The inhibition of miR-17-5p promotes cortical neuron neurite growth via STAT3/GAP-43 pathway

Combined Catalpol and Tetramethylpyrazine Promote Axonal Plasticity in Alzheimer's Disease by Inducing Astrocytes to Secrete Exosomes Carrying CDK5 mRNA and Regulating STAT3 Phosphorylation

Alzheimer's disease (AD) is a common progressive degenerative disease of the central nervous system in aging populations. This study aimed to investigate the effects of combined catalpol and tetramethylpyrazine (CT) in promoting axonal plasticity in AD and the potential underlying mechanism. Astrocytes were treated with different concentrations of compatible CT. Exosomes were collected and subjected to sequencing analysis, which was followed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes. Amyloid precursor protein/presenilin 1 (APP/PS1) double-transfected male mice were used as the in vivo AD models. Astrocyte-derived exosomes that were transfected with cyclin-dependent kinase 5 (CDK5) or CT treatment were injected into the tail vein of mice. The levels of CDK5, synaptic plasticity marker protein neurofilament 200 (NF200), and growth-associated protein 43 (GAP-43) in the hippocampus of mice were compared in each group. Immunofluorescence staining was used to detect the localization of STAT3 and to visualize synaptic morphology via β-tubulin-III (TUBB3). Astrocyte-derived exosomes transfected with siCDK5 or treated with CT were co-cultured with HT-22 cells, which were untransfected or silenced for signal transducer and activator of transcription 3 (STAT3). Amyloid β-protein (Aβ)1-42 was induced in the in vitro AD models. The viability, apoptosis, and expression levels of NF200 and GAP-43 proteins in the hippocampal neurons of each group were compared. In total, 166 differentially expressed genes in CT-induced astrocyte-derived exosomes were included in the KEGG analysis, and they were found to be enriched in 12 pathways, mainly in axon guidance. CT treatment significantly increased the level of CDK5 mRNA in astrocyte-derived exosomes-these exosomes restored CDK5 mRNA and protein levels in the hippocampus of the in vivo AD model mice and the in vitro AD model; promoted p-STAT3 (Ser727), NF200 and GAP-43 proteins; and promoted the regeneration and extension of neuronal synapses. Silencing of CDK5 blocked both neuronal protection as well as induction of axonal plasticity in AD by CT-treated exosomes in vitro and in vivo. Moreover, silencing of STAT3 blocked both neuronal protection as well as induction of axonal plasticity in AD caused by CDK5 overexpression or CT-treated astrocyte-induced exosomes. CT promotes axonal plasticity in AD by inducing astrocytes to secrete exosomes carrying CDK5 mRNA and regulating STAT3 (Ser727) phosphorylation.

Genes in Axonal Regeneration

This review explores the molecular and genetic underpinnings of axonal regeneration and functional recovery post-nerve injury, emphasizing its significance in reversing neurological deficits. It presents a systematic exploration of the roles of various genes in axonal regrowth across peripheral and central nerve injuries. Initially, it highlights genes and gene families critical for axonal growth and guidance, delving into their roles in regeneration. It then examines the regenerative microenvironment, focusing on the role of glial cells in neural repair through dedifferentiation, proliferation, and migration. The concept of "traumatic microenvironments" within the central nervous system (CNS) and peripheral nervous system (PNS) is discussed, noting their impact on regenerative capacities and their importance in therapeutic strategy development. Additionally, the review delves into axonal transport mechanisms essential for accurate growth and reinnervation, integrating insights from proteomics, genome-wide screenings, and gene editing advancements. Conclusively, it synthesizes these insights to offer a comprehensive understanding of axonal regeneration's molecular orchestration, aiming to inform effective nerve injury therapies and contribute to regenerative neuroscience.

