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1.
Diabetes Metab Syndr Obes ; 17: 435-452, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38299195

RESUMO

Background: Electroacupuncture (EA) is used to treat inflammatory bowel disease (IBD). Nevertheless, the precise mechanisms by which this approach safeguards against obesity-induced intestinal barrier damage has not been fully understood. Objective: This study aimed to assess whether EA could ameliorate intestinal barrier damage that had been reversed in a mouse model of obesity induced by a high-fat diet (HFD) and whether this repair is correlated with ferroptosis and gut microbiota enhancement. Methods: To assess the potential of EA to prevent obesity and restore the intestinal barrier, we divided in C57BL/6J mice into two groups; one was fed with HFD and another one with a normal diet. Samples of stool, blood, fat, and intestinal epithelium were then evaluated, along with body weight. Results: Following EA, we observed a significant reduction in body weight, fat accumulation, and serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels; an increase was seen in high-density lipoprotein cholesterol (HDL-C) levels. EA also activated the Nrf2 signaling pathway; upregulated the expression of GPX4, FTH1, and SLC7A11; and downregulated the expression of TFR1. In addition, the administration of EA resulted in a notable modification of the gut microbiota composition, characterized by a decrease in the Firmicutes to Bacteroidetes ratio. Conclusion: EA had beneficial effects on weight loss and showed potential ability to repair the intestinal barrier by activating the Nrf2 signaling pathway, inhibiting intestinal inflammation and ferroptosis, and regulating the intestinal microbiota to treat IBD caused by HFD-induced obesity.

2.
Brain Sci ; 13(4)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37190506

RESUMO

BACKGROUND: Multiple studies have suggested that paralgesia (hyperalgesia and cutaneous allodynia) in migraine reflects the activation and sensitisation of the trigeminovascular system (TGVS). In particular, it reflects the second-order and higher nerve centre sensitisation, which is caused and maintained by neuroinflammation. Microglia activation leads to the release of proinflammatory cytokines involved in inflammatory responses. Accumulating evidence indicates that electroacupuncture (EA) is effective in ameliorating paralgesia, but the underlying mechanisms of EA in migraine attacks caused by microglia and microglia-mediated inflammatory responses are still unclear. The purpose of this study was to explore whether EA could ameliorate the dysregulation of pain sensation by suppressing microglial activation and the resulting neuroinflammatory response, and to evaluate whether this response was regulated by Toll-like receptor 4 (TLR4)/nuclear factor-kappa B(NF-κB) in the trigeminal nucleus caudalis (TNC) in a rat model of migraine. METHODS: Repeated Inflammatory Soup (IS) was infused into the dura for seven sessions to establish a recurrent migraine-like rat model, and EA treatment was administered at Fengchi (GB20) and Yanglingquan (GB34) after daily IS infusion. Facial mechanical withdrawal thresholds were measured to evaluate the change in pain perception, and plasma samples and the TNC tissues of rats were collected to examine the changes in calcitonin gene-related peptide (CGRP), the Ibal-1-labelled microglial activation, and the resulting inflammatory response, including interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and their regulatory molecules TLR4/NF-κB, via enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (RT-PCR), immunohistochemistry (IHC) and Western blot analysis. RESULTS: Repeated IS injections into the dura induced facial mechanical paralgesia, which is the manifestation of migraine attacks, and increased the expression of CGRP, Ibal-1, microglial mediated inflammatory cytokines (IL-1ß, TNF-α, IL-6), and regulatory molecules TLR4/NF-κB. EA at GB20/34 significantly attenuated repetitive IS-induced pain hypersensitivity. This effect was consistent with decreased levels of CGRP and inflammatory cytokines in the plasma and the TNC via the inhibition of microglia activation, and this response may be regulated by TLR4/NF-κB. CONCLUSIONS: EA ameliorated paralgesia in repetitive IS-induced migraine-like rats, which was mainly mediated by a reduction in microglial activation and microglial-mediated inflammatory responses that could be regulated by TLR4/NF-κB.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 298: 122775, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37150073

