Mediating a host cell signaling pathway linked to overwinter mortality offers a promising therapeutic approach for improving bee health

INTRODUCTION

Honey bees provides valuable pollination services for world food crops and wild flowering plants which are habitats of many animal species and remove carbon dioxide from the atmosphere, a powerful tool in the fight against climate change. Nevertheless, the honey bee population has been declining and the majority of colony losses occur during the winter.

OBJECTIVES

The goal of this study was to understand the mechanisms underlying overwinter colony losses and develop novel therapeutic strategies for improving bee health.

METHODS

First, pathogen prevalence in overwintering bees were screened between 2015 and 2018. Second, RNA sequencing (RNA-Seq) for transcriptional profiling of overwintering honey bees was conducted and qRT-PCR was performed to confirm the results of the differential expression of selected genes. Lastly, laboratory bioassays were conducted to measure the effects of cold challenges on bee survivorship and stress responses and to assess the effect of a novel medication for alleviating cold stress in honey bees.

RESULTS

We identified that sirtuin signaling pathway is the most significantly enriched pathway among the down-regulated differentially expressed genes (DEGs) in overwintering diseased bees. Moreover, we showed that the expression of SIRT1 gene, a major sirtuin that regulates energy and immune metabolism, was significantly downregulated in bees merely exposed to cold challenges, linking cold stress with altered gene expression of SIRT1. Furthermore, we demonstrated that activation of SIRT1 gene expression by SRT1720, an activator of SIRT1 expression, could improve the physiology and extend the lifespan of cold-stressed bees.

CONCLUSION

Our study suggests that increased energy consumption of overwintering bees for maintaining hive temperature reduces the allocation of energy toward immune functions, thus making the overwintering bees more susceptible to disease infections and leading to high winter colony losses. The novel information gained from this study provides a promising avenue for the development of therapeutic strategies for mitigating colony losses, both overwinter and annually.

[The value of nomogram for predicting microvascular invasion based on clinical and Gd-EOB-DTPA-enhanced magnetic resonance imaging features]

Objective: To investigate the risk factors of microvascular invasion (MVI) in China liver cancer staging system stage Ⅰa (CNLC Ⅰa) hepatocellular carcinoma (HCC), and develop a nomogram for predicting MVI based on clinical and radiographic data. Methods: This retrospective study focused on CNLC Ⅰa HCC patients who underwent radical resection at the Cancer Hospital, Chinese Academy of Medical Sciences from January 2016 to December 2020. Patients' clinical characteristics and laboratory test results and pre-surgery gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging results were collected. The clinical and radiographic risk factors for MVI were identified by univariate and multivariate logistic regression analyses and used for the construction of the predictive nomogram. The nomogram model was then internally validated, and its performance was assessed. Results: A total of 104 patients were divided into the MVI-positive group (n=28) and the MVI-negative group (n=76). Multivariate logistic regression analysis at the P<0.1 level identified serum alpha-ferroprotein >7 ng/ml, total bilirubin >21 μmol/L, prothrombin time >12.5 s, non-smooth margin, and incomplete or absent capsule as risk factors of MVI, based on which a nomogram model was built. The model achieved an area under the curve (AUC) value of 0.867 (95% confidence interval, 0.791-0.944) in the internal validation. The sensitivity and specificity of the nomogram model were 0.786 and 0.829, respectively, with the prediction curve nearly overlapping the ideal curve. Based on the Hosmer-Lemeshow test, the predicted and real results were not significantly different (P=0.956). Conclusions: The probability of MVI of CNLC Ⅰa HCC can be objectively predicted by the monogram model that quantifies the clinical and radiographic risk factors. The model can also help clinicians select individualized surgical plans to improve the long-term prognosis of patients.

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. II. Molecular genetic and ultrastructural study on the transforming activity of recombinant retrovirus containing human papillomavirus type 16 subgenomic sequences

In order to elucidate the role of HPV-16 in the development of genital cancer, NIH3T3 cells were transfected by HPV-16 whole genome and its two early genes, E6-E7. Besides ordinary calcium phosphate/DNA coprecipitation technique, a newly designed recombinant retrovirus containing the HPV-16 genome or subgenomes was used to infect cells for transfer of the target genes. The transforming activities have been demonstrated to be most efficient when a bioengineering technique of this kind is used. HPV-16 DNA was proved to have transforming potential for NIH3T3 cells, and the DNA of HPV-16 was proved to undergo multisite integration into transformed cells and nude mice tumour cells. The E6-E7 open reading frames are sufficient for transforming NIH3T3 cells independently in vitro, which implies that E6-E7 open reading frames are transforming genes or even viral oncogenes of HPV-16. The RNA transcribed by the E6-E7 of HPV-16 was expressed in transformed cells and in tumour cells of nude mice. The use of a recombinant retrovirus for gene transfer in this study is much more efficient than that of calcium phosphate/DNA coprecipitation. The lack of a tissue-culture system suitable for HPV replication in vitro makes HPV gene recombination into a specially engineered retrovirus for viral-mediated gene transfer of particular significance for the possible application of viral carcinogenesis, both in vitro and in vivo, for basic and clinical research.

[Studies on the physical state of human papillomavirus 16 DNA in biopsies of patients with cervical carcinoma]

Five biopsies from cervical cancer containing human papillomavirus (HPV) 16 DNA sequences confirmed by dot blot analysis were used to study the physical state of HPV 16 DNA in cervical cancer. Southern blots prepared after: 1) sample DNA was cleaved with restriction enzymes which do not digest HPV 16;2) sample DNA was cleaved with restriction enzymes (pstI) capable of digesting HPV 16 DNA; 3) sample DNA was not digested with restriction enzymes; and 4) two-dimensional agarose gel electrophoresis was performed on sample DNA digested with enzymes which do not cleave HPV 16 DNA. It was shown that HPV 16 DNA was integrated into the cellular genome.

Viral etiology of cervical carcinoma. Human papilloma virus and herpes simplex virus type 2

The possible role of human papilloma virus (HPV) and herpes simplex virus type 2 (HSV-2) in the viral etiology of cervical carcinoma was investigated a series of cervical lesions were studied for the presence of HPV and HSV-2 DNA sequences as well as HPV and HSV-2 antigens by DNA dot blot hybridization technique and high-specificity PAP staining method. The results obtained were correlated with the histologic diagnosis. HPV 16 DNA sequences detected in cervical carcinoma biopsies were 43%, whereas HSV-2 DNA sequences were only 8%. HPV antigens detected in cervical dysplasia were 31%, whereas those detected in cervical carcinoma and cervicitis were the least. HSV-2 antigens were detected in chronic cervicitis, dysplasia and cervical carcinoma. The difference in positive rate between the cervical carcinoma and cervicitis groups was statistically significant, (chi-square test, P less than 0.01). No HPV DNA and HSV-2 DNA sequences were found in the same specimen, although both HPV DNA sequences and HSV-2 antigens were found in the same sample in some cases. The results indicate that the viral etiology of cervical carcinoma may be multifactorial. Both HSV-2 and HPV may be associated with cervical carcinoma, but the mechanisms involved are different. HSV-2 and HPV may act synergistically in the development of cervical carcinoma.