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Araldi D, Khomula EV, Bonet IJM, Bogen O, Green PG, Levine JD. Role of pattern recognition receptors in chemotherapy-induced neuropathic pain. Brain 2024; 147:1025-1042. [PMID: 37787114 PMCID: PMC10907096 DOI: 10.1093/brain/awad339] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/25/2023] [Accepted: 09/12/2023] [Indexed: 10/04/2023] Open
Abstract
Progress in the development of effective chemotherapy is producing a growing population of patients with acute and chronic painful chemotherapy-induced peripheral neuropathy (CIPN), a serious treatment-limiting side effect for which there is currently no US Food and Drug Administration-approved treatment. CIPNs induced by diverse classes of chemotherapy drugs have remarkably similar clinical presentations, leading to the suggestion they share underlying mechanisms. Sensory neurons share with immune cells the ability to detect damage associated molecular patterns (DAMPs), molecules produced by diverse cell types in response to cellular stress and injury, including by chemotherapy drugs. DAMPs, in turn, are ligands for pattern recognition receptors (PRRs), several of which are found on sensory neurons, as well as satellite cells, and cells of the immune system. In the present experiments, we evaluated the role of two PRRs, TLR4 and RAGE, present in dorsal root ganglion (DRG), in CIPN. Antisense (AS)-oligodeoxynucleotides (ODN) against TLR4 and RAGE mRNA were administered intrathecally before ('prevention protocol') or 3 days after ('reversal protocol') the last administration of each of three chemotherapy drugs that treat cancer by different mechanisms (oxaliplatin, paclitaxel and bortezomib). TLR4 and RAGE AS-ODN prevented the development of CIPN induced by all three chemotherapy drugs. In the reversal protocol, however, while TLR4 AS-ODN completely reversed oxaliplatin- and paclitaxel-induced CIPN, in rats with bortezomib-induced CIPN it only produced a temporary attenuation. RAGE AS-ODN, in contrast, reversed CIPN induced by all three chemotherapy drugs. When a TLR4 antagonist was administered intradermally to the peripheral nociceptor terminal, it did not affect CIPN induced by any of the chemotherapy drugs. However, when administered intrathecally, to the central terminal, it attenuated hyperalgesia induced by all three chemotherapy drugs, compatible with a role of TLR4 in neurotransmission at the central terminal but not sensory transduction at the peripheral terminal. Finally, since it has been established that cultured DRG neurons can be used to study direct effects of chemotherapy on nociceptors, we also evaluated the role of TLR4 in CIPN at the cellular level, using patch-clamp electrophysiology in DRG neurons cultured from control and chemotherapy-treated rats. We found that increased excitability of small-diameter DRG neurons induced by in vivo and in vitro exposure to oxaliplatin is TLR4-dependent. Our findings suggest that in addition to the established contribution of PRR-dependent neuroimmune mechanisms, PRRs in DRG cells also have an important role in CIPN.
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Affiliation(s)
- Dionéia Araldi
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Eugen V Khomula
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Ivan J M Bonet
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Oliver Bogen
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Paul G Green
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
- Department of Preventative and Restorative Dental Sciences, Division of Neuroscience, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Jon D Levine
- Department of Oral and Maxillofacial Surgery, UCSF Pain and Addiction Research Center, University of California at San Francisco, San Francisco, CA 94143, USA
- Department of Medicine, Division of Neuroscience, University of California at San Francisco, San Francisco, CA 94143, USA
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Jiang M, Sun Y, Lei Y, Hu F, Xia Z, Liu Y, Ma Z, Gu X. GPR30 receptor promotes preoperative anxiety-induced postoperative hyperalgesia by up-regulating GABA A-α4β1δ subunits in periaqueductal gray in female rats. BMC Anesthesiol 2020; 20:93. [PMID: 32321426 PMCID: PMC7175561 DOI: 10.1186/s12871-020-01017-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/16/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND G-protein coupled estrogen receptor 30 (GPR30) was proved the specific estrogen receptor relating to mechanical hyperalgesia. Studies have shown that the GABAA receptor subunits α4, β1, and δ in the periaqueductal gray (PAG) neurons promote the descending facilitation system. This study inquired into whether and how GPR30 and GABAA-α4β1δ in the PAG promote preoperative anxiety-induced postoperative hyperalgesia in female rats. METHODS All the female rats were subjected to the single prolonged