Pharmacological Properties of Jaeumgeonbi-Tang on Redox System and Stress-Related Hormones in Chronic Subjective Dizziness: A Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Trial.

Jaeumgeonbi-Tang (JGT), a traditional herbal medicine, has been used to treat dizziness and vertigo in Korea and China for hundreds of years. The purpose of this study was to evaluate the pharmacological properties of JGT in chronic subjective dizziness (CSD) patients. A randomized, double-blind, parallel-group and placebo-controlled trial was performed with a total of 50 CSD patients. The patients were randomly assigned to one of two groups: JGT or placebo (n = 25 for each). All participants received the treatment (placebo or JGT, 24 g/day) for 4 weeks. We analyzed the serum levels of oxidative stressors, antioxidants, and stress hormones. Serum levels of lipid peroxidation, but not nitric oxide, were significantly decreased in the JGT group. JGT not only prevented the decline of serum total glutathione contents and total antioxidant capacity, but it also increased superoxide dismutase and catalase activities. Serum levels of stress hormones including cortisol, adrenaline, and serotonin were notably normalized by JGT treatment, but noradrenaline levels were not affected. Regarding the safety and tolerability of JGT, we found no allergic, adverse, or side effects in any of the participants. JGT showed beneficial effects on CSD patients by improving redox status and balancing psycho-emotional stress hormones.

Ukgansan Protects Dopaminergic Neurons against MPTP-Induced Neurotoxicity via the Nurr1 Signaling Pathway.

Nuclear receptor-related 1 protein (Nurr1) is a nuclear hormone receptor that protects dopaminergic neurons and is a promising therapeutic target for Parkinson's disease (PD). Parkinson's disease is a neurodegenerative disorder caused by the destruction of dopaminergic neurons in the substantia nigra pars compacta (SNpc), and the long-term use of conventional dopamine replacement therapies causes many side effects, highlighting the need for new treatments such as complementary and alternative medicine. Ukgansan has been used in East Asia to treat neurological disorders, including neurodegenerative diseases, and has been reported to have strong effects in treating patients with PD. In addition, recent studies have reported that Ukgansan has a neuroprotective potential. However, there are no detailed studies on the mechanism of action of Nurr1. Thus, unlike previous studies, we focused on the Nurr1 pathways. We confirmed neurotoxicity and apoptosis signaling in the differentiated PC12 cells. In addition, to confirm the protective effect of Ukgansan, we conducted behavioral tests (motor coordination and postural balance, and bradykinesia) and tyrosine hydroxylase immunohistochemistry in both the SNpc and striatum. Specifically, this study demonstrated the effect of Ukgansan in protecting dopaminergic neurons and increasing Nurr1 involved in maintaining dopamine levels by activating Nurr1 expression in MPTP-induced PC12 cells and a mouse model of PD. In this mechanism, the loss of dopaminergic neurons and dopamine depletion were suppressed, and motor impairment caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity was improved. These results provide evidence that Ukgansan ameliorates PD's motor symptoms and progression.

Pharmacological Effects of Gami-Yukmijihwang-Tang on the Lipopolysaccharide-Induced Hippocampus Oxidation and Inflammation via Regulation of Sirt6.

