Metabolomics Deciphers Potential Targets of Xuefu Zhuyu Decoction Against Traumatic Brain Injury in Rat

Xuefu Zhuyu Decoction Improves Blood-Brain Barrier Integrity in Acute Traumatic Brain Injury Rats via Regulating Adenosine

OBJECTIVE

To explore the neuroprotective effects of Xuefu Zhuyu Decoction (XFZYD) based on in vivo and metabolomics experiments.

METHODS

Traumatic brain injury (TBI) was induced via a controlled cortical impact (CCI) method. Thirty rats were randomly divided into 3 groups (10 for each): sham, CCI and XFZYD groups (9 g/kg). The administration was performed by intragastric administration for 3 days. Neurological functions tests, histology staining, coagulation and haemorheology assays, and Western blot were examined. Untargeted metabolomics was employed to identify metabolites. The key metabolite was validated by enzyme-linked immunosorbent assay and immunofluorescence.

RESULTS

XFZYD significantly alleviated neurological dysfunction in CCI model rats (P<0.01) but had no impact on coagulation function. As evidenced by Evans blue and IgG staining, XFZYD effectively prevented blood-brain barrier (BBB) disruption (P<0.05, P<0.01). Moreover, XFZYD not only increased the expression of collagen IV, occludin and zona occludens 1 but also decreased matrix metalloproteinase-9 (MMP-9) and cyclooxygenase-2 (COX-2), which protected BBB integrity (all P<0.05). Nine potential metabolites were identified, and all of them were reversed by XFZYD. Adenosine was the most significantly altered metabolite related to BBB repair. XFZYD significantly reduced the level of equilibrative nucleoside transporter 2 (ENT2) and increased adenosine (P<0.01), which may improve BBB integrity.

CONCLUSIONS

XFZYD ameliorates BBB disruption after TBI by decreasing the levels of MMP-9 and COX-2. Through further exploration via metabolomics, we found that XFZYD may exert a protective effect on BBB by regulating adenosine metabolism via ENT2.

Bioinformatics analysis of miRNAs germacrone protection on diabetic nephropathy

Diabetes nephropathy (DN) is a prevalent and severe microvascular diabetic complication. Despite the recent developments in germacrone-based therapies for DN, the underlying mechanisms of germacrone in DN remain poorly understood. This study used comprehensive bioinformatics analysis to identify critical microRNAs (miRNAs) and the potential underlying pathways related to germacrone activities. Additionally, we established a DN mice model, which was treated with germacrone, to investigate how it altered the miRNA transcriptome in mice kidneys. RNA sequencing was also performed on the DN mice model with and without germacrone pre-treatment. Based on our results, we found 23 miRNAs were differentially expressed in the DN group compared to the controls, and a total of 14 miRNAs were differentially expressed between the DN group and the germacrone-treated group. In addition, we identified three miRNAs (mmu-miR-542-5p, mmu-miR-149-5p and mmu-miR-196a-2-3p) that were upregulated with the DN group and downregulated in the germacrone-treated group. Bioinformatics analysis suggested that autophagy and apoptosis were related to the pathogenesis of DN and germacrone treatment. Subsequently, the expression level of mmu-miR-542-5p, mmu-miR-149-5p and mmu-miR-196a-2-3p were validated in a validation dataset. Altogether, these findings add important knowledge on the pathogenesis of DN and the impacts of germacrone.

Metabolomics integrated with network pharmacology of blood-entry constituents reveals the bioactive component of Xuefu Zhuyu decoction and its angiogenic effects in treating traumatic brain injury

BACKGROUND

Xuefu Zhuyu decoction (XFZYD) has been extensively utilized to treat traumatic brain injury (TBI). However, the bioactive compounds and the underlying mechanisms have not yet been elucidated.

OBJECTIVES

This study aimed to investigate the bioactive constituents of XFYZD that are absorbed in the blood and the mechanisms in treating TBI.

