Myoinositol Attenuates the Cell Loss and Biochemical Changes Induced by Kainic Acid Status Epilepticus

Long-term effects of myo-inositol on traumatic brain injury: Epigenomic and transcriptomic studies

Background and purpose

Traumatic brain injury (TBI) and its consequences remain great challenges for neurology. Consequences of TBI are associated with various alterations in the brain but little is known about long-term changes of epigenetic DNA methylation patterns. Moreover, nothing is known about potential treatments that can alter these epigenetic changes in beneficial ways. Therefore, we have examined myo-inositol (MI), which has positive effects on several pathological conditions.

Methods

TBI was induced in mice by controlled cortical impact (CCI). One group of CCI animals received saline injections for two months (TBI+SAL), another CCI group received MI treatment (TBI+MI) for the same period and one group served as a sham-operated control. Mice were sacrificed 4 months after CCI and changes in DNA methylome and transcriptomes were examined.

Results

For the first time we: (i) provide comprehensive map of long-term DNA methylation changes after CCI in the hippocampus; (ii) identify differences by methylation sites between the groups; (iii) characterize transcriptome changes; (iv) provide association between DNA methylation sites and gene expression. MI treatment is linked with upregulation of genes covering 33 biological processes, involved in immune response and inflammation. In support of these findings, we have shown that expression of BATF2, a transcription factor involved in immune-regulatory networks, is upregulated in the hippocampus of the TBI+MI group where the BATF2 gene is demethylated.

Conclusion

TBI is followed by long-term epigenetic and transcriptomic changes in hippocampus. MI treatment has a significant effect on these processes by modulation of immune response and biological pathways of inflammation.

Role of myo-inositol in acute kidney injury induced by cisplatin

There is an increasing evidence suggesting that myo-inositol (MI) may be a renoprotective factor. Our previous study revealed that decreased MI concentrations and increased excretion are often observed in animal models of renal injury and in patients with nephropathy. However, the role of MI supplementation in renal injury remains unclear. In this study, we aimed to explore the role of MI in cisplatin-induced acute kidney injury (AKI). We established a model of acute kidney injury caused by cisplatin (CDDP). Male Kunming mice were randomly divided into six groups: Sham (normal saline), CDDP (15 mg/kg), + MI (150 mg/kg), + MI (300 mg/kg), + MI (600 mg/kg) and MI (600 mg/kg). Human renal tubular epithelial cell line HK-2 cells were likewise separated into six groups at random: Control (normal saline), CDDP (20 µM), + MI (200 µM), + MI (400 µM), + MI (800 µM) and MI (800 µM). After the model was established, renal function indexes were subsequently detected, and experiments such as pathological staining analysis and protein expression analysis were performed. Our results showed that cisplatin administration led to AKI and apoptosis in mice and HK-2 cells, accompanied by markedly increased levels of MIOX, kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), whereas exogenous MI significantly attenuated kidney injury and HK-2 cell damage induced by cisplatin both in vivo and in vitro by inhibiting excessive apoptosis. Overall, our findings demonstrate that exogenous MI can reduce excessive apoptosis, thus playing a protective role in cisplatin-induced AKI, indicating that exogenous MI may be used as an adjunctive treatment modality in cisplatin-induced AKI.

Mechanism of cell death pathways in status epilepticus and related therapeutic agents

The most severe form of epilepsy, status epilepticus (SE), causes brain damage and results in the development of recurring seizures. Currently, the management of SE remains a clinical challenge because patients do not respond adequately to conventional treatments. Evidence suggests that neural cell death worsens the occurrence and progression of SE. The main forms of cell death are apoptosis, necroptosis, pyroptosis, and ferroptosis. Herein, these mechanisms of neuronal death in relation to SE and the alleviation of SE by potential modulators that target neuronal death have been reviewed. An understanding of these pathways and their possible roles in SE may assist in the development of SE therapies and in the discovery of new agents.

Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats

Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound-myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.

