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BACKGROUND:Bone formation is the process by which osteoblasts synthesize and secrete osteoid and promote its mineralization,which generally involves mechanical signal transduction.Osteoblasts are primarily regulated by mechanical factors such as gravity,compressive stress,tensile stress,fluid shear stress,and hydrostatic pressure in vivo,and different mechanical stimuli modulate the proliferation,differentiation,and apoptosis of osteoblasts through various mechanisms,including hormones,cytoskeletal proteins,and microRNAs.By clarifying the effects of biomechanical forces on osteoblasts,it provides ideas and a reference basis for the treatment of osteometabolic diseases involving osteoblasts. OBJECTIVE:To review the effects of different biomechanical forces on the biological characteristics of osteoblasts. METHODS:We conducted a literature search using PubMed,Web of Science,FMRS,CNKI,and WanFang databases for relevant publications published from 2000 to 2023,covering basic research and tissue engineering studies related to the effects of biomechanical forces on osteoblasts.Ultimately,a total of 70 articles were reviewed. RESULTS AND CONCLUSION:Different biomechanical forces have an impact on the biological characteristics of osteoblasts,including proliferation,differentiation,and apoptosis,and these effects are dependent on the intensity and duration of the applied force.Specifically,the effects are as follows:(1)Under microgravity conditions,osteoblast proliferation and differentiation are inhibited,resulting in a decrease in bone density and the development of osteoporosis.(2)Compared to microgravity,hypergravity has a promoting effect on osteoblast proliferation.(3)The effects of compressive stress on osteoblasts are dependent on the loading intensity and time.Appropriate compressive stress can promote osteoblast proliferation and differentiation,which is beneficial for bone tissue formation and repair,while excessive compressive stress can cause osteoblast apoptosis and bone tissue destruction.(4)The biological effects of different types of tensile stress on osteoblasts differ.Studies have shown that a strain rate within the range of 0-12%has a promoting effect on osteoblast proliferation.(5)Fluid shear stress can promote osteoblast proliferation and differentiation and enhance the bone-inducing effect of biomaterials.(6)Static hydrostatic pressure can affect the biological behavior of osteoblasts,including proliferation,differentiation,and apoptosis,and these effects are closely related to the time and intensity of the pressure.Understanding the effects of different biomechanical forces on osteoblasts is of great significance for a deeper understanding of bone growth and maintenance mechanisms.
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BACKGROUND:Intervertebral disc degeneration is a condition caused by the combined effects of various factors,such as cellular apoptosis,oxidative stress,and inflammatory responses.Currently,it is believed that the core of this condition lies in the degeneration and apoptosis of nucleus pulposus cells(NPCs).However,the specific pathological mechanisms remain unclear. OBJECTIVE:By investigating the expression of the phosphatidylinositol-3 kinase(PI3K)/protein kinase B(Akt)/hypoxia-inducible factor 1-alpha(HIF-1α)signaling pathway and the apoptosis of NPCs under different oxygen concentrations,to clarify the biological characteristics of NPCs under varying oxygen levels,and to explore the mechanisms of intervertebral disc degeneration. METHODS:Normal and degenerated NPCs were collected.The second-generation cells were used for imaging identification.The third-generation cells were cultured in the following conditions:37℃,air,100%humidity.Leibovitz's medium containing 100 μmol/L CoCl2 and 10%fetal bovine serum medium containing 100 μmol/L H2O2 were used to create distinct oxygen concentration environments for the third-generation cells,allowing for the investigation of cellular responses and behaviors under normal,low oxygen,and oxidative stress conditions.The third-generation cells were divided into six groups:normal NPCs+hypoxia,normal NPCs+normoxia,normal NPCs+oxidative stress,degenerated NPCs+hypoxia,degenerated NPCs+normoxia,and degenerated NPCs+oxidative stress groups.Cell viability and proliferation were assessed using the cell counting kit-8 method.Cell apoptosis was detected using flow cytometry.RT-PCR and western blot assay were utilized to examine the protein and mRNA expression levels of PI3K,AKT,and HIF-1α. RESULTS AND CONCLUSION:At different oxygen concentrations,the cell proliferation rate of both normal and degenerated NPCs decreased as the oxygen concentration increased.Conversely,the apoptosis rate increased as the oxygen concentration rose(P<0.05).With the normal NPCs+hypoxia group as the control group,the