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1.
Infect Immun ; 92(3): e0053923, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38299827

ABSTRACT

The obligate intracellular bacterium Chlamydia has a unique developmental cycle that alternates between two contrasting cell types. With a hardy envelope and highly condensed genome, the small elementary body (EB) maintains limited metabolic activities yet survives in extracellular environments and is infectious. After entering host cells, EBs differentiate into larger and proliferating reticulate bodies (RBs). Progeny EBs are derived from RBs in late developmental stages and eventually exit host cells. How expression of the chlamydial genome consisting of nearly 1,000 genes governs the chlamydial developmental cycle is unclear. A previous microarray study identified only 29 Chlamydia trachomatis immediate early genes, defined as genes with increased expression during the first hour postinoculation in cultured cells. In this study, we performed more sensitive RNA sequencing (RNA-Seq) analysis for C. trachomatis cultures with high multiplicities of infection. Remarkably, we observed well over 700 C. trachomatis genes that underwent 2- to 900-fold activation within 1 hour postinoculation. Quantitative reverse transcription real-time PCR analysis was further used to validate the activated expression of a large subset of the genes identified by RNA-Seq. Importantly, our results demonstrate that the immediate early transcriptome is over 20 times more extensive than previously realized. Gene ontology analysis indicates that the activated expression spans all functional categories. We conclude that over 70% of C. trachomatis genes are activated in EBs almost immediately upon entry into host cells, thus implicating their importance in initiating rapid differentiation into RBs and establishing an intracellular niche conducive with chlamydial development and growth.


Subject(s)
Chlamydia Infections , Chlamydia trachomatis , Humans , Cells, Cultured , Base Sequence , Transcriptome , Real-Time Polymerase Chain Reaction , Chlamydia Infections/genetics
2.
mBio ; 15(1): e0203623, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38112466

ABSTRACT

IMPORTANCE: Hallmarks of the developmental cycle of the obligate intracellular pathogenic bacterium Chlamydia are the primary differentiation of the infectious elementary body (EB) into the proliferative reticulate body (RB) and the secondary differentiation of RBs back into EBs. The mechanisms regulating these transitions remain unclear. In this report, we developed an effective novel strategy termed dependence on plasmid-mediated expression (DOPE) that allows for the knockdown of essential genes in Chlamydia. We demonstrate that GrgA, a Chlamydia-specific transcription factor, is essential for the secondary differentiation and optimal growth of RBs. We also show that GrgA, a chromosome-encoded regulatory protein, controls the maintenance of the chlamydial virulence plasmid. Transcriptomic analysis further indicates that GrgA functions as a critical regulator of all three sigma factors that recognize different promoter sets at developmental stages. The DOPE strategy outlined here should provide a valuable tool for future studies examining chlamydial growth, development, and pathogenicity.


Subject(s)
Chlamydia Infections , Chlamydia trachomatis , Humans , Chlamydia trachomatis/metabolism , Gene Expression Regulation, Bacterial , Transcription Factors/metabolism , Sigma Factor/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism
3.
bioRxiv ; 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37577610

ABSTRACT

Chlamydia, an obligate intracellular bacterial pathogen, has a unique developmental cycle involving the differentiation of invading elementary bodies (EBs) to noninfectious reticulate bodies (RBs), replication of RBs, and redifferentiation of RBs into progeny EBs. Progression of this cycle is regulated by three sigma factors, which direct the RNA polymerase to their respective target gene promoters. We hypothesized that the Chlamydia-specific transcriptional regulator GrgA, previously shown to activate σ66 and σ28, plays an essential role in chlamydial development and growth. To test this hypothesis, we applied a novel genetic tool known as dependence on plasmid-mediated expression (DOPE) to create Chlamydia trachomatis with conditional GrgA-deficiency. We show that GrgA-deficient C. trachomatis RBs have a growth rate that is approximately half of the normal rate and fail to transition into progeny EBs. In addition, GrgA-deficient C. trachomatis fail to maintain its virulence plasmid. Results of RNA-seq analysis indicate that GrgA promotes RB growth by optimizing tRNA synthesis and expression of nutrient-acquisition genes, while it enables RB-to-EB conversion by facilitating the expression of a histone and outer membrane proteins required for EB morphogenesis. GrgA also regulates numerous other late genes required for host cell exit and subsequent EB invasion into host cells. Importantly, GrgA stimulates the expression of σ54, the third and last sigma factor, and its activator AtoC, and thereby indirectly upregulating the expression of σ54-dependent genes. In conclusion, our work demonstrates that GrgA is a master transcriptional regulator in Chlamydia and plays multiple essential roles in chlamydial pathogenicity.

