Olfactory Mucosa Mesenchymal Stem Cells Alleviate Cerebral Ischemia/Reperfusion Injury Via Golgi Apparatus Secretory Pathway Ca2+ -ATPase Isoform1

Priming and Combined Strategies for the Application of Mesenchymal Stem Cells in Ischemic Stroke: A Promising Approach

Ischemic stroke (IS) is a leading cause of death and disability worldwide. Tissue plasminogen activator (tPA) administration and mechanical thrombectomy are the main treatments but have a narrow time window. Mesenchymal stem cells (MSCs), which are easily scalable in vitro and lack ethical concerns, possess the potential to differentiate into various types of cells and secrete a great number of growth factors for neuroprotection and regeneration. Moreover, MSCs have low immunogenicity and tumorigenic properties, showing safety and preliminary efficacy both in preclinical studies and clinical trials of IS. However, it is unlikely that MSC treatment alone will be sufficient to maximize recovery due to the low survival rate of transplanted cells and various mechanisms of ischemic brain damage in the different stages of IS. Preconditioning was used to facilitate the homing, survival, and secretion ability of the grafted MSCs in the ischemic region, while combination therapies are alternatives that can maximize the treatment effects, focusing on multiple therapeutic targets to promote stroke recovery. In this case, the combination therapy can yield a synergistic effect. In this review, we summarize the type of MSCs, preconditioning methods, and combined strategies as well as their therapeutic mechanism in the treatment of IS to accelerate the transformation from basic research to clinical application.

Artemisinin attenuated ischemic stroke induced pyroptosis by inhibiting ROS/TXNIP/NLRP3/Caspase-1 signaling pathway

BACKGROUND

To explore the neuroprotective mechanism of artemisinin against ischemic stroke from the perspective of NLRP3-mediated pyroptosis.

METHODS

Serum metabolomics technology was used to analyze the serum samples of mice, and KEGG metabolic pathway was analyzed for the different metabolites in the samples. PIT model and OGD/R model were used to simulate ischemic stroke damage in vivo and in vitro. Hoechst 33342 staining, Annexin V-FITC/PI staining and TUNEL staining were used to detect the pyroptosis rate of cells. The contents of IL-1β and IL-18 in PC12 cells and serum of mice were detected by ELISA. The expressions of NLRP3, ASC-1, Caspase-1 and TXNIP in PC12 cells and mouse brain tissue were detected by Western Blot.

RESULTS

Serum metabolic profiles of animal models identified 234 different metabolites and 91 metabolic pathways. Compared with the Sham group and the Stroke+ART group, the KEGG pathway in the Stroke group was concentrated in the Necroptosis pathway associated with cell growth and death, and the NLRP3 inflammasome-mediated pyroptosis pathway was activated in the Necroptosis pathway after ischemic stroke. The results of in vivo and in vitro experiments showed that pretreatment with 10 μM artemisinin reduced ROS production, decreased Δψm, reduced pyroptosis, maintained neuronal cell morphology, and down-regulated the contents of IL-1β and IL-18 as well as the expression of key proteins of NLRP3, ASC-1, Caspase-1 and TXNIP(p<0.01).

CONCLUSION

Artemisinin can reduce neuronal pyroptosis induced by ischemic stroke by inhibiting ROS/TXNIP/NLRP3/Caspase-1 signaling pathway.

SENP1 facilitates OM-MSC differentiation through activating OPTN-mediated mitophagy to mitigate the neurologic impairment following ICH

Previous studies have indicated the neuroprotective effect of olfactory mucosa mesenchymal stem cells (OM-MSCs) on brain injury. Intracerebral hemorrhage (ICH) models were established in rats by injecting autologous blood. SENP1 expression was enhanced in neurons but decreased in astrocytes compared to that in OM-MSCs. Overexpression of SENP1 promoted the proliferation and neuronal differentiation, while inhibiting the astrocytic differentiation of OM-MSCs. Conversely, its knockdown had the opposite effect. Moreover, OM-MSCs reduced neurological dysfunction in rats after ICH, and the neuroprotective effect of OM-MSCs could be further enhanced by SENP1 overexpression. In addition, SENP1 promoted mitophagy, which might be related to SENP1-mediated OPTN deSUMOylation. Furthermore, SENP1 promoted neuronal differentiation of OM-MSCs through mitophagy mediated by OPTN. Similar to SENP1, OPTN transfection further enhanced the remission effect of OM-MSC on ICH rats. SENP1 promoted neuronal differentiation of OM-MSCs through OPTN-mediated mitophagy to improve neurological deficits in ICH rats.

