GH deficiency in patients with spinal cord injury: efficacy/safety of GH replacement, a pilot study

Gonadotropin-releasing hormone and growth hormone act as anti-inflammatory factors improving sensory recovery in female rats with thoracic spinal cord injury

The potential for novel applications of classical hormones, such as gonadotropin-releasing hormone (GnRH) and growth hormone (GH), to counteract neural harm is based on their demonstrated neurotrophic effects in both in vitro and in vivo experimental models and a growing number of clinical trials. This study aimed to investigate the effects of chronic administration of GnRH and/or GH on the expression of several proinflammatory and glial activity markers in damaged neural tissues, as well as on sensory recovery, in animals submitted to thoracic spinal cord injury (SCI). Additionally, the effect of a combined GnRH + GH treatment was examined in comparison with single hormone administration. Spinal cord damage was induced by compression using catheter insufflation at thoracic vertebrae 10 (T10), resulting in significant motor and sensory deficits in the hindlimbs. Following SCI, treatments (GnRH, 60 μg/kg/12 h, IM; GH, 150 μg/kg/24 h, SC; the combination of both; or vehicle) were administered during either 3 or 5 weeks, beginning 24 h after injury onset and ending 24 h before sample collection. Our results indicate that a chronic treatment with GH and/or GnRH significantly reduced the expression of proinflammatory (IL6, IL1B, and iNOS) and glial activity (Iba1, CD86, CD206, vimentin, and GFAP) markers in the spinal cord tissue and improved sensory recovery in the lesioned animals. Furthermore, we found that the caudal section of the spinal cord was particularly responsive to GnRH or GH treatment, as well as to their combination. These findings provide evidence of an anti-inflammatory and glial-modulatory effect of GnRH and GH in an experimental model of SCI and suggest that these hormones can modulate the response of microglia, astrocytes, and infiltrated immune cells in the spinal cord tissue following injury.

Phase II/III placebo-controlled randomized trial of safety and efficacy of growth hormone treatment in incomplete chronic traumatic spinal cord injury

STUDY DESIGN

This is a double blind phase II/III placebo-controlled randomized trial of the safety and efficacy of GH treatment in incomplete chronic traumatic spinal cord injury.

OBJECTIVE

The aim of this study was to investigate the possibility to use exogenous GH administration for motor recovery in chronic traumatic incomplete human SCI. The objectives were to establish safety and efficacy of a combined treatment of subcutaneous GH (or placebo) and rehabilitation in this population.

SETTING

Hospital Nacional de Parapléjicos METHODS: The pharmacological treatment was a subcutaneous daily dose of growth hormone (GH, Genotonorm 0.4 mg, Pfizer Pharmaceuticals) or placebo for one year. The pharmacological treatment was performed, during the first six months under hospitalization and supervised rehabilitation.

RESULTS

The main findings were that the combined treatment of GH plus rehabilitation treatment is feasible and safe, and that GH but not placebo increases the ISNCSCI motor score. On the other hand, the motor-score increment was marginal (after one-year combined treatment, the mean increment of the motor-score was around 2.5 points). Moreover, we found that intensive and long-lasting rehabilitation program per se increases the functional outcome of SCI individuals (measured using SCIM III and WISCI II).

CONCLUSIONS

It is important to highlight that our aim was to propose GH as a possible treatment to improve motor functions in incomplete SCI individuals. At least with the doses we used, we think that the therapeutic effects of this approach are not clinically relevant in most subjects with SCI.

Effects of Growth Hormone Treatment and Rehabilitation in Incomplete Chronic Traumatic Spinal Cord Injury: Insight from Proteome Analysis

Despite promising advances in the medical management of spinal cord injury (SCI), there is still no available effective therapy to repair the neurological damage in patients who experience this life-transforming condition. Recently, we performed a phase II/III placebo-controlled randomized trial of safety and efficacy of growth hormone (GH) treatment in incomplete chronic traumatic spinal cord injury. The main findings were that the combined treatment of GH plus rehabilitation treatment is feasible and safe, and that GH but not placebo slightly improves the SCI individual motor score. Moreover, we found that an intensive and long-lasting rehabilitation program per se increases the functional outcome of SCI individuals. To understand the possible mechanisms of the improvement due to GH treatment (motor score) and due to rehabilitation (functional outcome), we used a proteomic approach. Here, we used a multiple proteomic strategy to search for recovery biomarkers in blood plasma with the potential to predict response to somatropin treatment and to delayed intensive rehabilitation. Forty-six patients were recruited and followed for a minimum period of 1 year. Patients were classified into two groups based on their treatment: recombinant somatropin (0.4 mg) or placebo. Both groups received rehabilitation treatment. Our strategy allowed us to perform one of the deepest plasma proteomic analyses thus far, which revealed two proteomic signatures with predictive value: (i) response to recombinant somatropin treatment and (ii) response to rehabilitation. The proteins implicated in these signatures are related to homeostasis, inflammation, and coagulation functions. These findings open novel possibilities to assess and therapeutically manage patients with SCI, which could have a positive impact on their clinical response.