4.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-975162

ABSTRACT

ObjectiveHenoch-Schönlein purpura(HSP) is one of the dominant diseases in Mongolian medicine. Qishun Baolier(QSBLE), as the main prescription for the treatment of HSP, has significant clinical effect, but its mechanism is not yet clear. Baed on this, this study is intended to screen the differentially expressed proteins before and after treatment, and preliminarily explore the molecular mechanism of QSBLE in the treatment of HSP. MethodTaking oneself as the control, 30 HSP patients aged 6-45 years were collected, and QSBLE was taken orally at 12:00 and 24:00, respectively. The dose was adjusted according to age and the course of treatment was one week. The distribution of proteinuria, hematuria and skin purpura of all patients were determined before and after treatment. The serum samples of 10 patients with clinically significant remission after QSBLE treatment were randomly selected for proteomics. Isobaric tags for relative and absolute quantification(iTRAQ) combined with liquid chromatography tandem mass spectrometry(LC-MS/MS) was used to analyze the proteins in serum of HSP patients before and after treatment, and differential proteins were analyzed bioinformatically and the protein-protein interaction(PPI) networks were constructed. ResultA total of 378 proteins were identified from serum, including 18 differentially expressed proteins, of which 15 proteins were up-regulated and 3 proteins were down regulated. Bioinformatics showed that the differential proteins were mainly involved in biological processes such as immune response, immunoglobulin production, phagocytosis, adaptive immune response before and after treatment. Biological processes, pathways and proteins were used to construct the PPI network, the proteins represented by immunoglobulin heavy constant γ1(IGHG1), immunoglobulin λ-chain 7-43(IGLV7-43), gelsolin(GSN) and 60 kDa heat shock protein(HSPD1) were involved in biological processes and related pathways such as adaptive immune response, immunoglobulin production, leukocyte-mediated immunity, regulation of stress response, regulation of immune system processes, regulation of trauma response, and these proteins were at the center of the PPI network. ConclusionQSBLE may play a role in the treatment of HSP by regulating the expression of IGHG1, IGLV7-43, GSN, HSPD1 and other key proteins to affect immune-related biological processes.

5.
Chin Herb Med ; 14(3): 376-384, 2022 Jul.
Article in English | MEDLINE | ID: mdl-36118002

ABSTRACT

Sugemule-10, one of the traditional Mongolian medicine (TMM) formulae, is derived from Four Medical Classics (Vol. 4) and composed of 10 Mongolian medicines. It is used to treat kidney cold, low back pain, urinary obstruction, kidney/bladder stones, and is the main prescription for kidney cold. The current research on Sugemule-10 is mostly focused on its clinical efficacy, and few papers are available upon its historical changes. Therefore, we systematically reviewed Sugemule-10 from the aspects of prescription source, prescription interpretation, efficacy evolution, and modern clinical applications.

6.
Chinese Herbal Medicines ; (4): 376-384, 2022.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-953584

ABSTRACT

Sugemule-10, one of the traditional Mongolian medicine (TMM) formulae, is derived from Four Medical Classics (Vol. 4) and composed of 10 Mongolian medicines. It is used to treat kidney cold, low back pain, urinary obstruction, kidney/bladder stones, and is the main prescription for kidney cold. The current research on Sugemule-10 is mostly focused on its clinical efficacy, and few papers are available upon its historical changes. Therefore, we systematically reviewed Sugemule-10 from the aspects of prescription source, prescription interpretation, efficacy evolution, and modern clinical applications.

