mTOR pathway - a potential therapeutic target in stroke

Potential Ameliorating Effects of Fluvoxamine in a Rat Model of Endotoxin-Induced Neuroinflammation: Molecular Aspects Through SIRT-1/GPX-4 and HMGB-1 Signaling

Research on the tissue-protective effects of fluvoxamine (FLV), a selective serotonin reuptake inhibitor, rapidly expands. This study explores FLV's potential to protect against lipopolysaccharide (LPS)-induced neuroinflammation, a key factor in systemic inflammation-related neuronal damage. Four equal groups of thirty-two female Wistar Albino rats were created: FLV, LPS-FLV (50 mg/kg intraperitoneal), LPS (5 mg/kg intraperitoneal), and control. Both drugs were given in one dose on the same day. Tissues from the brain cortex, cerebellum, and hippocampus were taken for histopathology, immunohistochemistry, biochemistry, and genetic analysis. In the LPS group, histological examinations revealed hyperemia, edema, mild degeneration, neuronal death, and modest gliosis. Additionally, while apelin and total antioxidant status levels were reduced, greater levels of oxidative stress index, glial fibrillary acidic protein (GFAP), mammalian target of rapamycin (mTOR), and total oxidant status were noted. FLV treatment reversed all these findings. Genetic analyses revealed that LPS decreased sirtuin-1 (SIRT-1) and glutathione peroxidase 4 (GPX-4) while increasing high mobility group box protein 1 (HMGB-1). FLV treatment reversed all these parameters, and a significant result was obtained only with GPX-4. In this study, FLV treatment was shown to have anti-inflammatory and neuroprotective effects through various mechanisms on the brain cortex, cerebellum, and hippocampus tissues in addition to its antidepressant effects.

LM22A-4-loaded smart mesoporous balls enhance neuroprotection and functional recovery after ischemic stroke

Stroke is globally recognized as the second leading cause of death, significantly impairing both motor and cognitive functions. Enhancing regeneration after stroke is crucial for restoring these functions and necessitates strategies to promote neuroregeneration to achieve better post-stroke outcomes. Brain-derived neurotrophic factor (BDNF) plays a key role in neuroregeneration by influencing motor ability, learning, memory, and rehabilitation after stroke. However, challenges such as the substantial protein size, short half-life of BDNF, and blood-brain barrier hinder its efficient delivery to the brain. In this study, LM22A-4, a BDNF mimetic, was utilized and delivered through a Smart Mesoporous Ball (SMB-3) system to target the ischemic injured brain and explore its potential therapeutic effects in a mouse ischemic stroke model. Treatment with LM22A-4-loaded SMB-3 (LM22A-4-SMB-3) markedly restored neurological, motor, and cognitive deficits following ischemic stroke compared to LM22A-4 alone. Additionally, administration of LM22A-4-SMB-3 reduced apoptotic cell death and glial activation, as evidenced by the TUNEL assay results, and decreased GFAP and Iba-1 expression levels. Furthermore, the phosphorylation of TrkB and Akt, but not that of Erk, was considerably increased in the LM22A-4-SMB-3-treated group. Treatment also enhanced the number of BrdU+/NeuN+ cells, with a marked reduction in post-stroke brain atrophy. These findings suggest that LM22A-4-SMB-3 can attenuate ischemic damage and recover neurological, motor, and cognitive functions by increasing p-TrkB and p-Akt levels and promoting neurogenesis. Therefore, SMB-3-mediated delivery of LM22A-4 presents a potentially applicable delivery system, and LM22A-4-SMB-3 use could be considered a novel therapeutic strategy to improve post-stroke outcomes.

Moyamoya phenomenon following clipping of intracranial aneurysm: case report

Subarachnoid haemorrhage from aneurysmal rupture is a common emergency in neurosurgery. Depending on aneurysm position, morphology, size, associated clot, and symptoms, it is either managed by endovascular occlusion or by clipping. Here we report the first known case of secondary Moyamoya phenomenon following the clipping of a supraclinoid internal carotid artery Aneurysm. After making a complete recovery following clipping, this patient developed headaches 6 years later. Angiographic imaging revealing Moyamoya phenomenon characterized by total distal arterial occlusion and development of anastomotic collaterals. This phenomenon may be caused by neuroinflammation and suggests a tailored neuroimaging follow-up is required for such patients.

The effect of Miya on skeletal muscle changes by regulating gut microbiota in rats with osteoarthritis through AMPK pathway

BACKGROUND

The study aimed to explore whether Miya (MY), a kind of Clostridium butyricum, regulated osteoarthritis (OA) progression through adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway.

METHODS

The OA rats were orally given MY daily for 4 weeks and were intramuscularly injected with AMPK inhibitor once a week for 4 weeks. Hematoxylin eosin (HE) staining was used to observe the histological morphology of the knee joint. The levels of succinate dehydrogenase (SDH) and muscle glycogen (MG) in the tibia muscle of rats were detected by the corresponding kits, as well as the expression of related genes/proteins were assessed by real-time quantitative PCR (RT-qPCR) and western blot.