METHODS

The study presents an integrated strategy in three steps to investigate the material basis and pharmacological mechanisms of XFZYD. The first step involves: (1) performing metabolomics analysis of XFZYD to obtain the main functions and targets; (2) screening the blood-entry ingredients and targets of XFZYD from databases; (3) obtaining the potential components targeting the key functions by integrated analysis of metabolomics and network pharmacology. The second step involves screening pharmacological effects with active ingredients in vitro. In the third step, the effects of the top active compound were validated in vivo, and the mechanisms were explored by protein antagonist experiments.

RESULTS

Metabolomics analysis revealed that XFZYD treated TBI mice mainly through affecting the functions of blood vessels. We screened 62 blood-entry ingredients of XFZYD by network pharmacology. Then, we focused on 39 blood-entry ingredients related to vascular genes enriched by XFZYD-responsive metabolites. Performing the natural products library, we verified that hydroxysafflor yellow A (HSYA), vanillin, ligustilide, paeoniflorin, and other substances promoted endothelial cell proliferation significantly compared to the control group. Among them, the efficacy of HSYA was superior. Further animal studies demonstrated that HSYA treatment alleviated neurological dysfunction in TBI mice by mNSS and foot fault test, and decreased neuronal damage by HE, nissl, and TUNEL staining. HSYA increased the density of cerebral microvessels, raised the expression of angiogenesis marker proteins VEGFA and CD34, and activated the PI3K/Akt/mTOR signaling pathway significantly. The angiogenic effects disappeared after the intervention of PI3K antagonist LY294002.

CONCLUSION

By applying a novel strategy of integrating network pharmacology of constituents absorbed in blood with metabolomics, the research screened HSYA as one of the top bioactive constituents of XFZYD, which stimulates angiogenesis by activating the PI3K/Akt/mTOR signaling pathway after TBI.

Spatial amine metabolomics and histopathology reveal localized brain alterations in subacute traumatic brain injury and the underlying mechanism of herbal treatment

INTRODUCTION

Spatial changes of amine metabolites and histopathology of the whole brain help to reveal the mechanism of traumatic brain injury (TBI) and treatment.

METHODS

A newly developed liquid microjunction surface sampling-tandem mass tag-ultra performance liquid chromatography-mass spectrometry technique is applied to profile brain amine metabolites in five brain regions after impact-induced TBI at the subacute stage. H&E, Nissl, and immunofluorescence staining are performed to spatially correlate microscopical changes to metabolic alterations. Then, bioinformatics, molecular docking, ELISA, western blot, and immunofluorescence are integrated to uncover the mechanism of Xuefu Zhuyu decoction (XFZYD) against TBI.

RESULTS

Besides the hippocampus and cortex, the thalamus, caudate-putamen, and fiber tracts also show differentiated metabolic changes between the Sham and TBI groups. Fourteen amine metabolites (including isomers such as L-leucine and L-isoleucine) are significantly altered in specific regions. The metabolic changes are well matched with the degree of neuronal damage, glia activation, and neurorestoration. XFZYD reverses the dysregulation of several amine metabolites, such as hippocampal Lys-Phe/Phe-Lys and dopamine. Also, XFZYD enhances post-TBI angiogenesis in the hippocampus and the thalamus.

CONCLUSION

This study reveals the local amine-metabolite and histological changes in the subacute stage of TBI. XFZYD may promote TBI recovery by normalizing amine metabolites and spatially promoting dopamine production and angiogenesis.

Metabolomics reveals the effects of hydroxysafflor yellow A on neurogenesis and axon regeneration after experimental traumatic brain injury

CONTEXT

Hydroxysafflor yellow A (HSYA) is the main bioactive ingredient of safflower (Carthamus tinctorius L., [Asteraceae]) for traumatic brain injury (TBI) treatment.

OBJECTIVE

To explore the therapeutic effects and underlying mechanisms of HSYA on post-TBI neurogenesis and axon regeneration.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomly assigned into Sham, controlled cortex impact (CCI), and HSYA groups. Firstly, the modified Neurologic Severity Score (mNSS), foot fault test, hematoxylin-eosin staining, Nissl's staining, and immunofluorescence of Tau1 and doublecortin (DCX) were used to evaluate the effects of HSYA on TBI at the 14th day. Next, the effectors of HSYA on post-TBI neurogenesis and axon regeneration were screened out by pathology-specialized network pharmacology and untargeted metabolomics. Then, the core effectors were validated by immunofluorescence.

