ABSTRACT
OBJECTIVE@#To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR.@*METHODS@#Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining.@*RESULTS@#The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05).@*CONCLUSION@#Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.
Subject(s)
Rats , Male , Humans , Animals , Root Resorption/therapy , Rats, Sprague-Dawley , Osteoclasts , Tooth Movement Techniques , Stem CellsABSTRACT
Artemisia annua is the main natural source of artemisinin production. In A. annua, extended drought stress severely reduces its biomass and artemisinin production while short-term water-withholding or abscisic acid (ABA) treatment can increase artemisinin biosynthesis. ABA-responsive transcription factor AabZIP1 and JA signaling AaMYC2 have been shown in separate studies to promote artemisinin production by targeting several artemisinin biosynthesis genes. Here, we found AabZIP1 promote the expression of multiple artemisinin biosynthesis genes including AaDBR2 and AaALDH1, which AabZIP1 does not directly activate. Subsequently, it was found that AabZIP1 up-regulates AaMYC2 expression through direct binding to its promoter, and that AaMYC2 binds to the promoter of AaALDH1 to activate its transcription. In addition, AabZIP1 directly transactivates wax biosynthesis genes AaCER1 and AaCYP86A1. The biosynthesis of artemisinin and cuticular wax and the tolerance of drought stress were significantly increased by AabZIP1 overexpression, whereas they were significantly decreased in RNAi-AabZIP1 plants. Collectively, we have uncovered the AabZIP1-AaMYC2 transcriptional module as a point of cross-talk between ABA and JA signaling in artemisinin biosynthesis, which may have general implications. We have also identified AabZIP1 as a promising candidate gene for the development of A. annua plants with high artemisinin content and drought tolerance in metabolic engineering breeding.
ABSTRACT
Atropa belladonna L. is the officially medicinal plant species and the main commercial source of scopolamine and hyoscyamine in China. In this study, we reported the simultaneous overexpression of two functional genes involved in biosynthesis of scopolamine, which respectively encoded the upstream key enzyme putrescine N-methyltransferase (PMT; EC 2.1.1.53) and the downstream key enzyme hyoscyamine 6beta-hydroxylase (H6H; EC 1.14.11.11) in transgenic hair root cultures of Atropa belladonna L. HPLC results suggested that four transgenic hair root lines produced higher content of scopolamine at different levels compared with nontransgenic hair root cultures. And scopolamine content increased to 8.2 fold in transgenic line PH2 compared with that of control line; and the other four transgenic lines showed an increase of scopolamine compared with the control. Two of the transgenic hair root lines produced higher levels of tropane alkaloids, and the content increased to 2.7 fold in transgenic line PH2 compared with the control. The gene expression profile indicated that both PMT and H6H expressed at a different levels in different transgenic hair root lines, which would be helpful for biosynthesis of scopolamine. Our studies suggested that overexpression of A. belladonna endogenous genes PMT and H6H could enhance tropane alkaloid biosynthesis.
ABSTRACT
<p><b>OBJECTIVE</b>To study the variations of flavonoids contents in vine tips of sweetpotato (Ipomoea batatas) among different varieties, parts and the time of topping.</p><p><b>METHOD</b>The flavonoid contents in leaf, petiole and stem of vine tips at 6 different topping time of 3 varieties for vegetable-use Pushu 53, Guangcaishu No. 2 and Fushu 7-6, which were collected from Chongqing were determined by UV spectrophotometry with rutin as a standard substance.</p><p><b>RESULT</b>The results showed that the flavonoid content of Guangcaishu No. 2 was higher than that of Pusu 53, so was that of Pusu 53 than that of Fushu 7-6. The average flavonoid contents in leaf of 3 varieties were between 3.66 mg x L(-1) and 11.09 mg x L(-1) during 6 topping time, and those in petiole, stem were between 2.20-5.26 mg x L(-1) and 4.03-7.79 mg x L(-1), respectively. The rations of average flavonoid contents in leaf, petiole and stem to the total contents of vine tips among 3 varieties during their whole topping periods were 46.71%, 20.65% and 32.63%, respectively. The contents during earlier topping time were higher than those of later periods. The variance analysis of flavonoid contents revealed that there was significant difference between different varieties, parts and time of topping and significant interactions among varieties, parts and time of topping.</p><p><b>CONCLUSION</b>The results of the study indicate that the contents of flavonoid should be considered for the breeding, cultivation and industrialization of sweetpotato for vegetable-use.</p>