RESUMO

The biological microenvironment includes important parameters such as viscosity, polarity, temperature, oxygen content and pH. In particular, abnormal cell viscosity is associated with the development of major diseases. Sulphur dioxide (SO2) serves not only as an essential atmospheric pollutant but also an influential signalling molecule in biological cells, predisposing individuals to increased respiratory disease. In this work, we designed and synthesized a novel fluorescent probe CouCN-V&S with dual response to micro environmental viscosity and SO2. The probe monitored viscosity and SO2 separately through dual emission channels with a difference of 135 nm. The probe responded sensitively to SO2 (<1s) and exhibited satisfactory immunity to interference and pH stability. The probe was successfully applied to imaging cellular, intra-zebrafish viscosity and SO2 changes. Interestingly, we took onion epidermal cells as model and explored the capability of probe CouCN-V&S to image SO2 in plant cells for the first time.


Assuntos
Colorimetria , Cebolas , Humanos , Animais , Colorimetria/métodos , Peixe-Zebra , Viscosidade , Diagnóstico por Imagem , Células HeLa , Corantes Fluorescentes/química , Dióxido de Enxofre
4.
Brain Sci ; 13(3)2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36979246

RESUMO

Depression is a complex clinical disorder associated with poor outcomes. Electroacupuncture (EA) has been demonstrated to have an important role in both clinical and pre-clinical depression investigations. Evidence has suggested that the P2X7 receptor (P2X7R), NLRP3, and IL-1ß play an important role in depressive disorder. Our study is aimed at exploring the role of EA in alleviating depression-like behaviors in rats. We therefore investigated the effects of EA on the prefrontal cortex and liver of rats subjected to chronic unpredictable mild stress (CUMS) through behavior tests, transmission electron microscopy, Nissl staining, HE staining, immunohistochemistry and Western blotting. Five weeks after exposure to CUMS, Sprague-Dawley (SD) rats showed depression-like behavior. Three weeks after treatment with brilliant blue G (BBG) or EA, depressive symptoms were significantly improved. Liver cells and microglia showed regular morphology and orderly arrangement in the BBG and EA groups compared with the CUMS group. Here we show that EA downregulated P2X7R/NLRP3/IL-1ß expression and relieved depression-like behavior. In summary, our findings demonstrated the efficacy of EA in alleviating depression-like behaviors induced by CUMS in rats. This suggests that EA may serve as an adjunctive therapy in clinical practice, and that P2X7R may be a promising target for EA intervention on the liver-brain axis in treatment of depression.

