RESUMO
BACKGROUND AND AIMS: Data on the safety and effectiveness of tenofovir alafenamide (TAF) plus peginterferon-alpha (Peg-IFN-α) in children with chronic hepatitis B (CHB) are lacking. The current study aimed to present the characteristics of four pediatric CHB patients who obtained a functional cure by using TAF and Peg-IFN-α. METHODS: In this case series study initiated in May 2019, ten children who had no clinical symptoms or signs received response-guided (HBV DNA undetectable, hepatitis B e antigen [HBeAg] loss or seroconversion, and hepatitis B surface antigen [HBsAg] loss or seroconversion) and functional cure-targeted (HBsAg loss or seroconversion) TAF (25 mg/d, orally) plus Peg-IFN-α-2b (180 µg/1.73m2, subcutaneously, once weekly) in combination (9/10) or sequential (1/10) therapy. The safety and effectiveness of these treatments were monitored. RESULTS: As of April 2024, four out of ten children obtained a functional cure after a mean of 31.5 months of treatment, and the other six children are still undergoing treatment. These four cured children, aged 2, 4, 8, and 6 years, were all HBeAg-positive and had alanine aminotransferase levels of 80, 47, 114, and 40 U/L; HBV DNA levels of 71200000, 93000000, 8220, and 96700000 IU/mL; and HBsAg levels of 39442.8, 15431.2, 22, and 33013.1 IU/mL, respectively. During treatment, all the children (10/10) experienced mild or moderate adverse events, including flu-like symptoms, anorexia, fatigue, and cytopenia. Notably, growth retardation (8/10) was the most significant adverse event; and it occurred in three cured children (3/4) treated with combination therapy and was present to a low degree in the other cured child (1/4) treated with sequential therapy. Fortunately, all three cured children recovered to or exceeded the normal growth levels at 9 months posttreatment. CONCLUSIONS: TAF plus Peg-IFN-α-2b therapy is potentially safe and effective for pediatric CHB patients, which may provide important insights for future clinical practice and study designs targeting functional cures for children with CHB.
Assuntos
Antivirais , Quimioterapia Combinada , Hepatite B Crônica , Interferon-alfa , Polietilenoglicóis , Proteínas Recombinantes , Tenofovir , Humanos , Tenofovir/uso terapêutico , Tenofovir/administração & dosagem , Tenofovir/análogos & derivados , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Masculino , Feminino , Antivirais/uso terapêutico , Antivirais/efeitos adversos , Antivirais/administração & dosagem , Criança , Proteínas Recombinantes/uso terapêutico , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Polietilenoglicóis/uso terapêutico , Polietilenoglicóis/efeitos adversos , Polietilenoglicóis/administração & dosagem , Interferon-alfa/uso terapêutico , Interferon-alfa/administração & dosagem , Interferon-alfa/efeitos adversos , Pré-Escolar , Resultado do Tratamento , Interferon alfa-2/uso terapêutico , Interferon alfa-2/administração & dosagem , Antígenos de Superfície da Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/genética , Vírus da Hepatite B/efeitos dos fármacos , DNA Viral/sangue , Alanina/uso terapêutico , Alanina/análogos & derivadosRESUMO
BACKGROUND & AIMS: Data on long-term tenofovir alafenamide (TAF) therapy for pregnant women with active chronic hepatitis B (CHB) (immune clearance and reactivation phases, currently and previously diagnosed) and their infants are lacking. METHODS: Pregnant women with active CHB treated with TAF and tenofovir disoproxil fumarate (TDF) were enrolled in this multicenter prospective study, and infants received immunoprophylaxis. The primary outcomes were rates of adverse (safety) events in pregnant women and defects in infants and fetuses. The secondary outcomes were virologic responses in pregnant women, infants' safety, hepatitis B surface antigen (HBsAg) status, and growth conditions. RESULTS: One hundred three and 104 pregnant women were enrolled and 102 and 104 infants were born in the TAF and TDF groups, respectively. In the TAF group, the mean age, gestational age, alanine aminotransferase level, and viral loads at treatment initiation were 29.3 years, 1.3 weeks, 122.2 U/L, and 5.1 log10 IU/mL, respectively. TAF was well-tolerated, and the most common adverse event was nausea (29.1%) during a mean of 2 years of treatment. Notably, 1 (1.0%) TAF-treated pregnant woman underwent induced abortion due to noncausal fetal cleft lip and palate. No infants in either group had birth defects. In the TAF group, the hepatitis B e antigen seroconversion rate was 20.7% at postpartum month 6, infants had normal growth parameters, and no infants were positive for HBsAg at 7 months. The TDF group had comparable safety and effectiveness profiles. CONCLUSIONS: TAF administered throughout or beginning in early pregnancy is generally safe and effective for pregnant women with active CHB and their infants.
