Role of stromal interaction molecule 2 in chronic itch

基质相互作用分子2在慢性瘙痒中的作用

• 批准号: 10660144
• 负责人: Huijuan Hu
• 金额: $ 41.14万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-15 至 2028-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10660144
• 关键词: Ablation; Acute; Aftercare; Antibodies; Astrocytes; Attenuated; Behavior; Calcium; Calcium Channel; Chloroquine; Clinical; Couples; Cytomegalovirus; Data; Dinitrobenzenes; Dinitrofluorobenzene; Dryness; Endoplasmic Reticulum; Family member; Fluorescein-5-isothiocyanate; GRP gene; Genetic; Glial Fibrillary Acidic Protein; Histamine; Interleukin-1 beta; Interleukin-6; Knock-out; Knockout Mice; LCN2 gene; Measures; Mediating; Mediator; Messenger RNA; Microinjections; Molecular; Mus; Neurons; Nociception; Pain; Pathway interactions; Pattern; Play; Posterior Horn Cells; Production; Proteins; Pruritus; Research; Role; STIM1 gene; Signal Pathway; Signal Transduction; Skin; Slice; Spinal; Spinal Cord; Stains; Stat3 protein; TLR4 gene; TNF gene; Testing; Time; Touch sensation; Vertebral column; Western Blotting; Work; antagonist; cell type; chronic itch; conditional knockout; cytokine; dorsal horn; excitatory neuron; hindbrain; insight; knock-down; mouse model; neuronal excitability; novel; overexpression; response; sensor; transmission process; vesicular glutamate transporter 2

Abstract Chronic itch is a debilitating condition and represents a clinical challenge. Increase evidence has demonstrated that neuronal and astrocytic signaling pathways in the spinal cord play a crucial role in chronic itch. Although several molecules have been identified as key itch mediators/modulators, molecular mechanisms underlying chronic itch remain incompletely understood. Our research has been focused on role of store-operated calcium channels (SOCs) in pain and itch. We have shown that the primary SOC family members STIM1 and STIM2 (endoplasmic reticulum Ca2+ sensors) are expressed in dorsal horn neurons and astrocytes, but their functional significance in the spinal cord is still elusive. We recently generated vesicular glutamate transporters 2 (Vglut2, an excitatory neuron marker) conditional STIM1 and STIM2 knockout (KO) mice. Our pilot data showed that deletion of STIM1 in Vglut2+ neurons attenuated nociception, but did not affect pruritogen-induced scratches. In contrast, ablation of STIM2 in Vglut2+ neurons (v-STIM2 KO) markedly attenuated pruritogen-induced scratches, but had no effect on nociception. These exciting pilot work suggests that STIM1 and STIM2 play distinct roles in pain and itch. Our pilot data also show that inhibition of STIMs by intrathecal, not intradermal injection, decreased histamine (His)- and chloroquine (CQ)-induced itch behavior. Moreover, inhibition or deletion of excitatory neuronal STIM2 attenuated FITC- and DNFB-induced chronic itch, suggesting that neuronal STIM2 play a role in both acute and chronic itch. Importantly, STIM2 expression was increased in the dorsal horn from diphenylcyclopropenone (DCP)- and 1-fluoro-2, 4-dinitrobenzene (DNFB)-induced mouse models of chronic itch. GRPR plays a critical role in itch transmission. Our pilot data showed that deletion of STIM2 in Vglut2 or Lbx1 (specifically expressed in spinal and hindbrain neurons)-expressing neurons drastically attenuated GRP-induced Ca2+ responses and itch behavior. It is known that signal transducer and activator of transcription 3 (STAT3) and its downstream lipocalin-2 (LCN2) are key modulators of chronic itch. We found that activation of TLR4 upregulated STIM2 expression via STAT3 signaling. Based on these findings, we hypothesize that spinal STIM2 plays a crucial role in chronic itch through a combination of neuronal and astrocytic signaling pathways. In Aim 1, we will determine whether ablation or knockdown of spinal STIM2 attenuates chronic itch. In Aim 2, we will examine the expression and function of STIM2 under chronic itch conditions. In Aim 3, we will investigate the mechanisms underlying spinal STIM2 involvement in chronic itch. The proposed work will establish a novel role of STIM2 in itch sensation and will provide new insights into the mechanisms of GRPR in itch transmission. Successful completion of this research will not only identify STIM2 as a key modulator in chronic itch, but also decipher the cellular and molecular mechanisms underlying chronic itch.

摘要 慢性瘙痒是一种使人衰弱的病症，并且代表临床挑战。越来越多的证据表明 脊髓中的神经元和星形胶质细胞信号通路在慢性瘙痒中起关键作用。虽然 几种分子已被鉴定为关键的瘙痒介质/调节剂， 慢性瘙痒仍然不完全了解。我们的研究主要集中在钙库运作的钙在细胞内的作用 疼痛和瘙痒的通道（SOC）。我们已经表明，主要的SOC家族成员STIM 1和STIM 2 （内质网Ca 2+传感器）在背角神经元和星形胶质细胞中表达，但其功能性 在脊髓中的意义仍然是难以捉摸的。我们最近产生了囊泡谷氨酸转运蛋白2（VEGF 2， 兴奋性神经元标志物）条件性STIM 1和STIM 2敲除（KO）小鼠。我们的试点数据显示， VEGF 2+神经元中STIM 1的缺失减弱了伤害性感受，但不影响促纤维素原诱导的抓挠。在 相比之下，VSTM 2+神经元中STIM 2的消融（v-STIM 2 KO）显著减弱了促纤维素原诱导的划痕， 但对伤害感受没有影响。这些令人兴奋的试点工作表明STIM 1和STIM 2在以下方面发挥着不同的作用： 疼痛和瘙痒。我们的初步数据还表明，通过鞘内而不是皮内注射抑制STIM， 组胺（His）和氯喹（CQ）诱导瘙痒行为。此外，抑制或删除兴奋性 神经元STIM 2减弱FITC和DNFB诱导的慢性瘙痒，表明神经元STIM 2发挥作用， 在急性和慢性瘙痒中。重要的是，STIM 2表达在背角增加， 二苯环丙烯酮（DCP）和1-氟-2，4-二硝基苯（DNFB）诱导的小鼠慢性瘙痒模型。 GRPR在瘙痒传播中起关键作用。我们的初步数据显示，在VEGF 2或Lbx 1中缺失STIM 2， （在脊髓和后脑神经元中特异性表达）-表达神经元显著减弱GRP诱导的神经元损伤。 Ca 2+反应和瘙痒行为。已知信号转导子和转录激活子3（STAT 3）和 其下游脂质运载蛋白-2（LCN 2）是慢性瘙痒关键调节剂。我们发现TLR 4的激活 通过STAT 3信号转导上调STIM 2表达。基于这些发现，我们假设脊髓STIM 2 通过神经元和星形胶质细胞信号通路的组合在慢性瘙痒中起关键作用。在Aim中 1，我们将确定脊髓STIM 2的消融或敲低是否减轻慢性瘙痒。在目标2中，我们将 检测慢性瘙痒条件下STIM 2的表达和功能。在目标3中，我们将研究 脊髓STIM 2参与慢性瘙痒的潜在机制。拟议的工作将建立一个新的作用 STIM 2在瘙痒感觉中的作用，将为GRPR在瘙痒传播中的机制提供新的见解。 这项研究的成功完成不仅将确定STIM 2作为慢性瘙痒的关键调节剂，而且还将确定STIM 2作为慢性瘙痒的关键调节剂。 破译慢性瘙痒的细胞和分子机制。