Therapeutics effects of [Pyr1] apelin-13 on rat contusion model of spinal cord injury: An experimental study

Neuroprotective effect of human cord blood-derived extracellular vesicles by improved neuromuscular function and reduced gliosis in a rat model of Huntington's disease

Huntington's disease (HD) is a hereditary condition characterized by the gradual deterioration of nerve cells in the striatum. Recent scientific investigations have revealed the promising potential of Extracellular vesicles (EVs) as a therapy to mitigate inflammation and enhance motor function. This study aimed to examine the impact of administering EVs derived from human umbilical cord blood (HUCB) on the motor abilities and inflammation levels in a rat model of HD. After ultracentrifugation to prepare EVs from HUCB to determine the nature of the obtained contents, the expression of CD markers 81 and 9, the average size and also the morphology of its particles were investigated by DLS and Transmission electron microscopy (TEM). Then, in order to induce the HD model, 3-nitropropionic acid (3-NP) neurotoxin was injected intraperitoneal into the rats, after treatment by HUCB-EVs, rotarod, electromyogram (EMG) and the open field tests were performed on the rats. Finally, after rat sacrifice and the striatum was removed, Hematoxylin and eosin staining (H&E), stereology, immunohistochemistry, antioxidant tests, and western blot were performed. Our results showed that the contents of the HUCB-EVs express the CD9 and CD81 markers and have spherical shapes. In addition, the injection of HUCB-EVs improved motor and neuromuscular function, reduced gliosis, increased antioxidant activity and inflammatory factor, and partially prevented the decrease of neurons. The findings generally show that HUCB-EVs have neuroprotective effects and reduce neuroinflammation from the toxic effects of 3-NP, which can be beneficial for the recovery of HD.

The Role of Adipokines in the Pathologies of the Central Nervous System

Adipokines are protein hormones secreted by adipose tissue in response to disruptions in physiological homeostasis within the body's systems. The regulatory functions of adipokines within the central nervous system (CNS) are multifaceted and intricate, and they have been identified in a number of pathologies. Therefore, specific adipokines have the potential to be used as biomarkers for screening purposes in neurological dysfunctions. The systematic review presented herein focuses on the analysis of the functions of various adipokines in the pathogenesis of CNS diseases. Thirteen proteins were selected for analysis through scientific databases. It was found that these proteins can be identified within the cerebrospinal fluid either by their ability to modify their molecular complex and cross the blood-brain barrier or by being endogenously produced within the CNS itself. As a result, this can correlate with their measurability during pathological processes, including Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, depression, or brain tumors.

Neuroprotective Roles of Apelin-13 in Neurological Diseases

Apelin is a natural ligand for the G protein-coupled receptor APJ, and the apelin/APJ system is widely distributed in vivo. Among the apelin family, apelin-13 is the major apelin isoform in the central nervous system and cardiovascular system, and is involved in the regulation of various physiopathological mechanisms such as apoptosis, neuroinflammation, angiogenesis, and oxidative stress. Apelin is currently being extensively studied in the nervous system, and apelin-13 has been shown to be associated with the onset and progression of a variety of neurological disorders, including stroke, neurodegenerative diseases, epilepsy, spinal cord injury (SCI), and psychiatric diseases. This study summarizes the pathophysiological roles of apelin-13 in the development and progression of neurological related diseases.

Exogenous Apelin-13 Administration Ameliorates Cyclophosphamide- Induced Oxidative Stress, Inflammation, and Apoptosis in Rat Lungs

BACKGROUND

Apelin-13 is an endogenous adipocytokine known for its antioxidant, antiinflammatory, and antiapoptotic properties.

OBJECTIVE

We aimed to investigate the possible protective effects of exogenous Apelin-13 administration on oxidative stress, inflammation, and apoptosis induced by the cytotoxic agent cyclophosphamide (CP) in the lungs.

METHODS

Twenty-four male Wistar albino rats were divided into four groups: Control (saline), CP (200 mg/kg), Apelin-13 (10 μg/kg/day), and CP+Apelin-13. CP was administered as a single dose on the fifth day, and apelin-13 was administered intraperitoneally for five days. Total oxidant status (TOS), total antioxidant status (TAS), and lipid peroxidation were determined with spectrophotometry, TNFα and IL1β were determined with ELISA, APJ, Sirt1, NF-κB, and p53 mRNA expressions were determined with qRT-PCR, cytochrome (Cyt) C and caspase-3 protein expressions were studied with western blotting in lung tissues. The oxidative stress index (OSI) was also calculated. Furthermore, serum surfactant protein-D (SP-D) and Krebs von den Lungen-6 (KL-6) levels were measured with ELISA.

RESULTS

Compared to the control group, TOS, OSI, lipid peroxidation, TNFα, IL1β, cyt C, caspase-3, APJ, NF-κB, and p53 were higher, and Sirt1 was lower in the lung tissue of rats in the CP group. Serum KL-6 and SP-D levels were higher in the CP group. Co-administration of CP with Apelin-13 completely reversed the changes induced by CP administration.

