Bioconversion of C1 gases and genetic engineering modification of gas-utilizing microorganisms / 生物工程学报

C1 gases including CO, CO2 and CH4, are mainly derived from terrestrial biological activities, industrial waste gas and gasification syngas. Particularly, CO2 and CH4 are two of the most important greenhouse gases contributing to climate change. Bioconversion of C1 gases is not only a promising solution to addressing the problem of waste gases emission, but also a novel route to produce fuels or chemicals. In the past few years, C1-gas-utilizing microorganisms have drawn much attention and a variety of gene-editing technologies have been applied to improve their product yields or to expand product portfolios. This article reviewed the biological characteristics, aerobic or anaerobic metabolic pathways as well as the metabolic products of methanotrophs, autotrophic acetogens, and carboxydotrophic bacteria. In addition, gene-editing technologies (e.g. gene interruption technology using homologous recombination, group Ⅱ intron ClosTron technology, CRISPR/Cas gene editing and phage recombinase-mediated efficient integration of large DNA fragments) and their application in these C1-gas-utilizing microorganisms were also summarized.

Experimental research progress of genetically modified mesenchymal stem cells in the treatment of radiation-induced lung injury / 中华放射医学与防护杂志

Radiation-induced lung injury is a common complication of thoracic malignant tumor radiotherapy and severe nuclear accident injury. Currently, there is no effective treatment on this injury. Mesenchymal stem cells (MSCs) are a group of cells with multi-directional differentiation potential and they can protect lung tissue from radiation damage by homing to the injured site and differentiating to the damaged tissues, secreting cytokines and immune regulation. Further, the genetically modifying mesenchymal stem cells have not only the main characteristics of MSCs, but also can efficiently and stably express or knock down a certain of target genes, thereby enhancing or reducing the sensitivity of mesenchymal stem cells to various physiological stimulus and enhancing its therapeutic effect in radiation-induced lung injury, providing new ideas and new strategies for clinical treatment. This paper reviewed the relevant research progress in recent years.

Novel angucycline/angucyclinone family of natural products discovered between 2010 and 2020 / 生物工程学报

Angucyclines/angucyclinones are a large group of polycyclic aromatic polyketides and their producers are widely distributed in nature. This family of natural products attracts great attention because of their diverse biological activities and unique chemical structures. With the development of synthetic biology and the exploitation of the actinomycetes from previously unexplored environments, angucyclines/angucyclinones-like natural products with new skeletons were continuously discovered, thus enriching the structural diversity of this family. In this review we summarize the new angucyclines/angucyclinones analogues discovered in the last decade (2010-2020) by using different strategies, such as changing cultivation conditions, genetic modification, genome mining, bioactivity-guided compound isolation, and fermentation of actinomycetes from underexplored environments. We also discuss the role of synthetic biology in the discovery and development of new compounds of the angucycline/angucyclinone family.

Two-plasmid scarless genetic modification in Escherichia coli hfq and rne-710 / 生物工程学报

Gene modification is an important technique to understand gene function. We firstly constructed Δhfq::Spe and Δrne-710::Spe mutant strains of Escherichia coli MG1655. The fragment lacking of hfq and rne-710 was ligated to the auxiliary plasmid and separately replace the spectinomycin box by homologous recombinase system to obtain the Δhfq and Δrne-710 mutant strains. The combination of two-plasmid scarless genetic modification and fusion PCR led to a new way for the long DNA fragment gene deletions.

Challenges of NK cell-based immunotherapy in the new era / 医学前沿

Natural killer cells (NKs) have a great potential for cancer immunotherapy because they can rapidly and directly kill transformed cells in the absence of antigen presensitization. Various cellular sources, including peripheral blood mononuclear cells (PBMCs), stem cells, and NK cell lines, have been used for producing NK cells. In particular, NK cells that expanded from allogeneic PBMCs exhibit better efficacy than those that did not. However, considering the safety, activities, and reliability of the cell products, researchers must develop an optimal protocol for producing NK cells from PBMCs in the manufacture setting and clinical therapeutic regimen. In this review, the challenges on NK cell-based therapeutic approaches and clinical outcomes are discussed.

Progress in the research of tumor adoptive cellular immunotherapy / 基础医学与临床

Adoptive immune cells can regulate and strengthen immune function of cancer patients,thus effectively inhibit tumor escaping.Cytokine induced killer cells (CIK),natural killer cells (NK),tumor infiltrating lymphocytes (TIL),dendritic cells (DC),T cell receptor-modified T cells (TCR-T) and chimeric antigen receptor-modified T cells (CAR-T) eliminate tumor by killing tumor cells directly or stimulating the immune response against tumor cells through different mechanisms.

Advances in tumor-therapy using genetically modified Salmonella / 生物工程学报

Tumor is a neoplasm formed by the abnormal proliferation of local tissue cells under the effects of different tumorigenic factors. Tumor-therapy has always been a difficult clinical issue, while regular cancer treatments, such as radiotherapy, chemotherapy and surgery, have obvious limitations. Earlier studies have shown that some obligate anaerobes or facultative anaerobes have anti-tumor effects, for example, Salmonella typhymurium as facultative anaerobic bacteria can selectively colonize tumors and inhibit their growth. Besides, Salmonella has many advantages in tumor-therapy. In the past decade or two, many researchers have carried out genetic manipulation to attenuate the virulence of Salmonella, to improve their specificity of tumor colonization and specially to use attenuated Salmonella as carriers to deliver a variety of anti-tumor therapeutic molecules, and these genetically modified Salmonella have shown good anti-tumor effects in many animal experiments. Along with further research of Salmonella-mediated antitumor treatment, applications of genetically modified Salmonella for more effective tumor-therapy are promising. We reviewed the anti-tumor mechanisms of Salmonella, the research progress in tumor-therapy using genetically modified Salmonella, and current problems and possible solutions.

