Cost-effectiveness of IVF with PGT-M/A to prevent transmission of spinal muscular atrophy in offspring of carrier couples.

PURPOSE: To evaluate the cost-effectiveness of in-vitro fertilization with preimplantation genetic testing for aneuploidy and monogenic disorders (IVF with PGT-M/A) to prevent transmission of spinal muscular atrophy to offspring of carrier couples. METHODS: A decision-analytic model was created to compare the cost-effectiveness of IVF with PGT-M/A to unassisted conception with prenatal diagnostic testing and termination (if applicable). IVF with PGT-M/A costs were determined using a separate Markov state-transition model. IVF outcomes data was derived from 76 carriers of monogenic disorders who underwent IVF with PGT-M/A at a single academic REI center. Other probabilities, costs, and utilities were derived from the literature. Costs were modeled from healthcare perspective. Utilities were modeled from the parental perspective as quality-adjusted life-years (QALYs). RESULTS: The incremental cost-effectiveness ratio for IVF with PGT-M/A compared to unassisted conception is $22,050 per quality-adjusted life-year. The average cost of IVF with PGT-M/A is $41,002 (SD: $8,355). At willingness-to-pay thresholds of $50,000 and $100,000, IVF with PGT-M/A is cost-effective 93.3% and 99.5% of the time, respectively. CONCLUSIONS: Compared to unassisted conception, IVF with PGT-M/A is cost-effective for preventing the transmission of spinal muscular atrophy to the offspring of carrier couples. These findings support insurance coverage of IVF with PGT-M/A for carriers of spinal muscular atrophy.

Bioinformatic analysis of SMN1-ACE/ACE2 interactions hinted at a potential protective effect of spinal muscular atrophy against COVID-19-induced lung injury.

Patients with spinal muscular atrophy (SMA) are susceptible to the respiratory infections and might be at a heightened risk of poor clinical outcomes upon contracting coronavirus disease 2019 (COVID-19). In the face of the COVID-19 pandemic, the potential associations of SMA with the susceptibility to and prognostication of COVID-19 need to be clarified. We documented an SMA case who contracted COVID-19 but only developed mild-to-moderate clinical and radiological manifestations of pneumonia, which were relieved by a combined antiviral and supportive treatment. We then reviewed a cohort of patients with SMA who had been living in the Hubei province since November 2019, among which the only 1 out of 56 was diagnosed with COVID-19 (1.79%, 1/56). Bioinformatic analysis was carried out to delineate the potential genetic crosstalk between SMN1 (mutation of which leads to SMA) and COVID-19/lung injury-associated pathways. Protein-protein interaction analysis by STRING suggested that loss-of-function of SMN1 might modulate COVID-19 pathogenesis through CFTR, CXCL8, TNF and ACE. Expression quantitative trait loci analysis also revealed a link between SMN1 and ACE2, despite low-confidence protein-protein interactions as suggested by STRING. This bioinformatic analysis could give hint on why SMA might not necessarily lead to poor outcomes in patients with COVID-19.

Nusinersen ameliorates motor function and prevents motoneuron Cajal body disassembly and abnormal poly(A) RNA distribution in a SMA mouse model.

Spinal muscular atrophy (SMA) is a devastating autosomal recessive neuromuscular disease characterized by degeneration of spinal cord alpha motor neurons (αMNs). SMA is caused by the homozygous deletion or mutation of the survival motor neuron 1 (SMN1) gene, resulting in reduced expression of SMN protein, which leads to αMN degeneration and muscle atrophy. The majority of transcripts of a second gene (SMN2) generate an alternative spliced isoform that lacks exon 7 and produces a truncated nonfunctional form of SMN. A major function of SMN is the biogenesis of spliceosomal snRNPs, which are essential components of the pre-mRNA splicing machinery, the spliceosome. In recent years, new potential therapies have been developed to increase SMN levels, including treatment with antisense oligonucleotides (ASOs). The ASO-nusinersen (Spinraza) promotes the inclusion of exon 7 in SMN2 transcripts and notably enhances the production of full-length SMN in mouse models of SMA. In this work, we used the intracerebroventricular injection of nusinersen in the SMN∆7 mouse model of SMA to evaluate the effects of this ASO on the behavior of Cajal bodies (CBs), nuclear structures involved in spliceosomal snRNP biogenesis, and the cellular distribution of polyadenylated mRNAs in αMNs. The administration of nusinersen at postnatal day (P) 1 normalized SMN expression in the spinal cord but not in skeletal muscle, rescued the growth curve and improved motor behavior at P12 (late symptomatic stage). Importantly, this ASO recovered the number of canonical CBs in MNs, significantly reduced the abnormal accumulation of polyadenylated RNAs in nuclear granules, and normalized the expression of the pre-mRNAs encoding chondrolectin and choline acetyltransferase, two key factors for αMN homeostasis. We propose that the splicing modulatory function of nusinersen in SMA αMN is mediated by the rescue of CB biogenesis, resulting in enhanced polyadenylated pre-mRNA transcription and splicing and nuclear export of mature mRNAs for translation. Our results support that the selective restoration of SMN expression in the spinal cord has a beneficial impact not only on αMNs but also on skeletal myofibers. However, the rescue of SMN expression in muscle appears to be necessary for the complete recovery of motor function.

