced by heat stress, while the expression of CaHsp16.6b, 16.7, and 23.8 were only detected in specific tissues and were not so sensitive to heat stress like other CaHsp20 genes. In addition, compared to those in thermotolerant line R9, the expression peak of most CaHsp20 genes in thermosensitive line B6 under heat stress was hysteretic, and several CaHsp20 genes (CaHsp16.4, 18.2a, 18.7, 21.2, 22.0, 25.8, and 25.9) showed higher expression levels in both line B6 and R9. These data suggest that the CaHsp20 genes may be involved in heat stress and defense responses in pepper, which provides the basis for further functional analyses of CaHsp20s in the formation of pepper acquired thermotoleance.

Cathepsins mediate tumor metastasis.

Cathepsins are highly expressed in various human cancers, associated with tumor metastasis. It is superfamily, concluding A, B, C, D, E, F, G, H, L, K, O, S, V, and W family members. As a group of lysosomal proteinases or endopeptidases, each member has a different function, playing different roles in distinct tumorigenic processes such as proliferation, angiogenesis, metastasis, and invasion. Cathepsins belong to a diverse number of enzyme subtypes, including cysteine proteases, serine proteases and aspartic proteases. The contribution of cathepsins to invasion in human cancers is well documented, although the precise mechanisms by which cathepsins exert their effects are still not clear. In the present review, the role of cathepsin family members in cancer is discussed.