CONCLUSION

Exogenous Apelin-13 treatment protected lung tissue against injury by inhibiting cyclophosphamide-induced oxidative stress, inflammation, and apoptosis. This protective effect of apelin-13 was accompanied by upregulation of the Sirt1 and downregulation of NF-κB/p53 in the lungs.

Promising Advances in Pharmacotherapy for Patients with Spinal Cord Injury-A Review of Studies Performed In Vivo with Modern Drugs

Spinal cord injury (SCI) is a pathological neurological condition that leads to significant motor dysfunction. It is a condition that occurs as a result of tragic accidents, violent acts, or as a consequence of chronic diseases or degenerative changes. The current treatments for patients with SCI have moderate efficacy. They improve the quality of life of patients, but they are still doomed to long-term disability. In response to the modern directions of research on possible therapeutic methods that allow for the recovery of patients with SCI, a scientific review publication is needed to summarize the recent developments in this topic. The following review is focused on the available pharmacological treatments for SCIs and the problems that patients face depending on the location of the injury. In the following review, the research team describes problems related to spasticity and neuropathic pain; possible therapeutic pathways are also described for neuroprotection and the improvement of neurotransmission within the injured spinal cord, and the review focuses on issues related to oxidative stress.

Therapeutic Effects of Photobiomodulation Therapy on Multiple Sclerosis by Regulating the Inflammatory Process and Controlling Immune Cell Activity: A Novel Promising Treatment Target

Introduction: Multiple sclerosis (MS) is one of the autoimmune and chronic diseases of the central nervous system; this disease occurs more frequently in young people and women and leads to neurological symptoms. Oxidative stress, inflammatory processes, and oligodendrocyte dysfunction have a pivotal role in the pathophysiology of this disease. Nowadays it is reported that photobiomodulation (PBM) as a non-invasive treatment has neuroprotective potential, but the exact mechanisms are not understood. Methods: In this study, we reviewed the effects of PBM on MS. In this regard, we used the keywords "Photobiomodulation", "Laser therapy", and "Low-level laser therapy" on MS to find related studies on this subject in PubMed, Google scholar, Elsevier, Medline, and Scopus databases. Results: PBM has positive effects on MS by regulating the inflammatory process, controlling immune cell activity and mitochondrial functions, as well as inhibiting free radicals production which finally leads to a reduction in neurological defects and an improvement in the functional status of patients. Conclusion: Overall, researchers have suggested the use of laser therapy in neurodegenerative diseases due to its numerous therapeutic effects.

Apelin alleviated neuroinflammation and promoted endogenous neural stem cell proliferation and differentiation after spinal cord injury in rats

Background

Spinal cord injury (SCI) causes devastating neurological damage, including secondary injuries dominated by neuroinflammation. The role of Apelin, an endogenous ligand that binds the G protein-coupled receptor angiotensin-like receptor 1, in SCI remains unclear. Thus, our aim was to investigate the effects of Apelin in inflammatory responses and activation of endogenous neural stem cells (NSCs) after SCI.

Methods

Apelin expression was detected in normal and injured rats, and roles of Apelin in primary NSCs were examined. In addition, we used induced pluripotent stem cells (iPSCs) as a carrier to prolong the effective duration of Apelin and evaluate its effects in a rat model of SCI.

Results

Co-immunofluorescence staining suggested that Apelin was expressed in both astrocytes, neurons and microglia. Following SCI, Apelin expression decreased from 1 to 14 d and re-upregulated at 28 d. In vitro, Apelin promoted NSCs proliferation and differentiation into neurons. In vivo, lentiviral-transfected iPSCs were used as a carrier to prolong the effective duration of Apelin. Transplantation of transfected iPSCs in situ immediately after SCI reduced polarization of M1 microglia and A1 astrocytes, facilitated recovery of motor function, and promoted the proliferation and differentiation of endogenous NSCs in rats.

Conclusion

Apelin alleviated neuroinflammation and promoted the proliferation and differentiation of endogenous NSCs after SCI, suggesting that it might be a promising target for treatment of SCI.

Adipocytokines: Emerging therapeutic targets for pain management

Although pain has lower mortality rates than cancer, diabetes and stroke, pain is a predominate source of distress and disability. However, the management of pain remains an enormous problem. Many drugs used to pain treatment have more or less side effects. Therefore, the development of novel therapeutic target is critical for the treatment of pain. Notably, studies have shown that adipocytokines have a dual role in pain. Growing shreds of evidence shows that the levels of adipocytokines are upregulated or downregulated in the development of pain. In addition, substantial evidence indicates that regulation of adipocytokines levels in models of pain attenuates or promotes pain behaviors. In this review, we summarized and discussed the effect of adipocytokines in pain. These evidence indicates that adipocytokines attenuate or promote pain behaviors through interacting with their receptors, activating serotonin pathway, interacting with μ-opioid receptor, activating microglia, infiltrating macrophage and so on. Overall, adipocytokines have some potential in treating pain, but the underlying mechanisms remain unclear and need to be further studied.

