Minocycline Preserves the Integrity and Permeability of BBB by Altering the Activity of DKK1-Wnt Signaling in ICH Model

Drug delivery strategy of hemostatic drugs for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is associated with high rates of mortality and disability, underscoring an urgent need for effective therapeutic interventions. The clinical prognosis of ICH remains limited, primarily due to the absence of targeted, precise therapeutic options. Advances in novel drug delivery platforms, including nanotechnology, gel-based systems, and exosome-mediated therapies, have shown potential in enhancing ICH management. This review delves into the pathophysiological mechanisms of ICH and provides a thorough analysis of existing treatment strategies, with an emphasis on innovative drug delivery approaches designed to address critical pathological pathways. We assess the benefits and limitations of these therapies, offering insights into future directions in ICH research and highlighting the transformative potential of next-generation drug delivery systems in improving patient outcomes.

Wnt1 oversees microglial activation by the Wnt/LRP5/6 receptor signaling pathway during lipopolysaccharide-mediated toxicity

BACKGROUND

The protective effects of autophagy-mediated microglial inflammatory regulation on diseases of the central nervous system (CNS) has been a recent field of interest. The canonical signaling pathway activated by Wnt1, the Wnt/β-catenin signaling cascade, also plays a crucial protective role in neurodegenerative diseases. However, the relationship between Wnt1/β-catenin signaling and microglial activation remains unclear. Our study focused on understanding the impact and mechanism of Wnt1 on microglial activation.

METHODS AND RESULTS

To simulate neuroinflammatory conditions in vitro, BV2 cells were exposed to 1 μg/mL lipopolysaccharide. CD86- and CD206-positive cells were identified by flow cytometry and immunofluorescence assays. Inflammatory and anti-inflammatory factors were measured using enzyme-linked immunosorbent assays. Autophagy was analyzed by expression of LC3B puncta, LC3, P62, and beclin1 expression. The inflammatory activation suppressed by rhWnt1 was restricted by DKK1, siRNA-β-catenin and siRNA-LKB1, respectively, with concomitant changes in β-catenin expression and phosphorylation of NFκB-p65, LKB1, and AMPK. Although the anti-inflammatory effect of Wnt1/LKB1 pathway was independent of β-catenin, Wnt1/LKB1 regulated β-catenin. The reduced inflammation caused by rhWnt1 is linked to its enhancement of autophagy, a process blocked by siRNA-LKB1 and 3-MA partially.

CONCLUSIONS

The anti-inflammatory effects of Wnt1 on BV2 cells improved autophagy, a mechanism partly dependent on the β-catenin pathway or the phosphorylation of LKB1. Furthermore, the Wnt1/LKB1 pathway was activated independently of β-catenin and participated in regulating its expression. Our research unveils a previously unknown method through which Wnt1 exerts its anti-inflammatory effects, which may have a potential protective role against CNS diseases.

A crosstalk between autophagy and apoptosis in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a severe condition that devastatingly harms human health and poses a financial burden on families and society. Bcl-2 Associated X-protein (Bax) and B-cell lymphoma 2 (Bcl-2) are two classic apoptotic markers post-ICH. Beclin 1 offers a competitive architecture with that of Bax, both playing a vital role in autophagy. However, the interaction between Beclin 1 and Bcl-2/Bax has not been conjunctively analyzed. This review aims to examine the crosstalk between autophagy and apoptosis in ICH by focusing on the interaction and balance of Beclin 1, Bax, and Bcl-2. We also explored the therapeutic potential of Western conventional medicine and traditional Chinese medicine (TCM) in ICH via controlling the crosstalk between autophagy and apoptosis.