Cdk1 protects against oxygen-glucose deprivation and reperfusion-induced Golgi fragmentation and apoptosis through mediating GM130 phosphorylation

Increasing evidence has indicated that the Golgi apparatus (GA) is involved in the development of cerebral ischemia-reperfusion (IR) injury. Finding effective neuroprotective agents targeting GA has become a priority in the treatment of ischemic stroke. GM130, a key structural protein present on the cis-face of the GA, maintains its structure through its phosphorylation and dephosphorylation. However, the molecular mechanisms by which GM130 regulates IR-induced neuronal apoptosis are not well elucidated. Mouse neuroblastoma Neuro2a (N2A) cells were subjected to oxygen-glucose deprivation and reperfusion (OGDR) insult. Cell proliferation and apoptosis were determined using MTT assay, TUNEL staining, and flow cytometry. GA morphology was detected by immunocytochemical staining and immunofluorescence microscopy. GA-related protein and mRNA levels were detected by WB and qPCR, respectively. Treatment with Purvalanol A, an effective Cdk1 inhibitor, and transfection of Cdk1-shRNA were carried out to inhibit OGDR-induced Cdk1 elevation. The results demonstrated that OGDR induced Golgi fragmentation, neuronal apoptosis, GM130 phosphorylation, and p115 cleavage in N2A cells. Cdk1 elevation after OGDR was closely correlated with GM130 phosphorylation, not p115. Inhibition of Cdk1 significantly attenuated OGDR-induced Golgi fragmentation and cell apoptosis. Cdk1 interacted with GM130 and decreased its phosphorylation on the serine 25 site in N2A cells exposed to OGDR. The present findings reveal that Cdk1 protects against IR-induced GA fragmentation and apoptosis, likely through the mediation of GM130 phosphorylation. This neuroprotective potential of Cdk1 against IR insult and the underlying mechanism will pave the way for potential clinical applications targeting the GA organelle for cerebral IR-related disorders.

Curcumin preconditioning enhances the neuroprotective effects of olfactory mucosa-derived mesenchymal stem cells on experimental intracerebral hemorrhage

Oxidative stress is essential in brain injury after intracerebral hemorrhage (ICH). Ferroptosis, iron-dependent oxidative cell death, overwhelms the antioxidant system. Recently, Olfactory mucosa-derived mesenchymal stem cells (OM-MSCs) hold great potential for treating ferroptosis-mediated oxidative brain damage after ICH. However, massive grafted cell death, possibly caused by a hostile host brain microenvironment, lessens the effectiveness of OM-MSCs. Therefore, it is necessary to develop strategies to upregulate the therapeutic efficacy of OM-MSCs in ICH. Curcumin, a well-established traditional herbal substance, has potent antioxidant property. In the present study, curcumin preconditioning might enhance the anti-oxidative activity of OM-MSCs, thereby augmenting the therapeutic efficacy of OM-MSCs in ICH. In vitro model of ICH, we demonstrated that curcumin-preconditioned OM-MSCs co-culture is more effective in attenuating the cell injury, oxidative stress, and ferroptosis of neuronal cells compared to the native OM-MSCs treatment. In vivo model of ICH, transplantation of curcumin-preconditioned OM-MSCs also showed better neuroprotective effects. Moreover, curcumin pretreatment promoted the survival of OM-MSCs under a conditioned medium from hemin-insulted neurons by improving the anti-oxidative capacities of OM-MSCs. Collectively, our investigation suggested that curcumin preconditioning effectively enhanced the survival and neuroprotective effects of OM-MSCs in the ICH model by upregulating the anti-oxidative capacities of OM-MSCs. Curcumin-preconditioned OM-MSCs might be taken as a novel therapeutic strategy for treating ICH.

Ultrashort wave alleviates oxygenglucose deprivation/reoxygenation injury via upregulation of SPCA1 expression in N2a cells

OBJECTIVES

Application of ultrashort wave (USW) to rats with cerebral ischemia and reperfusion injury could inhibit the decrease of expression of secretory pathway Ca2+-ATPase 1 (SPCA1), an important participant in Golgi stress, reduce the damage of Golgi apparatus and the apoptosis of neuronal cells, thereby alleviating cerebral ischemia-reperfusion injury. This study aims to investigate the effect of USW on oxygen-glucose deprivation/reperfusion (OGD/R) injury and the expression of SPCA1 at the cellular level.

METHODS

N2a cells were randomly divided into a control (Con) group, an OGD/R group, and an USW group. The cells in the Con group were cultured without exposure to OGD. The cells in the OGD/R group were treated with OGD/R. The cells in the USW group were treated with USW after OGD/R. Cell morphology was observed under the inverted phase-contrast optical microscope, cell activity was detected by cell counting kit-8 (CCK-8), apoptosis was detected by flow cytometry, and SPCA1 expression was detected by Western blotting.

