Transglutaminase 3 expression in C57BL／6J mouse embryo epidermis and the correlation with its differentiation

Epidermal-type transglutaminase 3 (TGM3) is involved in the cross-linking of structural proteins to form the cornified envelope in the epidermis. In the present study, we detected the expression of TGM3 in the mouse embryo using RT-PCR.TGM3 mRNA is weakly presented from E11.5 to E14.5 and increases significantly from E15.5 to birth. Then we determined the spatial and temporal expression pattern of TGM3 in the skin and other organs by in situ hybridization. We found a deprivation of TGM3 in skin at E11.5, while a rich supply in periderm cells and a weak expression in basal cells from E12.5 to E14.5. From the period of E15.5 to E16.5, after keratinization in the epidermis, TGM3 was expressed in the granular and cornified layers. The electron microscopic observation of the C57BL/6J mouse limb bud skin development provided several morphological evidences for the epidermal differentiation. The above findings suggest that the expression of TGM3 plays a important role in the epidermis differentiation in embryogenesis.     

小鼠早期胚胎发育过程中TGF-α和EGF-R mRNA的表达

This study was conducted to examine the activity of TGF α and EGF R mRNA using the RT PCR technique in the early embryonic development of the mouse. Expression of TGF α mRNA was initially observed in the 8 cell stage embryo of the mouse. The level of expression gradually increased in the morula and blastula. Expression of EGF R mRNA was initially observed in the 4 cell stage embryo of the mouse and 8 cell stage embryo;morula and blastula all expressed EGF R mRNA and the levels of expression had not changed. These results confirm that epidermal growth factors play a key role in early embryonic development of the mouse, especially TGF α which can stimulate and regulate embryonic development via the autocrine system.     

Expression and regulation of mRNAs for insulin-like growth factor-I receptor and LH receptor in corpora lutea

Relationship between insulin-like growth factor-l receptor (IGF-IR) and luteinizing hormone receptor (LHR) mRNA expression as well as their regulation was determined in rat corpora lutea (CL) . In the CL of estrous cycle rat, LHR mRNA positive CL expressed high level of mRNA of IGF-IR. While the expression of LHR mRNA decreased on estrus, the CL still expressed relatively high level of IGF-IR mRNA. In pseudopregnant rat CL, the expression level of LHR mRNA was low on day 1, the most intense signals were detected on day 8, the signals of LHR mRNA became undetectable on day 14. In contrast to LHR expression, the high level of IGF-IR mRNA was observed in pseudopregnant CL of day 1, and thereafter its signals were detected from day 2 to day 14. Pregnant rat CL expressed both LHR and IGF-IR mRNAs. IGF-I stimulated LHR expression in CL. PGF2ainhibited expression of IGF-IR and LHR. PGE2 negated the inhibiting effects of PGF2α. These data suggest that IGF-I may be involved in regulating CL function, and maintai     

Clusterin mRNA expression in apoptotic and activated rat thymocytes

Clusterin is a 75-80 kDa heterodimeric glycoprotein,that is produced in most tissues but which exact biological role is still not clear.Pwarticularly,its role in protection or promotion of apoptosis is heavily disputed,since data supporting both views have been reported in several independent sutdies.To clarify this issue,and also to determine whether clusterin expression itself might be affected by apoptosis,in the present study,rat thymocytes were treated with dexamethasone,-a synthetic glucocorticoid that elicits apoptosis in thymocytes-,and clusterin mRNA expression was analyzed by semi-quantitative RT-PCR before and after induction of apoptosis.Interestingly,neither the treatment with dexamethasone in vitro nor triggering of apoptosis in vivo up-regulated clusterin expression,opposing the view that clusterin is involved in apoptotic processes.On the other hand,a new clusterin mRNA isoform was detected and isolated,whose expression ws restricted to freshly isolated thymocytes.This novel isoform lacks the post-translational proteolytic cleavage site and is therefore predicted to encode a monomeric protein.The biological function under normal circumstances,however,will nedd further investigations for clarification.While apoptosis could not modulate clusterin expression,activation of thymocytes with concanavalin A and interleukin-2 resulted in up-regulation of clusterin mRNA level,indicating that clusterin expression is rather under the control of cell activation-mediated rather than apoptosis-induced signals.     

The kinetics of IL—4 and IFN—γ gene expression in Mice after Trichosansin immunization

Trichosanthin (TCS) is a potent allergen to mice.According to our previous experiments,it could bring out the IgE response to ovabumin (OVA) if TCS was given one day before OVA immunization,while OVA alone could not induce IgE to it.In this work,the kinetics of interleukin 4(IL-4) and interferon γ(IFN-γ) gene expression in the mesenteric lymph node (MLN) of TCS-immunized mice was investigated using a semi-quantitative RT-PCR method.It indicated that TCS induced significant IL-4 gene expression and the peaks of IL4 gene expression were on day one after TCS immunization in both primary and secondary response.In contrast,the IFN-γ gene expression was suppressed.Furthermor,the IL-4 gene expression in the secondary response was lower than that in the primary response.Thus the presence of IgE memory B cells were studied.Results showed that the amount of mature IgE mRNA arose significantly and rapidly one day after TCS restimulation,while in the MLN of the mice primed 30 days before and without boost,it was almost as the same amount of the unimmunized control.These findings suggest the existence of the IgE memory B cells in the mice after the primary TCS immunization.     

Generation and Characterization of a Transgenic Zebrafish Expressing the Reverse Tetracycline Transactivator

Conditional expression of a target gene during zebrafish development is a powerful approach to elucidate gene functions. The tetracycline-controlled systems have been successfully used in the modulation of gene expression in mammalian cells, but few lines of zebrafish carrying these systems are currently available. In this study, we had generated a stable transgenic zebrafish line that ubiquitously expressed the second-generation of reverse Tet transactivator （rtTA-M2）. Southern blotting analysis and high-throughput genome sequencing verifed that a single copy of rtTA-M2 gene had stably integrated into the zebrafish genome. After induction with doxycycline （Dox）, a strong green fluorescent protein （GFP） was seen in rtTA-transgenic eggs injected with pTRE--EGFP plasmids. The fluorescent signal gradually decreased after the withdrawal of Dox and disappeared. However, leaky expression of GFP was undetectable before Dox- induction. Additionally, transgenic embryos expressing rtTA-M2 exhibited no obvious defects in morphological phenotypes, hatching behavior and expression patterns of developmental marker genes, suggesting that rtTA-M2 had little effect on the development of transgenic zebrafish. Moreover, expressed Dickkopf-1 （DKK1） in pTRE-DKKl-injected embryos led to alterations in the expression of marker genes associated with Wnt signaling. Thus, this rtTA-transgenic zebrafish can be utilized to dissect functions of genes in a temporal manner.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.