Endothelial Dysfunctions in Blood-Brain Barrier Breakdown in Alzheimer's Disease: From Mechanisms to Potential Therapies

Recent research has shown the presence of blood-brain barrier (BBB) breakdown in Alzheimer's disease (AD). BBB is a dynamic interface consisting of a continuous monolayer of brain endothelial cells (BECs) enveloped by pericytes and astrocytes. The restricted permeability of BBB strictly controls the exchange of substances between blood and brain parenchyma, which is crucial for brain homeostasis by excluding blood-derived detrimental factors and pumping out brain-derived toxic molecules. BBB breakdown in AD is featured as a series of BEC pathologies such as increased paracellular permeability, abnormal levels and functions of transporters, and inflammatory or oxidative profile, which may disturb the substance transportation across BBB, thereafter induce CNS disorders such as hypometabolism, Aβ accumulation, and neuroinflammation, eventually aggravate cognitive decline. Therefore, it seems important to protect BEC properties for BBB maintenance and neuroprotection. In this review, we thoroughly summarized the pathological alterations of BEC properties reported in AD patients and numerous AD models, including paracellular permeability, influx and efflux transporters, and inflammatory and oxidative profiles, and probably associated underlying mechanisms. Then we reviewed current therapeutic agents that are effective in ameliorating a series of BEC pathologies, and ultimately protecting BBB integrity and cognitive functions. Regarding the current drug development for AD proceeds extremely hard, this review aims to discuss the therapeutic potentials of targeting BEC pathologies and BBB maintenance for AD treatment, therefore expecting to shed a light on the future AD drug development by targeting BEC pathologies and BBB protection.

Immune-mediated disruption of the blood-brain barrier after intracerebral hemorrhage: Insights and potential therapeutic targets

AIMS

Intracerebral hemorrhage (ICH) is a condition that arises due to the rupture of cerebral blood vessels, leading to the flow of blood into the brain tissue. One of the pathological alterations that occurs during an acute ICH is an impairment of the blood-brain barrier (BBB), which leads to severe perihematomal edema and an immune response.

DISCUSSION

A complex interplay between the cells of the BBB, for example, pericytes, astrocytes, and brain endothelial cells, with resident and infiltrating immune cells, such as microglia, monocytes, neutrophils, T lymphocytes, and others accounts for both damaging and protective mechanisms at the BBB following ICH. However, the precise immunological influence of BBB disruption has yet to be richly ascertained, especially at various stages of ICH.

CONCLUSION

This review summarizes the changes in different cell types and molecular components of the BBB associated with immune-inflammatory responses during ICH. Furthermore, it highlights promising immunoregulatory therapies to protect the integrity of the BBB after ICH. By offering a comprehensive understanding of the mechanisms behind BBB damage linked to cellular and molecular immunoinflammatory responses after ICH, this article aimed to accelerate the identification of potential therapeutic targets and expedite further translational research.

Enhancing motor functional recovery in spinal cord injury through pharmacological inhibition of Dickkopf-1 with BHQ880 antibody

BACKGROUND

Mounting experimental evidence has underscored the remarkable role played by the Wnt family of proteins in the spinal cord functioning and therapeutic potential in spinal cord injury (SCI). We aim to provide a therapeutic prospect associated with the modulation of canonical Wnt signaling, examining the spatio-temporal expression pattern of Dickkopf-1 (Dkk1) and its neutralization after SCI. We employ an intraparenchymal injection of the clinically validated Dkk1-blocking antibody, BHQ880, to elucidate its effects in SCI.

METHODS

A rat model of contusion SCI was used. Histological analyses were performed, wherein Dkk1 protein was sought, and ELISA analyses were employed for Dkk1 detection in cerebrospinal fluid and serum. To ascertain the BHQ880 therapeutic effect, rats were subjected to SCI and then injected with the antibody in the lesion epicenter 24 hours post-injury (hpi). Subsequent evaluation of motor functional recovery extended up to 56 days post-injury (dpi). qRT-PCR and histological analyses were conducted.

RESULTS

We demonstrate the presence of Dkk1 in the healthy rat spinal cord, with pronounced alterations observed following injury, primarily concentrated in the epicenter regions. Notably, a significative upregulation of Dkk1 was detected at 24 hpi, peaking at 3 dpi and remaining elevated until 42 dpi. Moreover, we revealed that early administration of BHQ880 considerably improved motor functional recovery, promoted preservation of myelinated tissue, and reduced astroglial and microglia/macrophage reactivity. Furthermore, there was a decrease in the acute expression of different inflammatory genes.

CONCLUSIONS

Collectively, our findings highlight the therapeutic potential of BHQ880 treatment in the context of SCI.

