Objective:To explore the therapeutic effect of Bupiqiangli compound on experimental myasthenia gravis with sub-clinical hypothyroidism in rats and the influence of hypothalamus-pituitary-thyroid-thymus(HPTT)axis.Methods:SPF Lewis rats were randomly divided into normal group,model group,Bupiqiangli compound low-dose,medium-dose and high-dose groups.Model rats were immunized with AchR-α subunit 97-116 peptide sequence to construct an experimental myasthenia gravis model,and then methimazole was used to prepare an experimental myasthenia gravis with subclinical hypothyroidism model.Bupiqiangli compound low-dose,medium-dose and high-dose groups were given 4.57 g/kg,7.12 g/kg and 9.49 g/kg of Bupiqiangli compound by gavage,nor-mal group and model group were given an equal volume of normal saline by gavage,once a day,for 4 weeks.After the last gavage,Lennon scores of rats in each group were recorded;HE staining was used to detect pathological changes of thymus and thyroid;ELISA was used to detect expression levels of acetylcholine receptor antibody(AchRab),thyroid stimulating hormone(TSH),thyrotropin releasing hormone(TRH),free thyroxine(FT4)and thyroxine(T4)in serum;mRNA level of TRH in hypothalamus and TSH in pituitary tissue were detected by qPCR;Western blot detected changes of protein expressions of Cleaved Caspase3,Bcl2 associated X protein(Bax)and B-cell lymphoma-2(Bcl2)in thymus.Results:Compared with normal group,model group showed obvious symp-toms of muscle weakness,Lennon score increased significantly(P<0.05),obvious pathological changes in thymus and thyroid tissues,while no significant changes in expressions of FT4 and T4 in serum(P>0.05),expressions of AchRab,TSH and TRH in serum were significantly increased(P<0.05),expressions of TRH in hypothalamus and TSH in pituitary were significantly increased(P<0.05),protein expressions of Cleaved Caspase3 and Bax in thymus were significantly decreased(P<0.05),while expression of Bcl2 protein in thymus increased significantly(P<0.05).Compared with model group,myasthenia symptoms of compound high-dose group were im-proved,Lennon score was significantly decreased(P<0.05),pathological changes of thymus and thyroid tissues were improved,ex-pressions of FT4 and T4 in serum had no significant changes(P>0.05),expressions of AchRab,TSH and TRH in serum were signifi-cantly decreased(P<0.05),expressions of TRH in hypothalamus and TSH in pituitary were significantly decreased(P<0.05),expres-sions of Cleaved Caspase3 and Bax in thymus were significantly increased(P<0.05),while expression of Bcl2 in thymus was signifi-cantly decreased(P<0.05).Conclusion:Bupiqiang compound can improve clinical symptoms of experimental myasthenia gravis with subclinical hypothyroidism in rats,and its mechanism may be related to the regulation of HPTT axis.

Objective:To explore the therapeutic effect of Bupiqiangli compound on experimental myasthenia gravis with sub-clinical hypothyroidism in rats and the influence of hypothalamus-pituitary-thyroid-thymus(HPTT)axis.Methods:SPF Lewis rats were randomly divided into normal group,model group,Bupiqiangli compound low-dose,medium-dose and high-dose groups.Model rats were immunized with AchR-α subunit 97-116 peptide sequence to construct an experimental myasthenia gravis model,and then methimazole was used to prepare an experimental myasthenia gravis with subclinical hypothyroidism model.Bupiqiangli compound low-dose,medium-dose and high-dose groups were given 4.57 g/kg,7.12 g/kg and 9.49 g/kg of Bupiqiangli compound by gavage,nor-mal group and model group were given an equal volume of normal saline by gavage,once a day,for 4 weeks.After the last gavage,Lennon scores of rats in each group were recorded;HE staining was used to detect pathological changes of thymus and thyroid;ELISA was used to detect expression levels of acetylcholine receptor antibody(AchRab),thyroid stimulating hormone(TSH),thyrotropin releasing hormone(TRH),free thyroxine(FT4)and thyroxine(T4)in serum;mRNA level of TRH in hypothalamus and TSH in pituitary tissue were detected by qPCR;Western blot detected changes of protein expressions of Cleaved Caspase3,Bcl2 associated X protein(Bax)and B-cell lymphoma-2(Bcl2)in thymus.Results:Compared with normal group,model group showed obvious symp-toms of muscle weakness,Lennon score increased significantly(P<0.05),obvious pathological changes in thymus and thyroid tissues,while no significant changes in expressions of FT4 and T4 in serum(P>0.05),expressions of AchRab,TSH and TRH in serum were significantly increased(P<0.05),expressions of TRH in hypothalamus and TSH in pituitary were significantly increased(P<0.05),protein expressions of Cleaved Caspase3 and Bax in thymus were significantly decreased(P<0.05),while expression of Bcl2 protein in thymus increased significantly(P<0.05).Compared with model group,myasthenia symptoms of compound high-dose group were im-proved,Lennon score was significantly decreased(P<0.05),pathological changes of thymus and thyroid tissues were improved,ex-pressions of FT4 and T4 in serum had no significant changes(P>0.05),expressions of AchRab,TSH and TRH in serum were signifi-cantly decreased(P<0.05),expressions of TRH in hypothalamus and TSH in pituitary were significantly decreased(P<0.05),expres-sions of Cleaved Caspase3 and Bax in thymus were significantly increased(P<0.05),while expression of Bcl2 in thymus was signifi-cantly decreased(P<0.05).Conclusion:Bupiqiang compound can improve clinical symptoms of experimental myasthenia gravis with subclinical hypothyroidism in rats,and its mechanism may be related to the regulation of HPTT axis.

Non-conventional yeasts such as Yarrowia lipolytica, Pichia pastoris, Kluyveromyces marxianus, Rhodosporidium toruloides and Hansenula polymorpha have proven to be efficient cell factories in producing a variety of natural products due to their wide substrate utilization spectrum, strong tolerance to environmental stresses and other merits. With the development of synthetic biology and gene editing technology, metabolic engineering tools and strategies for non-conventional yeasts are expanding. This review introduces the physiological characteristics, tool development and current application of several representative non-conventional yeasts, and summarizes the metabolic engineering strategies commonly used in the improvement of natural products biosynthesis. We also discuss the strengths and weaknesses of non-conventional yeasts as natural products cell factories at current stage, and prospects future research and development trends.
Yeasts/genetics* ; Yarrowia/metabolism* ; Gene Editing ; Metabolic Engineering

To obtain fusion protein of Mycobacterium bovis with high purity, the recombinant prokaryotic expression vector for Mb2277 gene was constructed and the immunogenicity of its products was initially investigated in the present study.A pair of primer was designed according the gene sequence Mb2277 from the genomic DNA of M.Bovis in GenBank. and was amplified by PCR using DNA of M.Bovis 93006 strain as template. The PCR product and pET-28a(+) was then digested by BamHⅠ and EcoR Ⅰdouble enzyme. To constructed a prokaryotic expression plasmid, the purified Mb2277 was cloned to pET28a(+). Then the recombinant plasmid was transformed into competent cell of E.coli BL21(DE3).The bacteria were induced by IPTG and its lysates were analyzed by SDS-PAGE and Western-blotting. In this way, the prokaryotic expression plasmid for M. bovis Mb 2277 protin was obtained, and a expression band with molecular of 25 ku could be found in SDS-PAGE analysis. As demonstrated by Western blotting this expression product showed excellent reactivity with rabbit immune sera against M. bovis.