Yukmijihwang-Tang is widely used in traditional Korean medicine to treat age-related disorders. In the present study, we re-prescribed Gami-Yukmijihwang-Tang (YJT), which is slightly modified from Yukmijihwang-Tang by adding more medicinal plants to evaluate its pharmacological effects on underlying mechanisms against repeated lipopolysaccharide (LPS)-injection-induced neuroinflammation in the hippocampus regions. C57BL/6J male mice (16-24 weeks old) were divided into six groups: (1) the control group (DW with 0.9% saline injection), (2) LPS group (DW with LPS injection), YJT groups ((3) 100, (4) 200, or (5) 400 mg/kg of YJT with LPS injection), and (6) glutathione (GSH) group (100 mg/kg of GSH with LPS injection), respectively. Mice were orally administrated with various doses of YJT or glutathione (GSH) for the first five days. Neuroinflammation in the hippocampus region was induced by repeated injection of LPS during the last three days. As predicted, LPS not only increased oxidative stress-related markers including malondialdehyde, 4-hydroxynonenal, nitrotryptophan, and hydrogen peroxide, but also drastically enhanced inflammatory reactions including nitric oxide, inducible nitric oxide synthase, p65, and toll-like receptor 4, respectively. YJT administration, on the other hand, notably decreased the above pathological alterations by enhancement of antioxidant capacities such as superoxide dismutase and catalase activities. To explain the underlying pharmacological actions of YJT, we focused on a representative epigenetic regulator, a nicotinamide adenine dinucleotide + (NAD+)-dependent chromatin enzyme, Sirtuin 6 (Sirt6). Neuroinflammation in hippocampus regions depleted Sirt6 at the protein level and this alteration directly affected the nuclear factor erythroid 2-related factor (Nrf2)/hemeoxygenase (HO)-1 signaling pathway in the LPS group; however, YJT significantly recovered the Sirt6 protein levels, and it could recover the abnormal status of Nrf2/HO-1 signaling pathways in the hippocampus regions. Additionally, Sirt6 led to the up-regulation of GSH sub-enzymes of mRNA expression and protein levels of total GSH content. These findings suggest that YJT can protect against LPS-induced neuroinflammation and oxidative stress by regulating the Sirt6-related pathways and normalizing the GSH redox cycle.

Antiviral Effect of Hyunggaeyungyo-Tang on A549 Cells Infected with Human Coronavirus.

BACKGROUND: Herbal medicine is widely recommended to treat viral infectious diseases. Over 123,000,000 individuals have been infected with the coronavirus since a worldwide pandemic was declared in March 2020. We conducted this research to confirm the potential of herbal medicine as a treatment for coronavirus. METHODS: We infected the A549 cell line with betacoronavirus OC43 and then treated it with 100 µg/mL Hyunggaeyungyo-tang (HGYGT) or distilled water with a control of HGYGT. We measured the mRNA expression levels of proinflammatory cytokines and interferon stimulated genes (ISGs) to confirm the effectiveness of HGYGT upon coronavirus infection. RESULTS: We found that the effects of HYGYT decrease the expression level of pPKR, peIF2α, IFI6, IFI44, IFI44L, IFI27, IRF7, OASL, and ISG15 when administered to cells with coronavirus infection. The expressions of IL-1, TNF-α, COX-2, NF-κB, iNOS, and IKK mRNA were also significantly decreased in the HGYGT group than in the control group. CONCLUSION: Through the reduction of the amount of coronavirus RNA, our research indicates that HGYGT has antiviral effects. The reduction of IKK and iNOS mRNA levels indicate that HGYGT reduces coronavirus RNA expression and may inhibit the replication of coronavirus by acting on NF-kB/Rel pathways to protect oxidative injury. In addition, decreases in mRNA expression levels of proinflammatory cytokines indicate that the HGYGT may relieve the symptoms of coronavirus infections.

Traditional Korean herbal formulae, Yuk-Mi-Ji-Hwang-Tang, ameliorates impairment of hippocampal memory ability by chronic restraint stress of mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: Yuk-Mi-Jihwang-Tang (YJT) has been popularly prescribed to treat aging related disorders over than hundreds of years in East Asia countries. AIM OF THE STUDY: To investigate possible modulatory actions of YJT on chronic restraint stress (CRS)-induced neurodegeneration on hippocampus neuronal injuries. MATERIALS AND METHODS: Mice were orally administered with YJT (100, 200, or 400 mg/kg) or ascorbic acid (100 mg/kg) before 4 h of stress for 28 days. Morris water maze task was completed from day 24th to 28th, and stress hormones and biochemical analyzes were measured. RESULTS: Four weeks of the CRS abnormally affected memory impairments by measurement of escape latency and time spent in the target quadrant. Additionally, neurotransmitters were also drastically altered in serum or hippocampus protein levels by CRS. Gene expressions for 5-hydroxytryptamine (5-HT) receptor, 5-HT-transport, and tryptophan hydroxylase were also altered, whereas YJT led to normalize the above alterations. Additionally, YJT also beneficially worked on endogenous redox system as well as inflammatory reactions in the hippocampal neurons. We observed that hippocampal excitotoxicity was induced by CRS which were evidenced by depletion of phosphor-cAMP response element-binding protein, brain-derived neurotrophic factor, nuclear factor erythroid-2-related factor 2, heme oxygenase-1 and abnormally increases of acetylcholine esterase activities in hippocampus protein levels; however, YJT considerably improved the above pathological conditions. CONCLUSIONS: Our findings supported YJT enhance memory function via regulation of hippocampal excitotoxicity-derived memory impairment, stress hormone, and endogenous redox, respectively.