RESULTS

HSYA alleviated mNSS, foot fault rate, inflammatory cell infiltration, and Nissl's body loss. Moreover, HSYA increased not only hippocampal DCX but also cortical Tau1 and DCX following TBI. Metabolomics demonstrated that HSYA significantly regulated hippocampal and cortical metabolites enriched in 'arginine metabolism' and 'phenylalanine, tyrosine and tryptophan metabolism' including l-phenylalanine, ornithine, l-(+)-citrulline and argininosuccinic acid. Network pharmacology suggested that neurotrophic factor (BDNF) and signal transducer and activator of transcription 3 (STAT3) were the core nodes in the HSYA-TBI-neurogenesis and axon regeneration network. In addition, BDNF and growth-associated protein 43 (GAP43) were significantly elevated following HSYA treatment in the cortex and hippocampus.

DISCUSSION AND CONCLUSIONS

HSYA may promote TBI recovery by facilitating neurogenesis and axon regeneration through regulating cortical and hippocampal metabolism, BDNF and STAT3/GAP43 axis.

Therapy of traumatic brain injury by modern agents and traditional Chinese medicine

Traumatic brain injury (TBI) is the leading cause of disability and death, and the social burden of mortality and morbidity caused by TBI is significant. Under the influence of comprehensive factors, such as social environment, lifestyle, and employment type, the incidence of TBI continues to increase annually. Current pharmacotherapy of TBI mainly focuses on symptomatic supportive treatment, aiming to reduce intracranial pressure, ease pain, alleviate irritability, and fight infection. In this study, we summarized numerous studies covering the use of neuroprotective agents in different animal models and clinical trials after TBI. However, we found that no drug has been approved as specifically effective for the treatment of TBI. Effective therapeutic strategies for TBI remain an urgent need, and attention is turning toward traditional Chinese medicine. We analyzed the reasons why existing high-profile drugs had failed to show clinical benefits and offered our views on the research of traditional herbal medicine for treating TBI.

Bioinformatics Analysis of miRNAs and mRNAs Network-Xuefu Zhuyu Decoction Exerts Neuroprotection of Traumatic Brain Injury Mice in the Subacute Phase

Xuefu Zhuyu decoction (XFZYD) is used to treat traumatic brain injury (TBI). XFZYD-based therapies have achieved good clinical outcomes in TBI. However, the underlying mechanisms of XFZYD in TBI remedy remains unclear. The study aimed to identify critical miRNAs and putative mechanisms associated with XFYZD through comprehensive bioinformatics analysis. We established a controlled cortical impact (CCI) mice model and treated the mice with XFZYD. The high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) confirmed the quality of XFZYD. The modified neurological severity score (mNSS) and Morris water maze (MWM) tests indicated that XFZYD improved the neurological deficit (p < 0.05) and cognitive function (p < 0.01). Histological analysis validated the establishment of the CCI model and the treatment effect of XFZYD. HE staining displayed that the pathological degree in the XFZYD-treated group was prominently reduced. The transcriptomic data was generated using microRNA sequencing (miRNA-seq) of the hippocampus. According to cluster analysis, the TBI group clustered together was distinct from the XFZYD group. Sixteen differentially expressed (5 upregulated; 11 downregulated) miRNAs were detected between TBI and XFZYD. The reliability of the sequencing data was confirmed by qRT-PCR. Three miRNAs (mmu-miR-142a-5p, mmu-miR-183-5p, mmu-miR-96-5p) were distinctively expressed in the XFZYD compared with the TBI and consisted of the sequencing results. Bioinformatics analysis suggested that the MAPK signaling pathway contributes to TBI pathophysiology and XFZYD treatment. Subsequently, the functions of miR-96-5p, miR-183-5p, and miR-142a-5p were validated in vitro. TBI significantly induces the down-expression of miR-96-5p, and up-expression of inflammatory cytokines, which were all inhibited by miR-96-5p mimics. The present research provides an adequate fundament for further knowing the pathologic and prognostic process of TBI and supplies deep insights into the therapeutic effects of XFZYD.

