Functional identification of AeHMGR gene involved in regulation of saponin biosynthesis in Aralia elata.

Aralia elata (Miq.) Seem, a significant tree species in the Araliaceae family, has medicinal and edible properties. Saponins are the primary active components of A. elata. The 3-hydroxy-3-methylglutaryl- CoA reductase (HMGR) is the initial rate-limiting enzyme of the major metabolic pathway of saponins in A. elata. In this study, the AeHMGR gene was identified through screening of transcriptome data. Through the qRT-PCR analysis, it was determined that the expression level of AeHMGR gene is highest in the somatic embryo and stem of A. elata. Heterologous transformation in tobacco revealed that ectopic expression of the AeHMGR gene leads to a significant reduction in the expression levels of the NtSS, NtFPS, and NtSE genes in transgenic tobacco lines, with a minimum expression level of 0.24 times that of the wild type. In the overexpressed callus lines of A. elata, the expression levels of the AeFPS, AeSE, AeSS, and Aeß-AS genes were also significantly lower compared to the wild type, with a minimum expression level of approximately 0.3 times that of the wild type. Interestingly, the overexpression of the AeHMGR gene in A. elata somatic embryos led to a substantial decrease in the expression levels of AeFPS and AeSS, while the expression levels of AeSE and Aeß-AS increased. Among the transgenic somatic embryo strain lines, line 7 exhibited the highest expression levels of AeSE and Aeß-AS, with fold increases of 11.51 and 9.38, respectively, compared with that of the wild-type. Additionally, a high-performance liquid chromatography method was established to detect five individual saponins in transgenic A. elata. The total saponin content in line 7 somatic embryos was 1.14 times higher than that of wild-type materials, but only 0.30 times that of wild-type cultivated leaves. Moreover, the content of oleanolic acid saponin in line 7 was 1.35 times higher than that of wild-type cultivated leaves. These indicate that HMGR can affect triterpene biosynthesis.

Expression of PnSS Promotes Squalene and Oleanolic Acid (OA) Accumulation in Aralia elata via Methyl Jasmonate (MeJA) Induction.

Aralia elata is an important herb due to the abundance of pentacyclic triterpenoid saponins whose important precursors are squalene and OA. Here, we found that MeJA treatment promoted both precursors accumulation, especially the latter, in transgenic A. elata, overexpressing a squalene synthase gene from Panax notoginseng(PnSS). In this study, Rhizobium-mediated transformation was used to express the PnSS gene. Gene expression analysis and high-performance liquid chromatography (HPLC) were used to identify the effect of MeJA on squalene and OA accumulation. The PnSS gene was isolated and expressed in A. elata. Transgenic lines showed a very high expression of the PnSS gene and farnesyl diphosphate synthase gene (AeFPS) and a slightly higher squalene content than the wild-type, but endogenous squalene synthase (AeSS), squalene epoxidase (AeSE), and ß-amyrin synthase (Aeß-AS) gene were decreased as well as OA content. Following one day of MeJA treatment, the expression levels of PeSS, AeSS, and AeSE genes increased significantly. On day 3, the maximum content of both products reached 17.34 and 0.70 mg·g-1, which increased 1.39- and 4.90-fold than in the same lines without treatment. Transgenic lines expressing PnSS gene had a limited capability to promote squalene and OA accumulation. MeJA strongly activated their biosynthesis pathways, leading to enhance yield.

Prevalence of hyperthyroidism with hypercalcemia in Xindu district and the efficacy of vitamin D3 treatment in these patients: a randomized trial.

BACKGROUND: This trial aimed to analyze the relationship between hyperthyroidism and the morbidity rate of hypercalcemia in the Xindu district, Chengdu, Sichuan province. We observed the level of serum calcium, the bone metabolic and thyroid autoimmune-related antibodies index during vitamin D3 treatment combined with traditional antithyroid drugs (ATD). METHODS: Our research included hyperthyroid patients with a first-time diagnosis of Graves diseases (GD) combined with hypercalcemia on the basis of conventional anti-hyperthyroidism therapy, which were randomized into a vitamin D3 group (vitamin D3, 800-1,200 IU/day) and an ATD group (methimazole, 15-30 mg/day). All hyperthyroidism patients with hypercalcemia were analyzed, and changes in serum calcium (Ca2+), parathyroid hormone (PTH), thyroid function, thyroid autoimmune-related antibodies, and 25-dihydroxyvitamin D (25-OHVit D) levels during treatment of thyrotoxicosis with added vitamin D3 were explored. RESULTS: In total, 184 patients with hyperthyroidism were observed, including 36 (19.57%) patients associated with hypercalcemia, with an age of onset of (56.39±5.80) years old. Twelve (6.52%) of these 36 cases reported digestive symptoms as the first manifestation, and four (2.17%) patients presented with a hypercalcemia crisis as the first manifestation. Serum Ca2+, free triiodothyronine (FT3), free thyroxine (FT4), and thyrotropin hormone receptor antibody (TRAb) levels increased in patients with hypercalcemia. Following the addition of vitamin D3 treatment, serum Ca2+, FT3, FT4, and TRAb levels were significantly decreased relative to the ATD group, while the thyroid-stimulating hormone (TSH), PTH, and 25-OHVit D levels were normalized. CONCLUSIONS: Our study highlighted the importance of taking functional digestive disturbance into consideration in hyperthyroidism diagnosis, even in the absence of the typical symptoms. The level of thyroid related antibodies, thyroid function, and bone metabolism in hyperthyroidism patients combined with hypercalcemia could be improved by vitamin D3 adjuvant therapy. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2100047870.

Nitrogen and Fluorine Dual Doping of Soft Carbon Nanofibers as Advanced Anode for Potassium Ion Batteries.

Potassium-ion batteries (PIBs) are recognized as promising alternatives for lithium-ion batteries as the next-generation energy storage systems. However, the larger radius of K+ hinders the K+ insertion into the conventional carbon electrode and results in sluggish potassiation kinetics and poor cycling stability. Here, nitrogen and fluorine dual doping of soft carbon nanotubes (NFSC) anode are synthesized in one pot, achieving extraordinary electrochemical performance for PIBs. It is demonstrated that NFSC with a doping dose of 5.6 at% nitrogen and 1.3 at% fluorine together exhibits the highest reversible capacity of 238 mAh g-1 at 0.2 A g-1 and cycling stability of 186 mAh g-1 after 1000 cycles at 1 A g-1 . The extraordinary electrochemical performance can be attributed to the hollow structure, expanded interlayer distance, nitrogen and fluorine dual doping, and the binding ability of abundant defect sites. Moreover, density functional theory shows that the extra fluorine modification can dramatically enhance the conventional nitrogen doping effect and reduces the formation energy which makes a great contribution to the improvement of electrical conduction and K-ions insert. This work may promote the development of low-cost and sustainable carbon-based materials for PIBs and other advanced energy storage devices.

Temperature and solvent isotope dependent hierarchical self-assembly of a heterografted block copolymer.

A heterografted block copolymer with doubly thermoresponsive grafts is designed to address the challenge in hierarchical self-assembly. Upon heating, solvent isotope dependent morphology transitions from spheres to nanobowls, vesicles, disks, nanosheets, nanoribbons and hyperbranched micelles can be achieved. The strategy provides a general platform to prepare diverse thermoreversible nano-objects.