Drugs, genes and screens: The ethics of preventing and treating spinal muscular atrophy.

Spinal muscular atrophy (SMA) is the most common genetic disease that causes infant mortality. Its treatment and prevention represent the paradigmatic example of the ethical dilemmas of 21st-century medicine. New therapies (nusinersen and AVXS-101) hold the promise of being able to treat, but not cure, the condition. Alternatively, genomic analysis could identify carriers, and carriers could be offered in vitro fertilization and preimplantation genetic diagnosis. In the future, gene editing could prevent the condition at the embryonic stage. How should these different options be evaluated and compared within a health system? In this paper, we discuss the ethical considerations that bear on the question of how to prioritize the different treatments and preventive options for SMA, at a policy level. We argue that despite the tremendous value of what we call 'ex-post' approaches to treating SMA (such as using pharmacological agents or gene therapy), there is a moral imperative to pursue 'ex-ante' interventions (such as carrier screening in combination with prenatal testing and preimplantation genetic diagnosis, or gene editing) to reduce the incidence of SMA. There are moral reasons relating to autonomy, beneficence and justice to prioritize ex-ante methods over ex-post methods.

The Protective Effects of Levetiracetam on a Human iPSCs-Derived Spinal Muscular Atrophy Model.

Spinal muscular atrophy (SMA) is an inherited disease characterized by progressive motor neuron death and subsequent muscle weakness and is caused by deletion or mutation of survival motor neuron (SMN) 1 gene. Protecting spinal motor neuron is an effective clinical strategy for SMA. The purpose of this study was to investigate the potential effect of an anti-epileptic drug levetiracetam on SMA. In the present study, we used differentiated spinal motor neurons (MNs) from SMA patient-derived induced pluripotent stem cells (SMA-iPSCs) to investigate the effect of levetiracetam. Levetiracetam promoted neurite elongation in SMA-iPSCs-MNs. TUNEL-positive spinal motor neurons were significantly reduced by levetiracetam in SMA-iPSCs-MNs. In addition, the expression level of cleaved-caspase 3 was decreased by levetiracetam in SMA-iPSCs-MNs. Furthermore, levetiracetam improved impaired mitochondrial function in SMA-iPSCs-MNs. On the other hand, levetiracetam did not affect the expression level of SMN protein in SMA-iPSCs-MNs. These findings indicate that levetiracetam has a neuroprotective effect for SMA.

Denervation-activated STAT3-IL-6 signalling in fibro-adipogenic progenitors promotes myofibres atrophy and fibrosis.

Fibro-adipogenic progenitors (FAPs) are typically activated in response to muscle injury, and establish functional interactions with inflammatory and muscle stem cells (MuSCs) to promote muscle repair. We found that denervation causes progressive accumulation of FAPs, without concomitant infiltration of macrophages and MuSC-mediated regeneration. Denervation-activated FAPs exhibited persistent STAT3 activation and secreted elevated levels of IL-6, which promoted muscle atrophy and fibrosis. FAPs with aberrant activation of STAT3-IL-6 signalling were also found in mouse models of spinal cord injury, spinal muscular atrophy, amyotrophic lateral sclerosis (ALS) and in muscles of ALS patients. Inactivation of STAT3-IL-6 signalling in FAPs effectively countered muscle atrophy and fibrosis in mouse models of acute denervation and ALS (SODG93A mice). Activation of pathogenic FAPs following loss of integrity of neuromuscular junctions further illustrates the functional versatility of FAPs in response to homeostatic perturbations and suggests their potential contribution to the pathogenesis of neuromuscular diseases.