RESULTS

Most of the cells in the Con group showed spindle shape with a clear outline and good adhesion. In the OGD/R group, cells were wrinkled, with blurred outline, poor adhesion, and lots of suspended dead cells appeared; compared with the OGD/R group, the cell morphology and adherence were improved, with clearer outlines and fewer dead cells in the USW group. Compared with the Con group, the OGD/R group showed decreased cell activity, increased apoptotic rate, and down-regulating SPCA1 expression with significant differences (all P<0.001); compared with the OGD/R group, the USW group showed increased cell activity, decreased apoptotic rate, and up-regulating SPCA1 expression with significant differences (P<0.01 or P<0.001).

CONCLUSIONS

USW alleviates the injury of cellular OGD/R, and its protective effect may be related to its up-regulation of SPCA1 expression.

Analysis of the mechanism of Buyang Huanwu Decoction against cerebral ischemia-reperfusion by multi-omics

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu Decoction (BYHW) is a classic representative formula for treating qi deficiency and the blood stasis syndrome of stroke in the Qing Dynasty physician Wang Qingren's Correction on the Errors of Medical Works. However, the research on the mechanism of BYHW in the treatment of stroke is not systematic and comprehensive.

AIM OF THE STUDY

Combined with multi-omics analysis methods to explore the potential targets of BYHW in the treatment of cerebral ischemia-reperfusion (I/R).

MATERIALS AND METHODS

The rat middle cerebral artery occlusion (MCAO) model was established to study the effect of BYHW on cerebral I/R injury in rats. Then, the potential targets and pathways of BYHW in the treatment of cerebral I/R injury were analyzed by proteomic, transcriptomic, and metabolomic methods. Finally, 4D-PRM was used to validate potential targets.

RESULTS

BYHW effectively improved the neurological function scores of MCAO rats and significantly reduced the rate of cerebral infarction in MCAO rats. Multi-omics analysis had identified 15 potential targets and 4 potential signaling pathways. The results of 4D-PRM targeted proteomics verification showed that Pde1b was reversed up-regulated, and Aprt, Gpd1, Glb1, HEXA, and HEXB were reversed down-regulated.

CONCLUSION

BYHW may improve cerebral I/R through Aprt, Pde1b, Gpd1, Glb1, HEXA and HEXB targets, and Glycerophospholipid metabolism, Purine metabolism and Glycosphingolipid biosynthesis - globoseries pathway.

Traditional Chinese medicine in treating ischemic stroke by modulating mitochondria: A comprehensive overview of experimental studies

Ischemic stroke has been a prominent focus of scientific investigation owing to its high prevalence, complex pathogenesis, and difficulties in treatment. Mitochondria play an important role in cellular energy homeostasis and are involved in neuronal death following ischemic stroke. Hence, maintaining mitochondrial function is critical for neuronal survival and neurological improvement in ischemic stroke, and mitochondria are key therapeutic targets in cerebral stroke research. With the benefits of high efficacy, low cost, and high safety, traditional Chinese medicine (TCM) has great advantages in preventing and treating ischemic stroke. Accumulating studies have explored the effect of TCM in preventing and treating ischemic stroke from the perspective of regulating mitochondrial structure and function. In this review, we discuss the molecular mechanisms by which mitochondria are involved in ischemic stroke. Furthermore, we summarized the current advances in TCM in preventing and treating ischemic stroke by modulating mitochondria. We aimed to provide a new perspective and enlightenment for TCM in the prevention and treatment of ischemic stroke by modulating mitochondria.

UBIAD1 protects against oxygen-glucose deprivation/reoxygenation injury via nNOS/NO pathway

OBJECTIVES

Cerebral infarction is a subtype of stroke with high incidence and disability rate. Ischemia reperfusion injury (IRI) is the key point of cerebral infarction treatment. UbiA prenyltransferase domain containing 1 (UBIAD1) is a kind of enzyme with various biological functions including electron transport in mitochondrial respiratory chain, lipid metabolism, and oxidative stress which are related to IRI. The purpose of this study aims to determine the neuroprotective effects and the underlying mechanisms of UBIAD1 in cerebral IRI.

METHODS

We employed oxygen-glucose deprivation/reoxygenation (OGD/R) model in mouse neuroblastoma Neuro2a (N2a) cells to mimic cerebral IRI. Lentivirus vector over-expressed UBIAD1 was transfacted into N2a cells to maintain high and stable expression of UBIAD1. In the first part of the experiment, N2a cells were divided into 5 groups: A non-OGD (N2a cells without exposure to OGD) group, groups of reoxygenation 0, 4, 12 and 24 h after 4 h of OGD, respectively. In the second part of the experiment, N2a cells were divided into 6 groups: A Con (normal cell)+non-OGD group, an EV (cell transfected with empty vector)+non-OGD group, an OE (over-expressed UBIAD1)+non-OGD group, a Con+OGD/R group, an EV+OGD/R group, and an OE+OGD/R group. In the third part, the N2a cells were divided into 8 groups: A Con+non-OGD group, an OE+non-OGD group, a Con+non-OGD+nNOS inhibitior 7-nitroindazole (7-NI) group, an OE+non-OGD+7-NI group, a Con+OGD/R group, an OE+OGD/R group, a Con+OGD/R+7-NI group, and an OE+OGD/R+7-NI group. The morphological changes of Golgi apparatus were observed under the confocal laser scanning microscope. The mRNA and protein levels of UBIAD1, secretory pathway Ca2+-ATPase isoform 1 (SPCA1), and NOS were determined by real-time PCR and Western blotting, respectively. Cell apoptosis rate was detected with flow cytometry; cell viability was detected with MTT assay, and NO release was determined with Griess assay.

