[Mechanism of oxymatrine in treatment of collagen-induced arthritis in mice].

Sophorae Flavescentis Radix, the root of Sophora flavescens Ait., has been widely applied in the medical field due to its anti-inflammatory, analgesic, bacteriostatic, antiviral, antitumor, and other pharmacological effects. The present study investigated the anti-rheumatoid arthritis effect of oxymatrine(OMT), the active component of Sophorae Flavescentis Radix by observing its effect on the function of B lymphocytes in collagen-induced arthritis(CIA) mice through the Toll-like receptor 9(TLR9)/myeloid differentiation factor 88(MyD88)/signal transducer and activator of transcription 3(STAT3) pathway. The CIA model in DBA/1 J mice was induced by bovine type Ⅱ collagen and complete Freund's adjuvant(CFA). Fifteen days after the primary immunization, mice were treated with OMT for 30 days by intraperitoneal injection. Paw swelling and arthritis index(AI) score were evaluated every 3 days. Joint histopathologic changes were observed by HE staining. Magnetic-activated cell sorting(MACS) was used to isolate B lymphocytes from the spleen of CIA mice spleen. The serum expression level of interleukin(IL)-21 was examined by the enzyme-linked immunosorbent assay(ELISA). The expression of TLR9, STAT3, p-STAT3, and IL-21 in B lymphocytes was detected by Western blot. The mRNA expression of TLR9, STAT3, and IL-21 in B lymphocytes was detected by real-time fluorescence-based quantitative PCR(qRT-PCR). The results showed that OMT could significantly alleviate the paw swelling, decrease the AI score, relieve synovial inflammatory cell infiltration and hyperplasia, reduce the level of inflammatory cytokines, and inhibit the expression of TLR9, STAT3, p-STAT3, and IL-21 of B lymphocytes in CIA mice. Therefore, OMT may alleviate rheumatoid arthritis by regulating TLR9/MyD88/STAT3 pathway in B lymphocytes, providing a valuable reference for the application of OMT in the clinical treatment of rheumatoid arthritis.

Long-term preservation of potato leafroll virus, potato virus S, and potato spindle tuber viroid in cryopreserved shoot tips.

Availability of and easy access to diverse plant viruses and viroids is a prerequisite in applied and basic studies related to viruses and viroids. Long-term preservation of viruses and viroids is difficult. A protocol was described for long-term preservation of potato leafroll virus (PLRV), potato virus S (PVS), and potato spindle tuber viroid (PSTVd) in cryopreserved shoot tips of potato cv. Zihuabai. Shoot regrowth levels following cryopreservation were higher in 1.5 mm-shoot tips (58-60%) than in 0.5-mm-ones (30-38%). All shoots recovered from 0.5-mm-shoot tips were PVS- and PSTVd-preserved, but none of them were PLRV-preserved. Cryopreservation of 1.5-mm-shoot tips resulted in 35% and 100% of PLRV- and PVS- and PSTVd-preserved shoots. Studies on cell survival patterns and virus localization provided explanations to the varying PLRV-preservation frequencies produced by cryopreservation of the two sizes of shoot tips. Although micropropagation efficiencies were low after 12 weeks of subculture following cryopreservation, similar efficiencies were obtained after 16 weeks of subculture in pathogen-preserved shoots recovered from cryopreservation, compared with the diseased in vitro stock shoots (the control). Pathogen concentrations in the three pathogens-preserved shoots analyzed by qRT-PCR were similar to those in micropropagated shoots. The three pathogens cryopreserved in shoot tips were readily transmitted by grafting and mechanical inoculation to potato plants. PLRV, PVS, and PSTVd represent a diverse range of plant viruses and viroid in terms of taxonomy and infectious ability. Therefore, shoot tip cryopreservation opens a new avenue for long-term preservation of the virus and viroid.

In vitro thermotherapy-based methods for plant virus eradication.

Production of virus-free plants is necessary to control viral diseases, import novel cultivars from other countries, exchange breeding materials between countries or regions and preserve plant germplasm. In vitro techniques represent the most successful approaches for virus eradication. In vitro thermotherapy-based methods, including combining thermotherapy with shoot tip culture, chemotherapy, micrografting or shoot tip cryotherapy, have been successfully established for efficient eradication of various viruses from almost all of the most economically important crops. The present study reviewed recent advances in in vitro thermotherapy-based methods for virus eradication since the twenty-first century. Mechanisms as to why thermotherapy-based methods could efficiently eradicate viruses were discussed. Finally, future prospects were proposed to direct further studies.

Combining Thermotherapy with Cryotherapy for Efficient Eradication of Apple stem grooving virus from Infected In-vitro-cultured Apple Shoots.

Apple stem grooving virus (ASGV), a difficult-to-eradicate virus from apple propagative materials, causes serious damage to apple production. The use of virus-free plants has been and is an effective strategy for control of plant viral diseases. This study aimed to eradicate ASGV from virus-infected in-vitro-cultured shoots of four apple cultivars and one rootstock by combining thermotherapy with cryotherapy. In vitro stock shoots infected with ASGV were thermo-treated using an alternating temperature of 36°C (day) and 32°C (night). Shoot tips were excised from the treated stock shoots and subjected to cryotherapy. Results showed that, although thermotherapy did not influence shoot survival rates, it reduced shoot growth and proliferation of in vitro shoots. Shoot regrowth rates decreased while virus eradication frequencies increased in cryo-treated shoot tips as time durations of thermotherapy increased from 0 to 6 weeks. Shoot regrowth and frequency of virus eradication were positively and negatively correlated, respectively, with the size of shoot tips. The protocol established here yielded shoot regrowth rates and virus eradication frequencies of 33 to 76% and 30 to 100%, respectively, in the four apple cultivars and one rootstock. Thermotherapy altered virus distribution patterns, subsequently resulting in production of a larger virus-free area in the thermo-treated shoot tips. Many cells in the top layers of apical dome and some cells in the youngest leaf primordia survived in cryo-treated shoot tips; these cells were most likely free of virus infection. Thus, plants regenerated from the procedure of combining thermotherapy with cryotherapy were free of ASGV, as judged by reverse-transcription polymerase chain reaction. To the best of our knowledge, this is the widest-spectrum technique reported thus far for the production of ASGV-free plants and provides a novel biotechnology for the production of virus-free plants in Malus spp.