Long-term exercise-specific neuroprotection in spinal muscular atrophy-like mice.

KEY POINTS: The real impact of physical exercise parameters, i.e. intensity, type of contraction and solicited energetic metabolism, on neuroprotection in the specific context of neurodegeneration remains poorly explored. In this study behavioural, biochemical and cellular analyses were conducted to compare the effects of two different long-term exercise protocols, high intensity swimming and low intensity running, on motor units of a type 3 spinal muscular atrophy (SMA)-like mouse model. Our data revealed a preferential SMA-induced death of intermediate and fast motor neurons which was limited by the swimming protocol only, suggesting a close relationship between neuron-specific protection and their activation levels by specific exercise. The exercise-induced neuroprotection was independent of SMN protein expression and associated with specific metabolic and behavioural adaptations with notably a swimming-induced reduction of muscle fatigability. Our results provide new insight into the motor units' adaptations to different physical exercise parameters and will contribute to the design of new active physiotherapy protocols for patient care. ABSTRACT: Spinal muscular atrophy (SMA) is a group of autosomal recessive neurodegenerative diseases differing in their clinical outcome, characterized by the specific loss of spinal motor neurons, caused by insufficient level of expression of the protein survival of motor neuron (SMN). No cure is at present available for SMA. While physical exercise might represent a promising approach for alleviating SMA symptoms, the lack of data dealing with the effects of different exercise types on diseased motor units still precludes the use of active physiotherapy in SMA patients. In the present study, we have evaluated the efficiency of two long-term physical exercise paradigms, based on either high intensity swimming or low intensity running, in alleviating SMA symptoms in a mild type 3 SMA-like mouse model. We found that 10 months' physical training induced significant benefits in terms of resistance to muscle damage, energetic metabolism, muscle fatigue and motor behaviour. Both exercise types significantly enhanced motor neuron survival, independently of SMN expression, leading to the maintenance of neuromuscular junctions and skeletal muscle phenotypes, particularly in the soleus, plantaris and tibialis of trained mice. Most importantly, both exercises significantly improved neuromuscular excitability properties. Further, all these training-induced benefits were quantitatively and qualitatively related to the specific characteristics of each exercise, suggesting that the related neuroprotection is strongly dependent on the specific activation of some motor neuron subpopulations. Taken together, the present data show significant long-term exercise benefits in type 3 SMA-like mice providing important clues for designing rehabilitation programmes in patients.

Protective effects of butyrate-based compounds on a mouse model for spinal muscular atrophy.

Proximal spinal muscular atrophy (SMA) is a childhood-onset degenerative disease resulting from the selective loss of motor neurons in the spinal cord. SMA is caused by the loss of SMN1 (survival motor neuron 1) but retention of SMN2. The number of copies of SMN2 modifies disease severity in SMA patients as well as in mouse models, making SMN2 a target for therapeutics development. Sodium butyrate (BA) and its analog (4PBA) have been shown to increase SMN2 expression in SMA cultured cells. In this study, we examined the effects of BA, 4PBA as well as two BA prodrugs-glyceryl tributyrate (BA3G) and VX563-on the phenotype of SMNΔ7 SMA mice. Treatment with 4PBA, BA3G and VX563 but not BA beginning at PND04 significantly improved the lifespan and delayed disease end stage, with administration of VX563 also improving the growth rate of these mice. 4PBA and VX563 improved the motor phenotype of SMNΔ7 SMA mice and prevented spinal motor neuron loss. Interestingly, neither 4PBA nor VX563 had an effect on SMN expression in the spinal cords of treated SMNΔ7 SMA mice; however, they inhibited histone deacetylase (HDAC) activity and restored the normal phosphorylation states of Akt and glycogen synthase kinase 3ß, both of which are altered by SMN deficiency in vivo. These observations show that BA-based compounds with favorable pharmacokinetics ameliorate SMA pathology possibly by modulating HDAC and Akt signaling.

