Dantrolene enhances the protective effect of hypothermia on cerebral cortex neurons

Current clinical application of dantrolene sodium

Dantrolene sodium (DS) was first introduced as an oral antispasmodic drug. However, in 1975, DS was demonstrated to be effective for managing malignant hyperthermia (MH) and was adopted as the primary therapeutic drug after intravenous administration. However, it is difficult to administer DS intravenously to manage MH. MH is life-threatening, pharmacogenomically related, and induced by depolarizing neuromuscular blocking agents or inhalational anesthetics. All anesthesiologists should know the pharmacology of DS. DS suppresses Ca2+ release from ryanodine receptors (RyRs). RyRs are expressed in various tissues, although their distribution differs among subtypes. The anatomical and physiological functions of RyRs have also been demonstrated as effective therapeutic drugs for cardiac arrhythmias, Alzheimer's disease, and other RyR-related diseases. Recently, a new formulation was introduced that enhanced the hydrophilicity of the lipophilic DS. The authors summarize the pharmacological properties of DS and comment on its indications, contraindications, adverse effects, and interactions with other drugs by reviewing reference articles.

Could dantrolene be explored as a repurposed drug to treat COVID-19 patients by restoring intracellular calcium homeostasis?

Dantrolene, an FDA approved drug to treat malignant hyperthermia and muscle spasm, has been demonstrated to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mediated toxicity of host cells. Ryanodine receptor overactivation and associated disruption of intracellular Ca2+ homeostasis play important roles in SARS-CoV-2 infection and replication of host cells. Dantrolene, as an inhibitor of RyRs, is expected to ameliorate these detrimental effects of SARS-CoV-2 in host cells. Additionally, dantrolene has also been shown to inhibit multiple cell or organ damage induced by hypoxia/ischemia, mitochondria damage, oxidative stresses, inflammation, impairment of autophagy and apoptosis, etc., which are often the causes of severity and mortality of COVID-19 patients. We have repurposed that dantrolene has a high potential at treating COVID-19 patients and reducing its morbidity and mortality.

Control of Shivering During Targeted Temperature Management

Targeted temperature management (TTM) is used frequently in patients with a variety of diseases, especially those who have experienced brain injury and/or cardiac arrest. Shivering is one of the main adverse effects of TTM that can often limit its implementation and efficacy. Shivering is the body's natural response to hypothermia and its deleterious effects can negate the benefits of TTM. The purpose of this article is to provide an overview of TTM strategies and shivering management.

Neuroprotection by Therapeutic Hypothermia

Hypothermia therapy is an old and important method of neuroprotection. Until now, many neurological diseases such as stroke, traumatic brain injury, intracranial pressure elevation, subarachnoid hemorrhage, spinal cord injury, hepatic encephalopathy, and neonatal peripartum encephalopathy have proven to be suppressed by therapeutic hypothermia. Beneficial effects of therapeutic hypothermia have also been discovered, and progress has been made toward improving the benefits of therapeutic hypothermia further through combination with other neuroprotective treatments and by probing the mechanism of hypothermia neuroprotection. In this review, we compare different hypothermia induction methods and provide a summarized account of the synergistic effect of hypothermia therapy with other neuroprotective treatments, along with an overview of hypothermia neuroprotection mechanisms and cold/hypothermia-induced proteins.

Effects of Therapeutic Hypothermia Combined with Other Neuroprotective Strategies on Ischemic Stroke: Review of Evidence

Ischemic stroke is a major cause of death and disability globally, and its incidence is increasing. The only treatment approved by the US Food and Drug Administration for acute ischemic stroke is thrombolytic treatment with recombinant tissue plasminogen activator. As an alternative, therapeutic hypothermia has shown excellent potential in preclinical and small clinical studies, but it has largely failed in large clinical studies. This has led clinicians to explore the combination of therapeutic hypothermia with other neuroprotective strategies. This review examines preclinical and clinical progress towards developing highly effective combination therapy involving hypothermia for stroke patients.

Protective effect of TSG against oxygen-glucose deprivation in cardiomyoblast cell line H9c2: involvement of Bcl-2 family, Caspase 3/9, and Akt signaling pathway

OBJECTIVE

This study was designed to investigate the effect of TSG (2, 3, 5, 4'-tetrahydroxystibene-2-O-β-D-glucoside) on ischemic cardiomyopathy (ICM) related cell apoptosis and the mechanism related to it in vitro.

METHODS

Rat cardiomyoblast cell line H9c2 was cultured in oxygen-glucose withdrawal medium for 8 hours to establish an in vitro cell model of oxygen-glucose deprivation (OGD). Cells were pretreated with TSG to test the protective effect of it against OGD. Cell viability, apoptosis, mitochondrial transmembrane potential (ΔΨ_m), and apoptosis related proteins were detected using appropriated methods. Differences between treatments were analyzed.

RESULTS

OGD treatment inhibited cell viability, expression of Akt and Bax, induced loss of ΔΨ_m, cell apoptosis, and triggered expression of Bcl-2 and Caspase-3/9. TSG pretreatment, on the contrary, suppressed OGD-induced cell apoptosis, ΔΨ_m loss, Bcl-2 and Caspase-3/9 expression, and promoted OGD-inhibited cell viability, Bax and Akt expression.

CONCLUSION

We concluded that TSG's protective effect against OGD-induced in vitro ischemic cell model was associated to Akt/Caspase-3 pathway. TSG might be explored as a therapeutic target for ICM.

Compound heterozygous RYR1 mutations in a preterm with arthrogryposis multiplex congenita and prenatal CNS bleeding

RYR1 mutations, the most common cause of non-dystrophic neuromuscular disorders, are associated with the malignant hyperthermia susceptibility (MHS) trait as well as congenital myopathies with widely variable clinical and histopathological manifestations. Recently, bleeding anomalies have been reported in association with certain RYR1 mutations. Here we report a preterm infant born at 32 weeks gestation with arthrogryposis multiplex congenita due to compound heterozygous, previously MHS-associated RYR1 mutations, with additional signs of prenatal hemorrhage. The patient presented at birth with multiple joint contractures, scoliosis, severe thoracic rigidity and respiratory failure. He continued to depend on mechanical ventilation and tube feeding. Muscle histopathology showed a marked myopathic pattern with eccentric cores. Interestingly, the patient had additional unusual prenatal intraventricular hemorrhage, resulting in post-hemorrhagic hydrocephalus as well as epidural hemorrhage affecting the spinal cord. This report adds to the phenotypic variability associated with RYR1 mutations, and highlights possible bleeding complications in affected individuals.