RESULTS

Compared with the non-OGD group, the expression levels of UBIAD1 mRNA and protein in N2a cells in the groups of 0, 4, 12 and 24 h reoxygenation after OGD 4 h decreased significantly (P<0.05 or P<0.01), and the longer the reoxygenation time, the more significant the reduction of UBIAD1 expression. Compared with the Con+OGD/R group and the EV+OGD/R group, mRNA and protein levels of UBIAD1 and SPCA1 were increased (P<0.05 or P<0.01), the apoptosis rate was decreased (all P<0.01), and the cell viability was increased (all P<0.01) in the OE+OGD/R group. The Golgi fragmentation was less in the OE+OGD/R group than that in the Con+ OGD/R group and the EV+OGD/R group. The mRNA and protein levels of endothelial NOS (eNOS) and neuronal NOS (nNOS) were decreased (P<0.05 or P<0.01), and the level of NO was decreased (all P<0.01) in the groups over-expressed UBIAD1 (OE+non-OGD group vs Con+non-OGD group, OE+OGD/R group vs Con+OGD/R group). The level of NO and apoptosis rate of N2a cells were decreased (all P<0.01) in the the groups pretreated with 7-NI (Con+OGD/R+7-NI group vs Con+OGD/R group, OE+OGD/R+7-NI group vs OE+OGD/R group).

CONCLUSIONS

UBIAD1 may exerts protective effects on OGD/R induced N2a cells by ameliorating Golgi apparatus dysfunction via the nNOS/NO pathway.

Neuroprotective Effect of Stroke Pretreated Mesenchymal Stem Cells Against Cerebral Ischemia/Reperfusion Injury in Rats

BACKGROUND

Mesenchymal stem cells (MSCs) have been shown to enhance neurological recovery after stroke. A rat middle cerebral artery occlusion model was designed to assess neuroprotective effects of stroke pretreated MSCs on cerebral ischemia/reperfusion injury.

METHODS

MSCs were isolated and cultured in medium with 10% fetal bovine serum, normal control serum, or stroke serum (SS). MSCs were then injected into rats (n = 6 in each group) 1 day after middle cerebral artery occlusion, and feeding continued for 28 days. A battery of behavioral tests, 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, enzyme-linked immunosorbent assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were used to assess neural injury. To detect enhancement of neuronal regeneration and angiogenesis, immunofluorescence and Western blotting were performed to assess expression of trophic factors and growth factors.

RESULTS

After treatment, behavior of rats improved significantly. Infarction area, brain lesion, and apoptosis cells were significantly decreased in the SS-MSCs group compared with the other groups. SS-MSCs also modulated inflammation by attenuating inflammatory cytokines. Furthermore, the number of neurogenesis-positive cells and expression of trophic factors and growth factors were significantly higher in the SS-MSCs group compared with the others. MSCs cultured with fetal bovine serum and normal control serum showed differences in expression of trophic factors and growth factors, but the results were not as good as with SS-MSCs.

CONCLUSIONS

Administration of SS-MCSs after reperfusion led to neuroprotection by inducing the recovery process, including improving pathological changes, behavioral improvement, neurogenesis, suppression of apoptosis and inflammation, and angiogenesis.

Intranasally applied human olfactory mucosa neural progenitor cells migrate to damaged brain regions

Aim:

To determine if intranasally administered olfactory mucosa progenitor cells (OMPCs) migrate to damaged areas of brain.

Materials & methods:

Rowett Nude (RNU) adult rats were injured using the Marmarou model then 2 weeks later received intranasally-delivered human OMPC. After 3 weeks, rats were sacrificed and brain sectioned. The mean distances from the human OMPCs to markers for degenerative neuronal cell bodies (p-c-Jun⁺), axonal swellings on damaged axons (β-APP⁺) and random points in immunostained sections were quantified. One-way ANOVA was used to analyze data.

Results:

The human OMPCs were seen in specific areas of the brain near degenerating cell bodies and damaged axons.

Conclusion:

Intranasally delivered human OMPC selectively migrate to brain injury sites suggesting a possible noninvasive stem cell delivery for brain injury.