effect of degenerated NPCs on the apoptosis rate was highly significant(P<0.001).Oxygen concentration had a highly significant impact on both NPC proliferation rate and apoptosis rate(P<0.001).The interaction between cell degeneration and oxygen concentration significantly affected both NPC proliferation and apoptosis rates(P<0.05).At different oxygen concentrations,the protein and mRNA expression levels of PI3K,AKT,and HIF-1α in normal NPCs were highest under low oxygen concentration,followed by oxidative stress environment,and lowest under normoxia.In degenerated NPCs,the protein and mRNA expression levels of PI3K,AKT,and HIF-1α decreasd as the oxygen concentration increased.The protein and mRNA expression levels of PI3K and Akt in normal NPCs were significantly higher than those in degenerated NPCs(P<0.05).With the normal NPCs+hypoxia group as the control group,the effects of normal or degenerated NPCs,as well as oxygen concentration,on the protein and mRNA expression of PI3K,AKT,and HIF-1α were highly significant.The interaction between cell degeneration and oxygen concentration also had an extremely significant effect on the protein and mRNA expression of PI3K,AKT,and HIF-1α(P<0.001).To conclude,there is a close correlation between the proliferation and apoptosis of NPCs and both oxygen concentration and the cellular functional state.The PI3K/Akt/HIF-1α signaling pathway exhibits antagonistic regulatory effects under various cellular functional states and different oxygen concentration environments.The mechanism may be associated with the activation of the PI3K/Akt signaling pathway,which consequently transcribes HIF-1α,thus maintaining the balance of reactive oxygen species metabolism.This pathway plays a significant role in inhibiting oxidative stress,antagonizing NPCs apoptosis,and consequently delaying intervertebral disc degeneration.
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Violet root rot is one of the main root diseases in the production process of Pseudostellaria heterophylla. To clarify the pathogenic species that cause the violet root rot of P. heterophylla in Fujian province, the roots and the sclerotia with violet root rot symptoms were collected from the main producing areas of P. heterophylla(Fujian province) from 2017 to 2021, and the pathogens were isolated by tissue separation method and identified by morphology and multi-gene phylogenetic analysis. Additionally, the biological characteristics of the pathogens were studied and the fungicides were determined. The results showed that 78 strains of violet root rot were isolated from the collected root samples, which belonged to one type after preliminary morphological identification. Two represen-tative strains were selected from the pathogens for multi-gene phylogenetic analysis, and they were clustered with Helicobasidium mompa together. The suitable culture conditions for the mycelium were OA medium, 25 ℃, pH 6, and ammonium oxalate as the nitrogen source. The lethal temperature of the mycelium was 50 ℃ for 10 minutes. Moreover, 99.1% propiconazole and 98.7% azoxystrobin had the optimal bacteriostatic effect, and the concentrations with the 50% bacteriostatic rate were 16.85 and 12.24 μg·mL~(-1), respectively. On the basis of the above results, the pathogen causing violet root rot of P. heterophylla in Fujian province was H. mompa. The medium type, growth temperature, pH value, nitrogen source, etc. had significant effect on the growth of mycelium.
Subject(s)
Plant Roots , Phylogeny , Temperature , Caryophyllaceae , NitrogenABSTRACT
In Zherong county, Fujian province, the black spot of Pseudostellaria heterophylla often breaks out in the rainy season from April to June every year. As one of the main leaf diseases of P. heterophylla, black spot seriously affects the yield and quality of the medicinal material. To identify and characterize the pathogens causing black spot, we isolated the pathogens, identified them as a species of Alternaria according to Koch's postulates, and then tested their pathogenicity and biological characteristics. The results showed that the pathogens causing P. heterophylla black spot were A. gaisen, as evidenced by the similar colony morphology, spore characteristics, sporulation phenotype, and the same clade with A. gaisen on the phylogenetic tree(the maximum likelihood support rate of 100% and the Bayesian posterior probability of 1.00) built based on the tandem sequences of ITS, tef1, gapdh, endoPG, Alta1, OPA10-2, and KOG1077. The optimum conditions for mycelial growth of the pathogen were 25 ℃, pH 5-8, and 24 h dark culture. The lethal conditions for mycelia and spores were both treatment at 50 ℃ for 10 min. We reported for the first time the A. gaisen-caused black spot of P. heterophylla. The results could provide a theoretical basis for the diagnosis and control of P. heterophylla leaf spot diseases.
