Оценка митохондриальной функции и жизнеспособности клеток в клетках почек гиперэкспрессией протеинкиназы С Изоферменты
Summary
Эффект активации протеинкиназы С (ПКС) изоферментов на митохондриальной функции, связанные с дыхания и окислительного фосфорилирования и на жизнеспособность клеток описаны. Подход адаптируется аденовирусной техники выборочно сверхэкспрессировать PKC изоферменты в первичной культуре клеток и различные анализы для определения функций митохондрий и энергетический статус клетки.
Abstract
The protein kinase C (PKC) family of isozymes is involved in numerous physiological and pathological processes. Our recent data demonstrate that PKC regulates mitochondrial function and cellular energy status. Numerous reports demonstrated that the activation of PKC-a and PKC-ε improves mitochondrial function in the ischemic heart and mediates cardioprotection. In contrast, we have demonstrated that PKC-α and PKC-ε are involved in nephrotoxicant-induced mitochondrial dysfunction and cell death in kidney cells. Therefore, the goal of this study was to develop an in vitro model of renal cells maintaining active mitochondrial functions in which PKC isozymes could be selectively activated or inhibited to determine their role in regulation of oxidative phosphorylation and cell survival. Primary cultures of renal proximal tubular cells (RPTC) were cultured in improved conditions resulting in mitochondrial respiration and activity of mitochondrial enzymes similar to those in RPTC in vivo. Because traditional transfection techniques (Lipofectamine, electroporation) are inefficient in primary cultures and have adverse effects on mitochondrial function, PKC-ε mutant cDNAs were delivered to RPTC through adenoviral vectors. This approach results in transfection of over 90% cultured RPTC.
Here, we present methods for assessing the role of PKC-ε in: 1. regulation of mitochondrial morphology and functions associated with ATP synthesis, and 2. survival of RPTC in primary culture. PKC-ε is activated by overexpressing the constitutively active PKC-ε mutant. PKC-ε is inhibited by overexpressing the inactive mutant of PKC-ε. Mitochondrial function is assessed by examining respiration, integrity of the respiratory chain, activities of respiratory complexes and F0F1-ATPase, ATP production rate, and ATP content. Respiration is assessed in digitonin-permeabilized RPTC as state 3 (maximum respiration in the presence of excess substrates and ADP) and uncoupled respirations. Integrity of the respiratory chain is assessed by measuring activities of all four complexes of the respiratory chain in isolated mitochondria. Capacity of oxidative phosphorylation is evaluated by measuring the mitochondrial membrane potential, ATP production rate, and activity of F0F1-ATPase. Energy status of RPTC is assessed by determining the intracellular ATP content. Mitochondrial morphology in live cells is visualized using MitoTracker Red 580, a fluorescent dye that specifically accumulates in mitochondria, and live monolayers are examined under a fluorescent microscope. RPTC viability is assessed using annexin V/propidium iodide staining followed by flow cytometry to determine apoptosis and oncosis.
These methods allow for a selective activation/inhibition of individual PKC isozymes to assess their role in cellular functions in a variety of physiological and pathological conditions that can be reproduced in in vitro.
Protocol
Representative Results
Discussion
Здесь подход позволяет избыточная экспрессия отдельных изоферментов PKC в первичной культуре почечных проксимальных канальцев клеток. Есть несколько сильных сторон этого подхода: 1. Это позволяет для исследования механизмов регулирования в однородной популяции клеток (почечные клетк…
Declarações
The authors have nothing to disclose.
Acknowledgements
Эта работа была поддержана грантом Национального института здоровья, Национальный институт диабета, желудочно-кишечных и почечных заболеваний, 2R01DK59558 (для GN). UAMS Поступательное научно-исследовательского института при поддержке Национального института здоровья Национальный научно-исследовательский центр ресурсов гранта UL1 RR029884 при условии частичного финансирования для ядра потока цитометрии в UAMS. Мы благодарим доктора Peipei Пинг (Калифорнийский университет в Лос-Анджелесе, Лос-Анджелес, Калифорния) за предоставление аликвоты аденовирус проведения кДНК, кодирующей доминантно негативной (неактивные) мутант PKC-ε и д-р Аллен Samarel (Университет Лойола Медицинского центра; Maywood, Иллинойс) для обеспечения аликвоты аденовирусных векторов кодирующих конститутивно активный мутант PKC-ε. Мы также благодарим доктора. Питер Паркер и Питер Сагден (Imperial College London, Лондон, Великобритания) для обеспечения кДНК, кодирующей постоянно активный PKC-ε.
