The aim of this study is to establish an gene editing method of Mesomycoplasma hyo-pneumoniae(Mhp)based on the homologous recombination principle.The restriction enzyme di-gestion and ligation method combined with gene synthesis were used to construct a shuttle plasmid to achieve replication in both Mhp and Escherichia coli(E.coli).The pGEM?-T vector was used as the skeleton.The oriC sequence of Mhp which can achieve the replication of the plasmid in Mhp was inserted into the vector.Sequences of the Spiroplasma promoter and puromycin resistance gene were then inserted into the above constructed plasmid to screen recombinant clones.The up-stream and downstream homologous arms of p97 were constructed to initiate homologous recombination.The recA gene of E.coli is inserted to improve the efficiency of homologous recom-bination.The obtained shuttle plasmid was then delivered into Mhp by electro-transformation or chemical transformation.A shuttle plasmid,pGEM?-Mhp-oriC-p 97,which can replicate in both Mhp and E.coli was constructed.With the transformation of this plasmid,the carried puromycin gene and recA gene can be expressed,the p97 gene can be edited.Finally,the genetically unstable p97 gene mutant was initially obtained.In this study,a tool for Mhp gene editing based on the principle of homologous recombination was established,which laid a foundation for the develop-ment of tools for studying the pathogenesis of Mhp.

The aim of this study is to establish an gene editing method of Mesomycoplasma hyo-pneumoniae(Mhp)based on the homologous recombination principle.The restriction enzyme di-gestion and ligation method combined with gene synthesis were used to construct a shuttle plasmid to achieve replication in both Mhp and Escherichia coli(E.coli).The pGEM?-T vector was used as the skeleton.The oriC sequence of Mhp which can achieve the replication of the plasmid in Mhp was inserted into the vector.Sequences of the Spiroplasma promoter and puromycin resistance gene were then inserted into the above constructed plasmid to screen recombinant clones.The up-stream and downstream homologous arms of p97 were constructed to initiate homologous recombination.The recA gene of E.coli is inserted to improve the efficiency of homologous recom-bination.The obtained shuttle plasmid was then delivered into Mhp by electro-transformation or chemical transformation.A shuttle plasmid,pGEM?-Mhp-oriC-p 97,which can replicate in both Mhp and E.coli was constructed.With the transformation of this plasmid,the carried puromycin gene and recA gene can be expressed,the p97 gene can be edited.Finally,the genetically unstable p97 gene mutant was initially obtained.In this study,a tool for Mhp gene editing based on the principle of homologous recombination was established,which laid a foundation for the develop-ment of tools for studying the pathogenesis of Mhp.

Objective:To evaluate the effect of esketamine on acute kidney injury (AKI) in the rats with sepsis and the role of autophagy.Methods:Forty SPF healthy adult male Sprague-Dawley rats, weighing 200-240 g, were divided into 5 groups ( n=8 each) by a random number table method: control group (Con group), esketamine group (Con+ Ket group), sepsis group (lipopolysaccharide [LPS] group), sepsis plus esketamine group (LPS+ Ket group), and sepsis plus esketamine plus 3-methyladenine (3MA) group (LPS+ Ket+ 3MA group). The model of AKI was established by intraperitoneal injection of LPS in anesthetized rats.Normal saline 10 ml/kg was intraperitoneally injected in Con group.In Con+ Ket group, normal saline 10 ml/kg was intraperitoneally injected, and 30 min later esketamine 10 mg/kg was injected via the tail vein.LPS 10 mg/kg was intraperitoneally injected in LPS group.In LPS+ Ket group, LPS 10 mg/kg was intraperitoneally injected, and 30 min later esketamine 10 mg/kg was injected via the tail vein.In LPS+ Ket+ 3MA group, LPS 10 mg/kg was intraperitoneally injected, and 30 min later esketamine 10 mg/kg and 3-MA 15 mg/kg were injected via the tail vein.The rats were anesthetized at 24 h after intraperitoneal injection of LPS and then sacrificed, and renal tissues were removed for microscopic examination of the pathological changes which were scored and for determination of contents of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, interleukin-1beta (IL-1β) and IL-18 (by enzyme-linked immunosorbent assay) and expression of LC3, P62 and Beclin-1 (by Western blot). Results:Compared with Con group, the score for pathological damage to renal tissues and contents of NLRP3, ASC, caspase-1, IL-1β and IL-18 were significantly increased, LC3-Ⅱ/LC3-Ⅰ ratio was decreased, the expression of Beclin-1 was down-regulated, and the expression of P62 was up-regulated in LPS group ( P<0.05). Compared with LPS group, the score for pathological damage to renal tissues and contents of NLRP3, ASC, caspase-1, IL-1β and IL-18 were significantly decreased, LC3-Ⅱ/LC3-Ⅰ ratio was increased, the expression of Beclin-1 was up-regulated, and the expression of P62 was down-regulated in LPS+ Ket group ( P<0.05). Compared with LPS+ Ket group, the score for pathological damage to renal tissues and contents of NLRP3, ASC, caspase-1, IL-1β and IL-18 were significantly increased, LC3-Ⅱ/LC3-Ⅰ ratio was decreased, the expression of Beclin-1 was down-regulated, and the expression of P62 was up-regulated in LPS+ Ket+ 3MA group ( P<0.05). Conclusion:Esketamine can reduce AKI and autophagy is involved in the process, which is related to inhibiting the activation of NLRP3 inflammasomes and decreasing inflammatory responses in rats with sepsis.