1
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Chang YJ, Lin KT, Shih O, Yang CH, Chuang CY, Fang MH, Lai WB, Lee YC, Kuo HC, Hung SC, Yao CK, Jeng US, Chen YR. Sulfated disaccharide protects membrane and DNA damages from arginine-rich dipeptide repeats in ALS. Sci Adv 2024; 10:eadj0347. [PMID: 38394210 PMCID: PMC10889363 DOI: 10.1126/sciadv.adj0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 01/22/2024] [Indexed: 02/25/2024]
Abstract
Hexanucleotide repeat expansion in C9ORF72 (C9) is the most prevalent mutation among amyotrophic lateral sclerosis (ALS) patients. The patients carry over ~30 to hundreds or thousands of repeats translated to dipeptide repeats (DPRs) where poly-glycine-arginine (GR) and poly-proline-arginine (PR) are most toxic. The structure-function relationship is still unknown. Here, we examined the minimal neurotoxic repeat number of poly-GR and found that extension of the repeat number led to a loose helical structure disrupting plasma and nuclear membrane. Poly-GR/PR bound to nucleotides and interfered with transcription. We screened and identified a sulfated disaccharide that bound to poly-GR/PR and rescued poly-GR/PR-induced toxicity in neuroblastoma and C9-ALS-iPSC-derived motor neurons. The compound rescued the shortened life span and defective locomotion in poly-GR/PR expressing Drosophila model and improved motor behavior in poly-GR-injected mouse model. Overall, our results reveal structural and toxicity mechanisms for poly-GR/PR and facilitate therapeutic development for C9-ALS.
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Affiliation(s)
- Yu-Jen Chang
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Taiwan University and Academia Sinica, Taipei 115, Taiwan
| | - Kai-Tai Lin
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Orion Shih
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
| | - Chi-Hua Yang
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Ching-Yu Chuang
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Ming-Han Fang
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 106, Taiwan
| | - Wei-Bin Lai
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Yi-Chung Lee
- Department of Neurology, Taipei Veterans General Hospital, Taipei 112, Taiwan
- Department of Neurology, National Yang Ming Chiao Tung University School of Medicine, Taipei, Taiwan
| | - Hung-Chih Kuo
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | | | - Chi-Kuang Yao
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 106, Taiwan
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Yun-Ru Chen
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Taiwan University and Academia Sinica, Taipei 115, Taiwan
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2
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Park HG, Kim YD, Cho E, Lu TY, Yao CK, Lee J, Lee S. Vav independently regulates synaptic growth and plasticity through distinct actin-based processes. J Cell Biol 2022; 221:213401. [PMID: 35976098 PMCID: PMC9388202 DOI: 10.1083/jcb.202203048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/23/2022] [Accepted: 08/03/2022] [Indexed: 11/22/2022] Open
Abstract
Modulation of presynaptic actin dynamics is fundamental to synaptic growth and functional plasticity; yet the underlying molecular and cellular mechanisms remain largely unknown. At Drosophila NMJs, the presynaptic Rac1-SCAR pathway mediates BMP-induced receptor macropinocytosis to inhibit BMP growth signaling. Here, we show that the Rho-type GEF Vav acts upstream of Rac1 to inhibit synaptic growth through macropinocytosis. We also present evidence that Vav-Rac1-SCAR signaling has additional roles in tetanus-induced synaptic plasticity. Presynaptic inactivation of Vav signaling pathway components, but not regulators of macropinocytosis, impairs post-tetanic potentiation (PTP) and enhances synaptic depression depending on external Ca2+ concentration. Interfering with the Vav-Rac1-SCAR pathway also impairs mobilization of reserve pool (RP) vesicles required for tetanus-induced synaptic plasticity. Finally, treatment with an F-actin–stabilizing drug completely restores RP mobilization and plasticity defects in Vav mutants. We propose that actin-regulatory Vav-Rac1-SCAR signaling independently regulates structural and functional presynaptic plasticity by driving macropinocytosis and RP mobilization, respectively.