β-elemene enhances cisplatin sensitivity of non-small cell lung cancer cells via the miR-17-5p/STAT3 axis

In China, β-elemene, a sesquiterpene compound derived from Curcuma wenyujin, is clinically used to treat many human malignancies, including non-small cell lung cancer (NSCLC). Nonetheless, the role of β-elemene in regulating cisplatin sensitivity of NSCLC cells and the related mechanisms are not clear. This study was conducted to investigate the role of β-elemene in sensitizing NSCLC cells to cisplatin. In this work, cisplatin-resistant NSCLC cell lines were constructed. CCK-8, colony formation, and flow cytometry assays were executed to examine cell viability, growth, and apoptosis. MiR-17-5p and STAT3 expression levels in cells were detected by qRT-PCR. Western blot was executed to determine the expression levels of STAT3 and apoptosis-related proteins (Bax and Bcl-2) in the cells. Dual-luciferase reporter gene experiments were performed to verify the targeting relationship between miR-17-5p and STAT3. Herein, we report that, β-elemene inhibits the viability, and induces the apoptosis of cisplatin-resistant NSCLC cells. Additionally, β-elemene induces the upregulation miR-17-5p and downregulation of STAT3. STAT3 is validated to be a target of miR-17-5p in NSCLC cells. Additionally, the role of β-elemene to repress the viability of cisplatin-resistant NSCLC cells is partially counteracted by miR-17-5p inhibitor or STAT3 overexpression. In summary, our study suggests that β-elemene enhances cisplatin sensitivity of NSCLC cells by modulating miR-17-5p/STAT3 axis, and it may be a choice for the complementary treatment of NSCLC patients.

Discovery of therapeutic targets for spinal cord injury based on molecular mechanisms of axon regeneration after conditioning lesion

BACKGROUND

Preinjury of peripheral nerves triggers dorsal root ganglia (DRG) axon regeneration, a biological change that is more pronounced in young mice than in old mice, but the complex mechanism has not been clearly explained. Here, we aim to gain insight into the mechanisms of axon regeneration after conditioning lesion in different age groups of mice, thereby providing effective therapeutic targets for central nervous system (CNS) injury.

METHODS

The microarray GSE58982 and GSE96051 were downloaded and analyzed to identify differentially expressed genes (DEGs). The protein-protein interaction (PPI) network, the miRNA-TF-target gene network, and the drug-hub gene network of conditioning lesion were constructed. The L4 and L5 DRGs, which were previously axotomized by the sciatic nerve conditioning lesions, were harvested for qRT-PCR. Furthermore, histological and behavioral tests were performed to assess the therapeutic effects of the candidate drug telmisartan in spinal cord injury (SCI).

RESULTS

A total of 693 and 885 DEGs were screened in the old and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in the inflammatory response, innate immune response, and ion transport. QRT-PCR results showed that in DRGs with preinjury of peripheral nerve, Timp1, P2ry6, Nckap1l, Csf1, Ccl9, Anxa1, and C3 were upregulated, while Agtr1a was downregulated. Based on the bioinformatics analysis of DRG after conditioning lesion, Agtr1a was selected as a potential therapeutic target for the SCI treatment. In vivo experiments showed that telmisartan promoted axonal regeneration after SCI by downregulating AGTR1 expression.

CONCLUSION

This study provides a comprehensive map of transcriptional changes that discriminate between young and old DRGs in response to injury. The hub genes and their related drugs that may affect the axonal regeneration program after conditioning lesion were identified. These findings revealed the speculative pathogenic mechanism involved in conditioning-dependent regenerative growth and may have translational significance for the development of CNS injury treatment in the future.

Advances in molecular therapies for targeting pathophysiology in spinal cord injury

INTRODUCTION

Spinal cord injury (SCI) affects 25,000-50,000 people around the world each year and there is no cure for SCI patients currently. The primary injury damages spinal cord tissues and secondary injury mechanisms, including ischemia, apoptosis, inflammation, and astrogliosis, further exacerbate the lesions to the spinal cord. Recently, researchers have designed various therapeutic approaches for SCI by targeting its major cellular or molecular pathophysiology.