5.
Zhen Ci Yan Jiu ; 47(7): 565-72, 2022 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-35880271

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expressions of tight junction related proteins Claudin-5, ZO-1 in the colon and hippocampus, Toll-like receptor 4/nuclear factor-kappa B/NOD-like receptor protein 3 (TLR4/NF-κB/NLRP3) pathway in the hippocampus of APP/PS1 mice, so as to explore its mechanisms underlying improvement of cognitive impairment. METHODS: Eighteen 5-month-old male APP/PS1 mice were equally randomized into model and EA groups,and nine 5-month-old male C57BL/6 mice were used as the normal control. EA(2 Hz, 1 mA) was applied to "Baihui" (GV20), "Dachangshu" (BL25) and "Zusanli" (ST36) for 15 min, once daily, 5 days a week for 5 weeks. The Morris water maze swimming test was used to evaluate the mice's cognitive impairment. Nissl staining was used to observe the pathological morphology of hippocampus. The expression of amyloid ß-peptide (Aß) in brain tissue was detect by immunohistochemistry; the contents of lipopolysaccharide (LPS) in colon, serum and hippocampus were detected by ELISA; the expression levels of Claudin-5, ZO-1 in colon and hippocampus, and TLR4/NF-κB/NLRP3 pathway related proteins in hippocampus were detected by Western blot. RESULTS: Compared with the normal group, the escape latency of the mice in the model group was prolonged from the 3rd day (P<0.05, P<0.01), the number of crossing the platform and the percentage of target quadrant residence time were significantly decreased (P<0.01), and the contents of LPS in colon, serum and hippocampus were significantly increased (P<0.01), the expression levels of TLR4, NF-κB p65, NLRP3, Caspase-1, interleukin (IL)-1ß and tumor necrosis factor (TNF)-α in hippocampus and Aß in brain tissue were significantly increased (P<0.01), while the expression levels of Claudin-5, ZO-1 in colon and hippocampus were significantly decreased (P<0.01). Compared with the model group, the escape latency of mice in the EA group was shortened from the 4th day (P<0.05, P<0.01), the number of crossing the platform and the percentage of target quadrant residence time were increased (P<0.01, P<0.05), and the contents of LPS in serum and hippocampus were decreased (P<0.05), and the expression levels of TLR4, NF-κB p65, Caspase-1, NLRP3, IL-1ß, TNF-α in hippocampus and Aß in brain tissue were significantly decreased (P<0.05, P<0.01), while the expression levels of Claudin-5, ZO-1 in colon and hippocampus were significantly increased (P<0.05, P<0.01). Outcomes of Nissl staining showed dispersed arrangement of neurons with nuclear pyknosis or hyperchromasia in the hippocampus, and a decreased number of cell layers in the model group, which was relatively milder in the EA group. CONCLUSION: EA may improve the cognitive impairment of APP/PS1 mice by up-regulating the expression of Claudin-5 and ZO-1, reducing the transposition of gut-derived LPS to the central nervous system, inhibiting the over-activation of TLR4/NF-κB/NLRP3 pathway, and alleviating the inflammatory reaction of the central nervous system.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Eletroacupuntura , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides , Animais , Caspases , Claudina-5 , Disfunção Cognitiva/genética , Disfunção Cognitiva/terapia , Hipocampo , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Receptor 4 Toll-Like/genética
6.
Zhen Ci Yan Jiu ; 47(1): 7-14, 2022 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-35128864

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) on physical strength and expression levels of hepatic AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), unc-51 like autophagy activating kinase 1 (ULK1) proteins and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs in aging (senescence accelerated mouse/prone 8, SAMP8)mice, so as to exp lore its mechanism underlying delaying aging by activating AMPK/mTOR/ULK1 signaling pathway. METHODS: Twenty-four male SAMP8 mice were randomly divided into model group, rapamycin (autophagy inducer) group, EA group and EA+autophagy inhibitor (EA+inhibitor) group, with 6 mice in each group, and 6 homologous anti-rapid aging male (SAMR1) mice in the same age were used as the control group. Mice of the rapamycin group received intraperitoneal injection of rapamycin solution (2 mg·kg-1·d-1). EA (2 Hz, 1 mA) was applied to bilateral "Taichong"(LR3)and "Shenshu"(BL23) for 15 min each time. Mice of the EA+inhibitor group received intraperitoneal injection of mTOR inhibitor 3-methyladenine (1.5 mg·kg-1·d-1) before the EA intervention each time. The above-mentioned interventions were conducted 6 times a week for 2 consecutive weeks. Physical conditions of mice were assessed by exhaustive swimming tests. Histopathological changes of the liver were observed by H.E. staining. Western blot was used to detect the expression of AMPK, phosphorylated AMPK (p-AMPK), mTOR, phosphorylated mTOR (p-mTOR), ULK1 and phosphorylated ULK1 (p-ULk1) in the liver tissues. The expression levels of Atg5, Atg7, Atg13, Beclin1 and ULK1 (cellular autophagy-related genes) mRNAs in the liver were detected by quantitative real-time PCR. The immunoactivity (IA) of heme oxygenase 1 (HO-1) in the liver was detected by immunohistochemistry, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) of the liver were measured by hydroxylamine method for assessing the level of oxidative stress. RESULTS: Compared with the control group, the duration of exhaustive swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNA, HO-1 IA and SOD activity were considerably down-regulated (P<0.01), while the expression levels of mTOR and p-mTOR and MDA content were significantly up-regulated (P<0.01) in the model group. In comparison with the model group, the duration of the exhausted swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs, HO-1 IA and SOD activity were significantly up-regulated (P<0.01, P<0.05), whereas the expression levels of mTOR and p-mTOR proteins and MDA content were notably down-regulated (P<0.01, P<0.05) in the rapamycin, EA and EA+inhibitor groups. The improvement of the abovementioned indexes of EA+inhibitor group was not as good as rapamycin and EA groups (P<0.01), suggesting an elimination of the therapeutic effects after administration of 3-methyladenine. No significant differences were found between the rapamycin and EA groups in the abovementioned indexes (P>0.05) except p-mTOR and mTOR which were higher in the EA group (P<0.01). H.E. staining showed ambiguous boundary of the liver lobule, disordered arrangement of hepatocytes with a large amount of fat vacuoles at different size and deviation of nucleus, and lysis of some hepatocytes. These situations were relatively milder in the rapamycin and EA groups. CONCLUSION: EA may enhance physical strength and promote cellular autophagy in the liver of aging mice by regulating AMPK/mTOR/ULK1 signaling, thereby inhibiting excessive oxidative stress, and delaying aging process to some extent.