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Bayes Theorem , Phylogeny , Caryophyllaceae , Alternaria , MyceliumABSTRACT
Tibetan medicine Lamiophlomis rotata(Benth.)Kudo is a plant belonging to the genus L.rotata(Benth.)in Labiatae,which is a commonly used bulk Tibetan medicine.As a first-class endangered Tibetan medicine,its sustainable utilization of resources is representative,and it is particularly important to master its species characteristics and adaptation mechanism under high Plateau adversity.This paper sorts out the habitat characteristics,morphological characteristics,population ecological characteristics,reproductive characteristics and other aspects of L.rotata(Benth.),analyzes the growth characteristics and adverse ecological factors of L.rotata(Benth.)in the Qinghai Tibet Plateau grassland,and analyzes its adaptation mechanism in drought,cold and different degraded grass from two aspects of biological characteristics and physiological characteristics.The author believes that it is necessary to study its stress resistance mechanism from many aspects,such as gene and molecular biology,and explore the suitable planting mode of monoculture,so as to provide a theoretical basis for introduction and domestication,cultivation management,resource protection and sustainable utilization.
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@#Objective To investigate the biological characteristics and clinical significance of cuproptosis-related genes in lung adenocarcinoma (LUAD) based on the multi-omics data from The Cancer Genome Atlas. Methods The cuproptosis-related genes were obtained from a study published in Science in March 2022. The whole genome data were used to reveal the mutation spectrum and copy number variation landscape of cuproptosis-related genes in LUAD and analyze its effects on transcriptome expression. Cuproptosis-related genes were annotated using Metascape analysis to further understand the pathways or functions in which these genes were involved. Subsequent univariate Cox analysis and Kaplan-Meier methods determined the prognosis of these genes in LUAD patients, and CellMiner analysis were used to identify those potential anticancer drugs for potentially targeting cuproptosis-related genes. Results Cuproptosis-related genes were less frequently mutated in LUAD, and the effect of gene mutations on transcriptomic expression may depend on the type of mutation. Gene copy number variation was an important factor resulting in the disordered expression of cuproptosis-related genes. The 16 cuproptosis-related genes were mainly involved in glyoxylate metabolism and glycine degradation, copper ion entry, proteolitidylation, cellular amino acid catabolism process, oxidative stress response, etc. Among them, 6 genes (DLD, FDX1, DLAT, DLST, PDHA1, CDKN2A) were prognostic risk genes in LUAD. The CellMiner analysis suggested that 13 drugs were associated with 7 cuproptosis-related genes and they might be potential anticancer drugs for potentially targeting cuproptosis. Conclusion This study reveals the biological characteristics and clinical significance of cuproptosis-related genes in LUAD, and provides some reference and theoretical basis for the subsequent research of cuproptosis in cancer.