AREAS COVERED

Some strategies have shown promise in repairing injured spinal cord for functional recoveries, such as administering neuroprotective reagents, targeting specific genes to promote robust axon regeneration of disconnected spinal fiber tracts, targeting epigenetic factors to enhance cell survival and neural repair, and facilitating neuronal relay pathways and neuroplasticity for restoration of function after SCI. This review focuses on the major advances in preclinical molecular therapies for SCI reported in recent years.

EXPERT OPINION

Recent progress in developing novel and effective repairing strategies for SCI is encouraging, but many challenges remain for future design of effective treatments, including developing highly effective neuroprotectants for early interventions, stimulating robust neuronal regeneration with functional synaptic reconnections among disconnected neurons, maximizing the recovery of lost neural functions with combination strategies, and translating the most promising therapies into human use.

Rab3A interacts with spastin to regulate neurite outgrowth in hippocampal neurons

Investigating novel mechanisms of neurite outgrowth via cytoskeleton is critical for developing therapeutic strategies against neural disorders. Rab3A is a vesicle-related protein distributed throughout the nervous system, but the detailed mechanism related to cytoskeleton remains largely unknown. Our previous reports show that spastin serves microtubule to regulate neurite outgrowth. Here, we asked whether Rab3A could function via modulating spastin during neuronal development. The results revealed that Rab3A colocalized with spastin in cultured hippocampal neurons. Immunoprecipitation assays showed that Rab3A physically interacted with spastin in rat brain lysates. Rab3A overexpression significantly induced spastin degradation; this effect was reversed by leupeptin- or MG-132- administration, suggesting the lysosomal and ubiquitin-mediated degradation system. Immunofluorescence staining further confirmed that Rab3A and spastin immune-colocalized with the lysosome marker lysotracker. In COS7 cells, Rab3A overexpression significantly downregulated spastin expression and abolished the spastin-mediated microtubule severing. Furthermore, overexpression inhibited while genetic knockdown of Rab3A promoted neurite outgrowth. However, this inhibitory effect on neurite outgrowth in hippocampal neurons could be reversed via co-transfection of spastin, indicating that Rab3A functions via its interaction protein spastin. In general, our data identify an interaction between Rab3A and spastin, and this interaction affects the protein stability of spastin and eliminates its microtubule severing function, thereby modulating neurite outgrowth.

YB-1 Expression Is Associated with Lymph Node Metastasis and Drug Resistance to Adriamycin in Breast Cancer

Background

Breast cancer (BC) is the most common malignant tumor among females. Although there are multiple treatments for breast cancer, many patients still face the dilemma of drug resistance after multiline treatment. It would be greatly helpful for clinical work to identify additional and improved prognostic predictors. Y-box binding protein-1 (YB-1) is a member of the cold shock protein family, and patients with overexpression of YB-1 have a worse prognosis.

Methods

This study collected 48 specimens from 48 patients with breast cancer and analyzed the clinicopathological characteristics of the patients. Immunohistochemistry, immunofluorescence, cell viability analysis, tumor spheroid formation and cell morphology, cell invasion, cycle analysis, qRT-PCR, Western blot, and tumorigenicity in BALB/c nude mice were performed to verify the results.

Results

We found that patients with overexpression of YB-1 were related to lymph node metastasis and the patients' age tended to be young. Because of the short follow-up time, a survival analysis could not be performed. Based on the results of in vitro and in vivo experiments, this study indicated that breast cancer cells with overexpression of YB-1 had stronger proliferation, migration, and invasion abilities than cells with low expression of YB-1. Compared with cells with low expression of YB-1, the proliferation, migration, and invasion abilities of YB-1 overexpressed cells were not significantly affected by adriamycin.

Conclusion

This suggested that breast cancer cells with overexpression of YB-1 were resistant to adriamycin. Therefore, YB-1 is associated with lymph node metastasis of breast cancer cell. YB-1 could be a prognostic, predictive factor and a novel therapeutic target of BC.

rhCNB Improves Cyclophosphamide-Induced Immunodeficiency in BALB/c Mice

Background

This study aims to explore the immunomodulatory effect of rhCNB on mice with cyclophosphamide (CTX)-induced immunodeficiency through TLR₄/MAPK pathway.