Assuntos
Eletroacupuntura , Proteínas Quinases Ativadas por AMP/genética , Animais , Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Hepatócitos , Masculino , Camundongos , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Serina-Treonina Quinases TOR/genética
7.
Zhen Ci Yan Jiu ; 46(1): 45-51, 2021 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-33559425

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Jiaji" (EX-B2) on the levels of autophagy and endoplasmic reticulum stress in mice with spinal cord injury (SCI), so as to explore its mechanism underlying improvement of SCI. METHODS: A total of 60 female C57BL/6 mice were randomly divided into sham operation, model and EA groups, which were further divided into 7 d and 14 d subgroups (10 mice in each subgroup). The SCI model was established by pressing the exposed spinal cord (L1) with a vascular clamp for 15 s. EA was applied to bilateral EX-B2 3 h after modeling, once a day for 7 and 14 d, respectively. Basso Mouse Scale(BMS) for locomotion was used to evaluate hindlimb motor function on day 7 and 14 after SCI. H.E. staining was used to observe histopathologic changes of the injured spinal cord tissue, and Western blot employed to detect the expression of glucose regulatory protein-78 (GRP78), Caspase-12, microtubule-associated protein light chain 3 II (LC-II) and P62(also known as sqstm1/Sequestome1) proteins. Immunofluorescence staining was used to detect the immunoacti-vities of spinal CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP, an endoplasmic reticulum stress-inducible protein) and P62. RESULTS: On the 7th and 14th day after SCI, the BMS scores and expression levels of LC3II protein were significantly down-regulated (P<0.05), and the expression levels of P62, GRP78 and Caspase-12 proteins, the immunoactivities of CHOP and P62 were all significantly up-regulated on both day 7 and 14 in the model group than in the sham operation group (P<0.05).Compared with the model group, the BMS scores and the expression levels of LC3II protein were significantly increased on both day 7 and 14 (P<0.05), while the expression levels of P62, GRP78 and Caspase-12 proteins, and the immunoactivities of CHOP and P62 were obviously decreased on day 7 and 14 in the EA group (P<0.05). Outcomes of H.E. stain showed that the cells with nuclei pyknosis and swelling and the necrotic cells appeared in the model group, which was relatively fewer in the EA group. CONCLUSION: EA of EX-B2 can improve the locomotor function in SCI mice, which may be related to its effects in up-regulating the expression of LC3II (to promote cell autophagy), and down-regulating the expression of P62, GRP78, Caspase-12 and CHOP proteins (to inhibit endoplasmic reticulum stress) in the spinal cord tissue.