Effects of Maclura tricuspidata (Carr.) Bur fruits and its phytophenolics on obesity-related enzymes.

The purpose of the present study was to investigate whether several phytophenolic ingredients isolated from Maclura tricuspidata (Carr.) Bur fruits inhibit the activity of obesity-related enzymes including pancreatic lipase, α-amylase, ß-glucosidase, phosphodiesterase IV, alkaline phosphatase, and citrate synthase, and the compounds play as an inhibitor against the target enzymes in kinetic studies. The enzyme assays indicated that the fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes. The kinetic studies demonstrated that the inhibitory properties of p-hydroxybenzoic acid (4-HA), protocatechuic acid (PA), and isovanillic acid (IA) against pancreatic lipase, ß-glucosidase, citrate synthase, or alkaline phosphatase. Our results suggested that the compounds detected from Maclura tricuspidata (Carr.) Bur fruit extract may regulate carbohydrate/lipid/energy metabolism by obesity-related enzymes' inhibition. PRACTICAL APPLICATIONS: The obesity-related metabolizing enzymes affect (in)directly the metabolites absorption on carbohydrate/lipid/energy metabolism. Accordingly, it is an important strategy to treat obesity through target pathways and enzymes which include the reduction in energy intake and consumption. In our results, Maclura tricuspidata (Carr.) Bur fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes, in particular, 4-HA, PA, and IA have each specific inhibition type on pancreatic lipase, ß-glucosidase, citrate synthase, and alkaline phosphatase. Therefore, M. tricuspidata (Carr.) Bur fruit may be a strong candidate as a food material or therapeutic agent for obesity improvement.

Current Usage of Terminologies Related to Acupotomy: A Literature Research and Standardization Suggestion.

OBJECTIVE: investigate the current usage of terminologies related to acupotomy through systematic search and analyze the pros and cons of each for proposing a standard terminology. METHODS: Seven medical journal databases were searched including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Oriental Medicine Advanced Searching Integrated System, KoreaMed, and Korean studies Information Service System using 10 candidate terminologies as searching terms. All studies published from their inception to July 26, 2017 were collected. Articles were included if the title stated one of the 10 candidate terminologies consistent with the definition of acupotomy. Priorly established frequency and consistency of each candidate terminology from medical databases were calculated and evaluated. Moreover, the pros and cons of each were analyzed to propose a standard terminology. RESULTS: A total of 112 studies in English databases, 1,129 studies in Chinese database, and 44 studies in Korean databases were included. The most frequently used terminologies were needle knife (35.71%), acupotomy (48.54%) and acupotomy (90.90%) in English, Chinese and Korean database, respectively. Overall, acupotomy and needle knife were the most frequently used. Others like acupotomology, needle scalpel, miniscalpel acupuncture and miniscalpel needle were used within 10% of the total searched literature. Acupotome, stiletto needle, sword like needle, and Xiaozhendao were rarely used. Acupotomy had the advantages of high frequency and consistency but lacked representativeness. Needle knife also showed a high frequency, but the consistency was poor. Though miniscalpel acupuncture and miniscule needle were used less frequently, they had advantages of inclusiveness and clarity. CONCLUSION: A debate for standardization of the terminology is necessary. This preliminary research can provide a basic outline for the standardization consensus process, and we believe it is noteworthy to discuss miniscalpel needle and miniscalpel acupuncture along with acupotomy and needle knife on the subject.