Deliberative Discussion Focus Groups.

This article discusses a new approach for the conduct of focus groups in health research. Identifying ways to educate and inform participants about the topic of interest prior to the focus group discussion can promote more quality data from informed opinions. Data on this deliberative discussion approach are provided from research within three federally funded studies. As healthcare continues to improve from scientific and technological advancements, educating the research participants prior to data collection about these complexities is essential to gather quality data.

IGF-1R Reduction Triggers Neuroprotective Signaling Pathways in Spinal Muscular Atrophy Mice.

Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by the selective loss of spinal motor neurons due to the depletion of the survival of motor neuron (SMN) protein. No therapy is currently available for SMA, which represents the leading genetic cause of death in childhood. In the present study, we report that insulin-like growth factor-1 receptor (Igf-1r) gene expression is enhanced in the spinal cords of SMA-like mice. The reduction of expression, either at the physiological (through physical exercise) or genetic level, resulted in the following: (1) a significant improvement in lifespan and motor behavior, (2) a significant motor neuron protection, and (3) an increase in SMN expression in spinal cord and skeletal muscles through both transcriptional and posttranscriptional mechanisms. Furthermore, we have found that reducing IGF-1R expression is sufficient to restore intracellular signaling pathway activation profile lying downstream of IGF-1R, resulting in both the powerful activation of the neuroprotective AKT/CREB pathway and the inhibition of the ERK and JAK pathways. Therefore, reducing rather than enhancing the IGF-1 pathway could constitute a useful strategy to limit neurodegeneration in SMA. SIGNIFICANCE STATEMENT: Recent evidence of IGF-1 axis alteration in spinal muscular atrophy (SMA), a very severe neurodegenerative disease affecting specifically the motor neurons, have triggered a renewed interest in insulin-like growth factor-1 (IGF-1) pathway activation as a potential therapeutic approach for motor neuron diseases. The present study challenges this point of view and brings the alternative hypothesis that reducing rather than enhancing the IGF-1 signaling pathway exerts a neuroprotective effect in SMA. Furthermore, the present data substantiate a newly emerging concept that the modulation of IGF-1 receptor expression is a key event selectively determining the activation level of intracellular pathways that lie downstream of the receptor. This aspect should be considered when designing IGF-1-based treatments for neurodegenerative diseases.

The effect of the DcpS inhibitor D156844 on the protective action of follistatin in mice with spinal muscular atrophy.

Spinal muscular atrophy (SMA), a leading genetic cause of pediatric death in the world, is an early-onset disease affecting the motor neurons in the anterior horn of the spinal cord. This degeneration of motor neurons leads to loss of muscle function. At the molecular level, SMA results from the loss of or mutation in the survival motor neuron 1 (SMN1) gene. The number of copies of the nearly duplicated gene SMN2 modulates the disease severity in humans as well as in transgenic mouse models for SMA. Most preclinical therapeutic trials focus on identifying ways to increase SMN2 expression and to alter its splicing. Other therapeutic strategies have investigated compounds which protect affected motor neurons and their target muscles in an SMN-independent manner. In the present study, the effect of a combination regimen of the SMN2 inducer D156844 and the protectant follistatin on the disease progression and survival was measured in the SMNΔ7 SMA mouse model. The D156844/follistatin combination treatment improved the survival of, delayed the end stage of disease in and ameliorated the growth rate of SMNΔ7 SMA mice better than follistatin treatment alone. The D156844/follistatin combination treatment, however, did not provide additional benefit over D156844 alone with respect to survival and disease end stage even though it provided some additional therapeutic benefit over D156844 alone with respect to motor phenotype.

Viral delivery of miR-196a ameliorates the SBMA phenotype via the silencing of CELF2.