Concentration- and time-dependent effects of myo-inositol on evoked epileptic afterdischarge in the hippocampus in vivo

Epilepsy is one of the most widespread neurological diseases characterized by spontaneous recurrent seizures. There is no cure for epilepsy, and available pharmacological treatments with anti-seizure drugs are only symptomatic. Moreover, about third of epilepsy patients are resistant to the anti-seizure drugs. Thus, it is essential to discover new anti-epilepsy drugs. Recently, myo-inositol has been identified as a promising antiepileptic compound. In the present study, using electrophysiological method, we examined for the first time, the effect of myo-inositol on the generation of epileptic afterdischarges in the hippocampus evoked by a local electrical stimulation. This was achieved by implanting two electrodes with a cannula into the same dorsal hippocampus, which allowed for simultaneous local injection of myo-inositol or saline and afterdischarges induction and recording from the same hippocampus. We found that myo-inositol has time- and concentration-dependent effects on the evoked afterdischarges. Specifically, 5 minutes after 1 M myo-inositol infusion, the afterdischarges duration was significantly decreased as compared to preinjection durations in the same animals and also as compared to preinjection level durations in saline injected or contralateral hippocampus myo-inositol infused animals. Further, 0.055 M myo-inositol significantly decreased afterdischarges duration at 5 minutes as compared to 40 minutes post-injection. At both concentrations, the afterdischarges duration recovered to the pre-injection value at 40 minutes after the myo-inositol injection. The present data, taken together with our previous results, strongly suggest that myo-inositol has significant local seizure-suppressant effect.

Long-Term Effects of Myoinositol on Behavioural Seizures and Biochemical Changes Evoked by Kainic Acid Induced Epileptogenesis

Epilepsy is one of the most devastating neurological diseases and despite significant efforts there is no cure available. Occurrence of spontaneous seizures in epilepsy is preceded by numerous functional and structural pathophysiological reorganizations in the brain—a process called epileptogenesis. Treatment strategies targeting this process may be efficient for preventing spontaneous recurrent seizures (SRS) in epilepsy, or for modification of disease progression. We have previously shown that (i) myoinositol (MI) pretreatment significantly decreases severity of acute seizures (status epilepticus: SE) induced by kainic acid (KA) in experimental animals and (ii) that daily post-SE administration of MI for 4 weeks prevents certain biochemical changes triggered by SE. However it was not established whether such MI treatment also exerts long-term effects on the frequency of SRS. In the present study we have shown that, in KA-induced post-SE epilepsy model in rats, MI treatment for 28 days reduces frequency and duration of behavioural SRS not only during the treatment, but also after its termination for the following 4 weeks. Moreover, MI has significant effects on molecular changes in the hippocampus, including mi-RNA expression spectrum, as well as mRNA levels of sodium-MI transporter and LRRC8A subunit of the volume regulated anionic channel. Taken together, these data suggest that molecular changes induced by MI treatment may counteract epileptogenesis. Thus, here we provide data indicating antiepileptogenic properties of MI, which further supports the idea of developing new antiepileptogenic and disease modifying drug that targets MI system.

Taurine reduces blue light-induced retinal neuronal cell apoptosis in vitro

BACKGROUND

The massive uptake of organic compatible osmolytes is a self-protective response to multiple stressors.

OBJECTIVE

This study aimed to determine the protective effects of the osmolyte taurine against blue light-induced apoptosis in retinal neuronal cells in vitro.

METHODS

Real-time PCR was used to measure osmolyte transport. Radioimmunoassays were performed to measure osmolyte uptake. Cell Counting Kit-8 assays were conducted to measure cellular viability. Flow cytometry analysis was used to measure apoptosis.

RESULTS

Compared with normotonic stress, hypertonic stress-induced uptake of osmolytes, including betaine, myoinositol, and taurine, into the retinal neuronal cells. Blue light increased osmolyte transporter mRNA expression together with osmolyte uptake. Furthermore, taurine significantly suppressed blue light-induced retinal neuronal cell apoptosis.

CONCLUSION

The compatible osmolyte taurine may have an important role in cell resistance to blue light and cell survival.