stress (SPS) to stimulate preoperative anxiety. Subsequently, mechanical allodynia was evaluated before and after the incision, based on the paw withdrawal mechanical threshold (PWMT). The selective GPR30 agonist G1 and antagonist G15 were locally microinjected into the PAG. The expression of GPR30, protein kinase A (PKA), and GABAA receptor subunits α4, β1, and δ in the PAG neurons were detected using western blotting and immunofluorescence. RESULTS Behavioral testing revealed that Group S and Group I decreased the nociceptive threshold levels of PWMT in female rats. PWMT in Group S + I decreased more than that of Group S and Group I. Further, results of western blotting showed the expression of GPR30, PKA, and GABAA α4, β1, and δ subunits significantly up-regulated in Group S + I, and immunofluorescence indicated that the neurons of PAG in Group S + I appeared simultaneously immunopositive for GPR30 and GABAA α4, β1, and δ receptors. After microinjection of G1 into the PAG, female rats with plantar incision continued to exhibit significant hyperalgesia until postoperative 48 h. On the other hand, microinjection of G15 with SPS and plantar incision procedure relieved postoperative hyperalgesia in female rats. Western blotting demonstrated that intra-PAG injection of G15 markedly decreased the GPR30, PKA, and GABAA α4, β1, and δ levels in Group G15 + I. CONCLUSIONS Our results indicate that the GPR30-PKA-GABAAα4β1δ pathway in the PAG promotes preoperative anxiety-induced postoperative hyperalgesia in female rats. This mechanism might be a potential novel therapeutic target for hyperalgesia in females.
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Affiliation(s)
- Ming Jiang
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China
| | - Yu'e Sun
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China
| | - Yishan Lei
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China
| | - Fan Hu
- Analytical & Testing Center, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Zhengrong Xia
- Analytical & Testing Center, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yue Liu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China
| | - Zhengliang Ma
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China
| | - Xiaoping Gu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, Jiangsu Province, China.
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Jiang M, Bo J, Lei Y, Hu F, Xia Z, Liu Y, Lu C, Sun Y, Hou B, Ni K, Ma Z, Gu X. Anxiety-induced hyperalgesia in female rats is mediated by cholecystokinin 2 receptor in rostral ventromedial medulla and spinal 5-hydroxytryptamine 2B receptor. J Pain Res 2019; 12:2009-2026. [PMID: 31308730 PMCID: PMC6613357 DOI: 10.2147/jpr.s187715] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 05/29/2019] [Indexed: 12/18/2022] Open
Abstract
Background Preoperative anxiety is associated with postoperative hyperalgesia; however, few studies have investigated the mechanism underlying this association in female surgical patients. Research has suggested that ON cells in the rostral ventromedial medulla (RVM) receive nerve impulses via cholecystokinin 2 (CCK2) receptors, facilitating hyperalgesia. Additionally, the downstream serotonergic projection system from the RVM to the spinal cord has a dual regulating effect on pain responses, and the 5-hydoxytryptophan 2B (5-HT2B) receptor in spinal dorsal horn neurons is critically involved in mechanical allodynia. Methods Ovariectomized rats were treated with estrogen replacement, single prolonged stress (SPS), and plantar incision. Various receptor agonists and antagonists were then administered into the RVM and spinal cord to study the mechanism underlying postoperative hyperalgesia caused by preoperative anxiety in female rats. Results Behavioral testing revealed that preoperative SPS induced postoperative hyperalgesia, as well as the expression of the CCK2 receptor in the RVM and the expression of the 5-HT2B receptor, protein kinase Cγ (PKCγ), and phosphorylation of the N-methyl-d-aspartate receptor1 (p-NR1) in the spinal cord increased confirmed by Western blot. RVM microinjection of the CCK2 receptor agonist CCK-8 and intrathecal injection of the 5-HT2B receptor agonist BW723C86 both produced hyperalgesia in female rats after plantar incision, whereas the CCK2 receptor antagonist YM022, the 5-HT2B receptor antagonist RS127445, and the PKCγ inhibitor C37H65N9O13 decreased the rats’ sensitivity to the same stimulus. Additionally, electrophysiological analysis suggested that activation of the 5-HT2B receptor increased the whole-cell current (IBa) in superficial dorsal horn neurons through the PKCγ pathway. Conclusion Our study demonstrated that preoperative anxiety-induced postoperative hyperalgesia in female rats is associated with descending pain pathways. The CCK2 receptor in the RVM and spinal 5-HT2B receptor may play a role in this hyperalgesic effect.