7.
J Adhes Dent ; 23(5): 461-467, 2021 Oct 01.
Article in English | MEDLINE | ID: mdl-34549929

ABSTRACT

PURPOSE: To evaluate the microtensile bond strength (µTBS) of a one-step self-etch adhesive (1-SEA) to dentin and its interfacial nanomechanical properties after 8 years of water storage. MATERIALS AND METHODS: Flat coronal dentin surfaces of extracted human third molars were bonded with a 1-SEA (Clearfil S3 Bond Plus, CS3+) and built up with a hybrid resin composite (Clearfil AP-X). After storage in water for 24 h or 8 years, non-trimmed stick-shaped specimens were fabricated from the central part of each bonded tooth and subjected to the µTBS test at a crosshead speed of 1.0 mm/min. Failure modes and the morphology of debonded interfaces were analyzed using a scanning electron microscope (SEM). In addition, the elastic modulus (E) and hardness (H) of the adhesive layer and the resin composite were determined by an instrumented nanoindentation test. The acquired µTBS, E, and H data were statistically analyzed using t-tests to examine the effect of storage time (α = 0.05). RESULTS: The 8-year µTBS was slightly lower than that after 24 h, but the difference was not significant (p = 0.123). The SEM observation of debonded surfaces after 8 years revealed extrusions and lacunas. E and H of the adhesive layer and the resin composite significantly decreased over the 8-year water storage (p < 0.001). CONCLUSIONS: Although 8 years of water storage did not decrease the µTBS of CS3+ significantly, the observed failure mode patterns and significantly decreased nanomechanical properties indicated resin degradation of the adhesive and the resin composite.


Subject(s)
Dental Bonding , Dentin , Composite Resins , Dental Cements , Dental Stress Analysis , Dentin-Bonding Agents , Humans , Materials Testing , Resin Cements , Stress, Mechanical , Surface Properties , Tensile Strength
8.
mSystems ; 6(4): e0073821, 2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34342542

ABSTRACT

Chlamydia trachomatis is an obligate intracellular bacterium whose unique developmental cycle consists of an infectious elementary body and a replicative reticulate body. Progression of this developmental cycle requires temporal control of the transcriptome. In addition to the three chlamydial sigma factors (σ66, σ28, and σ54) that recognize promoter sequences of genes, chlamydial transcription factors are expected to play crucial roles in transcriptional regulation. Here, we investigate the function of GrgA, a Chlamydia-specific transcription factor, in C. trachomatis transcriptomic expression. We show that 10 to 30 min of GrgA overexpression induces 13 genes, which likely comprise the direct regulon of GrgA. Significantly, σ66-dependent genes that code for two important transcription repressors are components of the direct regulon. One of these repressors is Euo, which prevents the expression of late genes during early phases. The other is HrcA, which regulates molecular chaperone expression and controls stress response. The direct regulon also includes a σ28-dependent gene that codes for the putative virulence factor PmpI. Furthermore, overexpression of GrgA leads to decreased expression of almost all tRNAs. Transcriptomic studies suggest that GrgA, Euo, and HrcA have distinct but overlapping indirect regulons. These findings, together with temporal expression patterns of grgA, euo, and hrcA, indicate that a transcriptional regulatory network of these three transcription factors plays critical roles in C. trachomatis growth and development. IMPORTANCE Chlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen worldwide and is a leading cause of preventable blindness in underdeveloped areas as well as some developed countries. Chlamydia carries genes that encode a limited number of known transcription factors. While Euo is thought to be critical for early chlamydial development, the functions of GrgA and HrcA in the developmental cycle are unclear. Activation of euo and hrcA immediately following GrgA overexpression indicates that GrgA functions as a master transcriptional regulator. In addition, by broadly inhibiting tRNA expression, GrgA serves as a key regulator of chlamydial protein synthesis. Furthermore, by upregulating pmpI, GrgA may act as an upstream virulence determinant. Finally, genes coregulated by GrgA, Euo, and HrcA likely play critical roles in chlamydial growth and developmental control.