Excitatory GABAergic Action and Increased Vasopressin Synthesis in Hypothalamic Magnocellular Neurosecretory Cells Underlie the High Plasma Level of Vasopressin in Diabetic Rats.

Diabetes mellitus (DM) is associated with increased plasma levels of arginine-vasopressin (AVP), which may aggravate hyperglycemia and nephropathy. However, the mechanisms by which DM may cause the increased AVP levels are not known. Electrophysiological recordings in supraoptic nucleus (SON) slices from streptozotocin (STZ)-induced DM rats and vehicle-treated control rats revealed that γ-aminobutyric acid (GABA) functions generally as an excitatory neurotransmitter in the AVP neurons of STZ rats, whereas it usually evokes inhibitory responses in the cells of control animals. Furthermore, Western blotting analyses of Cl- transporters in the SON tissues indicated that Na+-K+-2Cl- cotransporter isotype 1 (a Cl- importer) was upregulated and K+-Cl- cotransporter isotype 2 (KCC2; a Cl- extruder) was downregulated in STZ rats. Treatment with CLP290 (a KCC2 activator) significantly lowered blood AVP and glucose levels in STZ rats. Last, investigation that used rats expressing an AVP-enhanced green fluorescent protein fusion gene showed that AVP synthesis in AVP neurons was much more intense in STZ rats than in control rats. We conclude that altered Cl- homeostasis that makes GABA excitatory and enhanced AVP synthesis are important changes in AVP neurons that would increase AVP secretion in DM. Our data suggest that Cl- transporters in AVP neurons are potential targets of antidiabetes treatments.

A traditional Korean multiple herbal formulae (Yuk-Mi-Jihwang-Tang) attenuates acute restraint stress-induced brain tissue oxidation.

We aimed to evaluate the protective effects of Yuk-Mi-Jihwang-Tang (YJT) against acute restraint stress-induced brain oxidative damage. A water extract of YJT was prepared and subjected to high performance liquid chromatography - diode array detector-mass spectrometry (HPLC-DAD-MS). Thirty-six heads of C57BL/6J male mice (7 weeks) were divided into six groups (n = 6/group). The mice were orally administrated YJT (0, 50, 100, or 200 mg/kg) or vitamin C (100 mg/kg) for 5 consecutive days before 6 h of acute restraint stress. In the brain tissue, lipidperoxidation, antioxidant components, and pro-inflammatory cytokines were measured, and the serum corticosterone level was determined. Acute restraint stress-induced notably increased lipid peroxidation in brain tissues, and pretreatment with YJT showed a significant decreased the lipid peroxidation levels (p< 0.05). The levels of antioxidant components including total glutathione contents, activities of SOD and catalase were remarkably depleted by acute restraint stress, whereas these alterations were significantly restored by treatment with YJT (p< 0.05 or p< 0.01). The restraint stress markedly increased pro-inflammatory cytokines, such as TNF-α and IL-6 in the gene expression and protein levels (p< 0.05 or p< 0.01). Pretreatment with YJT significantly attenuated serum corticosterone (200 mg/kg, p < 0.05). YJT drastically attenuated the levels of 4- HNE, HO-1, Nox 2 and iNOSwhich were elevated during acute restraint stress, whereas the Nrf2 level was increased in brain tissue protein levels. Our data suggest that YJT protects the brain tissue against oxidative damage and regulates stress hormones.

Combination Therapy of Gefitinib and Korean Herbal Medicines Could be a Beneficial Option for Patients with Non-Small-Cell Lung Cancer.