Methods

BALB/c mice were randomly divided into three groups: a negative control group, an immunosuppression model group, and a rhCNB treatment group. Tail vein injection of cyclophosphamide (40 mg/kg) was used to establish a mouse immunosuppression model. Intraperitoneal injection of rhCNB (20 mg/kg) was administered to the treatment group, whereas equal quantities of normal saline were given to the control group and model group. Perform peripheral blood routine of CD4, CD8, and CD19 lymphocyte subsets and peripheral blood Th1/Th2 cell subsets 24 hours after the last administration. RT-PCR was used to detect mRNA levels of TLR₄, P38, JNK, T-bet, and GATA₃, the spleen immune organ index was measured, and the histopathological status of the spleen and thymus was observed.

Results

The results showed that compared with the control group, WBC, PLT, LYM, NEU, immune organ index, CD4⁺/CD8⁺ and CD19⁺ subgroup ratio, and peripheral blood Th1/Th2 cell subgroups decreased in the model group. The mRNA levels of TLR₄, P38, JNK, T-bet, and GATA₃ decreased compared with the model group, while they increased in the treatment group.

Conclusions

rhCNB has an immunomodulatory effect by regulating the expression of Th1/Th2 cytokine balance through the TLR₄/MAPK signaling pathway and promoting the differentiation and proliferation of lymphocytes, thereby improving the immune function.

KT2 alleviates ulcerative colitis by reducing Th17 cell differentiation through the miR-302c-5p/STAT3 axis

BACKGROUND

The abnormal differentiation of Th17 cells aggravates ulcerative colitis (UC). Antimicrobial peptides (AMPs) exert pivotal protection functions against UC. KT2 is a cationic AMP that mediates colon cancer development. However, KT2's function in UC remains unclear.

METHODS

The UC mouse model was induced by administering 2.5% dextran sulfate sodium, and the mice were given an enema of KT2. KT2's function in UC and Th17 cell differentiation in vivo was evaluated through various molecular experiments. The KT2's function in Th17 cell differentiation in vitro was evaluated by the proportion of CD4⁺ IL-17⁺ T cells, IL-17 levels, and RORγt expression levels. Meanwhile, the mechanism was assessed through quantitative real-time PCR, various loss-of-function assays, and dual-luciferase reporter gene assay.

RESULTS

KT2 restrained Th17 cell differentiation in both in vivo and in vitro UC models and slowed the UC process. KT2 elevated miR-302c-5p expression, as well as restrained Th17 cell differentiation by increasing miR-302c-5p. Meanwhile, miR-302c-5p interacted with the signal transducer and activator of transcription 3 (STAT3) and negatively regulated its expression. Furthermore, our data revealed that KT2 restrained the activation of STAT3 by elevating miR-302c-5p, thereby inhibiting Th17 cell differentiation.

CONCLUSION

KT2 alleviates UC by repressing Th17 cell differentiation through the miR-302c-5p/STAT3 axis.

Genes and miRNAs as Hurdles and Promoters of Corticospinal Tract Regeneration in Spinal Cord Injury

Spinal cord injury (SCI) is a devastating lesion to the spinal cord, which determines the interruption of ascending/descending axonal tracts, the loss of supraspinal control of sensory-motor functions below the injured site, and severe autonomic dysfunctions, dramatically impacting the quality of life of the patients. After the acute inflammatory phase, the progressive formation of the astrocytic glial scar characterizes the acute-chronic phase: such scar represents one of the main obstacles to the axonal regeneration that, as known, is very limited in the central nervous system (CNS). Unfortunately, a cure for SCI is still lacking: the current clinical approaches are mainly based on early vertebral column stabilization, anti-inflammatory drug administration, and rehabilitation programs. However, new experimental therapeutic strategies are under investigation, one of which is to stimulate axonal regrowth and bypass the glial scar. One major issue in axonal regrowth consists of the different genetic programs, which characterize axonal development and maturation. Here, we will review the main hurdles that in adulthood limit axonal regeneration after SCI, describing the key genes, transcription factors, and miRNAs involved in these processes (seen their reciprocal influencing action), with particular attention to corticospinal motor neurons located in the sensory-motor cortex and subjected to axotomy in case of SCI. We will highlight the functional complexity of the neural regeneration programs. We will also discuss if specific axon growth programs, that undergo a physiological downregulation during CNS development, could be reactivated after a spinal cord trauma to sustain regrowth, representing a new potential therapeutic approach.

