Casselini Carolina M, Parson Henri K, Frizzi Katie E, Marquez Alex, Smith Darrell R, Guernsey Lucie, Nemmani Rakesh, Tayarani Alireza, Jolivalt Corinne G, Weaver Jessica, Fernyhough Paul, Vinik Aaron I, Calcutt Nigel A
Department of Internal Medicine, Strelitz Diabetes Center, Endocrine and Metabolic Disorders, Eastern Virginia Medical School, Norfolk, VA, USA.
Department of Pathology, University of California San Diego, La Jolla, CA, USA.
Acta Neuropathol. 2024 Mar 25;147(1):60. doi: 10.1007/s00401-024-02710-4.
Preclinical studies indicate that diverse muscarinic receptor antagonists, acting via the M sub-type, promote neuritogenesis from sensory neurons in vitro and prevent and/or reverse both structural and functional indices of neuropathy in rodent models of diabetes. We sought to translate this as a potential therapeutic approach against structural and functional indices of diabetic neuropathy using oxybutynin, a muscarinic antagonist approved for clinical use against overactive bladder. Studies were performed using sensory neurons maintained in vitro, rodent models of type 1 or type 2 diabetes and human subjects with type 2 diabetes and confirmed neuropathy. Oxybutynin promoted significant neurite outgrowth in sensory neuron cultures derived from adult normal rats and STZ-diabetic mice, with maximal efficacy in the 1-100 nmol/l range. This was accompanied by a significantly enhanced mitochondrial energetic profile as reflected by increased basal and maximal respiration and spare respiratory capacity. Systemic (3-10 mg/kg/day s.c.) and topical (3% gel daily) oxybutynin reversed paw heat hypoalgesia in the STZ and db/db mouse models of diabetes and reversed paw tactile allodynia in STZ-diabetic rats. Loss of nerve profiles in the skin and cornea of db/db mice was also prevented by daily topical delivery of 3% oxybutynin for 8 weeks. A randomized, double-blind, placebo-controlled interventional trial was performed in subjects with type 2 diabetes and established peripheral neuropathy. Subjects received daily topical treatment with 3% oxybutynin gel or placebo for 6 months. The a priori designated primary endpoint, significant change in intra-epidermal nerve fibre density (IENFD) in skin biopsies taken before and after 20 weeks of treatments, was met by oxybutynin but not placebo. Secondary endpoints showing significant improvement with oxybutynin treatment included scores on clinical neuropathy, pain and quality of life scales. This proof-of-concept study indicates that muscarinic antagonists suitable for long-term use may offer a novel therapeutic opportunity for treatment of diabetic neuropathy. Trial registry number: NCT03050827.
临床前研究表明,通过 M 亚型作用的不同毒蕈碱受体拮抗剂可促进体外感觉神经元的神经突生成,并预防和/或逆转糖尿病啮齿动物模型的结构和功能神经病变的各种指标。我们试图使用氧苯丁胺(一种已被批准用于治疗膀胱过度活动症的毒蕈碱拮抗剂)作为一种潜在的治疗方法来对抗糖尿病神经病变的结构和功能指标。该研究使用体外维持的感觉神经元、1 型或 2 型糖尿病的啮齿动物模型以及患有 2 型糖尿病和确认的神经病变的人类受试者进行。氧苯丁胺可促进来自成年正常大鼠和 STZ 糖尿病小鼠的感觉神经元培养物中明显的神经突生长,在 1-100nmol/l 范围内具有最大功效。这伴随着线粒体能量谱的显著增强,表现为基础呼吸和最大呼吸以及备用呼吸能力的增加。全身性(每天皮下 3-10mg/kg)和局部(每天 3%凝胶)氧苯丁胺可逆转 STZ 和 db/db 糖尿病小鼠模型中的爪热痛觉过敏,并逆转 STZ 糖尿病大鼠的爪触觉过敏。通过每天局部给予 3%氧苯丁胺 8 周也可防止 db/db 小鼠皮肤和角膜中的神经谱丢失。在患有 2 型糖尿病和已建立的周围神经病变的受试者中进行了一项随机、双盲、安慰剂对照的干预性试验。受试者每天接受局部 3%氧苯丁胺凝胶或安慰剂治疗 6 个月。在 20 周的治疗前后进行皮肤活检,预先指定的主要终点,即表皮内神经纤维密度(IENFD)的显著变化,通过氧苯丁胺而非安慰剂实现。与氧苯丁胺治疗相关的次要终点显示出显著改善,包括临床神经病变、疼痛和生活质量量表的评分。这项概念验证研究表明,适合长期使用的毒蕈碱拮抗剂可能为治疗糖尿病神经病变提供新的治疗机会。试验注册号:NCT03050827。