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ObjectiveEstablish an animal model of preeclampsia in goats, collect data on various physiological indicators and maternal biological characteristics of the disease model to compare with clinical feature of the disease in humans, provide reference for the prevention and treatment of preeclampsia in humans.Methods Twenty-three goats bred in Chongming district were divided into three groups: Control group, no surgical procedure was performed on animals of this group; sham group, ewes in this group underwent the sham operation on the 100±5th day of gestation, and only the uterine artery was exposed and dissociated; surgical group, a silver vascular clamp was clipped on one side of the uterine body artery of the ewe to narrow the inner diameter of the artery at the same gestation period (100±5) days. Heart rate and hindlimb blood pressure were continuously monitored in control and surgical ewes from 100 to 140 d of gestation, and blood flow data within the lateral branches of the uterine arteries of ewes in the sham group were collected using a hemodynamometer in combination with a hemodynamic probe and an animal physiological signal collector, as well as changes in blood flow within the uterine arteries in the lateral branches of the uterine arteries of the surgical group before and after placement of vascular clips in the surgical ewes. At the expected date of delivery, jugular vein blood was taken from ewes for routine blood test, creatinine, urea nitrogen, and blood ion analysis; urine was also collected from ewes in each group for analysis of urinary protein and urinary creatinine. All experimental groups were subjected to cesarean section on the 140±5th day of gestation in ewes, and then liver, kidney, uterus and placenta tissues were taken from ewes in each group and stained with HE for pathological observation. Results After 15 minutes of preeclampsia modeling surgery, blood flow volume remained stable in the vessel stenosis segment and the volume differential was relatively reduced in comparison to the control group and sham group (P＜0.05，P＜0.01). Compared with the control group, the ewes in the surgical group showed prenatal changes such as increased serum osmolality, decreased hemoglobin, increased blood glucose and urea nitrogen values, as well as increased levels of calcium, sodium, and chloride ions (all P<0.05) and proteinuria, with urinary creatinine and urinary protein-creatinine ratios were significantly higher than those in the control group and sham group (all P<0.05). The elastic lamina of the uterine body arteries on the operated side of the animals in the surgical group was thicker than that on the opposite side, but the structure was loose. The placenta on the operated side showed pathological changes such as cell interstitial swelling and inflammatory cell infiltration. The above physiological index characteristics were more consistent with the clinical features of human preeclampsia disease.Conclusion In this experiment, we successfully constructed a goat preeclampsia model and obtained data on relevant physiological indexes of this model, which further verified the correlation between preeclampsia disease and uterine artery lesions.
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Mesenchymal stem cells (MSCs) have broad application potentials in regenerative medicine and translational medicine. Obtaining large quantities of primary-cultured MSCs and select the most suitable cell origin for targeted diseases are critical to research. To select the most suitable seed cells of MSCs from different origins for clinical treatment and research, biological characteristics of MSCs from human umbilical cord and placenta were compared. These include cell morphology, surface marker expression, differentiation and karyotype. Transcriptome sequencing of four MSCs from fetus were performed and the results were analyzed from the perspective of proliferation and cytokine secretion. The results revealed that MSCs from umbilical cord (UC), amniotic membrane (AM), chorionic membrane (CM), chorionic villi (CV) and deciduae (DC) met the minimum standards of the International Society of Cell Therapy (ISCT) in 2006 and had the general characteristics of stem cells. Karyotype analysis showed that MSCs derived from UC, AM, CM and CV were all from fetus except that the DC-MSCs were from mother. Transcriptome sequencing analysis showed that hMSCs from umbilical cord and placenta had similar gene expression patterns, while different expression patterns were observed in specific genes involved in cell cycle, cell division, cell death, cell growth and development. These genes play important roles in transcriptional regulation, DNA repair, DNA replication and chromosome stability, which were momentous components of cellular or subcellular fraction movement, cell communication, cell tissue protrusions, cytokine secretion and hormone metabolism. Transcriptome sequencing analysis explained the differences in biological characteristics among MSCs from different sources, while verification experiments based on the transcriptome sequencing results showed that the proliferation and cytokine secretion capabilities of MSCs from different sources were significantly different. In all, UC-MSCs and CV-MSCs with stronger proliferation and higher levels of paracrine factors secretion may show their respective advantages in treating diseases.
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Female , Humans , Pregnancy , Cell Differentiation , Fetus , Mesenchymal Stem Cells , Placenta , Umbilical CordABSTRACT
In Hezhang county, Guizhou province, black spot tends to occur to Aconitum carmichaelii in the hot rainy summer, with the incidence up to 50%-70%, seriously impacting the yield and quality of the medicinal material. Thus, this study aims to clarify the pathogen and the occurrence characteristics. To be specific, the pathogen was isolated and identified according to Koch's postulates and the pathogenicity and biological characteristics were determined. In addition, the sensitivity of the pathogen to four microbial fungicides, four botanical fungicides, and five chemical fungicides was determined with the mycelium growth rate method for the purpose of screening out optimal fungicides. The pathogen was identified as Alternaria alternate, as evidenced by the similar colony morphology and microscopic characteristics and 99.55%-100% similarity in sequences of rDNA-ITS, LSU, 18S, and TEF of the two. The optimum growth conditions for A. alternata were 28 ℃, pH 8, and continuous darkness. Bacillus subtilis had strong inhibitory effect on the pathogen, and the inhibition rate was more than 90% when the concentration was 1 mg·L~(-1). In addition, difenoconazole and quinoline copper can also control the pathogen, with median effective concentration(EC_(50)) of 2.92 and 9.02 mg·L~(-1), respectively. This study lays a theoretical basis for the field control of black spot in A. carmichaelii.