Trillium tschonoskii rhizomes' saponins induces oligodendrogenesis and axonal reorganization for ischemic stroke recovery in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Trillium tschonoskii Maxim. is one of traditional Chinese medical herbs that has been utilized to treat brain damages and cephalalgia. The neuroprotective effect of total saponins from Trillium tschonoskii rhizome (TSTT) has been demonstrated efficacy in rats following ischemia. However, the axonal remodeling effect of TSTT and the detailed mechanisms after ischemic stroke have not been investigated.

AIM OF THE STUDY

We aimed to estimate therapeutic role of TSTT in axonal remodeling using magnetic resonance imaging (MRI) technique, and explored possible mechanisms underlying this process followed by histological assays in ischemic rats.

METHODS

Male Sprague-Dawley (SD) rats underwent permanently focal cerebral ischemia induced by occluding right permanent middle cerebral artery. TSTT was intragastrically administrated 6 h after surgery and once daily for consecutive 15 days. Neurological function was assessed by the motor deficit score and beam walking test. T2 relaxation mapping and diffusion tensor imaging (DTI) were applied for detecting cerebral tissues damages and microstructural integrity of axons. Luxol fast blue (LFB) and transmission electron microscope (TEM) were performed to evaluate histopathology in myelinated axons. Double immunofluorescent staining was conducted to assess oligodendrogenesis. Furthermore, the protein expressions regarding to axonal remodeling related signaling pathways were detected by Western blot assays.

RESULTS

TSTT treatment (65, 33 mg/kg) markedly improved motor function after ischemic stroke. T2 mapping MRI demonstrated that TSTT decreased lesion volumes, and DTI further confirmed that TSTT preserved axonal microstructure of the sensorimotor cortex and internal capsule. Meanwhile, diffusion tensor tractography (DTT) showed that TSTT elevated correspondent density and length of fiber in the internal capsule. These MRI measurements were confirmed by histological examinations. Notably, TSTT significantly increased Ki67/NG2, Ki67/CNPase double-labeled cells along the boundary zone of ischemic cortex and striatum. Meanwhile, TSTT treatment up-regulated the phosphorylation level of Ser 9 in GSK-3β, and down-regulated phosphorylated β-catenin and CRMP-2 expression.

CONCLUSION

Taken together, our findings indicated that TSTT (65, 33 mg/kg) enhanced post-stroke functional recovery, amplified endogenous oligodendrogenesis and promoted axonal regeneration. The beneficial role of TSTT might be correlated with GSK-3/β-catenin/CRMP-2 modulating axonal reorganization after ischemic stroke.

MiRNA-494-3p Regulates Bupivacaine-Induced Neurotoxicity by the CDK6-PI3K/AKT Signaling

Bupivacaine (BUP) is a long-acting amide local anesthetic that may induce strong neurotoxicity and neurological complications. In this study, we elucidate the influence of microRNA-494-3p (miR-494-3p) in BUP-induced neurotoxicity in primary mouse hippocampal neuronal cells. In this study, primary hippocampal neurons were isolated from neonatal C57BL/6 mice. The isolated neurons were treated with various doses of BUP. MTT assay was conducted to analyze neuronal viability. Gene expression measurement was done by RT-qPCR. The impact of miR-494-3p in BUP-mediated neural injury was examined using TUNEL, flow cytometry, western blotting, and ROS activity detection. The regulatory relationship between miR-494-3p and cyclin-dependent kinases 4 and 6 (CDK6) was identified using a luciferase reporter assay. BUP treatment led to neurotoxicity and miR-494-3p upregulation in primary cultured hippocampal neurons. Functionally, miR-494-3p depletion alleviated neuronal apoptosis and oxidative damage induced by BUP. We verified that miR-494-3p targeted and negatively modulated CDK6. MiR-494-3p depletion also activated PI3K/AKT signaling by elevating CDK6 expression in BUP-treated neurons. Furthermore, CDK6 knockdown or PI3K/AKT inactivation attenuated the neuroprotective role of miR-494-3p depletion. Silencing miR-494-3p exerts neuroprotective function in hippocampal neuronal cells against BUP-induced injury by the CDK6-PI3K/AKT pathway.

