Sensory neurons derived from diabetic rats have diminished internal Ca2+ stores linked to impaired re-uptake by the endoplasmic reticulum
| Autor: | Alexei Verkhratsky, Randy Van der Ploeg, Paul Fernyhough, Jason Schapansky, Elena Zherebitskaya, Darrell R. Smith, Natasha Solovyova, Eli Akude |
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| Předmět: |
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thapsigargin Male Patch-Clamp Techniques sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) Endoplasmic Reticulum [Ca2+]I intracellular calcium concentration Rats Sprague-Dawley AUC area under the curve 0302 clinical medicine 0303 health sciences ATF3 activating transcription factor 3 CaM calmodulin PMPI plasma membrane potential indicator PBS-T PBS with 0.05% Tween 20 General Neuroscience Neurodegeneration neurodegeneration Immunohistochemistry diabetic neuropathy CCD charge-coupled device SERCA sarco/ER Ca2+-ATPase medicine.drug Research Article [Ca2+]ER ER calcium concentration medicine.medical_specialty SERCA axon plasticity Sensory Receptor Cells Blotting Western Biology S3 ERK extracellular-signal-regulated kinase SOCE store-operated calcium entry STZ streptozotocin Fura 2/AM fura 2 acetoxymethyl ester Diabetes Mellitus Experimental Sarcoplasmic Reticulum Calcium-Transporting ATPases ER endoplasmic reticulum 03 medical and health sciences Internal medicine medicine Animals Patch clamp 030304 developmental biology Endoplasmic reticulum R123 rhodamine 123 Streptozotocin medicine.disease GRP78 glucose-regulated protein of 78 kDa RyR ryanodine receptor Rats DRG dorsal root ganglia NT-3 neurotrophin-3 Endocrinology nervous system dorsal root ganglia (DRG) Unfolded protein response STIM stromal interaction molecule Calcium Neurology (clinical) 030217 neurology & neurosurgery Homeostasis |
| Zdroj: | Scopus-Elsevier ASN NEURO |
| Popis: | Distal symmetrical sensory neuropathy in diabetes involves the dying back of axons, and the pathology equates with axonal dystrophy generated under conditions of aberrant Ca2+ signalling. Previous work has described abnormalities in Ca2+ homoeostasis in sensory and dorsal horn neurons acutely isolated from diabetic rodents. We extended this work by testing the hypothesis that sensory neurons exposed to long-term Type 1 diabetes in vivo would exhibit abnormal axonal Ca2+ homoeostasis and focused on the role of SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase). DRG (dorsal root ganglia) sensory neurons from age-matched normal and 3–5-month-old STZ (streptozotocin)-diabetic rats (an experimental model of Type 1 diabetes) were cultured. At 1–2 days in vitro an array of parameters were measured to investigate Ca2+ homoeostasis including (i) axonal levels of intracellular Ca2+, (ii) Ca2+ uptake by the ER (endoplasmic reticulum), (iii) assessment of Ca2+ signalling following a long-term thapsigargin-induced blockade of SERCA and (iv) determination of expression of ER mass and stress markers using immunocytochemistry and Western blotting. KCl- and caffeine-induced Ca2+ transients in axons were 2-fold lower in cultures of diabetic neurons compared with normal neurons indicative of reduced ER calcium loading. The rate of uptake of Ca2+ into the ER was reduced by 2-fold ( P2+ homoeostasis in diabetic neurons could be mimicked via long-term inhibition of SERCA in normal neurons. In summary, axons of neurons from diabetic rats exhibited aberrant Ca2+ homoeostasis possibly triggered by suboptimal SERCA activity that could contribute to the distal axonopathy observed in diabetes. |
| Databáze: | OpenAIRE |
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