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Affiliation(s)
- Hyun Gwan Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea.,Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Yeongjin David Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea.,Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Eunsang Cho
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea.,Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Ting-Yi Lu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jihye Lee
- Department of Oral Pathology, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea.,Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
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3
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Kim J, Kim S, Nahm M, Li TN, Lin HC, Kim YD, Lee J, Yao CK, Lee S. ALS2 regulates endosomal trafficking, postsynaptic development, and neuronal survival. J Cell Biol 2021; 220:e202007112. [PMID: 33683284 PMCID: PMC7944400 DOI: 10.1083/jcb.202007112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 01/07/2021] [Accepted: 02/11/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations in the human ALS2 gene cause recessive juvenile-onset amyotrophic lateral sclerosis and related motor neuron diseases. Although the ALS2 protein has been identified as a guanine-nucleotide exchange factor for the small GTPase Rab5, its physiological roles remain largely unknown. Here, we demonstrate that the Drosophila homologue of ALS2 (dALS2) promotes postsynaptic development by activating the Frizzled nuclear import (FNI) pathway. dALS2 loss causes structural defects in the postsynaptic subsynaptic reticulum (SSR), recapitulating the phenotypes observed in FNI pathway mutants. Consistently, these developmental phenotypes are rescued by postsynaptic expression of the signaling-competent C-terminal fragment of Drosophila Frizzled-2 (dFz2). We further demonstrate that dALS2 directs early to late endosome trafficking and that the dFz2 C terminus is cleaved in late endosomes. Finally, dALS2 loss causes age-dependent progressive defects resembling ALS, including locomotor impairment and brain neurodegeneration, independently of the FNI pathway. These findings establish novel regulatory roles for dALS2 in endosomal trafficking, synaptic development, and neuronal survival.
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Affiliation(s)
- Joohyung Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Sungdae Kim
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Minyeop Nahm
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Tsai-Ning Li
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsin-Chieh Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yeongjin David Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Jihye Lee
- Department of Oral Pathology, Department of Life Science in Dentistry, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
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4
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Calonge WM, Meredith P, Kouakou-Adonis KA, Yao CK, N'da Assie KM, Asse H. Reconstructive surgery for sequellae of Mycobacterium ulcerans infection (Buruli ulcer) of the upper limb. J Plast Surg Hand Surg 2021; 55:339-344. [PMID: 33645421 DOI: 10.1080/2000656x.2021.1884083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Infection by Mycobacterium ulcerans constitutes a neglected tropical disease whose prevalence seems to have overrun those of cutaneous tuberculosis and leprosy. Its aggressivity depends on a mycolactone toxin. Lesions may involve skin, tendon and bone with a large spectrum of manifestations: non-ulcerative (papules, nodules, plaques), ulcerative and oedematous presentations as well as osteomyelitis with muscular contraction and ankylosis. Upper limbs account for more than two thirds of the infection sites. Surgical treatment may involve tendon transpositions, partial and total skin grafts. Amputation is relegated to extreme cases. MATERIAL AND METHODS Selected iconography from patients during the last 15 years is presented. At least 1500 cases had partial skin grafts (anterior thigh). Total skin grafts (inguinal region) were used in about 200 cases. Complex lesions involved 9 ilioinguinal flaps (5 boys, 4 girls, mean age 11.2 years, range 2-16 years), 5 tendon transfers (4 boys, one girl, mean age 15.4 years, range 12-19 years) and 3 resections of the first carpal row (2 girls, 1 boy, mean age 8 years, range 4-15 years). RESULTS AND DISCUSSION Out of 9 ilioinguinal flaps mild, marginal necrosis was the only complication in 2 patients without flap loss. Mean hospital stay was 26.44 days (range, 18-41 days), with return to full weight-bearing after a mean of 12 weeks (range 9-25 weeks) after discharge. Functional thumb opposition to allow pencil prehension was achieved in all three cases of resection of first carpal row resection without postoperative complications.