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.

Histone deacetylases inhibition and retinopathy / 中华实验眼科杂志

Histone acetyltransferases(HATs) faciliate histone acetylation and histone deacetylases(HDACs) serve to remove acetyl groups from histones.The activation and repression of gene expression can be regulated by the acetylation of histone or specific genes.It is certified that acetylation of related genes is down-regulated in diabetic retinopathy,retinal ischemia-reperfusion,degenerative retinopathy,infective retinopathy and retinal tumors,which results in cell apoptosis and retinal dysfunction.So the physiology and pathology of retina have a close relation.The effects of histone acetylation and deacetylases on retinal diseases are still studying because of the complexity and diversity of genetic modification io epigenetic inheritance.This article reviewed the classification of HATs and HDACs and their inhibitors,their effects and function,their relationship to retinopathy,and discuss the protection of their inhibitors to retina.

Preferencia de carne bovina con diferentes tipos de modificaciones genéticas en temuco, región de la Araucanía, Chile / Preference for Beef With Different Types of Genetic Modification in Temuco, La Araucanía Region, Chile

Considerando que las actitudes respecto a la biotecnología dependen del organismo sobre el cual se aplica y del tipo de modificación realizada se determinó la importancia del tipo de modificación genética (MG) en la compra de carne bovina en consumidores de Temuco (Región de La Araucanía, Chile) en diferentes segmentos de mercado, mediante una encuesta a 400 personas. Utilizando análisis de conjunto se determinó que el tipo de MG fue más importante que el precio en la compra (66,2 y 33,8%; respectivamente). Mediante análisis de conglomerados jerárquicos se distinguieron dos segmentos principales con diferencias significativas en la importancia de estos atributos. El segmento mayoritario (63,8%) dio alta importancia al tipo de MG, el segundo segmento (28,2%) atribuyó mayor importancia al precio, pero los consumidores de ambos segmentos prefirieron carne de un animal sin MG o de un animal con MG para disminuir el contenido de colesterol y rechazaron la carne de un animal alimentado con granos MG o de animales con MG para reducir el costo de alimentación. Los segmentos presentaron diferencias según el tamaño del grupo familiar, frecuencia de consumo de carne bovina y estilo de vida. Es posible concluir que la ausencia de MG en carne bovina es una condición deseable para los consumidores de Temuco, sin embargo, la totalidad de la muestra encuestada se muestra positiva hacia la carne de un animal MG que presente beneficios para la salud y el 8% acepta carne de un animal alimentado con granos MG.

Considering that attitudes to biotechnology depend on the organism to which it is applied and the type of modification made, a survey was carried out on 400 persons to determine the importance of the type of genetic modification (GM) in the purchase of beef by consumers in Temuco (La Araucanía Region, Chile) in different market segments. Using conjoint analysis it was determined that the type of GM was more important than the price in the purchase decision (66.2 and 33.8%, respectively). Two principal segments were identified by analysis of hierarchical conglomerates, with significant differences in the importance of these attributes. The majority segment (63.8%) attached great importance to the type of GM, the second segment (28.2%) attributed more importance to the price, however consumers of both segments preferred meat from an animal without GM or one with GM to reduce the cholesterol content, and rejected meat from an animal fed with GM grain or subjected to GM to reduce feeding costs. The segments presented differences related to the size of the family group, frequency of beef consumption and life-style. It may be concluded that the absence of GM in beef is a desirable condition for the consumers of Temuco, however the whole sample responded positively to meat from a GM animal which presents health benefits and 8% accept meat from an animal which has been fed with GM grain.

NGF、BDNF gene modified bone marrow stem cells transplantation with vein on spinal cord injnry / 中国矫形外科杂志

[Objective]To study NGF,BDNF gene modified bone marrowe stem cells transplantation with vein on spinal cord injury.[Method]Spinal cord injured rats were divided in to 3 groups.Group C consisted of the rats treated with the transplantation of modified NGF,BDNF genes BMSCs;group B of the rats with transplantation of BMSCs without genetic modification;group A of the rats without treatment and group D was the normal contral.At 2,6,10 weeks the rats were examined with GBS score and neurological function were tested.[Result]The vein with tintracord transplantation of modified BMSCs group was improved by the GBS score and neurological outcome of injured spinal cord was achieved well.[Conclusion]The vein with transplantation of modified NGF,BDNF genes BMSCs can recover of spinal cord injury.

Advances and Perspectives on Genetic Modification of Hevea brasiliensis / 中国生物工程杂志

As the major commercial source of natural rubber,Hevea brasiliensis attracts much attention.However,the heterozygous nature,long breeding cycle are strong limitations for conventional breeding.While genetic engineering,which can be used to widen the germplasm base and produce desirable agronomic traits quickly and efficiently,offers a viable alternative approach to complement traditional breeding.Comprehensive analysis indicates that in the past two decades,with calli derived from immature anther or integumental tissues of immature fruit as receptors,both biolistic and Agrobacterium-mediated transformation methods were employed for developping rubber genotypes with improved latex yield,tolerance to tapping panel dryness syndrome,producing high-value recombinant proteins,etc.Being recalcitrant to tissue culture,the transformation efficiency of Hevea is comparatively low,and the procedures are still needed to optimize.Finally,breeding objectives and strategies to improve transformation efficiency were also proposed in the review.