Skin-brain axis in Alzheimer's disease - Pathologic, diagnostic, and therapeutic implications: A Hypothetical Review

The dynamic interaction between the brain and the skin is termed the 'skin-brain axis.' Changes in the skin not only reflect conditions in the brain but also exert direct and indirect effects on the brain. Interestingly, the connection between the skin and brain is crucial for understanding aging and neurodegenerative diseases. Several studies have shown an association between Alzheimer's disease (AD) and various skin disorders, such as psoriasis, bullous pemphigoid, and skin cancer. Previous studies have shown a significantly increased risk of new-onset AD in patients with psoriasis. In contrast, skin cancer may reduce the risk of developing AD. Accumulating evidence suggests an interaction between skin disease and AD; however, AD-associated pathological changes mediated by the skin-brain axis are not yet clearly defined. While some studies have reported on the diagnostic implications of the skin-brain axis in AD, few have discussed its potential therapeutic applications. In this review, we address the pathological changes mediated by the skin-brain axis in AD. Furthermore, we summarize (1) the diagnostic implications elucidated through the role of the skin-brain axis in AD and (2) the therapeutic implications for AD based on the skin-brain axis. Our review suggests that a potential therapeutic approach targeting the skin-brain axis will enable significant advances in the treatment of AD.

Baicalein ameliorates oxidative stress and brain injury after intracerebral hemorrhage by activating the Nrf2/ARE pathway via miR-106a-5p/PHLPP2 axis

Intracerebral hemorrhage (ICH) is a devastating stroke subtype. Baicalein (BAI) has been reported to be effective in ischemic stroke. The aim of the present study was to investigate the mechanism of BAI on brain injury after ICH. Firstly, ICH mouse models were established by injecting collagenase into the right of basal ganglia, followed by detection of neurobehavioral scores, brain edema, oxidative stress (OS) level, neuronal apoptosis and pathological changes. Average neurologic scores, brain water content, and blood-brain barrier permeability and MDA level in ICH mice were reduced after BAI treatment, while serum SOD and GSH-Px levels were increased and neuronal apoptosis and pathological injury of the brain tissues were mitigated. miR-106a-5p downregulation averted the effect of BAI on ICH mice. miR-106a-5p targeted PHLPP2 and PHLPP2 overexpression reversed the effect of BAI on ICH mice. BAI activated the Nrf2/ARE pathway by inhibiting PHLPP2 expression. In conclusion, BAI inhibited OS and protected against brain injury after ICH by activating the Nrf2/ARE pathway through the miR-106a-5p/PHLPP2 axis.

CDC Guidelines for the Prevention and Treatment of Anthrax, 2023

This report updates previous CDC guidelines and recommendations on preferred prevention and treatment regimens regarding naturally occurring anthrax. Also provided are a wide range of alternative regimens to first-line antimicrobial drugs for use if patients have contraindications or intolerances or after a wide-area aerosol release of

Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis.

Changes from previous CDC guidelines and recommendations include an expanded list of alternative antimicrobial drugs to use when first-line antimicrobial drugs are contraindicated or not tolerated or after a bioterrorism event when first-line antimicrobial drugs are depleted or ineffective against a genetically engineered resistant

B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.

Minocycline relieves neuropathic pain in rats with spinal cord injury via activation of autophagy and suppression of PI3K/Akt/mTOR pathway

OBJECTIVE

In this study, we studied whether minocycline hydrochloride improved neuropathic pain induced by spinal cord injury (SCI) in rats through PI3K/Akt pathway.

METHODS

The SCI was induced by compressed at level of T9-T11 of spinal cord in Sprague Dawley male rats. Animals were given different concentrations of minocycline (3 mg/kg, 30 mg/kg, 90 mg/kg) at the first and 24 h after SCI, then subsequently every 7, 12, 16, 20, 25 days via peroral route. The locomotor function was assessed by Basso Mouse Scale (BMS). The changes of spinal cord tissues were observed by HE. The inflammatory cytokines in spinal cord, IL-6, IL-1β and TNF-α, were measured by ELISA. The LC3B levels of spinal cord were observed by immunofluorescence. The autophagy related proteins and PI3K/AKT pathway related proteins were analysed by Western blot. Furthermore, the PI3K/AKT pathway inhibitor LY294002, and activator IGF-1 were used to confirm the mechanism of minocycline.