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Aconitum , Alternaria , Fungicides, Industrial/pharmacology , MyceliumABSTRACT
Leaf blight outbroke in Rehmannia glutinosa plantation in Wenxian county, Henan province in 2019. R. glutinosa plants with diseased leaves were collected from the plantation, and three strains were isolated from the diseased leaf samples. Pathogenicity test, morphological observation, and phylogenetic analysis of ITS, EF1-α, and Tub suggested that they were respectively Fusarium proliferatum, F. oxysporum, and F.acuminatum. Among them, F. acuminatum, as a pathogen of R. glutinosa leaf disease, had never been reported. To clarify the biological characteristics of F. acuminatum, this study tested the influence of light, pH, temperature, medium, carbon source, and nitrogen source on the mycelial growth rate of the pathogen during a 5-day culture period, and explored the lethal temperature. The results showed that the mycelia grew well under the photoperiod of 12 h light/12 h darkness, at 5-40 ℃(optimal temperature: 25 ℃), at pH 4-11(optimal pH: 7.0), on a variety of media(optimal medium: oatmeal agar), and in the presence of diverse carbon and nitrogen sources(optimal carbon source: soluble starch; optimal nitrogen source: sodium nitrate). The lethal temperature was verified to be 51 ℃(10 min). The conclusion is expected to lay a scientific basis for diagnosis and control of R. glutinosa leaf diseases caused by F. acuminatum.
Subject(s)
Carbon , Nitrogen , Phylogeny , RehmanniaABSTRACT
Objective:To investigate the effect and mechanism of miR-195 regulating FOXK1 gene and PI3K/Akt pathway on stomach adenocarcinoma proliferation, invasion and migration ability.Methods:Public database samples were employed to analyze the expression differences and prognostic significance of miR-195 in stomach adenocarcinoma. After overexpression of mir-195-5p in two cell lines, MGC803 and AGS, altered cell proliferation, invasion, and migration abilities were detected by Alamar Blue, Wound healing, and Transwell assays. The potential target genes and binding sites of miR-195 were predicted by the starBase. Western blot was used to detect the expression levels of foxk1 and phosphorylation sites in the PI3K/Akt pathway of target genes after overexpression of mir-195-5p. A Dual-luciferase reporter assay was used to verify the relationship between mir-195-5p and foxk1. Statistical analyses were performed with IBM SPSS 22 software and R 4.0.3.Results:Our results showed a significant over-expression of miR-195 in the tumor tissues, compared with the paired normal tissues ( P<0.001) , which could inhibit the proliferation and invasion of stomach carcinoma cells and significantly correlated with survival ( P=0.011) . Moreover, our study indicated that miR-195 depressed the expression of FOXK1 and significantly reduced the activation of the PI3K/Akt pathway, which had a negative effect on the proliferation and invasion of stomach carcinoma cells. The phosphorylated Akt (s473 site) expression in the PI3K/Akt pathway was significantly decreased after overexpression of miR-195. Conclusion:Overall, our studies clarify the important function of the miR-195 in the diagnosis and therapy of patients with stomach carcinoma and reveal the FOXK1 and PI3K/Akt pathway regulation by the miR-195, which are of important clinical significance in the differential diagnosis.