Assuntos
Fenda Labial , Fissura Palatina , Hepatite B Crônica , Hepatite B , Feminino , Humanos , Gravidez , Recém-Nascido , Adulto , Antígenos de Superfície da Hepatite B , Hepatite B Crônica/tratamento farmacológico , Gestantes , Estudos Prospectivos , Fenda Labial/induzido quimicamente , Fenda Labial/tratamento farmacológico , Fissura Palatina/induzido quimicamente , Fissura Palatina/tratamento farmacológico , Tenofovir/efeitos adversos , Adenina/efeitos adversos , China , Antivirais/efeitos adversos , Hepatite B/diagnósticoRESUMO
BACKGROUND: Few safety and effectiveness results have been published regarding the administration of tenofovir alafenamide fumarate (TAF) during pregnancy for the prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV). METHODS: In this multicenter prospective observational study, pregnant women with HBV DNA levels higher than 200â 000 IU/mL who received TAF or tenofovir disoproxil fumarate (TDF) from gestational weeks 24-35 to delivery were 1:1 enrolled and followed until postpartum month 6. Infants received immunoprophylaxis. The primary endpoint was the safety of mothers and infants. The secondary endpoint was the hepatitis B surface antigen (HBsAg)-positive rate at 7 months for infants. RESULTS: In total, 116 and 116 mothers were enrolled, and 117 and 116 infants were born, in the TAF and TDF groups, respectively. TAF was well tolerated during a mean treatment duration of 11.0 weeks. The most common maternal adverse event was nausea (19.0%). One (0.9%), 3 (2.6%), and 9 (7.8%) mothers had abnormal alanine aminotransferase levels at delivery and at postpartum months 3 and 6, respectively. The TDF group had safety profiles that were comparable to those of the TAF group. No infants had birth defects in either group. The infants' physical and neurological development at birth and at 7 months in the TAF group were comparable with those in the TDF group. The HBsAg positive rate was 0% at 7 months in all 233 infants. CONCLUSIONS: Antiviral prophylaxis with TAF was determined to be generally safe for both mothers and infants and reduced the MTCT rate to 0%.
Assuntos
Hepatite B Crônica , Hepatite B , Complicações Infecciosas na Gravidez , Alanina , Antivirais/efeitos adversos , Feminino , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Hepatite B Crônica/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos Prospectivos , Tenofovir/análogos & derivados , Carga ViralRESUMO
Interleukin (IL)-17A is pro-inflammatory cytokine which has been identified as a noninvasive marker of the pathogenesis of non-alcoholic steatohepatitis (NASH). However, the underlying role of IL-17A in NASH progression remains unclear. This study was designed to investigate the biological function and molecular mechanism of IL-17A in the induction of NASH. The results showed that IL-17A was highly expressed in high-fat diet (HFD)-induced NASH mouse model. Intravenous injection of IL-17A exacerbated steatohepatitis process via promoting hepatocyte apoptosis. Furthermore, IL-17A-induced apoptosis was mediated by ERK1/2/p65 signaling pathway. In conclusion, we demonstrated that IL-17A-mediated ERK1/2/p65 signaling pathway was a promising target for the treatment of NASH. © 2018 IUBMB Life, 71(3):302-309, 2019.