Spinal and bulbar muscular atrophy (SBMA) is an inherited neurodegenerative disorder caused by the expansion of the polyglutamine (polyQ) tract of the androgen receptor (AR-polyQ). Characteristics of SBMA include proximal muscular atrophy, weakness, contraction fasciculation and bulbar involvement. MicroRNAs (miRNAs) are a diverse class of highly conserved small RNA molecules that function as crucial regulators of gene expression in animals and plants. Recent functional studies have shown the potent activity of specific miRNAs as disease modifiers both in vitro and in vivo. Thus, potential therapeutic approaches that target the miRNA processing pathway have recently attracted attention. Here we describe a novel therapeutic approach using the adeno-associated virus (AAV) vector­mediated delivery of a specific miRNA for SBMA. We found that miR-196a enhanced the decay of the AR mRNA by silencing CUGBP, Elav-like family member 2 (CELF2). CELF2 directly acted on AR mRNA and enhanced the stability of AR mRNA. Furthermore, we found that the early intervention of miR-196a delivered by an AAV vector ameliorated the SBMA phenotypes in a mouse model. Our results establish the proof of principle that disease-specific miRNA delivery could be useful in neurodegenerative diseases.

Testosterone reduced methylprednisolone-induced muscle atrophy in spinal cord-injured rats.

STUDY DESIGN: Male rats with complete transections of the spinal cord were administered vehicle or methylprednisolone (MP) for 24 h, with or without infusion, for 7 days, of testosterone at either a replacement or low pharmacological doses. Muscles were collected at 7 days after SCI. OBJECTIVE: The objective of this study is to determine, in a rat model of complete spinal cord transection, whether testosterone reduces muscle atrophy or upregulates muscle atrophy-linked genes, induced by 24 h of MP administration at doses comparable to those prescribed in man during the period immediately following acute spinal cord injury (SCI) in an attempt to preserve neurological function. RESULTS: MP significantly reduced the mass of triceps, soleus and plantaris, and significantly increased expression of genes that promote atrophy. Testosterone significantly reduced muscle atrophy induced by MP, but did not prevent it; there was no difference between low- or high-dose testosterone in reducing MP-induced muscle loss. High-dose testosterone reduced expression of muscle atrophy genes more than did low dose. Testosterone-induced declines in mRNA levels for these atrophy-associated genes did not correlate well with protection against MP-induced muscle atrophy. CONCLUSIONS: MP induces marked and lasting changes in the biology of muscle that persisted for at least 7 days, or 6 days after MP has been eliminated from the body. Testosterone partially protected against muscle atrophy and gene expression changes caused by 1 day of MP.

In vivo NMDA receptor activation accelerates motor unit maturation, protects spinal motor neurons, and enhances SMN2 gene expression in severe spinal muscular atrophy mice.

Spinal muscular atrophy (SMA), a lethal neurodegenerative disease that occurs in childhood, is caused by the misexpression of the survival of motor neuron (SMN) protein in motor neurons. It is still unclear whether activating motor units in SMA corrects the delay in the postnatal maturation of the motor unit resulting in an enhanced neuroprotection. In the present work, we demonstrate that an adequate NMDA receptor activation in a type 2 SMA mouse model significantly accelerated motor unit postnatal maturation, counteracted apoptosis in the spinal cord, and induced a marked increase of SMN expression resulting from a modification of SMN2 gene transcription pattern. These beneficial effects were dependent on the level of NMDA receptor activation since a treatment with high doses of NMDA led to an acceleration of the motor unit maturation but favored the apoptotic process and decreased SMN expression. In addition, these results suggest that the NMDA-induced acceleration of motor unit postnatal maturation occurred independently of SMN. The NMDA receptor activating treatment strongly extended the life span in two different mouse models of severe SMA. The analysis of the intracellular signaling cascade that lay downstream the activated NMDA receptor revealed an unexpected reactivation of the CaMKII/AKT/CREB (cAMP response element-binding protein) pathway that induced an enhanced SMN expression. Therefore, pharmacological activation of spinal NMDA receptors could constitute a useful strategy for both increasing SMN expression and limiting motor neuron death in SMA spinal cord.

Spinal muscular atrophy: newborn and carrier screening.

Spinal muscular atrophy (SMA) is a common autosomal-recessive neuromuscular disorder caused by mutations in the survival motor neuron (SMN1) gene, affecting approximately 1 in 10,000 live births. The disease is characterized by progressive symmetric muscle weakness resulting from the degeneration and loss of anterior horn cells in the spinal cord and brainstem nuclei. The management of SMA involves supportive and preventive strategies. New treatments based on increasing the expression of full-length SMN protein levels from the SMN2 gene are being investigated and may be dependent on early detection of the disorder, before the irreversible loss of motor neurons. This article focuses on the prevention of SMA through population carrier screening and newborn screening as a means of ensuring early intervention for SMA.