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Objective:To evaluate the feasibility and applicability of using phospholipid-hybridization method for preparing biomimetic microbubbles (Bio-MBs) ultrasound contrast agents.Methods:Leukocyte biomimetic microbubbles (MB leu), platelet biomimetic microbubbles (MB pla) and erythrocyte biomimetic microbubbles (MB ery) were prepared by multiple steps: film-hydration, phospholipid-hybridization, mechanical oscillation. The size and zeta potential of Bio-MBs were measured by dynamic light scattering. A laser scanning confocal microscopy experiment was performed to confirm the presence of membrane proteins on the shell of Bio-MBs. The fluorescence of FITC-labeled typical membrane protein was evaluated using a flow cytometer. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was used to characterize the membrane protein. Biosafety of Bio-MBs was evaluated by CCK-8 counting kit, blood and major organs. The contrast enhancement effect and stability were observed in vitro and in vivo. An in vivo fluorescence imaging system was performed to evaluate the distribution of Bio-MBs. The application value of biomimetic microbubbles was measured by ultrasound molecular imaging by using ischemia-reperfusion rat models and acute hepatitis rat models. Results:Bio-MBs with spherical shape distributed homogenously, without obvious aggregation. The membrane proteins were successfully integrated into the shell of Bio-MBs.The diameter of three Bio-MBs was similar to that of control microbubbles (MB con) ( P>0.05), three Bio-MBs had a lower zeta potential than MB con ( P<0.05). The Bio-MBs had an appreciable performance in vitro and in vivo biosafety. The Bio-MBs retained the main proteins inherited from cell membrane. Contrast enhanced ultrasound imaging in vitro and in vivo showed that the Bio-MBs had a stable imaging ability.MB leu and MB pla have good targeted imaging effect in two disease models. Conclusions:A series of Bio-MBs ultrasound contrast agents, which have high stability, biosafety and targeted imaging efficiency, were successfully prepared by using phospholipid-hybridization method. This fabrication method for obtaining Bio-MBs can be applied to different clinical scenarios with different cell types in the future.
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Saccharomyces boulardii is a subspecies of Saccharomyces cerevisiae and is a fungal probiotic. It can regulate the intestinal flora and enhance the barrier function of the intestinal tract. Compared with bacterial probiotics, Saccharomyces boulardii is more resistant to acid and oxidation, does not transmit genetic material with bacteria, and can be used in combination with antibiotics. Saccharomyces boulardii can function through a variety of mechanisms, and many proteases secreted by it have antitoxin effects; its own bacteria contain more polyamines, which can nourish the intestinal mucosal cells and regulate the body's metabolic balance. Besides, it can regulate multiple signal pathways to enhance intestinal immunity. Saccharomyces boulardii has been used in the treatment of ulcerative colitis (UC). The results of animal experiments and clinical studies have shown that the application of Saccharomyces boulardii can improve intestinal inflammation and enhance the therapeutic effect of mesalazine. Saccharomyces boulardii can be used as an auxiliary drug for the treatment of UC.
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BACKGROUND: Previous studies have found that hypoxia has different effects on the proliferation and differentiation of mesenchymal stem cells and secretion of cytokines, but the effect of hypoxia on canine adipose-derived mesenchymal stem cells has not been seen. OBJECTIVE: To investigate the effect of hypoxic environment on the biological characteristics of canine adipose-derived mesenchymal stem cells. METHODS: Canine adipose-derived mesenchymal stem cells were isolated and cultured by enzyme digestion. Passage 2 adipose-derived mesenchymal stem cells could be divided into normoxia group (21% oxygen volume fraction) and hypoxia group (5% oxygen volume fraction). Morphological characteristics, proliferation speed, cell surface marker expression, differentiation capacity, and cytokine secretion level were compared between the two groups. RESULTS AND CONCLUSION: (1) The growth of adipose-derived mesenchymal stem cells cultured in hypoxic environment was good. The cell morphology was fusiform and polyhedral, the same as that of the normoxia group. (2) The proliferation rate of cells in the hypoxia group was accelerated, and the cell doubling time was shorter than that in the normoxia group (all P < 0.05). The differentiation time of lipogenesis and osteogenesis was shortened. (3) The expression of CD90, CD44 and CD105 was high in both normoxia group and hypoxia group, while the expression of CD45 was low. (4) The mRNA expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor in the hypoxia group were 2.3 times (P < 0.05) and 3.0 times (P < 0.05) higher than those in the normoxia group. (5) The results indicated that the hypoxic environment had no significant effect on the morphology and surface marker of adipose-derived mesenchymal stem cells, but promoted cell proliferation, differentiation and cytokine secretion.