Clinical effects of intrathecal administration of expanded Wharton jelly mesenchymal stromal cells in patients with chronic complete spinal cord injury: a randomized controlled study

BACKGROUND AIMS

Spinal cord injury (SCI) represents a devastating condition leading to severe disability related to motor, sensory and autonomic dysfunction. Stem cell transplantation is considered a potential emerging therapy to stimulate neuroplastic and neuroregenerative processes after SCI. In this clinical trial, the authors investigated the safety and clinical recovery effects of intrathecal infusion of expanded Wharton jelly mesenchymal stromal cells (WJ-MSCs) in chronic complete SCI patients.

METHODS

The authors designed a randomized, double-blind, crossover, placebo-controlled, phase 1/2a clinical trial (NCT03003364). Participants were 10 patients (7 males, 3 females, age range, 25-47 years) with chronic complete SCI (American Spinal Injury Association A) at dorsal level (T3-11). Patients were randomly assigned to receive a single dose of intrathecal ex vivo-expanded WJ-MSCs (10 × 10⁶ cells) from human umbilical cord or placebo and were then switched to the other arm at 6 months. Clinical evaluation (American Spinal Injury Association impairment scale motor and sensory score, spasticity, neuropathic pain, electrical perception and pain thresholds), lower limb motor evoked potentials (MEPs) and sensory evoked potentials (SEPs), Spinal Cord Independence Measure and World Health Organization Quality of Life Brief Version were assessed at baseline, 1 month, 3 months and 6 months after each intervention. Urodynamic studies and urinary-specific quality of life (Qualiveen questionnaire) as well as anorectal manometry, functional assessment of bowel dysfunction (Rome III diagnostic questionnaire) and severity of fecal incontinence (Wexner score) were conducted at baseline and at 6 months after each intervention.

RESULTS

Intrathecal transplantation of WJ-MSCs was considered safe, with no significant side effects. Following MSC infusion, the authors found significant improvement in pinprick sensation in the dermatomes below the level of injury compared with placebo. Other clinically relevant effects, such as an increase in bladder maximum capacity and compliance and a decrease in bladder neurogenic hyperactivity and external sphincter dyssynergy, were observed only at the individual level. No changes in motor function, spasticity, MEPs, SEPs, bowel function, quality of life or independence measures were observed.

CONCLUSIONS

Intrathecal transplantation of human umbilical cord-derived WJ-MSCs is a safe intervention. A single intrathecal infusion of WJ-MSCs in patients with chronic complete SCI induced sensory improvement in the segments adjacent to the injury site.

Growth hormone (GH) and synaptogenesis

Growth hormone (GH) is known to exert several roles during development and function of the nervous system. Initially, GH was exclusively considered a pituitary hormone that regulates body growth and metabolism, but now its alternative extrapituitary production and pleiotropic functions are widely accepted. Through excess and deficit models, the critical role of GH in nervous system development and adult brain function has been extensively demonstrated. Moreover, neurotrophic actions of GH in neural tissues include pro-survival effects, neuroprotection, axonal growth, synaptogenesis, neurogenesis and neuroregeneration. The positive effects of GH upon memory, behavior, mood, sensorimotor function and quality of life, clearly implicate a beneficial action in synaptic physiology. Experimental and clinical evidence about GH actions in synaptic function modulation, protection and restoration are revised in this chapter.

Regenerative Effect of Growth Hormone (GH) in the Retina after Kainic Acid Excitotoxic Damage

In addition to its role as an endocrine messenger, growth hormone (GH) also acts as a neurotrophic factor in the central nervous system (CNS), whose effects are involved in neuroprotection, axonal growth, and synaptogenic modulation. An increasing amount of clinical evidence shows a beneficial effect of GH treatment in patients with brain trauma, stroke, spinal cord injury, impaired cognitive function, and neurodegenerative processes. In response to injury, Müller cells transdifferentiate into neural progenitors and proliferate, which constitutes an early regenerative process in the chicken retina. In this work, we studied the long-term protective effect of GH after causing severe excitotoxic damage in the retina. Thus, an acute neural injury was induced via the intravitreal injection of kainic acid (KA, 20 µg), which was followed by chronic administration of GH (10 injections [300 ng] over 21 days). Damage provoked a severe disruption of several retinal layers. However, in KA-damaged retinas treated with GH, we observed a significant restoration of the inner plexiform layer (IPL, 2.4-fold) and inner nuclear layer (INL, 1.5-fold) thickness and a general improvement of the retinal structure. In addition, we also observed an increase in the expression of several genes involved in important regenerative pathways, including: synaptogenic markers (DLG1, NRXN1, GAP43); glutamate receptor subunits (NR1 and GRIK4); pro-survival factors (BDNF, Bcl-2 and TNF-R2); and Notch signaling proteins (Notch1 and Hes5). Interestingly, Müller cell transdifferentiation markers (Sox2 and FGF2) were upregulated by this long-term chronic GH treatment. These results are consistent with a significant increase in the number of BrdU-positive cells observed in the KA-damaged retina, which was induced by GH administration. Our data suggest that GH is able to facilitate the early proliferative response of the injured retina and enhance the regeneration of neurite interconnections.