Carbonic anhydrase-8 regulates inflammatory pain by inhibiting the ITPR1-cytosolic free calcium pathway.
Calcium dysregulation is causally linked with various forms of neuropathology including seizure disorders, multiple sclerosis, Huntington's disease, Alzheimer's, spinal cerebellar ataxia (SCA) and chronic pain. Carbonic anhydrase-8 (Car8) is an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1), which regulates intracellular calcium release fundamental to critical cellular functions including neuronal excitability, neurite outgrowth, neurotransmitter release, mitochondrial energy production and cell fate. In this report we test the hypothesis that Car8 regulation of ITPR1 and cytoplasmic free calcium release is critical to nociception and pain behaviors. We show Car8 null mutant mice (MT) exhibit mechanical allodynia and thermal hyperalgesia. Dorsal root ganglia (DRG) from MT also demonstrate increased steady-state ITPR1 phosphorylation (pITPR1) and cytoplasmic free calcium release. Overexpression of Car8 wildtype protein in MT nociceptors complements Car8 deficiency, down regulates pITPR1 and abolishes thermal and mechanical hypersensitivity. We also show that Car8 nociceptor overexpression alleviates chronic inflammatory pain. Finally, inflammation results in downregulation of DRG Car8 that is associated with increased pITPR1 expression relative to ITPR1, suggesting a possible mechanism of acute hypersensitivity. Our findings indicate Car8 regulates the ITPR1-cytosolic free calcium pathway that is critical to nociception, inflammatory pain and possibly other neuropathological states. Car8 and ITPR1 represent new therapeutic targets for chronic pain.
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Gerald Z
GZ
Zhuang
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Benjamin
B
Keeler
Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Jeff
J
Grant
Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Laura
L
Bianchi
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Eugene S
ES
Fu
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Yan Ping
YP
Zhang
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Diana M
DM
Erasso
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Jian-Guo
JG
Cui
Department of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, United States of America.
Tim
T
Wiltshire
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Qiongzhen
Q
Li
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Shuanglin
S
Hao
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Konstantinos D
KD
Sarantopoulos
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Keith
K
Candiotti
John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Sarah M
SM
Wishnek
Algynomics Inc., Chapel Hill, North Carolina, United States of America.
Shad B
SB
Smith
Algynomics Inc., Chapel Hill, North Carolina, United States of America.
William
W
Maixner
Algynomics Inc., Chapel Hill, North Carolina, United States of America.
Luda
L
Diatchenko
John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States of America; John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Eden R
ER
Martin
Department of Anesthesiology, Perioperative Medicine and Pain Management, University of Miami Miller School of Medicine, Miami, Florida, United States of America; John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States of America; John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States of America; Bruce W. Carter Miami Veterans Healthcare System, Miami, Florida, United States of America.
Roy C
RC
Levitt
D000818:Animals; D014408:Biomarkers, Tumor / Q000172:deficiency / Q000235:genetics*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D059350:Chronic Pain / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D003600:Cytosol / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000503:physiopathology; D005786:Gene Expression Regulation; D005816:Genetic Complementation Test; D006930:Hyperalgesia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D007249:Inflammation; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000235:genetics* / Q000378:metabolism; D017774:Long-Term Potentiation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D059225:Nociception / Q000502:physiology; D010766:Phosphorylation; D002256:Carbonic Anhydrases
D014408:Biomarkers, Tumor; D002118:Calcium; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009419:Nerve Tissue Proteins; C512821:Car8 protein, mouse; D002256:Carbonic Anhydrases; C025389:Itpr1 protein, mouse