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During the high-temperature and rainy season from June to October in 2017-2019,serious southern blight broke out in the Cynanchum stauntonii planting area in Tuanfeng county,Hubei province,which had a great impact on the yield and quality of medicinal materials. In this study,the pathogen of C. stauntonii was isolated,purified,and identified,and the pathogenicity was tested according to Koch's postulates. Meanwhile,the biological characteristics of the pathogen were analyzed. On this basis,the effective fungicides were screened in laboratory. Finally,the pathogen( BQ-1) was identified as Athelia rolfsii( Deuteromycotina,Basidiomycota,anamorph: Sclerotium rolfsii). The optimum growth conditions for BQ-1 were 25-30 ℃,p H 5-8,and alternating light and dark.The effective chemical fungicides were lime-sulphur-synthelic-solution( LSSS) and flusilazole,and the effective botanical fungicide was osthole. BQ-1 was highly homologous to the pathogen HS-1 of peanut southern blight,with the similarity of 18 S r DNA and TEF sequences at 99. 09%. The southern blight in C. stauntonii might be resulted from that in peanut. In the production of C. stauntonii,the following measures should be taken: avoiding rotation or neighboring with peanut,draining water from June to October to reduce humidity,and reasonably applying fungicides.
Subject(s)
Basidiomycota , Cynanchum , Fungicides, Industrial/pharmacology , HumidityABSTRACT
BACKGROUND@#Cullin1 is a representative member of the Cullin family, and it plays an important role in the ubiquitination of cell cycle, transcription and signal transduction related proteins. Cullin1 is closely related to the occurrence and development of a variety of malignant tumors. The aim of this study is to investigate the effects of Cullin1 on biological function of lung adenocarcinoma A549 and H1395 Cells.@*METHODS@#The expression of Cullin1 mRNA was detected by quantitative Real-time polymerase chain reaction in lung adenocarcinoma cells (A549, H358, H1395, H1650) and human normal lung epithelial cells BEAS-2B, siRNA technology was used to interfere with lung adenocarcinoma cells with relatively high expression of Cullin1 mRNA; cell proliferation, cell cycle distribution, early cell apoptosis, invasion and migration ability were detected by methyl thiazolyl tetrazolium assay (MTT), flow cytometry and Transwell experiment; Western blot was used to detect the expression levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), Cyclin D1, Cyclin E2, p21 and p27.@*RESULTS@#Compared with the BEAS-2B cell, Cullin1 mRNA was highly expressed in lung adenocarcinoma cells, especially in lung adenocarcinoma A549 and H1395 cells (P<0.05). The proliferation ability of lung adenocarcinoma cells was inhibited after interference with Cullin1, and the number of cells in G1 phase increased, the number of cells in S phase decreased, and the early apoptosis rate of lung adenocarcinoma cells is significantly increased (P<0.05); The invasion and migration ability of lung adenocarcinoma cells decreased (P<0.05). After interference with Cullin1, the protein expression of MMP-9, MMP-2, CyclinD1 and CyclinE2 decreased (P<0.05), while the expression of TIMP-1, p21 and p27 protein increased (P<0.05).@*CONCLUSIONS@#Interference with Cullin1 inhibits the proliferation, invasion and migration of lung adenocarcinoma A549 and H1395 cells, Cullin1 plays a role in promoting cancer in lung adenocarcinoma.
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Objective We explored the stability of the bacteria strains used in the Ames test to provide a basis for determining the appropriate passage number at which the biological characteristics of the strains would not change. Methods The Salmonella typhimurium (TA97a, TA98, TA100 and TA102 strains) were selected as the experimental strains.The original frozen strains and frozen strains with different passage times were used to compare the biological characteristics and the spontaneously reverting colonies. Results The biological characteristics of four kinds of strains, which were histidine deficiency, lipidpolysaccharide barrier defect, ampicillin resistance, UV sensitivity, and tetracycline resistance, did not change at F1-F6 generation when compared with the F0 generation.However, as for the number of spontaneously reverting colonies, a statistically significant difference (P < 0.05) occurred at F3 generation when compared with F0 generation for the TA97a strain, and a significant difference (P < 0.05) occurred at F4 generation for TA100 and TA102 strains. Conclusion Passage number of strains used in Ames test could affect their spontaneous reversion mutation rate.The passage number should be less than 4 for TA98、TA100、TA102 strains, and less than 3 for TA97a in Ames test.