Modulation of inflammation by vitamin E and C supplementation prior to anterior cruciate ligament surgery.

Muscle atrophy commonly follows anterior cruciate ligament (ACL) injury and surgery. Proinflammatory cytokines can induce and exacerbate oxidative stress, potentiating muscle atrophy. The purpose of this study was to evaluate the influence of prior antioxidant (AO) supplementation on circulating cytokines following ACL surgery. A randomized, double-blind, placebo-controlled trial was conducted in men undergoing ACL surgery, who were randomly assigned to either: (1) AO (200 IU of vitamin E (50% d-alpha-tocopheryl acetate and 50% d-alpha-tocopherol) and 500 mg ascorbic acid), or (2) matching placebos (PL). Subjects took supplements twice daily for 2 weeks prior to and up to 12 weeks after surgery. Each subject provided five blood samples: (1) baseline (Bsl, prior to supplementation and approximately 2 weeks prior to surgery), (2) presurgery (Pre), (3) 90 min, (4) 72 h, and (5) 7 days postsurgery. Following surgery, inflammation and muscle damage increased in both groups, as assessed by increased circulating IL-6, C-reactive protein, and creatine kinase. During AO supplementation, plasma alpha-T and AA increased while gamma-T concentrations decreased significantly (P< 0.05). At 90 min the AO group displayed a significant decrease in AA, an inverse correlation between AA and (interleukin) IL-8 (r(2)= 0.50, P< 0.05), and a significantly lower IL-10 response than that of the PL group. IL-10 was significantly elevated at 90 min and 72 h in the PL group. In summary, our findings show that circulating inflammatory cytokines increase and AO supplementation attenuated the increase in IL-10 in patients post-ACL surgery.

Understanding the experience of living with spinal muscular atrophy: a qualitative description.

Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease caused by the progressive degeneration of motor neurons in the spinal cord. The disorder causes weakness and wasting of voluntary muscles. The purpose of this study was to describe the experience of living with SMA. Strategies used to manage symptoms and progression were also identified. Through e-mail communication, 11 participants were asked to respond to 5 questions about experiences with parents, family, friends, school, and healthcare providers, as well as provide demographic information. Participants were asked to describe their illness and the strategies used to optimize management. Data were analyzed in an ongoing manner through a constant comparative method. The experience of living with SMA was described as challenging and constantly changing. Four major themes were generated that described the experience of living with SMA: establishing strong relationships, normalizing and mainstreaming in society, using an innovative approach to symptom management, and maintaining optimism. Participants described both physical and emotional strategies for symptom management.

Comparison of the effect of 3 different approaches to the lumbar spinal canal on postoperative paraspinal muscle damage.

BACKGROUND: To assess the effect of 3 different surgical approaches on paraspinal muscle atrophy in patients undergoing lumbar back surgery, we compared their pre- and postoperative CT scans and their serum Hb, CRP, and CPK levels. METHODS: The study population consisted of 71 patients who had undergone lumbar back surgery with microscopic posterior decompression without fusion. We examined the effect on paraspinal muscle atrophy of 3 different approaches to the spinal canal. Group 1 (n = 19) underwent unilateral paraspinal dissection from the spinous process with cutting of the spinous process. In group 2 (n = 24), we used modified bilateral decompression via hemilaminectomy, and group 3 (n = 28) was treated by modified bilateral decompression via spinous process splitting. We measured the levels of CPK, Hb, and CRP preoperatively and on the first postoperative day, and compared the preoperative volume of the paraspinal muscle with the volume measured 1 year after the operation. RESULTS: Age, sex, operative time, and CRP and Hb levels were not statistically different among the 3 groups. The postoperative elevation of CPK was significantly lower in groups 2 and 3 than in group 1. Group 3 manifested a significantly lower degree of atrophic changes of the paraspinal muscle than groups 1 and 2. CONCLUSIONS: We found that among the 3 approaches evaluated, modified bilateral decompression via spinous process splitting is less invasive, facilitates preservation of the paraspinal muscle, and is a useful approach to posterior spinal elements resulting in decreased muscle damage.