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Affiliation(s)
- Ming Jiang
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Jinhua Bo
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Yishan Lei
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Fan Hu
- Department of Basic Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
| | - Zhengrong Xia
- Department of Basic Medicine, Analytical & Testing Center, Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China
| | - Yue Liu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Cui'e Lu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Yu'e Sun
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Bailing Hou
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Kun Ni
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Zhengliang Ma
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
| | - Xiaoping Gu
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, Jiangsu Province, People's Republic of China
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Changyaleket B, Chong ZZ, Dull RO, Nanegrungsunk D, Xu H. Heparanase promotes neuroinflammatory response during subarachnoid hemorrhage in rats. J Neuroinflammation 2017; 14:137. [PMID: 28720149 PMCID: PMC5516362 DOI: 10.1186/s12974-017-0912-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/10/2017] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Heparanase, a mammalian endo-β-D-glucoronidase that specifically degrades heparan sulfate, has been implicated in inflammation and ischemic stroke. However, the role of heparanase in neuroinflammatory response in subarachnoid hemorrhage (SAH) has not yet been investigated. This study was designed to examine the association between heparanase expression and neuroinflammation during subarachnoid hemorrhage. METHODS Rats were subjected to SAH by endovascular perforation, and the expression of heparanase was determined by Western blot analysis and immunofluorescence in the ipsilateral brain cortex at 24 h post-SAH. Pial venule leukocyte trafficking was monitored by using intravital microscopy through cranial window. RESULTS Our results indicated that, compared to their sham-surgical controls, the rats subjected to SAH showed marked elevation of heparanase expression in the ipsilateral brain cortex. The SAH-induced elevation of heparanase was accompanied by increased leukocyte trafficking in pial venules and significant neurological deficiency. Intracerebroventricular application of a selective heparanase inhibitor, OGT2115, which was initiated at 3 h after SAH, significantly suppressed the leukocyte trafficking and improved the neurological function. CONCLUSIONS Our findings indicate that heparanase plays an important role in mediating the neuroinflammatory response after SAH and contributes to SAH-related neurological deficits and early brain injury following SAH.
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Affiliation(s)
| | - Zhao Zhong Chong
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Randal O Dull
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Danop Nanegrungsunk
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Haoliang Xu
- Department of Pathology, University of Illinois at Chicago, 840 South Wood Street, Chicago, IL, 60612, USA.
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Rehni AK, Liu A, Perez-Pinzon MA, Dave KR. Diabetic aggravation of stroke and animal models. Exp Neurol 2017; 292:63-79. [PMID: 28274862 PMCID: PMC5400679 DOI: 10.1016/j.expneurol.2017.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 02/03/2017] [Accepted: 03/03/2017] [Indexed: 12/16/2022]
Abstract
Cerebral ischemia in diabetics results in severe brain damage. Different animal models of cerebral ischemia have been used to study the aggravation of ischemic brain damage in the diabetic condition. Since different disease conditions such as diabetes differently affect outcome following cerebral ischemia, the Stroke Therapy Academic Industry Roundtable (STAIR) guidelines recommends use of diseased animals for evaluating neuroprotective therapies targeted to reduce cerebral ischemic damage. The goal of this review is to discuss the technicalities and pros/cons of various animal models of cerebral ischemia currently being employed to study diabetes-related ischemic brain damage. The rational use of such animal systems in studying the disease condition may better help evaluate novel therapeutic approaches for diabetes related exacerbation of ischemic brain damage.