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Affiliation(s)
- W M Calonge
- Institut de Chirurgie Reconstructive, Abidjan, Côte d'Ivoire.,Centre d'Image Corporelle, Nyon, Switzerland
| | - P Meredith
- Institut de Chirurgie Reconstructive, Abidjan, Côte d'Ivoire.,Centre d'Image Corporelle, Nyon, Switzerland
| | | | - C K Yao
- Institut de Chirurgie Reconstructive, Abidjan, Côte d'Ivoire
| | - K M N'da Assie
- Institut de Chirurgie Reconstructive, Abidjan, Côte d'Ivoire
| | - H Asse
- Institut de Chirurgie Reconstructive, Abidjan, Côte d'Ivoire
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5
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Li TN, Chen YJ, Lu TY, Wang YT, Lin HC, Yao CK. A positive feedback loop between Flower and PI(4,5)P 2 at periactive zones controls bulk endocytosis in Drosophila. eLife 2020; 9:60125. [PMID: 33300871 PMCID: PMC7748424 DOI: 10.7554/elife.60125] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/09/2020] [Indexed: 01/01/2023] Open
Abstract
Synaptic vesicle (SV) endocytosis is coupled to exocytosis to maintain SV pool size and thus neurotransmitter release. Intense stimulation induces activity-dependent bulk endocytosis (ADBE) to recapture large quantities of SV constituents in large endosomes from which SVs reform. How these consecutive processes are spatiotemporally coordinated remains unknown. Here, we show that Flower Ca2+ channel-dependent phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) compartmentalization governs control of these processes in Drosophila. Strong stimuli trigger PI(4,5)P2 microdomain formation at periactive zones. Upon exocytosis, Flower translocates from SVs to periactive zones, where it increases PI(4,5)P2 levels via Ca2+ influxes. Remarkably, PI(4,5)P2 directly enhances Flower channel activity, thereby establishing a positive feedback loop for PI(4,5)P2 microdomain compartmentalization. PI(4,5)P2 microdomains drive ADBE and SV reformation from bulk endosomes. PI(4,5)P2 further retrieves Flower to bulk endosomes, terminating endocytosis. We propose that the interplay between Flower and PI(4,5)P2 is the crucial spatiotemporal cue that couples exocytosis to ADBE and subsequent SV reformation.
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Affiliation(s)
- Tsai-Ning Li
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Jung Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Ting-Yi Lu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - You-Tung Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsin-Chieh Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
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6
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Lin SS, Hsieh TL, Liou GG, Li TN, Lin HC, Chang CW, Wu HY, Yao CK, Liu YW. Dynamin-2 Regulates Postsynaptic Cytoskeleton Organization and Neuromuscular Junction Development. Cell Rep 2020; 33:108310. [DOI: 10.1016/j.celrep.2020.108310] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 09/23/2020] [Accepted: 10/05/2020] [Indexed: 11/30/2022] Open
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7
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Peng JJ, Lin SH, Liu YT, Lin HC, Li TN, Yao CK. A circuit-dependent ROS feedback loop mediates glutamate excitotoxicity to sculpt the Drosophila motor system. eLife 2019; 8:47372. [PMID: 31318331 PMCID: PMC6682402 DOI: 10.7554/elife.47372] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/17/2019] [Indexed: 12/12/2022] Open
Abstract
Overproduction of reactive oxygen species (ROS) is known to mediate glutamate excitotoxicity in neurological diseases. However, how ROS burdens can influence neural circuit integrity remains unclear. Here, we investigate the impact of excitotoxicity induced by depletion of Drosophila Eaat1, an astrocytic glutamate transporter, on locomotor central pattern generator (CPG) activity, neuromuscular junction architecture, and motor function. We show that glutamate excitotoxicity triggers a circuit-dependent ROS feedback loop to sculpt the motor system. Excitotoxicity initially elevates ROS, thereby inactivating cholinergic interneurons and consequently changing CPG output activity to overexcite motor neurons and muscles. Remarkably, tonic motor neuron stimulation boosts muscular ROS, gradually dampening muscle contractility to feedback-enhance ROS accumulation in the CPG circuit and subsequently exacerbate circuit dysfunction. Ultimately, excess premotor excitation of motor neurons promotes ROS-activated stress signaling that alters neuromuscular junction architecture. Collectively, our results reveal that excitotoxicity-induced ROS can perturb motor system integrity through a circuit-dependent mechanism.