9.
Microb Pathog ; 156: 104917, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33940135

ABSTRACT

The obligate intracellular bacterium Chlamydia trachomatis is an important human pathogen with a biphasic developmental cycle comprised of an infectious elementary body (EB) and a replicative reticulate body (RB). Whereas σ66, the primary sigma factor, is necessary for transcription of most chlamydial genes throughout the developmental cycle, σ28 is required for expression of some late genes. We previously showed that the Chlamydia-specific transcription factor GrgA physically interacts with both of these sigma factors and activates transcription from σ66- and σ28-dependent promoters in vitro. Here, we investigated the organismal functions of GrgA. We show that overexpression of GrgA slows EB-to-RB conversion, decreases RB proliferation, and reduces progeny EB production. In contrast, overexpression of a GrgA variant without the σ28-binding domain shows significantly less severe inhibitory effects, while overexpression of a variant without the σ66-binding domain demonstrates no adverse effects. These findings indicate that GrgA plays important roles in the expression regulation of both σ66-dependent genes and σ28-dependent genes during the chlamydial developmental cycle.


Subject(s)
Chlamydia trachomatis , Gene Expression Regulation, Bacterial , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Chlamydia trachomatis/genetics , Humans , Sigma Factor/genetics , Sigma Factor/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
10.
Mol Cell Biochem ; 476(3): 1455-1465, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33389496

ABSTRACT

Melanoma ranks second in aggressive tumors, and the occurrence of metastasis in melanoma results in a persistent drop in the survival rate of patients. Therefore, it is very necessary to find a novel therapeutic method for treating melanoma. It has been reported that lncRNA XIST could promote the tumorigenesis of melanoma. However, the mechanism by which lncRNA XIST regulates the progression of melanoma remains unclear. The proliferation of A375 cells was measured by clonal formation. Cell viability was detected by MTT assay. Flow cytometry was performed to detect cell apoptosis and cycle. The level of GINS2, miR-23a-3p, and lncRNA XIST was investigated by qRT-PCR. Protein level was detected by Western blot, and the correctness of prediction results was confirmed by Dual luciferase. In present study, GINS2 and lncRNA XIST were overexpressed in melanoma, while miR-23a-3p was downregulated. Silencing of GINS2 or overexpression of miR-23a-3p reversed cell growth and promoted apoptosis in A375 cells. Mechanically, miR-23a-3p directly targeted GINS2, and XIST regulated GINS2 level though mediated miR-23a-3p. Moreover, XIST exerted its function on cell proliferation, cell viability, and promoted the cell apoptosis of A375 cells though miR-23a-3p/GINS2 axis. LncRNA XIST significantly promoted the tumorigenesis of melanoma via sponging miR-23a-3p and indirectly targeting GINS2, which can be a potential new target for treating melanoma.


Subject(s)
Apoptosis , Chromosomal Proteins, Non-Histone/biosynthesis , Gene Expression Regulation, Neoplastic , MicroRNAs/metabolism , RNA, Long Noncoding/genetics , Cell Cycle , Cell Line, Tumor , Cell Movement , Cell Proliferation , Cell Survival , Down-Regulation , Gene Expression Regulation , Gene Silencing , HEK293 Cells , Humans , Melanocytes/metabolism , Melanoma/metabolism , MicroRNAs/genetics , Signal Transduction , Tetrazolium Salts/pharmacology , Thiazoles/pharmacology
11.
Front Microbiol ; 12: 812448, 2021.
Article in English | MEDLINE | ID: mdl-35046926