As a first step toward helping those with brain or spinal cord injury, human stem cells from the nose were applied to the inside of the nose of brain injured rats. These stem cells migrated to specific areas of damage in the brain. Stem cells from the nose are special, in that these cells continuously divide and form nerve cells. This study may lead to an uncomplicated treatment where tissue is taken from one side of the nose and later the stem cells from the tissue are delivered to the other side of the nose.

The role of metal ions in the Golgi apparatus

The Golgi apparatus is a membrane-bound organelle that functions as a central role in the secretory pathway. Since the discovery of the Golgi apparatus, its structure and function have attracted ever-increasing attention from researchers. Recently, it has been demonstrated that metal ions are necessary for the Golgi apparatus to maintain its proper structure and functions. Given that metal ions play an important role in various biological processes, their abnormal homeostasis is related to many diseases. Therefore, in this paper, we reviewed the uptake and release mechanisms of the Golgi apparatus Ca²⁺ , Cu, and Zn²⁺ . Furthermore, we describe the diseases associated with Golgi apparatus Ca²⁺ , Cu, and Zn²⁺ imbalance.

Mesenchymal Stem Cell Therapy: A Potential Treatment Targeting Pathological Manifestations of Traumatic Brain Injury

Traumatic brain injury (TBI) makes up a large proportion of acute brain injuries and is a major cause of disability globally. Its complicated etiology and pathogenesis mainly include primary injury and secondary injury over time, which can cause cognitive deficits, physical disabilities, mood changes, and impaired verbal communication. Recently, mesenchymal stromal cell- (MSC-) based therapy has shown significant therapeutic potential to target TBI-induced pathological processes, such as oxidative stress, neuroinflammation, apoptosis, and mitochondrial dysfunction. In this review, we discuss the main pathological processes of TBI and summarize the underlying mechanisms of MSC-based TBI treatment. We also discuss research progress in the field of MSC therapy in TBI as well as major shortcomings and the great potential shown.

Preconditioned MSCs Alleviate Cerebral Ischemia-Reperfusion Injury in Rats by Improving the Neurological Function and the Inhibition of Apoptosis

Mesenchymal stem cells (MSCs) have great application prospects in the treatment of ischemic injury. However, their long-time cultivation before transplantation and poor survival after transplantation greatly limit the therapeutic effect and applications. This study aimed to investigate whether MSCs under the ischemic microenvironment could improve their survival and better alleviate cerebral ischemic injury. Firstly, we used ischemic brain tissue to culture MSCs and evaluated the functional changes of MSCs. Then a middle cerebral artery occlusion (MCAO) model was induced in rats, and the pretreated MSCs were injected via the tail vein. The adhesive removal test, rotarod test, modified neurological severity score, and pathological analyses were applied to assess the rats' neurological function. Then the expression of neuron and apoptosis related markers was detected. The results indicated that ischemic brain tissue pretreated MSCs promoted the proliferation and the release of the growth factors of MSCs. Meanwhile, in MCAO model rats, transplantation of pretreated MSCs enhanced the neurogenesis, attenuated behavioral changes, reduced infarct size, and inhibited apoptosis. The expression of B-cell lymphoma-2 (Bcl-2), brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP), NF-L, and NeuN were increased, while BCL2-Associated X (Bax) and Caspase-3 decreased. Our results suggest that MSCs pretreatment with stroke brain tissue could be an effective strategy in treating cerebral ischemic injury.

UBIAD1 alleviates ferroptotic neuronal death by enhancing antioxidative capacity by cooperatively restoring impaired mitochondria and Golgi apparatus upon cerebral ischemic/reperfusion insult

Background

Neuronal death due to over-oxidative stress responses defines the pathology of cerebral ischemic/reperfusion (I/R) insult. Ferroptosis is a form of oxidative cell death that is induced by disruption of the balance between antioxidants and pro-oxidants in cells. However, the potential mechanisms responsible for cerebral I/R-induced ferroptotic neuronal death have not been conclusively determined. UBIAD1, is a newly identified antioxidant enzyme that catalyzes coenzyme Q10 (CoQ10) and vitamin K2 biosynthesis in the Golgi apparatus membrane and mitochondria, respectively. Even though UBIAD1 is a significant mediator of apoptosis in cerebral I/R challenge, its roles in ferroptotic neuronal death remain undefined. Therefore, we investigated whether ferroptotic neuronal death is involved in cerebral I/R injury. Further, we evaluated the functions and possible mechanisms of UBIAD1 in cerebral I/R-induced ferroptotic neuronal death, with a major focus on mitochondrial and Golgi apparatus dysfunctions.