RESULTS

Contrasted to sham group, the inflammatory response in spinal cord was enhanced after SCI. Compared with the SCI rats, minocycline treatment significantly improved the locomotor activity, pathological injury of spinal cord, suppressed the levels of inflammatory factors. In addition, minocycline treatment upregulated autophagy response in damaged spinal cord through increasing LC3B, Beclin-1 and decreasing P62. The results of mechanism study showed that minocycline treatment clearly suppressed phosphorylation of PI3K, Akt and mTOR proteins expression.

CONCLUSION

Minocycline could improve neuropathic pain induced by SCI through activating autophagy and inhibiting PI3K/AKT/mTOR pathway.

Mesenchymal stem cells transplantation combined with IronQ attenuates ICH-induced inflammation response via Mincle/syk signaling pathway

BACKGROUND

Intracerebral hemorrhage (ICH) is a severe brain-injured disease accompanied by cerebral edema, inflammation, and subsequent neurological deficits. Mesenchymal stem cells (MSCs) transplantation has been used as a neuroprotective therapy in nervous system diseases because of its anti-inflammatory effect. Nevertheless, the biological characteristics of transplanted MSCs, including the survival rate, viability, and effectiveness, are restricted because of the severe inflammatory response after ICH. Therefore, improving the survival and viability of MSCs will provide a hopeful therapeutic efficacy for ICH. Notably, the biomedical applications of coordination chemistry-mediated metal-quercetin complex have been verified positively and studied extensively, including growth-promoting and imaging probes. Previous studies have shown that the iron-quercetin complex (IronQ) possesses extraordinary dual capabilities with a stimulating agent for cell growth and an imaging probe by magnetic resonance imaging (MRI). Therefore, we hypothesized that IronQ could improve the survival and viability of MSCs, displaying the anti-inflammation function in the treatment of ICH while also labeling MSCs for their tracking by MRI. This study aimed to explore the effects of MSCs with IronQ in regulating inflammation and further clarify their potential mechanisms.

METHODS

C57BL/6 male mice were utilized in this research. A collagenase I-induced ICH mice model was established and randomly separated into the model group (Model), quercetin gavage group (Quercetin), MSCs transplantation group (MSCs), and MSCs transplantation combined with IronQ group (MSCs + IronQ) after 24 h. Then, the neurological deficits score, brain water content (BWC), and protein expression, such as TNF-α, IL-6, NeuN, MBP, as well as GFAP, were investigated. We further measured the protein expression of Mincle and its downstream targets. Furthermore, the lipopolysaccharide (LPS)-induced BV2 cells were utilized to investigate the neuroprotection of conditioned medium of MSCs co-cultured with IronQ in vitro.

RESULTS

We found that the combined treatment of MSCs with IronQ improved the inflammation-induced neurological deficits and BWC in vivo by inhibiting the Mincle/syk signaling pathway. Conditioned medium derived from MSCs co-cultured with IronQ decreased inflammation, Mincle, and its downstream targets in the LPS-induced BV2 cell line.

CONCLUSIONS

These data suggested that the combined treatment exerts a collaborative effect in alleviating ICH-induced inflammatory response through the downregulation of the Mincle/syk signaling pathway following ICH, further improving the neurologic deficits and brain edema.

A Causal-Pathway Phenotype of Chronic Fatigue Syndrome due to Hemodialysis in Patients with End-Stage Renal Disease

BACKGROUND

End-stage renal disease (ESRD) is associated with fatigue and physiosomatic symptoms.

OBJECTIVE

The objective of this study is to delineate the associations between severity of fatigue and physio-somatic symptoms and glomerular filtration rate, inflammatory biomarkers, and Wnt/cateninpathway proteins.

METHODS

The Wnt-pathway related proteins β-catenin, Dickkopf-related protein 1 (DKK1), R-spondin- 1, and sclerostin were measured by ELISA technique in 60 ESRD patients and 30 controls. The Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale was used to assess the severity of FF symptoms.