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Carbon dots are an emerging nanomaterial with excellent fluorescent properties. Compared with traditional organic dyes and semiconductor quantum dots, carbon dots possess advantages of low toxicity and good biocompatibility. At present, carbon dots are widely used in many fields such as analytical detection, fluorescence imaging and drug delivery. Cervi Cornu Pantotrichum, a rare mammalian organ with ability of full regeneration, has been used as famous traditional Chinese medicine. The biological functions and efficacy of Cervi Cornu Pantotrichum are closely related to their chemical constituents. In this paper, we briefly reviewed the progress of carbon dots research in fluorescence detection, fluorescence imaging and phototherapy, carried out the bioimaging and cell cytotoxicity test by carbon dots, and discussed the feasibility of carbon dots in biological features and chemical composition analysis of Cervi Cornu Pantotrichum.
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LysR-type transcriptional regulators are involved in the regulation of numerous cellular metabolic processes in Klebsiella pneumoniae, leading to severe infection. Earlier, we found a novel LysR family gene, named kp05372, in a strain of K. pneumoniae (designated GPKP) isolated from forest musk deer. To study the function of this gene in relation to the biological characteristics of GPKP, we used the suicide plasmid and conjugative transfer methods to construct deletion mutant strain GPKP-Δkp05372; moreover, we also constructed the GPKP-Δkp05372+ complemented strain. The role of this gene was determined by comparing the following characteristics of three strains: growth curves, biofilm formation, drug resistance, stress resistance, median lethal dose (LD50), organ colonization ability, and the histopathology of GPKP. Real-time polymerase chain reaction (RT-PCR) was used to test the expression level of seven genes upstream of kp05372. There was no significant difference in the growth rates when comparing the three bacterial strains, and no significant difference was recorded at different osmotic pressures, temperatures, salt contents, or hydrogen peroxide concentrations. The GPKP-Δkp05372 mutant formed a weak biofilm, and the other two strains formed medium biofilm. The drug resistance of the GPKP-Δkp05372 mutant toward cephalothin, cotrimoxazole, and polymyxin B was changed. The acid tolerance of the deletion strain was strongerthan that of the othertwo strains. The LD50 values of the wild-type and complemented strains were 174-fold and 77-fold higher than that of the GPKP-Δkp05372 mutant, respectively. The colonization ability of the GPKP-Δkp05372 mutant in the heart, liver, spleen, kidney, and intestine was the weakest. The three strains caused different histopathological changes in the liver and lungs. In the GPKP-Δkp05372 mutant, the relative expression levels of kp05374 and kp05379 were increased to 1.32-fold and 1.42-fold, respectively, while the level of kp05378 was decreased by 42%. Overall, the deletion of kp05372 gene leads to changes in the following: drug resistance and acid tolerance; decreases in virulence, biofilm formation, and colonization ability of GPKP; and regulation of the upstream region of adjacent genes.
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BACKGROUND: Tissue engineering technology has emerged to solve the repair and reconstruction of tissues and organs. The selection and application of seed cells become an issue of concern. Fibroblasts are a popular choice in various tissue engineering studies. OBJECTIVE: To summarize the biological characteristics of fibroblasts, their multi-potential differentiation and their effects on the proliferation and differentiation of stem cells. METHODS: A computer-based research of CNKI (2015-2019) and PubMed (2005-2019) databases was performed for the articles about the biological characteristics of fibroblasts and multipotential differentiation. The articles were systematically summarized and analyzed. The newest research process of multi-potential differentiation of fibroblasts was reviewed. RESULTS AND CONCLUSION: Fibroblasts hold strong metabolism and proliferation abilities, which can synthesize and secrete protein. Fibroblasts can differentiate into different cells under different environments, and exhibit the same strong multi-potential differentiation with stem cells. Therefore, it is commonly used in the transdifferentiation, cell culture, injury repair and tissue engineering, and their effects on promoting proliferation and inducing differentiation of stem cells are particularly significant. We should fully utilize the biological characteristics and multi-potential differentiation of fibroblasts, and co-culture of fibroblasts with stem cells can provide seed cells for tissue engineering, which further provide an idea for traumatic repair in clinic.