ABSTRACT

Cells reprogram their transcriptome in response to stress, such as heat shock. In free-living bacteria, the transcriptomic reprogramming is mediated by increased DNA-binding activity of heat shock sigma factors and activation of genes normally repressed by heat-induced transcription factors. In this study, we performed transcriptomic analyses to investigate heat shock response in the obligate intracellular bacterium Chlamydia trachomatis, whose genome encodes only three sigma factors and a single heat-induced transcription factor. Nearly one-third of C. trachomatis genes showed statistically significant (≥1.5-fold) expression changes 30 min after shifting from 37 to 45°C. Notably, chromosomal genes encoding chaperones, energy metabolism enzymes, type III secretion proteins, as well as most plasmid-encoded genes, were differentially upregulated. In contrast, genes with functions in protein synthesis were disproportionately downregulated. These findings suggest that facilitating protein folding, increasing energy production, manipulating host activities, upregulating plasmid-encoded gene expression, and decreasing general protein synthesis helps facilitate C. trachomatis survival under stress. In addition to relieving negative regulation by the heat-inducible transcriptional repressor HrcA, heat shock upregulated the chlamydial primary sigma factor σ66 and an alternative sigma factor σ28. Interestingly, we show for the first time that heat shock downregulates the other alternative sigma factor σ54 in a bacterium. Downregulation of σ54 was accompanied by increased expression of the σ54 RNA polymerase activator AtoC, thus suggesting a unique regulatory mechanism for reestablishing normal expression of select σ54 target genes. Taken together, our findings reveal that C. trachomatis utilizes multiple novel survival strategies to cope with environmental stress and even to replicate. Future strategies that can specifically target and disrupt Chlamydia's heat shock response will likely be of therapeutic value.

12.
J Environ Manage ; 264: 110328, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32224293

ABSTRACT

The inclusive wealth approach is increasingly common to measure the sustainable development of the countries. It comprised the natural, human and produced capital of nations to measure social wellbeing. We measure the inclusive wealth of the provinces in China from 2000 to 2015 and reports the sustainable use of the resources. We identify that three types of capital have increased to varying degrees, with produced capital increasing by 615.6%, natural capital increasing by 33.8%, and human capital increased by 337.0%. The total amount of inclusive wealth has increased by 300.4% in the past 15 years. However, the provinces in China are still facing unbalanced development across the country compared to developed nations. The use of the natural capital, more specifically now-renewable resources, has been restricting the wealth growth in some provinces. Although ecological services account for a small proportion of the total inclusive wealth, more attention is essential for sustainable development. Meanwhile, the rapid growth of carbon damages posed threat to future wealth accumulation. Innovative, coordinated, green, open and shared development are the goals of China 13th and 14th five-year plan and our inclusive wealth of China will be key measurement tool of this achievement.


Subject(s)
Conservation of Natural Resources , China , Humans
13.
China Pharmacy ; (12): 144-148, 2020.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-817352

ABSTRACT

OBJECTIVE:To establish a method for the content determination of apigenin and piperine in the water extract as well as eucalyptol and cumin aldehyde in the volatile oil of Mongolian medicine Sugmel- 3 decoction. METHODS :HPLC method was adopted for the content determination of apigenin and piperine. GC method was used for the content determination of eucalyptol and cumin aldehyde. The determination of HPLC method was performed on Agilent Eclipse XDB-C 18 column with mobile phase consisted of methanol- 0.1% phosphoric acid aqueous solution at flow rate of 1.0 mL/min;the detection wavelength was set at 225 nm(apigenin)and 342 nm(piperine);the column temperature was set at 30 ℃ with sample size of 10 μL. The determination of GC method was performed on Dimensions SH-Rtx- 1 capillary column with high-purity hydrogen as carrier gas ; the injector temperature was set at 270 ℃,with flow rate of carrier gas 1 mL/min by temperature programmed ;the sample size was 1 μL,and split ratio was 1 ∶ 10. RESULTS:The linear ranges of apigenin ,piperine,eucalyptol and cumin aldehyde were 12.5-200 μg/g/mL(r=0.999 6),87.3-139.7 μg/mL(r=0.999 9),136-2 187 μg/mL(r=0.999 9),39-635 μg/mL(r=0.999 9), respectively. The quantitation limits were 0.02,0.06,0.06,0.12 μg/mL,respectively. The detection limits were 0.01,0.02,0.03, 0.04 μg/mL. RSDs of precision,stability and reproducibility tests were all less than 4%. The recovery rates of the samples were 89.26% -97.26%(RSD=2.69% ,n=6),94.20% -104.01%(RSD=3.64% ,n=6),98.51% -110.11%(RSD=3.87% ,n=6), 95.76%-107.82%(RSD=4.12%,n=6),respectively. The contents of above components were 0.769-0.828,7.741-7.981,5.284 7- 5.846 6,1.038 6-1.101 2 mg/g(n=3). CONCLUSIONS:The established method is simple and feasible ,and can be used for quality control of different parts of Mongolian medicine Sugmel- 3 decoction.