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Affiliation(s)
- Jhan-Jie Peng
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Shih-Han Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Yu-Tzu Liu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Hsin-Chieh Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Tsai-Ning Li
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan, Republic of China
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8
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Yao CK, Liu YT, Lee IC, Wang YT, Wu PY. A Ca2+ channel differentially regulates Clathrin-mediated and activity-dependent bulk endocytosis. PLoS Biol 2017; 15:e2000931. [PMID: 28414717 PMCID: PMC5393565 DOI: 10.1371/journal.pbio.2000931] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/21/2017] [Indexed: 11/19/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) and activity-dependent bulk endocytosis (ADBE) are two predominant forms of synaptic vesicle (SV) endocytosis, elicited by moderate and strong stimuli, respectively. They are tightly coupled with exocytosis for sustained neurotransmission. However, the underlying mechanisms are ill defined. We previously reported that the Flower (Fwe) Ca2+ channel present in SVs is incorporated into the periactive zone upon SV fusion, where it triggers CME, thus coupling exocytosis to CME. Here, we show that Fwe also promotes ADBE. Intriguingly, the effects of Fwe on CME and ADBE depend on the strength of the stimulus. Upon mild stimulation, Fwe controls CME independently of Ca2+ channeling. However, upon strong stimulation, Fwe triggers a Ca2+ influx that initiates ADBE. Moreover, knockout of rodent fwe in cultured rat hippocampal neurons impairs but does not completely abolish CME, similar to the loss of Drosophila fwe at the neuromuscular junction, suggesting that Fwe plays a regulatory role in regulating CME across species. In addition, the function of Fwe in ADBE is conserved at mammalian central synapses. Hence, Fwe exerts different effects in response to different stimulus strengths to control two major modes of endocytosis.
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Affiliation(s)
- Chi-Kuang Yao
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
- Neuroscience Program in Academia Sinica, Academia Sinica, Nankang, Taipei, Taiwan
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
- * E-mail:
| | - Yu-Tzu Liu
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - I-Chi Lee
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - You-Tung Wang
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
| | - Ping-Yen Wu
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan
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9
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Peters SL, Yao CK, Philpott H, Yelland GW, Muir JG, Gibson PR. Editorial: gut-directed hypnotherapy or low FODMAP diet for the treatment of irritable bowel syndrome? Authors' reply. Aliment Pharmacol Ther 2016; 44:902-3. [PMID: 27634231 DOI: 10.1111/apt.13791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- S L Peters
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia.