ABSTRACT: Lung cancer has a high mortality rate and is often diagnosed at the metastatic stage. Gefitinib is a targeted molecular therapeutic drug used to treat patients with non-small-cell lung cancer (NSCLC). Korean herbal medicines may also have therapeutic efficacy against lung cancer, reduce the side effects associated with chemotherapy, and improve patient quality of life (QOL). This case report describes the effects of a Korean herbal medicine regimen combined with gefitinib in a patient with NSCLC and bone metastasis. The Korean herbal medicine regimen included woohwanggeosa-dan, hwanggibujeong-dan and geonchilgyebok-jeong. The computed tomography (CT) findings showed that following combination treatment, the size of the tumor was markedly decreased without serious adverse events. Moreover, the Eastern Cooperative Oncology Group (ECOG) performance status was improved and cancer-related pain was decreased. These results suggest that a combination of Korean herbal medicines and gefitinib may be an effective therapeutic option for patients with advanced NSCLC and bone metastasis. Further studies are needed to examine the mechanism and the clinical efficacy of Korean herbal medicines against NSCLC. Lung cancer has a high mortality rate and is often diagnosed at the metastatic stage. Gefitinib is a targeted molecular therapeutic drug used to treat patients with non-small-cell lung cancer (NSCLC). Korean herbal medicines may also have therapeutic efficacy against lung cancer, reduce the side effects associated with chemotherapy, and improve patient quality of life (QOL). This case report describes the effects of a Korean herbal medicine regimen combined with gefitinib in a patient with NSCLC and bone metastasis. The Korean herbal medicine regimen included woohwanggeosa-dan, hwanggibujeong-dan and geonchilgyebok-jeong. The computed tomography (CT) findings showed that following combination treatment, the size of the tumor was markedly decreased without serious adverse events. Moreover, the Eastern Cooperative Oncology Group (ECOG) performance status was improved and cancer-related pain was decreased. These results suggest that a combination of Korean herbal medicines and gefitinib may be an effective therapeutic option for patients with advanced NSCLC and bone metastasis. Further studies are needed to examine the mechanism and the clinical efficacy of Korean herbal medicines against NSCLC.

ACE Reduces Metabolic Abnormalities in a High-Fat Diet Mouse Model.

The medicinal plants Artemisia iwayomogi (A. iwayomogi) and Curcuma longa (C. longa) radix have been used to treat metabolic abnormalities in traditional Korean medicine and traditional Chinese medicine (TKM and TCM). In this study we evaluated the effect of the water extract of a mixture of A. iwayomogi and C. longa (ACE) on high-fat diet-induced metabolic syndrome in a mouse model. Four groups of C57BL/6N male mice (except for the naive group) were fed a high-fat diet freely for 10 weeks. Among these, three groups (except the control group) were administered a high-fat diet supplemented with ACE (100 or 200 mg/kg) or curcumin (50 mg/kg). Body weight, accumulation of adipose tissues in abdomen and size of adipocytes, serum lipid profiles, hepatic steatosis, and oxidative stress markers were analyzed. ACE significantly reduced the body and peritoneal adipose tissue weights, serum lipid profiles (total cholesterol and triglycerides), glucose levels, hepatic lipid accumulation, and oxidative stress markers. ACE normalized lipid synthesis-associated gene expressions (peroxisome proliferator-activated receptor gamma, PPARγ; fatty acid synthase, FAS; sterol regulatory element-binding transcription factor-1c, SREBP-1c; and peroxisome proliferator-activated receptor alpha, PPARα). The results from this study suggest that ACE has the pharmaceutical potential reducing the metabolic abnormalities in an animal model.

GABAergic excitation of vasopressin neurons: possible mechanism underlying sodium-dependent hypertension.

RATIONALE: Increased arginine-vasopressin (AVP) secretion is a key physiological response to hyperosmotic stress and may be part of the mechanism by which high-salt diets induce or exacerbate hypertension. OBJECTIVE: Using deoxycorticosterone acetate-salt hypertension model rats, we sought to test the hypothesis that changes in GABA(A) receptor-mediated inhibition in AVP-secreting magnocellular neurons contribute to the generation of Na(+)-dependent hypertension. METHODS AND RESULTS: In vitro gramicidin-perforated recordings in the paraventricular and supraoptic nuclei revealed that the GABAergic inhibition in AVP-secreting neurons was converted into excitation in this model, because of the depolarization of GABA equilibrium potential. Meanwhile, in vivo extracellular recordings in the supraoptic nuclei showed that the GABAergic baroreflexive inhibition of magnocellular neurons was transformed to excitation, so that baroreceptor activation may increase AVP release. The depolarizing GABA equilibrium potential shift in AVP-secreting neurons occurred progressively over weeks of deoxycorticosterone acetate-salt treatment along with gradual increases in plasma AVP and blood pressure. Furthermore, the shift was associated with changes in chloride transporter expression and partially reversed by bumetanide (Na(+)-K(+)-2Cl(-) cotransporter inhibitor). Intracerebroventricular bumetanide administration during deoxycorticosterone acetate-salt treatment hindered the development of hypertension and rise in plasma AVP level. Muscimol (GABA(A) agonist) microinjection into the supraoptic nuclei in hypertensive rats increased blood pressure, which was prevented by previous intravenous V1a AVP antagonist injection. CONCLUSIONS: We conclude that the inhibitory-to-excitatory switch of GABAA receptor-mediated transmission in AVP neurons contributes to the generation of Na(+)-dependent hypertension by increasing AVP release. We speculate that normalizing the GABA equilibrium potential may have some utility in treating Na(+)-dependent hypertension.