14.
Pathog Dis ; 77(9)2019 12 01.
Article in English | MEDLINE | ID: mdl-32011704

ABSTRACT

Chlamydiae are common, important pathogens for humans and animals alike. Despite recent advancement in genetics, scientists are still searching for efficient tools to knock out or knock down the expression of chromosomal genes. We attempted to adopt a dCas9-based CRISPR interference (CRISPRi) technology to conditionally knock down gene expression in Chlamydia trachomatis using an anhydrotetracycline (ATC)-inducible expression system. Surprisingly, expression of the commonly used Streptococcus pyogenes dCas9 in C. trachomatis causes strong inhibition in the absence of any guide RNA (gRNA). Staphylococcus aureus dCas9 also shows strong toxicity in the presence of only an empty gRNA scaffold. Toxicity of the S. pyogenes dCas9 is readily observed with as little as 0.2 nM ATC. Growth inhibition by S. aureus dCas9 is evident starting at 1.0 nM ATC. In contrast, C. trachomatis growth was not affected by methionine-tRNA ligase overexpression induced with 10 nM ATC. We conclude that S. pyogenes and S. aureus dCas9 proteins in their current forms have limited utility for chlamydial research and suggest strategies to overcome this problem.


Subject(s)
CRISPR-Cas Systems , Chlamydia trachomatis/genetics , Staphylococcus aureus/genetics , Streptococcus pyogenes/genetics , Chlamydia trachomatis/metabolism , RNA, Guide, Kinetoplastida/antagonists & inhibitors , RNA, Guide, Kinetoplastida/metabolism
15.
J Bacteriol ; 200(20)2018 10 15.
Article in English | MEDLINE | ID: mdl-30061357

ABSTRACT

The obligate intracellular bacterial pathogen Chlamydia trachomatis has a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primary Chlamydia sigma factor, σ66, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, σ28 In prior work, we identified GrgA as a Chlamydia-specific transcription factor that activates σ66-dependent transcription by binding DNA and interacting with a nonconserved region (NCR) of σ66 Here, we extend these findings by showing GrgA can also activate σ28-dependent transcription through direct interaction with σ28 We measure the binding affinity of GrgA for both σ66 and σ28, and we identify regions of GrgA important for σ28-dependent transcription. Similar to results obtained with σ66, we find that GrgA's interaction with σ28 involves an NCR located upstream of conserved region 2 of σ28 Our findings suggest that GrgA is an important regulator of both σ66- and σ28-dependent transcription in C. trachomatis and further highlight NCRs of bacterial RNA polymerase as targets for regulatory factors unique to particular organisms.IMPORTANCEChlamydia trachomatis is the number one sexually transmitted bacterial pathogen worldwide. A substantial proportion of C. trachomatis-infected women develop infertility, pelvic inflammatory syndrome, and other serious complications. C. trachomatis is also a leading infectious cause of blindness in underdeveloped countries. The pathogen has a unique developmental cycle that is transcriptionally regulated. The discovery of an expanded role for the Chlamydia-specific transcription factor GrgA helps us understand the progression of the chlamydial developmental cycle.


