A <em>Caenorhabditis elegans</em> Model System for Amylopathy Study

Abstract

Amylopathy is a term that describes abnormal synthesis and accumulation of amyloid beta (Aβ) in tissues with time. Aβ is a hallmark of Alzheimer's disease (AD) and is found in Lewy body dementia, inclusion body myositis and cerebral amyloid angiopathy [1][2][3][4] . Amylopathies progressively develop with time. For this reason simple organisms with short lifespans may help to elucidate molecular aspects of these conditions. Here, we describe experimental protocols to study Aβ-mediated neurodegeneration using the worm Caenorhabditis elegans. Thus, we construct transgenic worms by injecting DNA encoding human Aβ 42 into the syncytial gonads of adult hermaphrodites. Transformant lines are stabilized by a mutagenesis-induced integration. Nematodes are age synchronized by collecting and seeding their eggs. The function of neurons expressing Aβ 42 is tested in opportune behavioral assays (chemotaxis assays). Primary neuronal cultures obtained from embryos are used to complement behavioral data and to test the neuroprotective effects of anti-apoptotic compounds. Video LinkThe video component of this article can be found at

Guanine Nucleotide Exchange Factor OSG-1 Confers Functional Aging via Dysregulated Rho Signaling in Caenorhabditis elegans Neurons

“…We previously proposed that the lost GFP phenotype reflects neuronal apoptosis (Cotella et al 2012;Duan and Sesti 2013). Here, we sought to corroborate this notion by genetic and pharmacological evidence.…”

“…In consequence, treatment with generic caspase inhibitor N-(2-quinolyl)valylaspartyl-(2,6-difluorophenoxy)methyl ketone (Q-VD-Oph) prolonged the life of GFP signals ( Figure 1C). Q-VD-Oph was more efficient in cultured ASER neurons obtained from embryos (Duan and Sesti 2013) than in live worms. However, these results are largely expected, because many factors contribute to hamper drug uptake in C. elegans.…”

“…We constructed the strains listed below, by crossing, by microinjection as previously described (integrated transgenic lines were outcrossed four times to remove undesired mutations) (Duan and Sesti 2013) or by ethyl methanesulfonate (EMS) mutagenesis:…”

“…Age-synchronization was performed as previously described (Duan and Sesti 2013). Briefly, nematodes were grown in standard 10-cm NGM plates + OP50 Escherichea coli until a large population of gravid adults was reached (3-5 days).…”

C. elegans neurons jettison protein aggregates and mitochondria under neurotoxic stress

“…C. elegans strains were cultured at 20 °C with standard methods 31 . Strains used were SK4005 zdIs5 [P mec-4 GFP] (abbreviated in the text as Is[P mec-4 GFP]), ZB4065 bzIs166 [P mec-4 mCherry1](abbreviated in the text as Is[P mec-4 mCh1]), ZB4066 bzIs167 [P mec-4 mitogfp P mec-4 mCherry2] (abbreviated in the text as Is[P mec-4 mCh2]), ZB4067 bzIs167 [P mec-4 mitogfp P mec-4 mCherry4]; igIs1 [P mec-7 YFP P mec-3 htt57Q128::cfp lin-15 + ] 10 (abbreviated in the text as Is[mCh2 ; Q128CFP]), sesIs2512 [P gcy -5GFP], sesIs25 [P flp-6 Aβ; P gcy-5 GFP] 32 , KWN176 rnyIs014 [P mec-4 mCherry unc-119(+) ], ZB4071 bzIs169 [P mec-18 sid-1 P sng - 1 YFP]; bzIs101 [P mec-4 mCherry; P unc-119 + ], ZB4087 bzIs169 [P mec-18 sid-1 P sng - 1 YFP]; bzIs101 [P mec-4 mCherry; P unc-119 + ]; hsf-1(sy441), BZ555 egIs1 [P dat-1 GFP], ZB4070 bzIs168 [ P mec-7 LMP-1::GFP] , ZB4509 bzIs166[ P mec-4 mCherry] ; bzIs168 [P mec-7 LMP-1::GFP], ZB4082 cup-4(ok837); bzIs166 [ p mec-4 mCherry], ZB4083 smIS76 [ P hsp-16 ANV::GFP] 33 ; bzIs166 [P mec-4 mCherry], ZB4084 hsf-1(sy441); zdIs5 [P mec-4 GFP], ZB4085 hsf-1(sy441); bzIs166 [P mec-4 mCherry] , ZB4086 zdIs5 [P mec-4 GFP] ; bzIs166 [P mec-4 mCherry], PTN73 pha-1(e2123); him-5(e1490); zhsEx17 [P mec-4 mitoLS::ROGFP], RBW2834 rbw2834Si[P mec-3 ::mitotimer::T54, CB- unc-119 + II ttTi5605] in unc-119 (ed3 ) 20 , QH3738 ced-1(e1735); zdIs5 , QH3737 ced-6 (n1813); zdIs5 , QH4623 ced-5(n1812); zdIs5 , QH3768 ced- 7(n2690); zdIs5, QH3130 ced-10 ( n3246); zdIs5 , QH3533 psr-1 (ok714); zdIs5 34 , ZB4526 bzIs166 [P mec-4 mCherry]; pdr-1(gk448) , ZB4525 bzIs166 [P mec-4 mCherry]; ( pwIs979 [P cup-4 GFP:: vps-29 ]cB-unc119), ZB4528 bzIs166 [P mec-4 mCherry]; zhsEx17 [P mec-4 mitoLS::ROGFP], ZB4059 bzIs163 [P mec-4 ::GCaMP3.0::SL2::mCherry], ZB4524 bzEx242 [P mec-4 ::PH(plcDelta)::GFP] 35 , and wild type N2.…”