Assuntos
Eletroacupuntura , Traumatismos da Medula Espinal , Animais , Autofagia/genética , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/genética , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Medula Espinal , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/terapia
8.
Zhen Ci Yan Jiu ; 45(4): 281-6, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32333532

RESUMO

OBJECTIVE: To investigate the effect of electroacupuncture (EA) combined with Donepezil on learning-memory ability and gene expression of ß-amyloid (Aß) clearance-related factors in the hippocampus in senescence-accelerated mouse prone 8 (SAMP8) mice, so as to explore their synthetic effect in improving dementia of Alzheimer's disease (AD).. METHODS: Male SAMP8 mice (30-week-old) were randomly divided into model, medication and EA+medication groups (n=6 mice in each group), and other 6 senescence-resistant 1 (SAMR1) mice were used as the control group. Mice of the medication and EA+medication group received gavage of Donepezil (1.3 mg•kg-1•d-1) once daily for 4 weeks. EA (2 Hz, 1 mA) was applied to "Baihui"(GV20) and "Yintang" (EX-HN3) for 15 min, once daily, 6 days a week for 4 weeks for rats in the EA+medication group. The Morris water maze (MWM) task (including place navigation tests and space exploration trials) was used to assess the mouse's learning-memory ability. Histopathological changes of hippocampus tissue were observed by H.E. staining. The expression levels of matrix metalloprotein 9 (MMP-9), low density lipoprotein receptor-related protein-1 (LRP-1), P-glycoprotein (Pgp, an important drug transporter responsible for multidrug resistance), Claudin-5 (a component of tight junction strands that serves as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets of blood-brain barrier, BBB) and Aß mRNAs of the hippocampus tissue were detected by quantitative real-time PCR. RESULTS: Compared with the control group, the average escape latency of place navigation tests, and the expression levels of MMP-9 and Aß mRNAs were significantly increased (P<0.01), and the number of platform quadrant-crossing times of space exploration trials, and the expression levels of LRP-1, Pgp and Claudin-5 mRNAs considerably decreased in the model group (P<0.01). After the intervention, the learning-memory ability was significantly improved in the medication and EA+medication groups (P<0.01,P<0.05), the expression levels of Aß mRNAs in the medication and EA+medication groups and MMP-9 mRNA in the EA+medication group were obviously down-regulated (P<0.01), and those of LRP-1 and Pgp mRNAs in the medication and EA+medication groups and Claudin-5 mRNA in the EA+medication group were remarkably up-regulated (P<0.05, P<0.01). The therapeutic effect of EA+medication was apparently superior to that of simple medication in shortening the escape latency (P<0.05,P<0.01) and in down-regulating the expression of MMP-9 and Aß mRNAs(P<0.01), and in increasing the number of platform quadrant-crossing times(P<0.01), and expression levels of LRP-1, Pgp and Claudin-5 mRNAs (P<0.01). H.E. staining showed scatted and loose arrangement of neurons in the hippocampus, with reduction of number of cell layers and unclear nucleoli, which was relatively milder in the medication and EA+medication groups. CONCLUSION: EA can enhance the effect of Donepezil in improving learning-memory ability in AD mice possibly by regulating expression of MMP-9, LRP-1, Pgp and Claudin-5 mRNAs and strengthening the effect of Donepezil in transporting Aß via BBB.


Assuntos
Eletroacupuntura , Doença de Alzheimer , Animais , Donepezila , Hipocampo , Aprendizagem , Masculino , Memória , Camundongos , Ratos
9.
Zhen Ci Yan Jiu ; 45(12): 973-9, 2020 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-33415855