Subject(s)
Bacterial Proteins/metabolism , Chlamydia trachomatis/genetics , Gene Expression Regulation, Bacterial , Sigma Factor/metabolism , Transcription Factors/metabolism , Bacterial Proteins/genetics , Chlamydia trachomatis/metabolism , Cytoplasm/metabolism , DNA-Directed RNA Polymerases , Escherichia coli/genetics , Genes, Bacterial , Humans , Sigma Factor/genetics , Transcription Factors/genetics
16.
Genet Mol Res ; 15(3)2016 Aug 29.
Article in English | MEDLINE | ID: mdl-27706629

ABSTRACT

The trans-translation pathway, mediated by the transfer messenger RNA (tmRNA; encoded by the ssrA gene) and the SmpB protein (tmRNA-binding protein expressed in Salmonella enterica), which is conserved in bacteria, is required for various cellular processes. A previous study has shown that trans-translation is required to ensure timely (non-delayed) dnaA transcription and consequent initiation of DNA replication in Caulobacter crescentus. In this study, we observed that initiation of chromosome replication was delayed in Escherichia coli lacking the smpB and/or ssrA genes (DssrA, DsmpB, or DsmpBDssrA mutants). We observed that the growth rate of the mutant cells was much slower than that of its wild-type counterpart. However, the delayed initiation of replication and slower growth in the DssrA or DsmpB mutants were reversed by ectopic expression of tmRNA or SmpB. A synchronized DsmpBDssrA cell culture containing the dnaC2 mutant allele showed delayed protein (total and DnaA) accumulation per cell; DnaA accumulation was also delayed in the DsmpB. These results indicated that absence of trans-translation leads to a delay in initiation of DNA replication, synthesis of total protein (including DnaA), and a decrease in E. coli growth rate. In summary, we propose that the trans-translation pathway is required to ensure timely initiation of replication, protein synthesis, and subsequent cell cycle progression.


Subject(s)
DNA Replication , Escherichia coli/genetics , Gene Expression Regulation, Bacterial , Protein Biosynthesis , RNA, Bacterial/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Caulobacter crescentus/genetics , Caulobacter crescentus/metabolism , Cell Cycle , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Escherichia coli/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Gene Deletion , Protein Binding , RNA, Bacterial/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Salmonella enterica/genetics , Salmonella enterica/metabolism
17.
Article in English | MEDLINE | ID: mdl-28050194

ABSTRACT

Objective. Insomnia is one of the most common sleep disorders. Hypnotics have poor long-term efficacy. Mongolian medical warm acupuncture has significant efficacy in treating insomnia. The paper evaluates the role of Mongolian medical warm acupuncture in treating insomnia by investigating the Mongolian medicine syndromes and conditions, Pittsburgh sleep quality index, and polysomnography indexes. Method. The patients were diagnosed in accordance with International Classification of Sleep Disorders (ICSD-2). The insomnia patients were divided into the acupuncture group (40 cases) and the estazolam group (40 cases). The patients underwent intervention of Mongolian medical warm acupuncture and estazolam. The indicators of the Mongolian medicine syndromes and conditions, Pittsburgh sleep quality index (PSQI), and polysomnography indexes (PSG) have been detected. Result. Based on the comparison of the Mongolian medicine syndrome scores between the warm acupuncture group and the drug treatment group, the result indicated P < 0.01. The clinical efficacy result showed that the effective rate (85%) in the warm acupuncture group was higher than that (70%) in the drug group. The total scores of PSQI of both groups were approximated. The sleep quality indexes of both groups decreased significantly (P < 0.05). The sleep quality index in the Mongolian medical warm acupuncture group decreased significantly (P < 0.01) and was better than that in the estazolam group. The sleep efficiency and daytime functions of the patients in the Mongolian medical warm acupuncture group improved significantly (P < 0.01). The sleep time was significantly extended (P < 0.01) in the Mongolian medical warm acupuncture group following PSG intervention. The sleep time during NREM in the Mongolian warm acupuncture group increased significantly (P < 0.01). The sleep time exhibited a decreasing trend during REM and it decreased significantly in the Mongolian warm acupuncture group (P < 0.01). The percentage of sleep time in the total sleep time during NREM3+4 in the Mongolian medical warm acupuncture group increased significantly. Conclusion. Mongolian medical warm acupuncture is efficient and safe in treating insomnia. It is able to better improve the patients' sleep time and daytime functions. It is better than that in the estazolam group following drug withdrawal in terms of improving the sleep time. It is more effective in helping the insomnia patients than hypnotics.

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