RESULTS

ESRD is characterized by a significant increase in the total FF score, muscle tension, fatigue, sadness, sleep disorders, gastro-intestinal (GI) symptoms, and a flu-like malaise. The total-FF score was significantly correlated with serum levels of urea, creatinine, and copper (positively), and β-catenin, eGFR, hemoglobin, albumin, and zinc (inversely). The total-FF score was associated with the number of total dialysis and weekly dialysis sessions, and these dialysis characteristics were more important in predicting FF scores than eGFR measurements. Partial Least Squares analysis showed that the FF score comprised two factors that are differently associated with biomarkers: a) 43.0% of the variance in fatigue, GI symptoms, muscle tension, sadness, and insomnia is explained by hemoglobin, albumin, zinc, β-catenin, and R-spondin-1; and b) 22.3% of the variance in irritability, concentration and memory impairments by increased copper and cations/chloride ratio, and male sex.

CONCLUSION

ESRD patients show high levels of fatigue and physio-somatic symptoms associated with hemodialysis and mediated by dialysis-induced changes in inflammatory pathways, the Wnt/catenin pathway, and copper.

Therapeutic strategies for intracerebral hemorrhage

Stroke is the second highest cause of death globally, with an increasing incidence in developing countries. Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes. ICH is associated with poor neurological outcomes and high mortality due to the combination of primary and secondary injury. Fortunately, experimental therapies are available that may improve functional outcomes in patients with ICH. These therapies targeting secondary brain injury have attracted substantial attention in their translational potential. Here, we summarize recent advances in therapeutic strategies and directions for ICH and discuss the barriers and issues that need to be overcome to improve ICH prognosis.

Molecular, Pathological, Clinical, and Therapeutic Aspects of Perihematomal Edema in Different Stages of Intracerebral Hemorrhage

Acute intracerebral hemorrhage (ICH) is a devastating type of stroke worldwide. Neuronal destruction involved in the brain damage process caused by ICH includes a primary injury formed by the mass effect of the hematoma and a secondary injury induced by the degradation products of a blood clot. Additionally, factors in the coagulation cascade and complement activation process also contribute to secondary brain injury by promoting the disruption of the blood-brain barrier and neuronal cell degeneration by enhancing the inflammatory response, oxidative stress, etc. Although treatment options for direct damage are limited, various strategies have been proposed to treat secondary injury post-ICH. Perihematomal edema (PHE) is a potential surrogate marker for secondary injury and may contribute to poor outcomes after ICH. Therefore, it is essential to investigate the underlying pathological mechanism, evolution, and potential therapeutic strategies to treat PHE. Here, we review the pathophysiology and imaging characteristics of PHE at different stages after acute ICH. As illustrated in preclinical and clinical studies, we discussed the merits and limitations of varying PHE quantification protocols, including absolute PHE volume, relative PHE volume, and extension distance calculated with images and other techniques. Importantly, this review summarizes the factors that affect PHE by focusing on traditional variables, the cerebral venous drainage system, and the brain lymphatic drainage system. Finally, to facilitate translational research, we analyze why the relationship between PHE and the functional outcome of ICH is currently controversial. We also emphasize promising therapeutic approaches that modulate multiple targets to alleviate PHE and promote neurologic recovery after acute ICH.

Role of complement C1q/C3-CR3 signaling in brain injury after experimental intracerebral hemorrhage and the effect of minocycline treatment

Aim

The complement cascade is activated and may play an important pathophysiologic role in brain injury after experimental intracerebral hemorrhage (ICH). However, the exact mechanism of specific complement components has not been well studied. This study determined the role of complement C1q/C3-CR3 signaling in brain injury after ICH in mice. The effect of minocycline on C1q/C3-CR3 signaling-induced brain damage was also examined.

Methods

There were three parts to the study. First, the natural time course of C1q and CR3 expression was determined within 7 days after ICH. Second, mice had an ICH with CR3 agonists, LA-1 or vehicle. Behavioral score, neuronal cell death, hematoma volume, and oxidative stress response were assessed at 7 days after ICH. Third, the effect of minocycline on C1q/C3-CR3 signaling and brain damage was examined.