The Involvement of Long Non-coding RNA and Messenger RNA Based Molecular Networks and Pathways in the Subacute Phase of Traumatic Brain Injury in Adult Mice

Traumatic brain injury (TBI) is a complex injury with a multi-faceted recovery process. Long non-coding RNAs (lncRNAs) are demonstrated to be involved in central nervous system (CNS) disorders. However, the roles of lncRNAs in long-term neurological deficits post-TBI are poorly understood. The present study depicted the microarray’s lncRNA and messenger RNA (mRNA) profiles at 14 days in TBI mice hippocampi. LncRNA and mRNA microarray was used to identify differentially expressed genes. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to validate the microarray results. Bioinformatics analysis [including Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, lncRNA-mRNA co-expression network, and lncRNA-miRNA-mRNA network] were applied to explore the underlying mechanism. A total of 264 differentially expressed lncRNAs and 232 expressed mRNAs were identified (fold change > 1.5 and P-value < 0.05). Altered genes were enriched in inflammation, immune response, blood–brain barrier, glutamatergic neurological effects, and neuroactive ligand-receptor, which may be associated with TBI-induced pathophysiologic changes in the long-term neurological deficits. The lncRNAs-mRNAs co-expression network was generated for 74 lncRNA-mRNA pairs, most of which are positive correlations. The lncRNA-miRNA-mRNA interaction network included 12 lncRNAs, 59 miRNAs, and 25 mRNAs. Numerous significantly altered lncRNAs and mRNAs in mice hippocampi were enriched in inflammation and immune response. Furthermore, these dysregulated lncRNAs and mRNAs may be promising therapeutic targets to overcome obstacles in long-term recovery following TBI.

Construction and imaging of a neurovascular unit model

In 2001, the concept of the neurovascular unit was introduced at the Stroke Progress Review Group meeting. The neurovascular unit is an important element of the health and disease status of blood vessels and nerves in the central nervous system. Since then, the neurovascular unit has attracted increasing interest from research teams, who have contributed greatly to the prevention, treatment, and prognosis of stroke and neurodegenerative diseases. However, additional research is needed to establish an efficient, low-cost, and low-energy in vitro model of the neurovascular unit, as well as enable noninvasive observation of neurovascular units in vivo and in vitro. In this review, we first summarize the composition of neurovascular units, then investigate the efficacy of different types of stem cells and cell culture methods in the construction of neurovascular unit models, and finally assess the progress of imaging methods used to observe neurovascular units in recent years and their positive role in the monitoring and investigation of the mechanisms of a variety of central nervous system diseases.

Quantitative Mass Spectrometry Imaging of Metabolomes and Lipidomes for Tracking Changes and Therapeutic Response in Traumatic Brain Injury Surrounding Injured Area at Chronic Phase

Traumatic brain injury (TBI) is a complex disease process that may contribute to temporary or permanent disability. Tracking spatial changes of lipids and metabolites in the brain helps unveil the underlying mechanisms of the disease procession and therapeutic response. Here, the liquid microjunction surface sampling technique was used for mass spectrometry imaging of both lipids and metabolites in rat models of controlled cortical impact with and without XueFu ZhuYu decoction treatment, and the work was focused on the diffuse changes outside the injured area at chronic phase (14 days after injury). Quantitative information was provided for phosphotidylcholines and cerebrosides by adding internal standards in the sampling solvent. With principal component analysis for the imaging data, the midbrain was found to be the region with the largest diffuse changes following TBI outside the injured area. In detail, several phosphatidylcholines, phosphatidylethanolamines, phosphatidic acids, and diacylglycerols were found to be significantly up-regulated particularly in midbrain and thalamus after TBI and XFZY treatment. It is associated with the reported "self-repair" mechanisms at the chronic phase of TBI activated by neuroinflammation. Several glycosphingolipids were found to be increased in most of brain regions after TBI, which was inferred to be associated with neuroinflammation and oxidative stress triggered by TBI. Moreover, different classes of small matabolites were significantly changed after TBI, including fatty acids, amino acids, and purines. All these compounds were involved in 10 metabolic pathway networks, and 6 target proteins of XFZY were found related to the impacted pathways. These results shed light on the molecular mechanisms of TBI pathologic processes and therapeutic response.