| | - C K Yao
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - H Philpott
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - G W Yelland
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - J G Muir
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - P R Gibson
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
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10
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Peters SL, Yao CK, Philpott H, Yelland GW, Muir JG, Gibson PR. Randomised clinical trial: the efficacy of gut-directed hypnotherapy is similar to that of the low FODMAP diet for the treatment of irritable bowel syndrome. Aliment Pharmacol Ther 2016; 44:447-59. [PMID: 27397586 DOI: 10.1111/apt.13706] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/13/2016] [Accepted: 06/06/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND A low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet is effective in treating irritable bowel syndrome (IBS). AIM To compare the effects of gut-directed hypnotherapy to the low FODMAP diet on gastrointestinal symptoms and psychological indices, and assess additive effects. METHODS Irritable bowel syndrome patients were randomised (computer-generated list), to receive hypnotherapy, diet or a combination. Primary end-point: change in overall gastrointestinal symptoms across the three groups from baseline to week 6. Secondary end-points: changes in psychological indices, and the durability of effects over 6 months. RESULTS Of 74 participants, 25 received hypnotherapy, 24 diet and 25 combination. There were no demographic differences at baseline across groups. Improvements in overall symptoms were observed from baseline to week 6 for hypnotherapy [mean difference (95% CI): -33 (-41 to -25)], diet [-30 (-42 to -19)] and combination [-36 (-45 to -27)] with no difference across groups (P = 0.67). This represented ≥20 mm improvement on visual analogue scale in 72%, 71% and 72%, respectively. This improvement relative to baseline symptoms was maintained 6 months post-treatment in 74%, 82% and 54%. Individual gastrointestinal symptoms similarly improved. Hypnotherapy resulted in superior improvements on psychological indices with mean change from baseline to 6 months in State Trait Personality Inventory trait anxiety of -4(95% CI -6 to -2) P < 0.0001; -1(-3 to 0.3) P = ns; and 0.3(-2 to 2) P = ns, and in trait depression of -3(-5 to -0.7) P = 0.011; -0.8(-2 to 0.2) P = ns; and 0.6(-2 to 3) P = ns, respectively. Groups improved similarly for QOL (all p ≤ 0.001). CONCLUSIONS Durable effects of gut-directed hypnotherapy are similar to those of the low FODMAP diet for relief of gastrointestinal symptoms. Hypnotherapy has superior efficacy to the diet on psychological indices. No additive effects were observed.
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Affiliation(s)
- S L Peters
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - C K Yao
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - H Philpott
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - G W Yelland
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - J G Muir
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
| | - P R Gibson
- Department of Gastroenterology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, Vic., Australia
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11
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Yao CK, Muir JG, Gibson PR. Review article: insights into colonic protein fermentation, its modulation and potential health implications. Aliment Pharmacol Ther 2016; 43:181-96. [PMID: 26527169 DOI: 10.1111/apt.13456] [Citation(s) in RCA: 244] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 09/11/2015] [Accepted: 10/13/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Beneficial effects of carbohydrate fermentation on gastrointestinal health are well established. Conversely, protein fermentation generates harmful metabolites but their relevance to gastrointestinal health is poorly understood. AIM To review the effects of increased protein fermentation on biomarkers of colonic health, factors influencing fermentative activity and potential for dietary modulation to minimise detrimental effects. METHODS A literature search was performed in PubMed, Medline, EMBASE and Google scholar for clinical and pre-clinical studies using search terms - 'dietary protein', 'fermentation', 'putrefaction', 'phenols', 'sulphide', 'branched-chain fatty acid', 'carbohydrate fermentation', 'gastrointestinal'. RESULTS High protein, reduced carbohydrate diets alter the colonic microbiome, favouring a potentially pathogenic and pro-inflammatory microbiota profile, decreased short-chain fatty acid production and increased ammonia, phenols and hydrogen sulphide concentrations. These metabolites largely compromise the colonic epithelium structure, causing mucosal inflammation but may also directly modulate the enteric nervous system and intestinal motility. Increased protein fermentation as a result of a high-protein intake can be attenuated by addition of oligosaccharides, resistant starch and nonstarch polysaccharides and a reduction in total protein or specifically, aromatic and sulphur-containing amino acids. These factors may have clinical importance as novel therapeutic approaches to problems, in which protein fermentation may be implicated, such as malodorous flatus, irritable bowel syndrome, ulcerative colitis and prevention of colorectal cancer. CONCLUSIONS The direct clinical relevance of excessive protein fermentation in the pathogenesis of irritable bowel syndrome, malodorous flatus and ulcerative colitis are underexplored. Manipulating dietary carbohydrate and protein intake have potential therapeutic applications in such settings and warrant further clinical studies.