Assuntos
Apoptose/genética , Interleucina-17/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Hepatopatia Gordurosa não Alcoólica/genética , Fator de Transcrição RelA/genética , Animais , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Progressão da Doença , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Hepatócitos/patologia , Interleucina-17/administração & dosagem , Interleucina-17/sangue , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Transdução de Sinais , Fator de Transcrição RelA/metabolismoRESUMO
BACKGROUND: The medicinal plant, Catharanthus roseus (C. roseus), accumulates a wide range of terpenoid indole alkaloids (TIAs). Ethylene (ET) and methyl-jasmonate (MeJA) were previously reported as effective elicitors for the production of various valuable secondary metabolites of C. roseus, while a few ET or MeJA induced transcriptomic research is yet reported on this species. In this study, the de-novo transcriptome assembly of C. roseus is performed by using the next-generation sequencing technology. RESULTS: The result shows that phenolic biosynthesis genes respond specifically to ET in leaves, monoterpenoid biosynthesis genes respond specifically to MeJA in roots. By screening the database, 23 ATP-binding cassette (ABC) transporter partial sequences are identified in C. roseus. On this basis, more than 80 key genes that encode key enzymes (namely TIA pathway, transcriptional factor (TF) and candidate ABC transporter) of alkaloid synthesis in TIA biosynthetic pathways are chosen to explore the integrative responses to ET and MeJA at the transcriptional level. Our data indicated that TIA accumulation is strictly regulated by the TF ethylene responsive factor (ERF) and bHLH iridoid synthesis 1 (BIS1). The heatmap, combined with principal component analysis (PCA) of C. roseus, shows that ERF co-expression with ABC2 and ABC8 specific expression in roots affect the root-specific accumulation of vinblastine in C. roseus. On the contrast, BIS1 activities follow a similar pattern of ABC3 and CrTPT2 specific expression in leaves, which affects the leaf-specific accumulation of vindoline in C. roseus. CONCLUSIONS: Results presented above illustrate that ethylene has a stronger effect than MeJA on TIA induction at both transcriptional and metabolite level. Furthermore, meta-analysis reveals that ERF and BIS1 form a positive feedback loop connecting two ABC transporters respectively and are actively involved in TIAs responding to ET and MeJA in C. roseus.
Assuntos
Acetatos/farmacologia , Catharanthus/genética , Ciclopentanos/farmacologia , Etilenos/farmacologia , Oxilipinas/farmacologia , Alcaloides de Triptamina e Secologanina/metabolismo , Transcriptoma/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Catharanthus/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Análise de Componente Principal , Alcaloides de Triptamina e Secologanina/químicaRESUMO
This study aims to evaluate the potential involvement and regulatory mechanism of miR-19a in hepatocytes autophagy of acute liver failure (ALF). The in vitro hepatocytes injury model of primary hepatocyte and hepatocytes line HL-7702 was established by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) co-treatment. Relative expression level of miR-19a and NBR2 was determined by qRT-PCR. Protein expression of AMPK/PPARα and autophagy-related gene was determined by Western blot. In hepatic tissue of 20 ALF patients and D-GalN/LPS-stimulated hepatocytes, miR-19a was upregulated and NBR2 was downregulated. D-GalN/LPS stimulation caused the inactivation of AMPK/PPARα signaling and the decrease of autophagy-related LC3-II/LC3-I ratio and beclin-1 expression in hepatocytes. The expression of both AMPK/PPARα and NBR2 were negatively controlled by miR-19a overexpression or knockdown. Moreover, both NBR2 and PPARα were targeted regulated by miR-19a according to luciferase reporter assay. In D-GalN/LPS-stimulated hepatocytes, AMPK activation promoted PPARα expression. AMPK inactivation inhibited the pro-autophagy effect of miR-19a and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. PPARα activation abrogated the anti-autophagy effect of miR-19a mimic and caused the increase of LC3-II/LC3-I ratio and beclin-1 expression. NBR2 knockdown reversed the anti-autophagy impact of miR-19a inhibitor and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. In summary, our data suggested that miR-19a negatively controlled the autophagy of hepatocytes attenuated in D-GalN/LPS-stimulated hepatocytes via regulating NBR2 and AMPK/PPARα signaling. J. Cell. Biochem. 119: 358-365, 2018. © 2017 Wiley Periodicals, Inc.
Assuntos
Autofagia/efeitos dos fármacos , Galactosamina/toxicidade , Hepatócitos/metabolismo , Lipopolissacarídeos/toxicidade , MicroRNAs/metabolismo , PPAR alfa/metabolismo , Proteínas Quinases/metabolismo , RNA Longo não Codificante/metabolismo , Transdução de Sinais/efeitos dos fármacos , Quinases Proteína-Quinases Ativadas por AMP , Linhagem Celular , Hepatócitos/patologia , Humanos , Falência Hepática Aguda/metabolismo , Falência Hepática Aguda/patologiaRESUMO
BACKGROUND: Acute-on-chronic liver failure (ACLF) is increasingly recognized as a distinct clinical entity and is associated with a high short-term mortality. The most common cause of ACLF is chronic hepatitis B worldwide. Currently, there is no standardized approach for the management of ACLF and the efficacy and safety of therapeutic modalities are uncertain. DATA SOURCES: PubMed and Web of Science were searched for English-language articles. The search criteria focused on clinical trials and observational studies on the treatment of patients with HBV-related ACLF. RESULTS: Therapeutic approaches for ACLF in patients with chronic hepatitis B included nucleos(t)ide analogues, artificial liver support systems, immune regulatory therapy, stem cell therapy and liver transplantation. All of these therapeutic approaches have shown the potential to improve liver function and increase patients' survival rate, but most of the studies were not randomized or controlled. CONCLUSION: Substantial challenges for the treatment of HBV-related ACLF remain and further basic research and randomized controlled clinical trials are needed.