Results

Ferroptosis occurred in cerebral I/R. Ferroptotic neuronal death promoted cerebral I/R-induced brain tissue injury and neuronal impairment. UBIAD1 was expressed in cerebral tissues and was localized in neurons, astrocytes, and microglia. Under cerebral I/R conditions overexpressed UBIAD1 significantly suppressed lipid peroxidation and ferroptosis. Moreover, upregulated UBIAD1 protected against brain tissue damage and neuronal death by alleviating I/R-mediated lipid peroxidation and ferroptosis. However, UBIAD1 knockdown reversed these changes. Enhanced UBIAD1-mediated ferroptosis elevated the antioxidative capacity by rescuing mitochondrial and Golgi apparatus dysfunction in cerebral I/R-mediated neuronal injury. They improved the morphology and biofunctions of the mitochondria and Golgi apparatus, thereby elevating the levels of SOD, T-AOC and production of CoQ10, endothelial nitric oxide synthase (eNOS)-regulated nitric oxide (NO) generation as well as suppressed MDA generation.

Conclusions

The neuroprotective agent, UBIAD1, modulates I/R-mediated ferroptosis by restoring mitochondrial and Golgi apparatus dysfunction in damaged brain tissues and neurons, thereby enhancing antioxidative capacities. Moreover, the rescue of impaired mitochondrial and Golgi apparatus as a possible mechanism of regulating ferroptotic neuronal death is a potential treatment strategy for ischemic stroke.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00776-9.

Designing Olfactory Ensheathing Cell Transplantation Therapies: Influence of Cell Microenvironment

Olfactory ensheathing cell (OEC) transplantation is emerging as a promising treatment option for injuries of the nervous system. OECs can be obtained relatively easily from nasal biopsies, and exhibit several properties such as secretion of trophic factors, and phagocytosis of debris that facilitate neural regeneration and repair. But a major limitation of OEC-based cell therapies is the poor survival of transplanted cells which subsequently limit their therapeutic efficacy. There is an unmet need for approaches that enable the in vitro production of OECs in a state that will optimize their survival and integration after transplantation into the hostile injury site. Here, we present an overview of the strategies to modulate OECs focusing on oxygen levels, stimulating migratory, phagocytic, and secretory properties, and on bioengineering a suitable environment in vitro.

Mitochondrial-Respiration-Improving Effects of Three Different Gardeniae Fructus Preparations and Their Components

The processing method for Chinese traditional herbal medicine is "Pao Zhi" in Chinese. This study examined the efficacy of the Pao Zhi on the preparations of Gardeniae Fructus (GF) on a mitochondrial respiratory function in rats. To determine the efficacy of Pao Zhi, we investigated the effects of GF heat processing on mitochondrial respiratory function. To test the GF components, the rats were randomly divided into a geniposide-alone group, crocin-alone group, and combination groups and treated with geniposide and crocin at different ratios. The results showed that a high dose, raw GF was more effective in improving the neurological function, mitochondrial respiratory function, and activities of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase than the preparations that underwent heating. Moreover, mitochondrial ROS production was the lowest in the raw GF-treated group. In addition, treatments with crocin and GC3 were more effective than geniposide in improving the functional deficit in MCAO rats. In conclusion, our results suggest that raw GF is the most suitable preparation for the treatment of cerebral ischemia, and its underlying mechanisms may be associated with the improvement of mitochondrial respiratory function, increased activities of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase, and reduced oxidative stress in mitochondria. Our findings suggest that raw GF, especially crocin, could be an ideal therapeutic agent for ischemic stroke.

Storax, A Promising Botanical Medicine for Treating Cardio-Cerebrovascular Diseases: A Review

In recent years, the incidence and mortality of cardio-cerebrovascular diseases have been increasing year by year, which has become global burden and challenge. Based on the holistic thinking of “brain disease affects the heart” and “heart disease affects the brain,” as well as the characteristics of multi-target and multi-path effects of Chinese medicine, Chinese medicine is more advantageous in the treatment of cardio-cerebrovascular diseases. As a botanical medicine, storax is known for its resuscitation, filth avoidance and pain-relieving effects in the treatment of cardio-cerebrovascular diseases. By reviewing and collating the relevant domestic and international literature in the past 10 years, we have sorted out an overview of the medicinal parts, traditional uses and chemical composition of storax. For the first time, based on the idea of “cerebral and cardiac simultaneous treatment,” the pharmacological activities and mechanisms of heart and brain protection of storax for treating cardio-cerebrovascular diseases were summarized and analyzed, showing that storax has the pharmacological effects of anti-cerebral ischemia, regulation of blood-brain barrier, bidirectional regulation of the central nervous system, anti-myocardial ischemia, anti-arrhythmia, anti-thrombosis and anti-platelet aggregation. It mainly exerts its protective effects on the brain and heart through mechanisms such as inhibition of inflammatory immune factors, anti-oxidative stress, anti-apoptosis, pro-neovascularization and regulation of NO release. On the basis of the current findings and limitations, the future research strategies and perspectives of storax are proposed, with a view to providing a reference for further application and development of this medicine, as well as contributing new thoughts and visions for the clinical application of “treating brain-heart synchronously”.