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Affiliation(s)
- C K Yao
- Department of Gastroenterology, Monash University, Alfred Health, Melbourne, Vic., Australia
| | - J G Muir
- Department of Gastroenterology, Monash University, Alfred Health, Melbourne, Vic., Australia
| | - P R Gibson
- Department of Gastroenterology, Monash University, Alfred Health, Melbourne, Vic., Australia
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12
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Tsai YC, Grimm S, Chao JL, Wang SC, Hofmeyer K, Shen J, Eichinger F, Michalopoulou T, Yao CK, Chang CH, Lin SH, Sun YH, Pflugfelder GO. Optomotor-blind negatively regulates Drosophila eye development by blocking Jak/STAT signaling. PLoS One 2015; 10:e0120236. [PMID: 25781970 PMCID: PMC4363906 DOI: 10.1371/journal.pone.0120236] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 01/27/2015] [Indexed: 12/23/2022] Open
Abstract
Organ formation requires a delicate balance of positive and negative regulators. In Drosophila eye development, wingless (wg) is expressed at the lateral margins of the eye disc and serves to block retinal development. The T-box gene optomotor-blind (omb) is expressed in a similar pattern and is regulated by Wg. Omb mediates part of Wg activity in blocking eye development. Omb exerts its function primarily by blocking cell proliferation. These effects occur predominantly in the ventral margin. Our results suggest that the primary effect of Omb is the blocking of Jak/STAT signaling by repressing transcription of upd which encodes the Jak receptor ligand Unpaired.
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Affiliation(s)
- Yu-Chen Tsai
- Institute of Genetics, National Yang-Ming University, Taipei; Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan, Republic of China
| | - Stefan Grimm
- Theodor-Boveri-Institut, Biozentrum, Lehrstuhl für Genetik und Neurobiologie, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Ju-Lan Chao
- Institute of Genetics, National Yang-Ming University, Taipei; Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Shih-Chin Wang
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan, Republic of China
| | - Kerstin Hofmeyer
- Theodor-Boveri-Institut, Biozentrum, Lehrstuhl für Genetik und Neurobiologie, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Jie Shen
- Institut für Genetik, Universität Mainz, Mainz, Germany
- Department of Entomology, China Agricultural University, Beijing, China
| | | | | | - Chi-Kuang Yao
- Institute of Genetics, National Yang-Ming University, Taipei; Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Chih-Hsuan Chang
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan, Republic of China
| | - Shih-Han Lin
- Department of Life Science and Life Science Center, Tunghai University, Taichung, Taiwan, Republic of China
| | - Y. Henry Sun
- Institute of Genetics, National Yang-Ming University, Taipei; Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
- * E-mail: (YHS); (GOP)
| | - Gert O. Pflugfelder
- Theodor-Boveri-Institut, Biozentrum, Lehrstuhl für Genetik und Neurobiologie, Universität Würzburg, Am Hubland, Würzburg, Germany
- Institut für Genetik, Universität Mainz, Mainz, Germany
- * E-mail: (YHS); (GOP)
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Sandoval H, Yao CK, Chen K, Jaiswal M, Donti T, Lin YQ, Bayat V, Xiong B, Zhang K, David G, Charng WL, Yamamoto S, Duraine L, Graham BH, Bellen HJ. Mitochondrial fusion but not fission regulates larval growth and synaptic development through steroid hormone production. eLife 2014; 3. [PMID: 25313867 PMCID: PMC4215535 DOI: 10.7554/elife.03558] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/13/2014] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial fusion and fission affect the distribution and quality control of mitochondria. We show that Marf (Mitochondrial associated regulatory factor), is required for mitochondrial fusion and transport in long axons. Moreover, loss of Marf leads to a severe depletion of mitochondria in neuromuscular junctions (NMJs). Marf mutants also fail to maintain proper synaptic transmission at NMJs upon repetitive stimulation, similar to Drp1 fission mutants. However, unlike Drp1, loss of Marf leads to NMJ morphology defects and extended larval lifespan. Marf is required to form contacts between the endoplasmic reticulum and/or lipid droplets (LDs) and for proper storage of cholesterol and ecdysone synthesis in ring glands. Interestingly, human Mitofusin-2 rescues the loss of LD but both Mitofusin-1 and Mitofusin-2 are required for steroid-hormone synthesis. Our data show that Marf and Mitofusins share an evolutionarily conserved role in mitochondrial transport, cholesterol ester storage and steroid-hormone synthesis. DOI:http://dx.doi.org/10.7554/eLife.03558.001 Mitochondria are the main source of energy for cells. These vital and highly dynamic organelles continually change shape by fusing with each other and splitting apart to create new mitochondria, repairing and replacing those damaged by cell stress. For nerve impulses to be transmitted across the gaps (called synapses) between nerve cells, mitochondria need to supply the very ends of the nerve fibers with energy. To do this, the mitochondria must be transported from the main body of the nerve cell to the tips of the nerve