Assuntos
Insuficiência Hepática Crônica Agudizada/terapia , Antivirais/uso terapêutico , Hepatite B Crônica/terapia , Imunoterapia/métodos , Transplante de Fígado , Fígado Artificial , Transplante de Células-Tronco , Insuficiência Hepática Crônica Agudizada/diagnóstico , Insuficiência Hepática Crônica Agudizada/mortalidade , Insuficiência Hepática Crônica Agudizada/virologia , Antivirais/efeitos adversos , Terapia Combinada , Hepatite B Crônica/complicações , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/mortalidade , Humanos , Imunoterapia/efeitos adversos , Transplante de Fígado/efeitos adversos , Fígado Artificial/efeitos adversos , Fatores de Risco , Transplante de Células-Tronco/efeitos adversos , Fatores de Tempo , Resultado do TratamentoRESUMO
Introduction: Data on the management of patients aged more than 85 years with chronic hepatitis C virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequential infections are lacking. Methods: The current study described the management of an older couple aged more than 85 years with these above-mentioned two diseases treated with 12 weeks of sofosbuvir/velpatasvir (Epclusa®) and 5 days of nirmatrelvir/ritonavir (Paxlovid®) sequentially. The effectiveness and safety profiles were closely monitored during therapy and till 9 months posttreatment. Results: In late March 2023, the husband with the main complaint of repeated gingival bleeding and asymptomatic wife were 86 and 85 years old, and had HCV RNA levels of 91,800 and 6,630,000 IU/mL, respectively. On the fourth day of sofosbuvir/velpatasvir treatment, the husband had a moderate headache, and the wife had severe headache and moderate fever and dizziness. We then found that their SARS-CoV-2 test results were positive. After careful consideration, the expert panel decided to treat the couple with oral nirmatrelvir/ritonavir (300 mg/100 mg, twice daily) beginning on the fifth day of sofosbuvir/velpatasvir treatment for 5 days. During the 5 days of nirmatrelvir/ritonavir treatment, the patient's symptoms and signs gradually improved, and the patient was negative for SARS-CoV-2 RNA on the fifth day of nirmatrelvir/ritonavir therapy. Meanwhile, the husband's HCV RNA was not detectable after one week of sofosbuvir/velpatasvir treatment till posttreatment month 9, and his ALT level was normal beginning at week 1 of sofosbuvir/velpatasvir treatment. Moreover, the wife's HCV RNA was not detectable after week 4 of sofosbuvir/velpatasvir treatment till posttreatment month 9. Notably, no other symptoms or signs occurred during the treatment or follow-up period, and other serum biochemical parameters remained stable until 9 months after the discontinuation of sofosbuvir/velpatasvir treatment. Conclusion: The older couple aged more than 85 years with chronic HCV and SARS-CoV-2 sequential infection were safely cured by the sofosbuvir/velpatasvir and nirmatrelvir/ritonavir sequential treatment. Discussion: This study suggested that old age should not be a barrier to HCV/SARS-CoV-2 treatment. Given that the proportion of older HCV-infected patients is increasing, clinical trials of direct-acting antiviral agents should include older HCV-infected individuals.