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture(EA) on proangiogenesis process and protein turn-over in a mouse model of sarcopenia, so as to explore its potential molecular mechanism anti-aging. METHODS: Fourteen 30-week-old male SAMP8 mice were randomly divided into a model group (n=7) and an EA group (n=7). Seven anti-rapidly aging SAMR1 mice of the same age were used as the control group (n=7). EA (1 mA, 4 Hz) was applied to bilateral "Zusanli"(ST36) and "Yanglingquan"(GB34) for 20 minutes each time once a day, 6 times a week for 4 weeks. The exhausted running platform was used to test the sports function. Gastrocnemius muscle mass and relative ratio of gastrocnemius muscle mass to body mass were measured. HE staining and transmission electron microscope were used to observe the morphology, and the cross-sectional area of gastrocnemius muscle was calculated. Relative protein expressions of protein kinase B (AKT) , phosphorylated (p) -AKT, mammalian target of rapamycin (mTOR) , p-mTOR, p70 ribosomal protein S6 kinase (p70S6K) , p-p70S6K,hypoxia inducible factor-1α (HIF-1α) and relative mRNA expressions of HIF-1α, vascular endothelial growth factor A (VEGF-A) , muscle RING finger-1 (MuRF-1) and muscle atrophy F-box (MAFbx) were detected by Western blot and real-time fluorescence quantitative PCR, seperatively. RESULTS: Compared with the control group, the running time and distance, body mass and gastrocnemius mass, and the ratio of gastrocnemius mass to body mass decreased(P<0.01, P<0.05), cross-sectional area of gastrocnemius, related protein expression of p-AKT,p-mTOR, p-p70S6K and HIF-1α, mRNA expression of HIF-1α and VEGF-A decreased (P<0.01), while mRNA expression of MuRF1 and MAFbx increased (P<0.01) in the model group. Following EA intervention, the running time and distance, body mass and gastrocnemius mass and the ratio of gastrocnemius mass to body mass increased (P<0.05), cross-sectional area of gastrocnemius, related protein expression of p-AKT,p-mTOR, p-p70S6K and HIF-1α, mRNA expression of HIF-1α and VEGF-A were significantly up-regulated (P<0.01), mRNA expression of MuRF1 and MAFbx down-regulated (P<0.01, P<0.05) in the EA group compared with the model group. CONCLUSION: EA may delay the aging muscle atrophy in mice by regulating the gastrocnemius muscle's proangiogenesis process and protein turnover.


Assuntos
Eletroacupuntura , Sarcopenia , Animais , Masculino , Camundongos , Atrofia Muscular , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/genética
10.
Water Res ; 125: 449-457, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28898702

RESUMO

Climate warming and eutrophication are regarded as two important contributors to the occurrence of cyanobacteria blooms in aquatic ecosystems. However, the feedback of cyanobacteria blooms to climate warming and eutrophication is not fully clear. In this study, a microcosm system was established to simulate the decomposition processes of cyanobacteria blooms. It was observed that a large amount of nitrogen and phosphorus was released into the overlying water, and the concentrations of nitrogen and phosphorus were increased with the amount of added cyanobacteria bloom biomass addition. Subsequently, these released nutrients became available for primary production and intensified the eutrophic state of freshwater lakes. During the decomposition of cyanobacteria blooms, the microenvironment acquired low DO, low pH, and reductive conditions. Together with abundant organic matter in the water column and sediment, a large amount of CH4 and CO2 produced through organic matter mineralization, in which CH4 was the dominant fraction, occupied 50%-92% in mass of emitted carbon. Furthermore, a certain amount of N2O, probably underestimated, was produced with a strong greenhouse effect, even though its magnitude was small. These observations clarify that the feedbacks among cyanobacteria blooms formation and climate warming as well as the eutrophication of freshwater lakes are not unidirectional, but bidirectional. Given that climate warming enhanced the occurrence of cyanobacteria blooms, it was proposed that there are two vicious loops between cyanobacteria blooms, lake eutrophication and climate warming, which should be considered in the future management of aquatic ecosystems.


Assuntos
Cianobactérias/crescimento & desenvolvimento , Eutrofização , Água Doce/microbiologia , Nitrogênio/análise , Fósforo/análise , Biomassa , Mudança Climática , Ecossistema , Lagos/química
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