Chronic hyperosmotic stress converts GABAergic inhibition into excitation in vasopressin and oxytocin neurons in the rat.

In mammals, the increased secretion of arginine-vasopressin (AVP) (antidiuretic hormone) and oxytocin (natriuretic hormone) is a key physiological response to hyperosmotic stress. In this study, we examined whether chronic hyperosmotic stress weakens GABA(A) receptor-mediated synaptic inhibition in rat hypothalamic magnocellular neurosecretory cells (MNCs) secreting these hormones. Gramicidin-perforated recordings of MNCs in acute hypothalamic slices prepared from control rats and ones subjected to the chronic hyperosmotic stress revealed that this challenge not only attenuated the GABAergic inhibition but actually converted it into excitation. The hyperosmotic stress caused a profound depolarizing shift in the reversal potential of GABAergic response (E(GABA)) in MNCs. This E(GABA) shift was associated with increased expression of Na(+)-K(+)-2Cl(-) cotransporter 1 (NKCC1) in MNCs and was blocked by the NKCC inhibitor bumetanide as well as by decreasing NKCC activity through a reduction of extracellular sodium. Blocking central oxytocin receptors during the hyperosmotic stress prevented the switch to GABAergic excitation. Finally, intravenous injection of the GABA(A) receptor antagonist bicuculline lowered the plasma levels of AVP and oxytocin in rats under the chronic hyperosmotic stress. We conclude that the GABAergic responses of MNCs switch between inhibition and excitation in response to physiological needs through the regulation of transmembrane Cl(-) gradients.

Shengmai-san-mediated enhancement of regenerative responses of spinal cord axons after injury in rats.

Shengmai-san (SMS) is a traditional Chinese medicine used to treat diverse symptoms including cardiovascular and neurological disorders. Here we investigated the effects of SMS on regenerative responses of spinal cord axons in rats that were given contusion injury at the lower thoracic level. The injury cavity was confined to a restricted area by SMS treatment, and the signals of glial scar protein chondroitin sulphate proteoglycan (CSPG) and inflammatory cell marker protein CD11beta were heavily observed within the injury cavity in SMS-treated animals. Anterograde tracing of DiI-labeled corticospinal tract (CST) axons revealed increases in collateral arborization around and within the injury cavity and caudal elongation by SMS treatment. Furthermore, SMS treatment facilitated neurite elongation of dorsal root ganglion (DRG) sensory neurons that were co-cultured with non-neuronal cells prepared from injured spinal cord. Phospho-Erk1/2 was strongly induced in both spinal cord and motor cortical areas after spinal cord injury (SCI), and it was further unregulated in the motor cortex by SMS treatment. In contrast, upregulation of cell division cycle 2 (Cdc2) production by SMS treatment was limited to a local, SCI area. These data suggest that SMS may play an active role in regenerative responses and facilitate axonal regrowth after SCI.

Polyamine biosynthesis regulated by StARD expression plays an important role in potato wound periderm formation.