RESUMO
After acute myocardial infarction (AMI), intercellular communication is crucial for maintaining cardiac homeostasis and patient survival. Exosomes secreted by cardiomyocytes serve as carriers for transporting microRNA(miRNAs), participating in intercellular signaling and the regulation of cardiac function. This study aims to investigate the role of exosomal microRNA-30a(miR-30a) during AMI and its underlying mechanisms. AMI was induced by permanent ligation of the left anterior descending (LAD) artery in C57BL/6 mice. The expression of miR-30a in mice was respectively enhanced and inhibited by administering agomiR-30a and antagomiR-30a. Using HL-1 cardiomyocytes and RAW264.7 macrophages for in vitro experiments, HL-1 cardiomyocytes were cultured under hypoxic conditions to induce ischemic injury. Following isolation and injection of exosomals, a variety of validation methods were utilized to assess the expression of miR-30a, and investigate the effects of enriched exosomal miR-30a on the state of cardiomyocytes. After AMI, the level of exosomal miR-30a in the serum of mice significantly increased and was highly enriched in cardiac tissue. Cardiomyocytes treated with agomiR-30a and miR-30a-enriched exosomes exhibited inhibition of cell autophagy, increased cell apoptosis, mice showed an larger myocardial infarct area and poorer cardiac function. Exosomes released from hypoxic cardiomyocytes transferred miR-30a to cardiac resident macrophages, promoting the polarization into pro-inflammatory M1 macrophages. In conclusion, murine exosomal miR-30a exacerbates cardiac dysfunction post-AMI by disrupting the autophagy-apoptosis balance in cardiomyocytes and polarizing cardiac resident macrophages into pro-inflammatory M1 macrophages. Modulating the expression of miR-30a may reduce cardiac damage following AMI, and targeting exosomal miR-30a could be a potential therapeutic approach for AMI.
RESUMO
BACKGROUND: None of the current guidelines recommend antiviral therapy for inactive hepatitis B virus (HBV) carriers (IHCs). METHODS: In this real-world, multicenter, nonrandomized study, 32 participants meeting the inclusion criteria were enrolled 1:1 for treatment with peginterferon α-2b or monitoring without treatment based on participant preference. The expected treatment duration was 48 weeks. The primary end point was hepatitis B surface antigen (HBsAg) loss. The HBV vaccine could be injected after HBsAg loss. RESULTS: All patients had HBsAg levels of <20 IU/mL. The mean baseline HBsAg levels were 6.6 IU/mL and 5.8 IU/mL in the treated and untreated groups, respectively. Fifteen (93.8%) participants achieved HBsAg loss, 5 obtained HBsAg seroconversion after undergoing a mean of 19.7 weeks of therapy in the treated group, and no one in the follow-up group achieved HBsAg loss during a mean follow-up time of 12.6 months (P < .0001). Generally, the therapy was well tolerated. Nine of 11 individuals who exhibited HBsAg loss benefited from receiving the HBV vaccine. CONCLUSIONS: This study provides justification for further studies of short-course peginterferon α-2b for the functional cure of IHCs with low HBsAg levels. Additionally, HBV vaccine injection is beneficial after interferon-induced HBsAg loss.
RESUMO
AIM: To evaluate the efficacy and safety of a modified technique [trocar opening (TO)] for silicone oil removal (SOR) in combination with phacoemulsification and intraocular lens (IOL) implantation. METHODS: A total of 60 eyes of 60 patients with cataract and silicone oil-filled eyes were enrolled in this study. The patients were divided into two groups: the patients in the control group underwent 23-gauge pars plana active SOR surgery with phacoemulsiï¬cation and IOL implantation, while the patients in the TO group underwent TO methods during surgery. Best corrected visual acuity (BCVA), surgery time, intraocular pressure, and operative complications were observed 6mo after surgery. RESULTS: There was no significant difference between the two groups in terms of age, gender, preoperative, intraocular pressure, or time of silicone oil stay. Prior to surgery, the mean BCVA for the control and TO groups was 1.34±0.44 and 1.36±0.42. At 6mo following surgery, the mean BCVA improved to 0.74±0.36 and 0.77±0.32, respectively (P<0.001). There was no significant difference between the two groups. The mean SOR time was 6.9±2.3min and 4.8±1.2min in the control and TO groups (P=0.008). The total operation time was 28.2±8.5min and 24.6±6.4min, respectively (P=0.035). Posterior capsule rupture occurred in four eyes of control and none of TO group (P<0.01). Late recurrent retinal detachment occurred in one eye in the control group (2mo after surgery) and in one eye in the TO group (4mo after surgery). CONCLUSION: TO is a simple, effective, time-saving, and safe method for SOR combined with phacoemulsification and IOL implantation.