The ROCK inhibitor Y-27632 ameliorates blood-spinal cord barrier disruption by reducing tight junction protein degradation via the MYPT1-MLC2 pathway after spinal cord injury in rats

The blood-spinal cord barrier (BSCB) is a physiological barrier between the blood and spinal cord parenchyma. This study aims to determine whether Y-27632, a Rho-associated protein kinase (ROCK) inhibitor, can protect the BSCB using in vivo models. The Evans blue fluorescence assay was used to detect leakage of the BSCB. Western blotting was used to define alterations in ROCK-related and tight junction (TJ) protein expression. Immunofluorescence triple-staining was used to evaluate histologic alterations in TJs. Locomotor function was evaluated using the open-field test, the Basso-Beattie-Bresnahan score, and footprint analysis. Two peaks of BSCB leakage after spinal cord injury (SCI) occurred at 24 h and 5 days. The ROCK inhibitor reduced the BSCB leakage at the second peak after SCI. Moreover, the ROCK inhibitor ameliorated the integrity of the BSCB and improved motor function recovery after SCI by regulating the phosphorylation of myosin phosphatase subunit-1 (MYPT1) and cofilin. ROCK inhibitors might protect the BSCB, which provides a new strategy for transitioning SCI treatment from the bench to bedside.

Photobiomodulation therapy improved functional recovery and overexpression of interleukins-10 after contusion spinal cord injury in rats

Following severe Spinal Cord Injury (SCI), regeneration is inadequate, and functional recovery is incomplete. The occurrence of oxidative stress and the spread of inflammation play a crucial role in the failure to regenerate the injury site. In this way, we explored the neuroprotective effects of PhotoBioModulation (PBM), as the main factor in controlling these two destructive factors, on SCI. fifty-four female adult Wistar rats divided into three groups: sham group (just eliminate vertebra lamina, n = 18), SCI group (n = 18), and SCI-PBM group which exposed to PBM (150 MW, 50 min/day, 14 days, n = 18). After SCI induction at the endpoint of the study (the end of 8 week), we took tissue samples from the spinal cord for evaluating the biochemical profiles that include Catalase (CAT), Malondialdehyde (MDA), Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-PX) levels, immunohistochemistry for Caspase-3, gene expressions of Interleukin-1β (IL-1β), Tumor Necrosis Factor-alpha (TNF-α), and Interleukin (IL-10). Also, stereological assessments evaluated the spinal cord, central cavity volumes, and numerical density of the glial and neural cells in the traumatic area. The open-field test, rotarod test, Narrow Beam Test (NBT), Electromyography recording (EMG) test and the Basso-Beattie-Bresnehan (BBB) evaluated the neurological functions. Our results showed that the stereological parameters, biochemical profiles (except MDA), and neurological functions were markedly greater in the SCI-PBM group in comparison with SCI group. The transcript for the IL-10 gene was seriously upregulated in the SCI-PBM group compared to the SCI group. This is while gene expression of TNF-α and IL-1β, also density of apoptosis cells in Caspase-3 evaluation decreased significantly more in the SCI-PBM group compared to the SCI group. Overall, using PBM treatment immediately after SCI has neuroprotective effects by controlling oxidative stress and inflammation and preventing the spread of damage.

Apelin-13 prevents apoptosis in the cochlear tissue of noise-exposed rat via Sirt-1 regulation

Noise-induced hearing loss (NIHL) is the second most common cause of acquired hearing loss. Acoustic trauma can cause oxidative damage in the cochlear hair cells (HCs) through apoptotic pathways. Apelin is a newly discovered neuropeptide with neuroprotective effects against the oxidative stress in neurodegenerative disorder. We investigated the preventive effects of apelin-13 on the cochlear HCs and spiral ganglion neurons (SGNs) against acoustic trauma via Sirtuin-1 (Sirt-1) regulation in rats. Animals were assigned to control, control + apelin-13 (50 or 100 μg/kg, ip), and noise exposure groups without any treatment or were administered apelin-13 (50 or 100 μg/kg, ip) and EX-527 (an inhibitor of Sirt-1) prior to each noise session. In the noise groups, 110 dB white noise was applied for 6 h per 5 days. Pre- and post-exposure distortion product otoacoustic emissions (DPOAE) and cochlear superoxide dismutase (SOD) activity were assessed. Western blot evaluated the cochlear protein expressions of Sirt-1, cleaved-caspase-3, Bax, and Bcl-2. Cell apoptosis was detected through TUNEL staining. Immunofluorescence was used to examine expression of HCs and SGNs specific protein. DPOAE level were significantly improved in the noise exposure group receiving 100 μg/kg apelin-13. At high doses, apelin augmented SOD levels in the rat cochlea subjected to noise. Apelin 100 markedly increased Sirt-1, and decreased cleaved- caspase-3 expression as well as Bax/Bcl-2 ratio in the cochlea tissue of noise-exposed rats. These findings suggest the promising therapeutic potential of apelin-13 for the prevention of noise-induced injury to cochlea and hearing loss.