Лазерная микродиссекции является метод, который позволяет восстановление выделенных ячеек незначительное количество паренхимы. Здесь мы опишем протокол для приобретения человеческих панкреатических островков из операционного материала, который будет использоваться для транскриптомных исследований. Наш протокол улучшает внутреннее аутофлюоресценции человека бета-клетки, способствуя тем самым их коллекции.
Laser microdissection (LMD) is a technique that allows the recovery of selected cells and tissues from minute amounts of parenchyma 1,2. The dissected cells can be used for a variety of investigations, such as transcriptomic or proteomic studies, DNA assessment or chromosomal analysis 2,3. An especially challenging application of LMD is transcriptome analysis, which, due to the lability of RNA 4, can be particularly prominent when cells are dissected from tissues that are rich of RNases, such as the pancreas. A microdissection protocol that enables fast identification and collection of target cells is essential in this setting in order to shorten the tissue handling time and, consequently, to ensure RNA preservation.
Here we describe a protocol for acquiring human pancreatic beta cells from surgical specimens to be used for transcriptomic studies 5. Small pieces of pancreas of about 0.5-1 cm3 were cut from the healthy appearing margins of resected pancreas specimens, embedded in Tissue-Tek O.C.T. Compound, immediately frozen in chilled 2-Methylbutane, and stored at -80 °C until sectioning. Forty serial sections of 10 μm thickness were cut on a cryostat under a -20 °C setting, transferred individually to glass slides, dried inside the cryostat for 1-2 min, and stored at -80 °C.
Immediately before the laser microdissection procedure, sections were fixed in ice cold, freshly prepared 70% ethanol for 30 sec, washed by 5-6 dips in ice cold DEPC-treated water, and dehydrated by two one-minute incubations in ice cold 100% ethanol followed by xylene (which is used for tissue dehydration) for 4 min; tissue sections were then air-dried afterwards for 3-5 min. Importantly, all steps, except the incubation in xylene, were performed using ice-cold reagents – a modification over a previously described protocol 6. utilization of ice cold reagents resulted in a pronounced increase of the intrinsic autofluorescence of beta cells, and facilitated their recognition. For microdissection, four sections were dehydrated each time: two were placed into a foil-wrapped 50 ml tube, to protect the tissue from moisture and bleaching; the remaining two were immediately microdissected. This procedure was performed using a PALM MicroBeam instrument (Zeiss) employing the Auto Laser Pressure Catapulting (AutoLPC) mode. The completion of beta cell/islet dissection from four cryosections required no longer than 40-60 min. Cells were collected into one AdhesiveCap and lysed with 10 μl lysis buffer. Each single RNA specimen for transcriptomic analysis was obtained by combining 10 cell microdissected samples, followed by RNA extraction using the Pico Pure RNA Isolation Kit (Arcturus). This protocol improves the intrinsic autofluorescence of human beta cells, thus facilitating their rapid and accurate recognition and collection. Further improvement of this procedure could enable the dissection of phenotypically different beta cells, with possible implications for better understanding the changes associated with type 2 diabetes.
Мы описываем надежный подход для лазерных микродиссекции (LMD) человеческих островков от хирургического образца поджелудочной железы. При условии, что LMD микроскопа доступно, эта процедура может быть реализована в любой научно-исследовательского учреждения выполнения частичного pancreate…
The authors have nothing to disclose.
Мы хотим поблагодарить всех наших коллег, которые предоставили помощь, советы и критические входа на различных этапах этого проекта. Производство этого видео статьи была поддержана за счет средств IMIDIA ( http://www.imidia.org ), немецкого министерства образования и научных исследований (BMBF) к немецким центром исследований диабета (DZD, http://www.dzd -ev.de ) и Университетской больницы Карл Густав Карус в Технологическом университете Дрездена. Работы, ведущей к данной публикации получило поддержку со стороны Инновационные инициативы лекарственных средств совместного проекта по гранту соглашения N ° 155005 (IMIDIA), ресурсы которого состоят из финансового вклада Седьмой рамочной Европейского Союза, Программы (FP7/2007-2013) и EFPIA компаний в натуральном выражении.
Name of the reagent | Company | Catalogue number | Comments |
2-Methylbutane (isopentane) | ROTH | 3927.1 | |
AdhesiveCap (opaque, 500 μl) | ZEISS | 415190-9201-000 | |
Cellstar Tubes (50 ml) | greiner bio-one | 210 261 | with support skirt |
Cellstar Tubes (50 ml) | greiner bio-one | 227.261 | |
Diethyl pyrocarbonate (DEPC) | SIGMA | D 5758 | |
Dry ice | |||
Ethanol absolute | VWR | 20821.310 | |
Liquid nitrogen | |||
Paint brush | |||
PALM MicroBeam | ZEISS | ||
Peel-a-Way embedding moulds (truncated), 12 x 12 mm | ProSciTech | RR12 | Top internal 22×22 mm, depth 21 mm |
Arcturus PicoPure Frozen RNA Isolation Kit | Applied Biosystems | KIT 0204 | |
Plastic clamp | |||
Razor | |||
RNase-Free DNase Set | Qiagen | 79254 | |
RNaseZAP | SIGMA | R 2020 | |
Scalpel / surgical blade | Techno Cut | 2800111 | |
SuperFrost Plus adhesion microscope slides | Thermo Scientific | J1800AMNZ | 25x75x1.0 mm |
Tissue-Tek O.C.T Compound | Sakura | 4583 or 0807000022 | |
Tweezers | BRAUN | BD168R | |
Xylene | VWR | 28975.291 |