RESULTS

HE staining suggested that MY suppressed the symptoms of OA, which was abolished by AMPK inhibitor. Furthermore, the SDH and MG contents in the OA + MY + AMPK inhibitor group were lower than in the OA + MY group. At last, the levels of AMPK, PI3K, AKT1, Ldh, Myod, Chrna1, and Chrnd were notably decreased after AMPK inhibitor treatment, while the levels of Lcad and Mcad were up-regulated by AMPK inhibitor. Furthermore, their protein expression levels detected by western blot were consistent with those from RT-qPCR.

CONCLUSION

MY may partially regulate skeletal muscle changes and prevente OA development through the AMPK pathway.

mTOR Dysregulation, Insulin Resistance, and Hypertension

Worldwide, diabetes mellitus (DM) and cardiovascular diseases (CVDs) represent serious health problems associated with unhealthy diet and sedentarism. Metabolic syndrome (MetS) is characterized by obesity, dyslipidemia, hyperglycemia, insulin resistance (IR) and hypertension. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase with key roles in glucose and lipid metabolism, cell growth, survival and proliferation. mTOR hyperactivation disturbs glucose metabolism, leading to hyperglycemia and further to IR, with a higher incidence in the Western population. Metformin is one of the most used hypoglycemic drugs, with anti-inflammatory, antioxidant and antitumoral properties, having also the capacity to inhibit mTOR. mTOR inhibitors such as rapamycin and its analogs everolimus and temsirolimus block mTOR activity, decrease the levels of glucose and triglycerides, and reduce body weight. The link between mTOR dysregulation, IR, hypertension and mTOR inhibitors has not been fully described. Therefore, the main aim of this narrative review is to present the mechanism by which nutrients, proinflammatory cytokines, increased salt intake and renin-angiotensin-aldosterone system (RAAS) dysregulation induce mTOR overactivation, associated further with IR and hypertension development, and also mTOR inhibitors with higher potential to block the activity of this protein kinase.

Interaction of ncRNAs and the PI3K/AKT/mTOR pathway: Implications for osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents, and is characterized by high heterogeneity, high malignancy, easy metastasis, and poor prognosis. Recurrence, metastasis, and multidrug resistance are the main problems that limit the therapeutic effect and prognosis of OS. PI3K/AKT/mTOR signaling pathway is often abnormally activated in OS tissues and cells, which promotes the rapid development, metastasis, and drug sensitivity of OS. Emerging evidence has revealed new insights into tumorigenesis through the interaction between the PI3K/AKT/mTOR pathway and non-coding RNAs (ncRNAs). Therefore, we reviewed the interactions between the PI3K/AKT/mTOR pathway and ncRNAs and their implication in OS. These interactions have the potential to serve as cancer biomarkers and therapeutic targets in clinical applications.

GAS5 lncRNA: A biomarker and therapeutic target in breast cancer

Breast cancer is one of the most common causes of cancer-related mortality globally, and its aggressive phenotype results in poor treatment outcomes. Growth Arrest-Specific 5 long non-coding RNA has attracted considerable attention due to its pivotal function in apoptosis regulation and tumor aggressiveness in breast cancer. Gas5 enhances apoptosis by regulating apoptotic proteins, such as caspases and BCL2 family proteins, and the sensitivity of BCCs to chemotherapeutic agents. At the same time, low levels of GAS5 increased invasion, metastasis, and overall tumor aggressiveness. GAS5 also regulates EMT markers, critical for cancer metastasis, and influences tumor cell proliferation by regulating various signaling components. As a result, GAS5 can be restored to suppress tumor development as a possible therapeutic strategy, which might present promising prospects for a patient's treatment. Its activity levels might also be a crucial indicator and diagnostic parameter for prediction. This review highlights the significant role of GAS5 in modulating apoptosis and tumor aggressiveness in breast cancer, emphasizing its potential as a therapeutic target for breast cancer treatment and management.

Development of Pharmacological Strategies with Therapeutic Potential in Ischemic Stroke

Acute ischemic stroke constitutes a health challenge with great social impact due to its high incidence, with the social dependency that it generates being an important source of inequality. The lack of treatments serving as effective neuroprotective therapies beyond thrombolysis and thrombectomy is presented as a need. With this goal in mind, our research group's collaborative studies into cerebral ischemia and subsequent reperfusion concluded that there is a need to develop compounds with antioxidant and radical scavenger features. In this review, we summarize the path taken toward the identification of lead compounds as potential candidates for the treatment of acute ischemic stroke. Evaluations of the antioxidant capacity, neuroprotection of primary neuronal cultures and in vivo experimental models of cerebral ischemia, including neurological deficit score assessments, are conducted to characterize the biological efficacy of the various neuroprotective compounds developed. Moreover, the initial results in preclinical development, including dose-response studies, the therapeutic window, the long-term neuroprotective effect and in vivo antioxidant evaluation, are reported. The results prompt these compounds for clinical trials and are encouraging regarding new drug developments aimed at a successful therapy for ischemic stroke.