OM-MSCs Alleviate the Golgi Apparatus Stress Response following Cerebral Ischemia/Reperfusion Injury via the PEDF-PI3K/Akt/mTOR Signaling Pathway

The mechanism of Golgi apparatus (GA) stress responses mediated by GOLPH3 has been widely studied in ischemic stroke, and the neuroprotection effect of olfactory mucosa mesenchymal stem cells (OM-MSCs) against cerebral ischemia/reperfusion injury (IRI) has been preliminarily presented. However, the exact role of OM-MSCs in the GA stress response following cerebral IRI remains to be elucidated. In the present study, we used an oxygen-glucose deprivation/reoxygenation (OGD/R) model and reversible middle cerebral artery occlusion (MCAO) model to simulate cerebral IRI in vitro and in vivo. Our results showed that the level of GOLPH3 protein, reactive oxygen species (ROS), and Ca²⁺ was upregulated, SPCA1 level was downregulated, and GA fragmentation was increased in ischemic stroke models, and OM-MSC treatment clearly ameliorated these GA stress responses in vitro and in vivo. Subsequently, the knockdown of PEDF in OM-MSCs using PEDF-specific siRNA further demonstrated that secretion of PEDF in OM-MSCs protected OGD/R-treated N2a cells and MCAO rats from GA stress response. Additionally, rescue experiment using specific pathway inhibitors suggested that OM-MSCs could promote the phosphorylation of the PI3K/Akt/mTOR pathway, thereby mitigating OGD/R-induced GA stress response and excessive autophagy. In conclusion, OM-MSCs minimized the GA stress response following cerebral IRI, at least partially, through the PEDF-PI3K/Akt/mTOR pathway.

Extracellular vesicles derived from hypoxia-preconditioned olfactory mucosa mesenchymal stem cells enhance angiogenesis via miR-612

Mesenchymal stem cells (MSCs) play important roles in tissue repair and regeneration, such as the induction of angiogenesis, particularly under hypoxic conditions. However, the molecular mechanisms underlying hypoxic MSC activation remain largely unknown. MSC-derived extracellular vesicles (EVs) are vital mediators of cell-to-cell communication and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of EVs from human hypoxic olfactory mucosa MSCs (OM-MSCs) on angiogenesis and its underlying mechanism. EVs were isolated from normoxic (N) OM-MSCs (N-EVs) and hypoxic (H) OM-MSCs (H-EVs) using differential centrifugation and identified by transmission electron microscopy and flow cytometry. In vitro and in vivo, both types of OM-MSC-EVs promoted the proliferation, migration, and angiogenic activities of human brain microvascular endothelial cells (HBMECs). In addition, angiogenesis-stimulatory activity in the H-EV group was significantly enhanced compared to the N-EV group. MicroRNA profiling revealed a higher abundance of miR-612 in H-EVs than in N-EVs, while miR-612 inactivation abolished the N-EV treatment benefit. To explore the roles of miR-612, overexpression and knock-down experiments were performed using a mimic and inhibitor or agomir and antagomir of miR-612. The miR-612 target genes were confirmed using the luciferase reporter assay. Gain- and loss-of-function studies allowed the validation of miR-612 (enriched in hypoxic OM-MSC-EVs) as a functional messenger that stimulates angiogenesis and represses the expression of TP53 by targeting its 3′-untranslated region. Further functional assays showed that hypoxic OM-MSC-EVs promote paracrine Hypoxia-inducible factor 1-alpha (HIF-1α)-Vascular endothelial growth factor (VEGF) signaling in HBMECs via the exosomal miR-612-TP53-HIF-1α-VEGF axis. These findings suggest that hypoxic OM-MSC-EVs may represent a promising strategy for ischemic disease by promoting angiogenesis via miR-612 transfer.

Hypoxia-preconditioned mesenchymal stem cells attenuate microglial pyroptosis after intracerebral hemorrhage

Background

Microglia plays a vital role in neuroinflammation, contributing to the pathogenesis of intracerebral hemorrhage (ICH)-induced brain injury. Mesenchymal stem cells (MSCs) hold great potential for treating ICH. We previously revealed that MSCs ameliorate the microglial pyroptosis caused by an ischemic stroke. However, whether MSCs can modulate microglial pyroptosis after ICH remains unknown. This study aimed to investigate the neuroprotective effects of hypoxia-preconditioned olfactory mucosa MSCs (OM-MSCs) on ICH and the possible mechanisms.

Methods

ICH was induced in mice via administration of collagenase IV. At 6 h post-ICH, 2-4×10⁵ normoxic/hypoxic OM-MSCs or saline were intracerebrally administered. To evaluate the neuroprotective effects, the behavioral outcome, apoptosis, and neuronal injury were measured. Microglia activation and pro-inflammatory cytokines were applied to detect neuroinflammation. Microglial pyroptosis was determined by western blotting, immunofluorescence staining, and transmission electron microscopy (TEM).