The Pathogenesis and Therapeutic Approaches of Diabetic Neuropathy in the Retina

Diabetic retinopathy is a major retinal disease and a leading cause of blindness in the world. Diabetic retinopathy is a neurovascular disease that is associated with disturbances of the interdependent relationship of cells composed of the neurovascular units, i.e., neurons, glial cells, and vascular cells. An impairment of these neurovascular units causes both neuronal and vascular abnormalities in diabetic retinopathy. More specifically, neuronal abnormalities including neuronal cell death and axon degeneration are irreversible changes that are directly related to the vision reduction in diabetic patients. Thus, establishment of neuroprotective and regenerative therapies for diabetic neuropathy in the retina is an emergent task for preventing the blindness of patients with diabetic retinopathy. This review focuses on the pathogenesis of the neuronal abnormalities in diabetic retina including glial abnormalities, neuronal cell death, and axon degeneration. The possible molecular cell death pathways and intrinsic survival and regenerative pathways are also described. In addition, therapeutic approaches for diabetic neuropathy in the retina both in vitro and in vivo are presented. This review should be helpful for providing clues to overcome the barriers for establishing neuroprotection and regeneration of diabetic neuropathy in the retina.

Neuroinflammation: The next target of exosomal microRNAs derived from mesenchymal stem cells in the context of neurological disorders

Among different types of mechanisms involved in neurological disorders, neuroinflammation links initial insults to secondary injuries and triggers some chronic outcomes, for example, neurodegenerative disorders. Thus, anti-inflammatory substances can be targeted as a novel therapeutic option for translational and clinical research to improve brain disease outcomes. In this review, we propose to introduce a new insight into the anti-inflammatory effects of mesenchymal stem cells (MSCs) as the most frequent source for stem cell therapy in neurological diseases. Our insight incorporates a bystander effect of these stem cells in modulating inflammation and microglia/macrophage polarization through exosomes. Exosomes are nano-sized membrane vesicles that carry cell-specific constituents, including protein, lipid, DNA, and RNA. microRNAs (miRNAs) have recently been detected in exosomes that can be taken up by other cells and affect the behavior of recipient cells. In this article, we outline and highlight the potential use of exosomal miRNAs derived from MSCs for inflammatory pathways in the context of neurological disorders. Furthermore, we suggest that focusing on exosomal miRNAs derived from MSCs in the course of neuroinflammatory pathways in the future could reveal their functions for diverse neurological diseases, including brain injuries and neurodegenerative diseases. It is hoped that this study will contribute to a deep understanding of stem cell bystander effects through exosomal miRNAs.