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Affiliation(s)
- Ashish K Rehni
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Allen Liu
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Miguel A Perez-Pinzon
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Kunjan R Dave
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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Ritter L, Davidson L, Henry M, Davis-Gorman G, Morrison H, Frye JB, Cohen Z, Chandler S, McDonagh P, Funk JL. Exaggerated neutrophil-mediated reperfusion injury after ischemic stroke in a rodent model of type 2 diabetes. Microcirculation 2012; 18:552-61. [PMID: 21699626 DOI: 10.1111/j.1549-8719.2011.00115.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE We tested the hypothesis that both chronic and acute inflammatory processes contribute to worse reperfusion injury and stroke outcome in an experimental model of T2DM. MATERIALS AND METHODS Twelve- to thirteen-week-old male Zucker Diabetic Fatty (ZDF) rats vs. Zucker Lean Controls (ZLC) rats were tested at baseline and after middle cerebral artery occlusion (ischemia) and reperfusion (I-R). Neutrophil adhesion to the cerebral microcirculation, neutrophil expression of CD11b, infarction size, edema, neurologic function, sICAM, and cerebral expression of neutrophil-endothelial inflammatory genes were measured. RESULTS At baseline, CD11b and sICAM were significantly increased in ZDF vs. ZLC animals (p < 0.05). After I-R, significantly more neutrophil adhesion and cell aggregates were observed in ZDF vs. ZLC (p < 0.05); infarction size, edema, and neurologic function were significantly worse in ZDF vs. ZLC (p < 0.05). CD11b and sICAM-1 remained significantly increased in ZDFs (p < 0.05), and cerebral expression of IL-1β, GRO/KC, E-selectin, and sICAM were significantly induced in ZDF, but not ZLC groups (p < 0.05) after 2.5 hours of reperfusion. CONCLUSION Both sides of the neutrophil-endothelial interface appear to be primed prior to I-R, and remain significantly more activated during I-R in an experimental model of T2DM. Consequently, reperfusion injury appears to play a significant role in poor stroke outcome in T2DM.
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Affiliation(s)
- Leslie Ritter
- College of Nursing, University of Arizona, Tucson, Arizona, USA.
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Dempsie Y, Nilsen M, White K, Mair KM, Loughlin L, Ambartsumian N, Rabinovitch M, Maclean MR. Development of pulmonary arterial hypertension in mice over-expressing S100A4/Mts1 is specific to females. Respir Res 2011; 12:159. [PMID: 22185646 PMCID: PMC3276452 DOI: 10.1186/1465-9921-12-159] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 12/20/2011] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Idiopathic and familial forms of pulmonary arterial hypertension (PAH) occur more frequently in women than men. However, the reason for this remains unknown. Both the calcium binding protein S100A4/Mts1 (Mts1) and its endogenous receptor (receptor for advanced glycosylation end products; RAGE) have been implicated in the development of PAH. We wished to investigate if the Mts1/RAGE pathway may play a role in the gender bias associated with PAH. METHODS We investigated the effects of gender on development of PAH in mice over-expressing Mts1 (Mts1+ mice) via measurement of pulmonary arterial remodeling, systolic right ventricular pressure (sRVP) and right ventricular hypertrophy (RVH). Gender differences in pulmonary arterial Mts1 and RAGE expression were assessed by qRT-PCR and immunohistochemistry. Western blotting and cell counts were used to investigate interactions between 17β-estradiol, Mts1 and RAGE on proliferation of human pulmonary artery smooth muscle cells (hPASMCs). Statistical analysis was by one-way analysis of variance with Dunnetts post test or two-way analysis of variance with Bonferronis post test, as appropriate. RESULTS Female Mts1+ mice developed increased sRVP and pulmonary vascular remodeling, whereas male Mts1+ mice remained unaffected. The development of plexiform-like lesions in Mts1+ mice was specific to females. These lesions stained positive for both Mts1 and RAGE in the endothelial and adventitial layers. Expression of pulmonary arterial Mts1 was greater in female than male Mts1+ mice, and was localised to the medial and adventitial layers in non plexiform-like pulmonary arteries. RAGE gene expression and immunoreactivity were similar between male and female Mts1+ mice and RAGE staining was localised to the endothelial layer in non plexiform-like pulmonary arteries adjacent to airways. In non-plexiform like pulmonary arteries not associated with airways RAGE staining was present in the medial and adventitial layers. Physiological concentrations of 17β-estradiol increased Mts1 expression in hPASMCs. 17β-estradiol-induced hPASMC proliferation was inhibited by soluble RAGE, which antagonises the membrane bound form of RAGE. CONCLUSIONS Mts1 over-expression combined with female gender is permissive to the development of experimental PAH in mice. Up-regulation of Mts1 and subsequent activation of RAGE may contribute to 17β-estradiol-induced proliferation of hPASMCs.