Results

The two OM-MSC-transplanted groups exhibited significantly improved functional recovery and reduced neuronal injury, especially the hypoxic OM-MSCs group. Hypoxic OM-MSCs attenuated microglial activation as well as the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Moreover, we found that hypoxia-preconditioned OM-MSCs ameliorated pyroptosis by diminishing the levels of pyroptosis-associated proteins in peri-hematoma brain tissues, decreasing the expression of the microglial nod-like receptor family protein 3 (NLRP3) and caspase-1, and reducing the membrane pores on microglia post-ICH.

Conclusions

Our study showed that hypoxic preconditioning augments the therapeutic efficacy of OM-MSCs, and hypoxia-preconditioned OM-MSCs alleviate microglial pyroptosis in the ICH model.

Hypoxic preconditioning rejuvenates mesenchymal stem cells and enhances neuroprotection following intracerebral hemorrhage via the miR-326-mediated autophagy

BACKGROUND

Intracerebral hemorrhage (ICH) is a major public health concern, and mesenchymal stem cells (MSCs) hold great potential for treating ICH. However, the quantity and quality of MSCs decline in the cerebral niche, limiting the potential efficacy of MSCs. Hypoxic preconditioning is suggested to enhance the survival of MSCs and augment the therapeutic efficacy of MSCs in ICH. MicroRNAs (miRNAs) are known to mediate cellular senescence. However, the precise mechanism by which miRNAs regulate the senescence of hypoxic MSCs remains to be further studied. In the present study, we evaluated whether hypoxic preconditioning enhances the survival and therapeutic effects of olfactory mucosa MSC (OM-MSC) survival and therapeutic effects in ICH and investigated the mechanisms by which miRNA ameliorates hypoxic OM-MSC senescence.

METHODS

In the in vivo model, ICH was induced in mice by administration of collagenase IV. At 24 h post-ICH, 5 × 10⁵ normoxia or hypoxia OM-MSCs or saline was administered intracerebrally. The behavioral outcome, neuronal apoptosis, and OM-MSC survival were evaluated. In the in vitro model, OM-MSCs were exposed to hemin. Cellular senescence was examined by evaluating the expressions of P16INK4A, P21, P53, and by β-galactosidase staining. Microarray and bioinformatic analyses were performed to investigate the differences in the miRNA expression profiles between the normoxia and hypoxia OM-MSCs. Autophagy was confirmed using the protein expression levels of LC3, P62, and Beclin-1.

RESULTS

In the in vivo model, transplanted OM-MSCs with hypoxic preconditioning exhibited increased survival and tissue-protective capability. In the in vitro model, hypoxia preconditioning decreased the senescence of OM-MSCs exposed to hemin. Bioinformatic analysis identified that microRNA-326 (miR-326) expression was significantly increased in the hypoxia OM-MSCs compared with that of normoxia OM-MSCs. Upregulation of miR-326 alleviated normoxia OM-MSC senescence, whereas miR-326 downregulation increased hypoxia OM-MSC senescence. Furthermore, we showed that miR-326 alleviated cellular senescence by upregulating autophagy. Mechanistically, miR-326 promoted the autophagy of OM-MSCs via the PI3K signaling pathway by targeting polypyrimidine tract-binding protein 1 (PTBP1).

CONCLUSIONS

Our study shows that hypoxic preconditioning delays OM-MSC senescence and augments the therapeutic efficacy of OM-MSCs in ICH by upregulating the miR-326/PTBP1/PI3K-mediated autophagy.

Oxidative Stress, Inflammation, and Autophagy: Potential Targets of Mesenchymal Stem Cells-Based Therapies in Ischemic Stroke

Ischemic stroke is a leading cause of death worldwide; currently available treatment approaches for ischemic stroke are to restore blood flow, which reduce disability but are time limited. The interruption of blood flow in ischemic stroke contributes to intricate pathophysiological processes. Oxidative stress and inflammatory activity are two early events in the cascade of cerebral ischemic injury. These two factors are reciprocal causation and directly trigger the development of autophagy. Appropriate autophagy activity contributes to brain recovery by reducing oxidative stress and inflammatory activity, while autophagy dysfunction aggravates cerebral injury. Abundant evidence demonstrates the beneficial impact of mesenchymal stem cells (MSCs) and secretome on cerebral ischemic injury. MSCs reduce oxidative stress through suppressing reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation and transferring healthy mitochondria to damaged cells. Meanwhile, MSCs exert anti-inflammation properties by the production of cytokines and extracellular vesicles, inhibiting proinflammatory cytokines and inflammatory cells activation, suppressing pyroptosis, and alleviating blood–brain barrier leakage. Additionally, MSCs regulation of autophagy imbalances gives rise to neuroprotection against cerebral ischemic injury. Altogether, MSCs have been a promising candidate for the treatment of ischemic stroke due to their pleiotropic effect.