Mitochondria, the power house of cells, are important organelles in eukaryotic cells. Having their own unique and complete DNA (mtDNA) and genetic system, mitochondria play an essential role in cellular energy metabolism, intracel?lular signaling and apoptotic pathways, as well as many other biological functions, which are closely related with cellular met?abolic network. A disruption of mitochondrial genes can therefore result in mitochondrial dysfunction and human diseases, thus they have been widely used in molecular biology, development biology, genetics, forensic identification and clinical diag?nosis. Consequently, sequencing mitochondrial genome has shown great significance in mitochondrial structure and function research. In this review, research progress in mitochondrial genome sequencing method is summarized, mainly focusing on Sanger sequencing, long-PCR and next-generation sequencing. Also rolling circle amplification and indirect sequencing of mtDNA are reviewed. The ambiguities caused by numts in indirect sequencing are mentioned and resolved.

Objective To investigate the expression profile of mRNAs in brain samples collected from pronuclear transfer (PNT) mice. Methods Female CD-1 mice were superovulated, and zygotes were collected after mating with adult male mice. Zygotes with two pronuclei were selected for pronuclear transfer manipulation, and then the reconstructed zygotes were transferred into the oviduct of pseudopregnant female mice. The infant mice obtained from pronuclear transfer were called PNT group, while the embryoes that were not performed pronuclear transfer was regarded as control group. Total RNA were extracted from brain samples of both PNT and control mice, and cDNA were labeled with fluorescent dye. Genes that were differentially expressed were identified using the Agilent mouse mRNA array. Gene ontology analysis and pathway analysis were also completed. Results Compared with control group, 392 mRNAs were expressed differentially, which showed more than 2.0 times variation and statistical significance, accounting for 1.7% of all mRNAs. Among those 366 mRNAs were up-regulated and 26 mRNAs were down-regulated. Eleven mRNAs came to 4.0 times variation in total. Gene ontology analysis indicated that differentially expressed genes were significantly enriched in alternative mRNA splicing, small GTPase mediated signal transduction, regulation of insulin receptor signaling pathway, hydrolase activity, transmembrane transporter activity and pyrophosphatase activity. Significant enriched pathway terms contained ion channel transport, fatty acid metabolism, butanoate metabolism, triacylglycerol and ketone body metabolism. Conclusion Pronuclear transfer might influence some key metabolism process in mouse brain.

Objective:To analyze the clinical features and risk factors of invasive pulmonary aspergillosis (IPA) in patients with chronic obstructive pulmonary disease (COPD).Methods:Ninety COPD patients with IPA admitted in the First Affiliated Hospital, Zhejiang University School of Medicine and Zhejiang Provincial People’s Hospital from January 2015 to September 2019 were enrolled, and 180 COPD patients without IPA admitted in the same period were selected as control group. The clinical data of the patients in both groups were analyzed retrospectively. Chi square test was used to compare the imaging characteristics of patients in two groups, and multivariate conditional Logistic regression analysis was used to explore the risk factors of IPA in COPD patients. Results:Among 90 cases of COPD with IPA, the culture of lower respiratory tract samples identified Aspergillus fumigatus in 78 cases, Aspergillus flavus in 6 cases, Aspergillus fumigatus with Aspergillus flavus in 1 case, Aspergillu sterrus in 1 case, and Aspergillus nigerwere in 1 case; 1 case of Aspergillus mycelium was found by sputum exfoliation cytology and 2 cases were positive for serum galactomannan. Chest CT images showed patchy infiltrating shadow (87.8%), pleural effusion (36.7%), nodules (33.3%), cavity (18.9%), consolidation shadow (17.8%), halo sign (14.4%) and air crescent sign (2.2%). The incidence of patchy infiltrating shadow, consolidation shadow, halo sign and cavity were higher in COPD patients with IPA compared to control group ( P<0.05 or P<0.01). Multivariate conditional Logistic regression analysis showed that prolonged hospital stay ( OR=1.183, 95% CI 1.047-1.336), combination of two antibiotics ( OR=5.391, 95% CI 1.241-23.421), duration of antibiotic treatment ≥14 days ( OR=5.275, 95% CI 1.586-17.541), cumulative use of antibiotics ( OR=2.270, 95% CI 1.406-3.664) were the risk factors of COPD with IPA ( P<0.05 or P<0.01). Conclusion:The risk factors of IPA in COPD patients include long duration of hospital stay, combination of two kinds of antibiotics, more than 14 days of antibiotic treatment, and more varieties of antibiotics. If the above risk factors exist in patients with COPD, etiology and serology examination and dynamic monitoring of chest CT scan should be performed for early diagnosis and improved prognosis.

Accumulating evidence has confirmed the links between transfer RNA (tRNA) modifications and tumor progression. The present study is the first to explore the role of tRNA methyltransferase 5 (TRMT5), which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma (HCC) progression. Here, based on bioinformatics and clinical analyses, we identified that TRMT5 expression was upregulated in HCC, which correlated with poor prognosis. Silencing TRMT5 attenuated HCC proliferation and metastasis both in vivo and in vitro, which may be partially explained by declined extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Mechanistically, we discovered that knockdown of TRMT5 inactivated the hypoxia-inducible factor-1 (HIF-1) signaling pathway by preventing HIF-1α stability through the enhancement of cellular oxygen content. Moreover, our data indicated that inhibition of TRMT5 sensitized HCC to doxorubicin by adjusting HIF-‍1α. In conclusion, our study revealed that targeting TRMT5 could inhibit HCC progression and increase the susceptibility of tumor cells to chemotherapy drugs. Thus, TRMT5 might be a carcinogenesis candidate gene that could serve as a potential target for HCC therapy.
Humans ; Carcinoma, Hepatocellular/pathology* ; Cell Hypoxia ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Liver Neoplasms/pathology* ; Signal Transduction/genetics* ; tRNA Methyltransferases/metabolism*