fibers. This may not happen if mitochondria are the wrong shape, size or damaged. While searching for genetic mutations that disrupt nerve function in the fruit fly Drosophila, Sandoval et al. spotted mutations in a gene called Marf. Further investigations revealed that flies with mutant versions of Marf have small, round mitochondria, and their nerves cannot transmit signals to muscles when they are highly stimulated. This is because the mutant mitochondria are not easily transported along nerve fibers, and so not enough energy is supplied to the synapses. The synapses of the Marf mutants are also abnormally shaped. Sandoval et al. found that this is not because Marf is lost in the neurons themselves, but because it is lost from a hormone-producing tissue called the ring gland. Another problem found in flies with mutated Marf genes is that they stop developing while in their larval stage. Sandoval et al. established that this could also be related to the loss of Marf from the ring gland. The Marf protein has two different functions in the ring gland: forming and storing droplets of fatty molecules used in hormone production, and synthesising a hormone that controls when a fly larva matures into the adult fly. This suggests that the lower levels of this hormone produced by Marf mutant flies underlies their prolonged larval stages and synapse defects. Vertebrates (animals with backbones, such as humans) have two genes that are related to the fly's Marf gene. When the human forms of these genes were introduced into mutant flies that lack a working copy of Marf, hormone production was only restored if both genes were introduced together. This indicates that these genes have separate roles in vertebrates, but that these roles are both performed by the single fly gene. The role of Marf in tethering mitochondria in the ring gland may allow us to better understand how this process affects hormone production and how the different parts of the cell communicate. DOI:http://dx.doi.org/10.7554/eLife.03558.002
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Affiliation(s)
- Hector Sandoval
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Chi-Kuang Yao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Kuchuan Chen
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Manish Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Taraka Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Yong Qi Lin
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Vafa Bayat
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Bo Xiong
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Ke Zhang
- Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, United States
| | - Gabriela David
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Wu-Lin Charng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Lita Duraine
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Brett H Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
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Yao CK, Tan HL, van Langenberg DR, Barrett JS, Rose R, Liels K, Gibson PR, Muir JG. Dietary sorbitol and mannitol: food content and distinct absorption patterns between healthy individuals and patients with irritable bowel syndrome. J Hum Nutr Diet 2013; 27 Suppl 2:263-75. [PMID: 23909813 DOI: 10.1111/jhn.12144] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Sorbitol and mannitol are naturally-occurring polyol isomers. Although poor absorption and induction of gastrointestinal symptoms by sorbitol are known, the properties of mannitol are poorly described. We aimed to expand data on food composition of these polyols, and to compare their absorptive capacities and symptom induction in patients with irritable bowel syndrome (IBS) and healthy individuals. METHODS Food samples were analysed for sorbitol and mannitol content. The degree of absorption measured by breath hydrogen production and gastrointestinal symptoms (visual analogue scales) was evaluated in a randomised, double-blinded, placebo-controlled study in 21 healthy and 20 IBS subjects after challenges with 10 g of sorbitol, mannitol or glucose. RESULTS Certain fruits and sugar-free gum contained sorbitol, whereas mannitol content was higher in certain vegetables. Similar proportions of patients with IBS (40%) and healthy subjects (33%) completely absorbed sorbitol, although more so with IBS absorbed mannitol (80% versus 43%; P = 0.02). Breath hydrogen production was similar in both groups after lactulose but was reduced in patients with IBS after both polyols. No difference in mean (SEM) hydrogen production was found in healthy controls after sorbitol [area-under-the-curve: 2766 (591) ppm 4 h(-1) ] or mannitol [2062 (468) ppm 4 h(-1) ] but, in patients with IBS, this was greater after sorbitol [1136 (204) ppm 4 h(-1) ] than mannitol [404 (154) ppm 4 h(-1) ; P = 0.002]. Overall gastrointestinal symptoms increased significantly after both polyols in patients with IBS only, although they were independent of malabsorption of either of the polyols. CONCLUSIONS Increased and discordant absorption of mannitol and sorbitol occurs in patients with IBS compared to that in healthy controls. Polyols induced gastrointestinal symptoms in patients with IBS independently of their absorptive patterns, suggesting that the dietary restriction of polyols may be efficacious.