An acireductone dioxygenase (ARD) gene of potatoes was isolated from the expressed sequence tags (ESTs) of potato post-suberization cDNA libraries. The highest expression levels of the StARD gene and the protein appeared 36 h after suberization. An approximate 9-fold increase in ARD activity was detected at 36 h after wounding. Real-time reverse transcription-PCR (RT-PCR) analysis and immunolocalization studies revealed that StARD transcripts increase at the wound surface of potato tubers. The polyamine (PA) contents increased significantly after wounding at the wound surface. The increased PA content and ARD activity may play an important role in wound periderm formation.

Development of patatin knockdown potato tubers using RNA interference (RNAi) technology, for the production of human-therapeutic glycoproteins.

BACKGROUND: Patatins encoded by a multi-gene family are one of the major storage glycoproteins in potato tubers. Potato tubers have recently emerged as bioreactors for the production of human therapeutic glycoproteins (vaccines). Increasing the yield of recombinant proteins, targeting the produced proteins to specific cellular compartments, and diminishing expensive protein purification steps are important research goals in plant biotechnology. In the present study, potato patatins were eliminated almost completely via RNA interference (RNAi) technology to develop potato tubers as a more efficient protein expression system. The gene silencing effect of patatins in the transgenic potato plants was examined at individual isoform levels. RESULTS: Based upon the sequence similarity within the multi-gene family of patatins, a highly conserved target sequence (635 nts) of patatin gene pat3-k1 [GenBank accession no. DQ114421] in potato plants (Solanum tuberosum L.) was amplified for the construction of a patatin-specific hairpin RNAi (hpRNAi) vector. The CaMV 35S promoter-driven patatin hpRNAi vector was transformed into the potato cultivar Desiree by Agrobacterium-mediated transformation. Ten transgenic potato lines bearing patatin hpRNA were generated. The effects of RNA interference were characterized at both the protein and mRNA levels using 1D and 2D SDS/PAGE and quantitative real-time RT-PCR analysis. Dependent upon the patatin hpRNAi line, patatins decreased by approximately 99% at both the protein and mRNA levels. However, the phenotype (e.g. the number and size of potato tuber, average tuber weight, growth pattern, etc.) of hpRNAi lines was not distinguishable from wild-type potato plants under both in vitro and ex vitro growth conditions. During glycoprotein purification, patatin-knockdown potato tubers allowed rapid purification of other potato glycoproteins with less contamination of patatins. CONCLUSION: Patatin-specific hpRNAi effectively suppressed the expression of a majority of patatin variants in potato tubers via the specific degradation of individual mRNAs of the patatin multi-gene family. More importantly, patatin-knockdown potato tubers appear to be an ideal host for the production of human therapeutic glycoproteins, because they eventually allow fast, easy purification of recombinant proteins, with less contamination from potato glycoprotein patatins.

Elevated H(2)O (2) production via overexpression of a chloroplastic Cu/ZnSOD gene of lily (Lilium oriental hybrid 'Marco Polo') triggers ethylene synthesis in transgenic potato.

Transgenic potato plants (SS2 and SS4) that overexpressed a chloroplastic copper/zinc superoxide dismutase lily gene were utilized as an H(2)O(2)-inducible system in order to study the role of H(2)O(2) as a signaling molecule in the biosynthesis of ethylene. SS2 and SS4 plants grown in vitro under sealed microenvironment (SME) conditions displayed anomalous phenotypes including reduction of stem elongation, radial stem growth, and promotion of root hair formation in the generated root, which were similar to ethylene-induced responses. In addition, SS4 plants showed severe vitrification in developing leaves and elevated ethylene production under SME conditions. After the ethylene action inhibitor AgNO(3), 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) inhibitor CoCl(2), and ACC synthase inhibitor L -aminoethoxyvinylglycine were added to the growth media, the anomalous phenotypes in SS4 plants reverted to their normal phenotype with a concurrent decrease in ethylene production. Northern blot analysis showed that ACO transcripts in SS4 plants were constantly at high levels under normal and SME conditions, indicating that a high level of H(2)O(2) in SS4 plants up-regulates ACO transcripts. Moreover, the direct treatment of H(2)O(2) in potato plants confirmed the elevated expression of the ACO gene. Taken together, these data suggest that the high concentration of H(2)O(2) in transgenic potato plants stimulates ethylene biosynthesis by activating ACO gene expression.