RESUMO
The existing question whether ethylene is involved in the modulation of salt-induced cell death to mediate plant salt tolerance is important for understanding the salt tolerance mechanisms. Here, we employed Arabidopsis plants to study the possible role of ethylene in salt-induced growth inhibition and programmed cell death (PCD) profiles. The root length, DNA ladder and cell death indicated by Evan's blue detection were measured by compared to the control or salt-stressed seedlings. Secondly, the protoplasts isolated from plant leaves and dyed with Annexin V-FITC were subjected to flow cytometric (FCM) assay. Our results showed that ethylene works effectively in seedling protoplasts, antagonizing salt-included root retardation and restraining cell death both in seedlings or protoplasts. Due to salinity, the entire or partial insensitivity of ethylene signaling resulted in an elevated levels of cell death in ein2-5 and ein3-1 plants and the event were amended in ctr1-1 plants after salt treatment. The subsequent experiment with exogenous ACC further corroborated that ethylene could modulate salt-induced PCD process actively. Plant Bcl-2-associated athanogene (BAG) family genes are recently identified to play an extensive role in plant PCD processes ranging from growth, development to stress responses and even cell death. Our result showed that salinity alone significantly suppressed the transcripts of BAG6, BAG7 and addition of ACC in the saline solution could obviously re-activate BAG6 and BAG7 expressions, which might play a key role to inhibit the salt-induced cell death. In summary, our research implies that ethylene and salinity antagonistically control BAG family-, ethylene-, and senescence-related genes to alleviate the salt-induced cell death.
RESUMO
We selected different concentrations of ethephon, to stress C. roseus. We used qRT-PCR and HPLC followed by PCA to obtain comprehensive profiling of the vinblastine biosynthesis in response to ethephon. Based on our findings, the results showed that the high concentration of ethephon had a positive effect at both transcriptional and metabolite level. Meanwhile, there was a remarkable decrease of hydrogen peroxide content and a promoted peroxidase activity in leaves. The loading plot combination with correlation analysis suggested that CrPrx1 could be regarded as a positive regulator and interacts with ethylene response factor (ERF) to play a key role in vinblastine content and peroxidase (POD) activity. This study provides the foundation for a better understanding of the regulation and accumulation of vinblastine in response to ethephon.
Assuntos
Catharanthus/genética , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Vimblastina/metabolismo , Catharanthus/metabolismo , Etilenos/análise , Compostos Organofosforados/farmacologia , Oxirredução , Vimblastina/análiseRESUMO
Research on transcriptional regulation of terpenoid indole alkaloid (TIA) biosynthesis of the medicinal plant, Catharanthus roseus, has largely been focused on gene function and not clustering analysis of multiple genes at the transcript level. Here, more than ten key genes encoding key enzyme of alkaloid synthesis in TIA biosynthetic pathways were chosen to investigate the integrative responses to exogenous elicitor ethylene and copper (Cu) at both transcriptional and metabolic levels. The ethylene-induced gene transcripts in leaves and roots, respectively, were subjected to principal component analysis (PCA) and the results showed the overall expression of TIA pathway genes indicated as the Q value followed a standard normal distribution after ethylene treatments. Peak gene expression was at 15-30 µM of ethephon, and the pre-mature leaf had a higher Q value than the immature or mature leaf and root. Treatment with elicitor Cu found that Cu up-regulated overall TIA gene expression more in roots than in leaves. The combined effects of Cu and ethephon on TIA gene expression were stronger than their separate effects. It has been documented that TIA gene expression is tightly regulated by the transcriptional factor (TF) ethylene responsive factor (ERF) and mitogen-activated protein kinase (MAPK) cascade. The loading plot combination with correlation analysis for the genes of C. roseus showed that expression of the MPK gene correlated with strictosidine synthase (STR) and strictosidine b-D-glucosidase(SGD). In addition, ERF expression correlated with expression of secologanin synthase (SLS) and tryptophan decarboxylase (TDC), specifically in roots, whereas MPK and myelocytomatosis oncogene (MYC) correlated with STR and SGD genes. In conclusion, the ERF regulates the upstream pathway genes in response to heavy metal Cu mainly in C. roseus roots, while the MPK mainly participates in regulating the STR gene in response to ethylene in pre-mature leaf. Interestingly, the change in TIA accumulation does not correlate with expression of the associated genes. Our previous research found significant accumulation of vinblastine in response to high concentration of ethylene and Cu suggesting the involvement of posttranscriptional and posttranslational mechanisms in a spatial and temporal manner. In this study, meta-analysis reveals ERF and MPK form a positive feedback loop connecting two pathways actively involved in response of TIA pathway genes to ethylene and copper in C. roseus.