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Affiliation(s)
- C K Yao
- Departments of Gastroenterology, Eastern Health and Central Clinical Schools, Monash University, Melbourne, Victoria, Australia
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Yao CK, Lin YQ, Ly CV, Ohyama T, Haueter CM, Moiseenkova-Bell VY, Wensel TG, Bellen HJ. A synaptic vesicle-associated Ca2+ channel promotes endocytosis and couples exocytosis to endocytosis. Cell 2009; 138:947-60. [PMID: 19737521 PMCID: PMC2749961 DOI: 10.1016/j.cell.2009.06.033] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 04/27/2009] [Accepted: 06/12/2009] [Indexed: 02/06/2023]
Abstract
Synaptic vesicle (SV) exo- and endocytosis are tightly coupled to sustain neurotransmission in presynaptic terminals, and both are regulated by Ca(2+). Ca(2+) influx triggered by voltage-gated Ca(2+) channels is necessary for SV fusion. However, extracellular Ca(2+) has also been shown to be required for endocytosis. The intracellular Ca(2+) levels (<1 microM) that trigger endocytosis are typically much lower than those (>10 microM) needed to induce exocytosis, and endocytosis is inhibited when the Ca(2+) level exceeds 1 microM. Here, we identify and characterize a transmembrane protein associated with SVs that, upon SV fusion, localizes at periactive zones. Loss of Flower results in impaired intracellular resting Ca(2+) levels and impaired endocytosis. Flower multimerizes and is able to form a channel to control Ca(2+) influx. We propose that Flower functions as a Ca(2+) channel to regulate synaptic endocytosis and hence couples exo- with endocytosis.
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Affiliation(s)
- Chi-Kuang Yao
- Howard Hughes Medical Institute, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Ly CV, Yao CK, Verstreken P, Ohyama T, Bellen HJ. straightjacket is required for the synaptic stabilization of cacophony, a voltage-gated calcium channel alpha1 subunit. ACTA ACUST UNITED AC 2008; 181:157-70. [PMID: 18391075 PMCID: PMC2287295 DOI: 10.1083/jcb.200712152] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In a screen to identify genes involved in synaptic function, we isolated mutations in Drosophila melanogaster straightjacket (stj), an α2δ subunit of the voltage-gated calcium channel. stj mutant photoreceptors develop normal synaptic connections but display reduced “on–off” transients in electroretinogram recordings, indicating a failure to evoke postsynaptic responses and, thus, a defect in neurotransmission. stj is expressed in neurons but excluded from glia. Mutants exhibit endogenous seizure-like activity, indicating altered neuronal excitability. However, at the synaptic level, stj larval neuromuscular junctions exhibit approximately fourfold reduction in synaptic release compared with controls stemming from a reduced release probability at these synapses. These defects likely stem from destabilization of Cacophony (Cac), the primary presynaptic α1 subunit in D. melanogaster. Interestingly, neuronal overexpression of cac partially rescues the viability and physiological defects in stj mutants, indicating a role for the α2δ Ca2+ channel subunit in mediating the proper localization of an α1 subunit at synapses.
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Affiliation(s)
- Cindy V Ly
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
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