Endocrine Therapy for the Functional Recovery of Spinal Cord Injury

Spinal cord injury (SCI) is a major cause of physical disability and leads to patient dissatisfaction with their quality of life. Patients with SCI usually exhibit severe clinical symptoms, including sensory and motor dysfunction below the injured levels, paraplegia, quadriplegia and urinary retention, which can exacerbate the substantial medical and social burdens. The major pathological change observed in SCI is inflammatory reaction, which induces demyelination, axonal degeneration, and the apoptosis and necrosis of neurons. Traditional medical treatments are mainly focused on the recovery of motor function and prevention of complications. To date, numerous studies have been conducted to explore the cellular and molecular mechanism of SCI and have proposed lots of effective treatments, but the clinical applications are still limited due to the complex pathogenesis and poor prognosis after SCI. Endocrine hormones are kinds of molecules that are synthesized by specialized endocrine organs and can participate in the regulation of multiple physiological activities, and their protective effects on several disorders have been widely discussed. In addition, many studies have identified that endocrine hormones can promote nerve regeneration and functional recovery in individuals with central nervous system diseases. Therefore, studies investigating the clinical applications of endocrine hormones as treatments for SCI are necessary. In this review, we described the neuroprotective roles of several endocrine hormones in SCI; endocrine hormone administration reduces cell death and promotes functional repair after SCI. We also proposed novel therapies for SCI.

Pim-1 Protects Retinal Ganglion Cells by Enhancing Their Regenerative Ability Following Optic Nerve Crush

Provirus integration site Moloney murine leukemia virus (Pim-1) is a proto-oncogene reported to be associated with cell proliferation, differentiation and survival. This study was to explore the neuroprotective role of Pim-1 in a rat model subjected to optic nerve crush (ONC), and discuss its related molecules in improving the intrinsic regeneration ability of retinal ganglion cells (RGCs). Immunofluorescence staining showed that AAV2- Pim-1 infected 71% RGCs and some amacrine cells in the retina. Real-time PCR and Western blotting showed that retina infection with AAV2- Pim-1 up-regulated the Pim-1 mRNA and protein expressions compared with AAV2-GFP group. Hematoxylin-Eosin (HE) staining, γ-synuclein immunohistochemistry, Cholera toxin B (CTB) tracing and TUNEL showed that RGCs transduction with AAV2-Pim-1 prior to ONC promoted the survival of damaged RGCs and decreased cell apoptosis. RITC anterograde labeling showed that Pim-1 overexpression increased axon regeneration and promoted the recovery of visual function by pupillary light reflex and flash visual evoked potential. Western blotting showed that Pim- 1 overexpression up-regulated the expression of Stat3, p-Stat3, Akt1, p-Akt1, Akt2 and p-Akt2, as well as βIII-tubulin, GAP-43 and 4E-BP1, and downregulated the expression of SOCS1 and SOCS3, Cleaved caspase 3, Bad and Bax. These results demonstrate that Pim-1 exerted a neuroprotective effect by promoting nerve regeneration and functional recovery of RGCs. In addition, it enhanced the intrinsic regeneration capacity of RGCs after ONC by activating Stat3, Akt1 and Akt2 pathways, and inhibiting the mitochondrial apoptosis pathways. These findings suggest that Pim-1 may prove to be a potential therapeutic target for the clinical treatment of optic nerve injury.

STAT3 Pathway in Gastric Cancer: Signaling, Therapeutic Targeting and Future Prospects

Molecular signaling pathways play a significant role in the regulation of biological mechanisms, and their abnormal expression can provide the conditions for cancer development. The signal transducer and activator of transcription 3 (STAT3) is a key member of the STAT proteins and its oncogene role in cancer has been shown. STAT3 is able to promote the proliferation and invasion of cancer cells and induces chemoresistance. Different downstream targets of STAT3 have been identified in cancer and it has also been shown that microRNA (miR), long non-coding RNA (lncRNA) and other molecular pathways are able to function as upstream mediators of STAT3 in cancer. In the present review, we focus on the role and regulation of STAT3 in gastric cancer (GC). miRs and lncRNAs are considered as potential upstream mediators of STAT3 and they are able to affect STAT3 expression in exerting their oncogene or onco-suppressor role in GC cells. Anti-tumor compounds suppress the STAT3 signaling pathway to restrict the proliferation and malignant behavior of GC cells. Other molecular pathways, such as sirtuin, stathmin and so on, can act as upstream mediators of STAT3 in GC. Notably, the components of the tumor microenvironment that are capable of targeting STAT3 in GC, such as fibroblasts and macrophages, are discussed in this review. Finally, we demonstrate that STAT3 can target oncogene factors to enhance the proliferation and metastasis of GC cells.