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Affiliation(s)
- Yvonne Dempsie
- College of Medical, Veterinary and Life Sciences, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
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Abstract
OBJECTIVE Higher frequency of subclinical atherosclerosis has been linked with androgen levels in postmenopausal women. Advanced glycation end-products (AGEs) are well-recognized atherogenic molecules. Therefore, we investigated the association of postmenopausal sex steroid and metabolic status with serum AGE levels. METHODS Serum sex hormones, fasting glucose, fasting insulin, and AGEs were assessed in 106 healthy postmenopausal women. Insulin resistance was estimated by using the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS Women in the highest testosterone quartile (Q4) had higher serum AGE levels (Q1, 5.22 IU/mL ± 0.50; Q2, 5.08 ± 0.53 IU/mL; Q3, 5.78 ± 1.10 IU/mL vs Q4, 7.35 ± 1.23 IU/mL; P < 0.0005) compared with women in the lowest testosterone quartiles. Accordingly, women in the highest free androgen index (FAI) quartile had higher serum AGE levels (Q1, 5.36 ± 0.59 IU/mL; Q2, 5.28 ± 0.72 IU/mL vs Q4, 6.68 ± 1.48 IU/mL; P < 0.0005) compared with women in the lowest FAI quartile. These findings remained significant after adjustment for age, body mass index, HOMA-IR, and fasting glucose and fasting insulin levels. A highly significant correlation was found for testosterone and FAI with AGEs and persisted after adjustment for age, body mass index, HOMA-IR, and fasting glucose and fasting insulin levels (r = 0.67, P < 0.0005) CONCLUSIONS The data from the current study suggest that higher levels of AGEs are positively associated with higher androgen levels. This association, identified for the first time, may provide an additional insight into the pathophysiological mechanisms linking the described higher prevalence of cardiovascular events with higher androgen levels in postmenopausal women.
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Shen B, Vetri F, Mao L, Xu HL, Paisansathan C, Pelligrino DA. Aldose reductase inhibition ameliorates the detrimental effect of estrogen replacement therapy on neuropathology in diabetic rats subjected to transient forebrain ischemia. Brain Res 2010; 1342:118-26. [PMID: 20417192 DOI: 10.1016/j.brainres.2010.04.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/14/2010] [Accepted: 04/15/2010] [Indexed: 10/19/2022]
Abstract
Estrogen replacement therapy (ERT) elicits a deleterious, instead of protective, effect on neuropathology in diabetic ovariectomized (OVX) rats subjected to cerebral ischemia. This transformation may be linked to an estrogen-associated increase in function of the receptor for advanced glycation end-products (RAGE). Moreover, under diabetic conditions, advanced glycation end-products (AGEs) are excessively generated through the aldose reductase (AR)-polyol pathway. As such, in diabetic rats given ERT, a RAGE-related exacerbation of post-ischemic brain injury can occur. Thus, in the present study, we evaluated the contribution of AR in estrogen's detrimental effect on diabetic animals subjected to transient forebrain ischemia (TFI). Streptozotocin- and 17-beta estradiol-treated OVX female rats were divided into two groups, where AR activity was blocked using epalrestat; or AGEs production was restricted, via administrating the protein glycation crosslink breaker, ALT-711. In all animals, ERT was initiated approximately 10days before TFI. Pial venular leukocyte adhesion was evaluated over 10h post-TFI using a cranial window/intravital microscopy technique. In vehicle-treated control groups, a significant increase in leukocyte adhesion was observed post-TFI. Leukocyte extravasation, starting at approximately 6h post-TFI, was detected in most of the control animals. Chronic administration of either epalrestat or ALT-711 was associated with a marked decrease in post-TFI leukocyte adhesion, and the complete prevention of leukocyte extravasation. Animals receiving either epalrestat or ALT-711 exhibited a significant improvement in neurologic function, at 72h post-ischemia, compared to vehicle-treated controls. Post-ischemic (72h) histopathology was significantly reduced by epalrestat. Compared to the non-diabetic (ND) controls, diabetic OVX rats in the absence or presence of ERT showed a significant 2-fold or 3-fold increase in cortical AR mRNA levels, respectively. In contrast, only a modest increase in AR protein expression, relative to ND control, was detected in the two diabetic groups. The present findings suggest that AR participates in estrogen's deleterious action on post-ischemic neuropathology in diabetics by promoting inflammation. Targeting the AR-controlled polyol pathway may be a clinically promising strategy to restore the neuroprotection of ERT in diabetic females.
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Affiliation(s)
- Bin Shen
- Department of Emergency Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province 210029, PR China
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