Materials
| Name of the reagent | Company | Catalogue number |
| Laminar flow hood | Thermo Electron Corporation | FORMA 1104 |
| 2 ml and 15 ml Dounce tissue grinder | WHEATON | 989-24607, 357544 |
| 85 and 235 micron nylon mesh | Small Parts | CMN – 0085 – 10YD CMN – 0250 – 10YD |
| 50 ml sterile centrifuge tube | BIOLOGIX | BCT-P 50BS |
| 1.5 ml micro tube | Sarstedt | 72.690.001 |
| 35 x 10 mm sterile culture dishes | Corning | 430165 |
| Jouan Centrifuge | Jouan | Jouan CR3 11175704 Rotors: Jouan T40 |
| Adjustable micro-centrifuge | SIGMA | Model 1 – 15 |
| Biological Oxygen Monitor | YSI Incorporated | YSI Model 5300A |
| Single Chamber Micro Oxygen System | YSI Incorporated | 5356S |
| Oxygen Probe | YSI Incorporated | 5331A |
| Circulating Bath | YSI Incorporated | 5310 |
| KCl and Standard Membrane Kit | YSI Incorporated | 5775 |
| Magnetic Stirrer | YSI Incorporated | 5222 |
| Flatbed Recorder | Kipp & Zonen | BD 11E |
| 48-well and 96-well transparent plates | Costar | 3548, 3679 |
| Thermomixer R | Eppendorf | 5355 21919 |
| Orbital shaker MAXQ 2000 | Thermo Scientific | SHKA 2000 |
| Spectra FLUOR Plus (absorbance/fluorescence/luminescence reader) | Tecan | F129005 |
| Water-Jacketed US Autoflow Automatic CO2 Incubator | NUAIRE | NU 4850 |
| 12×75 mm polystyrene culture test tubes for flow cytometry | Fisher Brand | 14-961-20 |
| Axioskop Water immersion objective 63x / 0,90W |
Carl Zeiss | 114846 ACHROPLAN 44 00 67 |
| DMEM / F12 | Cellgro | 99 – 830 – PB |
| DMEM / F12 Ham | Sigma | D 2906 – 1L |
| Deferoxamine Mesylate | Hospira | D110 |
| Collagenase Type I | Worthington | 4196 |
| Trypsin inhibitor | Sigma | T 6522 – 500mg |
| 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) | Invitrogen | T3168 |
| Mitotracker Red | Invitrogen | M22425 |
| ATP Bioluminescence Assay Kit HS II | Roche | 11 699 709 001 |
| Annexin V – FITC solution | BioVision | 1001 – 200 |
| Flow cytometer | BD Biosciences | BD FACSCalibur |
Referências
- Nowak, G., Schnellmann, R. G. Improved culture conditions stimulate gluconeogenesis in primary cultures of renal proximal tubule cells. Am. J. Physiol. 268, C1053-C1061 (1995).
- Nowak, G., Schnellmann, R. G. L-ascorbic acid regulates growth and metabolism of renal cells: improvements in cell culture. Am. J. Physiol. 271, 2072-2080 (1996).
- Ping, P., Takano, H., Zhang, J., Tang, X. L., Qiu, Y., Li, R. C., Banerjee, S., Dawn, B., Balafonova, Z., Bolli, R. Isoform-selective activation of protein kinase C by nitric oxide in the heart of conscious rabbits: a signaling mechanism for both nitric oxide-induced and ischemia-induced preconditioning. Circ. Res. 84, 587-604 (1999).
- Wotton, D., Ways, D. K., Parker, P. J., Owen, M. J. Activity of both Raf and Ras is necessary for activation of transcription of the human T cell receptor beta gene by protein kinase C, Ras plays multiple roles. J. Biol. Chem. 268, 17975-17982 (1993).
- Nowak, G., Bakajsova, D., Samarel, A. M. Protein kinase C-ε activation induces mitochondrial dysfunction and fragmentation in renal proximal tubules. Am. J. Physiol. Renal Physiol. 301, F197-F208 (2011).
- Nowak, G., Clifton, G. L., Godwin, M. L., Bakajsova, D. Activation of ERK1/2 pathway mediates oxidant-induced decreases in mitochondrial function in renal cells. Am. J. Physiol. Renal Physiol. 291, 840-855 (2006).
- Shaik, Z. P., Fifer, E. K., Nowak, G. Akt activation improves oxidative phosphorylation in renal proximal tubular cells following nephrotoxicant injury. Am. J. Physiol. Renal Physiol. 294, F423-F432 (2008).
- Nowak, G. Protein kinase C-α and ERK1/2 mediate mitochondrial dysfunction, decreases in active Na+ transport, and cisplatin-induced apoptosis in renal cells. J. Biol. Chem. 277, 43377-43388 (2002).
- Liu, X., Godwin, M. L., Nowak, G. Protein kinase C- a inhibits the repair of oxidative phosphorylation after S-(1,2-dichlorovinyl)-L-cysteine injury in renal cells. Am. J. Physiol. Renal Physiol. 287, F64-F73 (2004).
- Nowak, G., Price, P. M., Schnellmann, R. G. Lack of a functional p21WAF1/CIP1 gene accelerates caspase-independent apoptosis induced by cisplatin in renal cells. Am. J. Physiol. Renal Physiol. 285, F440-F450 (2003).
- Cummings, B. S., Schnellmann, R. G. Cisplatin-induced renal cell apoptosis: caspase 3-dependent and -independent pathways. J. Pharmacol. Exp. Ther. 302, 8-17 (2002).