Results

There were increased numbers of C1q-positive and CR3-positive cells after ICH. Almost all perihematomal C1q-positive and CR3-positive cells were microglia/macrophages. CR3 agonist LA-1 aggravated neurological dysfunction, neuronal cell death, and oxidative stress response on day 7 after ICH, as well as enhancing the expression of the CD163/HO-1 pathway and accelerating hematoma resolution. Minocycline treatment exerted neuroprotective effects on brain injury following ICH, partly due to the inhibition of C1q/C3-CR3 signaling, and that could be reversed by LA-1.

Conclusions

The complement C1q/C3-CR3 signaling is upregulated after ICH. The activation of C1q/C3-CR3 signaling by LA-1 aggravates brain injury following ICH. The neuroprotection of minocycline, at least partly, is involved with the repression of the C1q/C3-CR3 signaling pathway.

A Drug Screening Reveals Minocycline Hydrochloride as a Therapeutic Option to Prevent Breast Cancer Cells Extravasation across the Blood-Brain Barrier

Among breast cancer (BC) patients, 15-25% develop BC brain metastases (BCBM), a severe condition due to the limited therapeutic options, which points to the need for preventive strategies. We aimed to find a drug able to boost blood-brain barrier (BBB) properties and prevent BC cells (BCCs) extravasation, among PI3K, HSP90, and EGFR inhibitors and approved drugs. We used BCCs (4T1) and BBB endothelial cells (b.End5) to identify molecules with toxicity to 4T1 cells and safe for b.End5 cells. Moreover, we used those cells in mixed cultures to perform a high-throughput microscopy screening of drugs' ability to ameliorate BBB properties and prevent BCCs adhesion and migration across the endothelium, as well as to analyse miRNAs expression and release profiles. KW-2478, buparlisib, and minocycline hydrochloride (MH) promoted maximal expression of the junctional protein β-catenin and induced 4T1 cells nucleus changes. Buparlisib and MH further decreased 4T1 adhesion. MH was the most promising in preventing 4T1 migration and BBB disruption, tumour and endothelial cytoskeleton-associated proteins modifications, and miRNA deregulation. Our data revealed MH's ability to improve BBB properties, while compromising BCCs viability and interaction with BBB endothelial cells, besides restoring miRNAs' homeostasis, paving the way for MH repurposing for BCBM prevention.

Targeting Oxidative Stress and Inflammatory Response for Blood-Brain Barrier Protection in Intracerebral Hemorrhage

Significance: Blood-brain barrier (BBB) disruption is a major pathological change after intracerebral hemorrhage (ICH) and is both the cause and result of oxidative stress and of the immune response post-ICH. These processes contribute to ICH-induced brain injury. Recent Advances: After the breakdown of cerebral vessels, blood components, including erythrocytes and their metabolites, thrombin, and fibrinogen, can access the cerebral parenchyma through the compromised BBB, triggering oxidative stress and inflammatory cascades. These aggravate BBB disruption and contribute to further infiltration of blood components, resulting in a vicious cycle that exacerbates brain edema and neurological injury after ICH. Experimental and clinical studies have highlighted the role of BBB disruption in ICH-induced brain injury. Critical Issues: In this review, we focus on the strategies to protect the BBB in ICH. Specifically, we summarize the evidence and the underlying mechanisms, including the ICH-induced process of oxidative stress and inflammatory response, and we highlight the potential therapeutic targets to protect BBB integrity after ICH. Future Directions: Future studies should probe the mechanism of ferroptosis as well as oxidative stress-inflammation coupling in BBB disruption after ICH and investigate the effects of antioxidants and immunomodulatory agents in more ICH clinical trials. Antioxid. Redox Signal. 37, 115-134.

Lithium attenuates blood-brain barrier damage and brain edema following intracerebral hemorrhage via an endothelial Wnt/β-catenin signaling-dependent mechanism in mice

Background

Vasogenic cerebral edema resulting from blood–brain barrier (BBB) damage aggravates the devastating consequences of intracerebral hemorrhage (ICH). Although augmentation of endothelial Wnt/β‐catenin signaling substantially alleviates BBB breakdown in animals, no agents based on this mechanism are clinically available. Lithium is a medication used to treat bipolar mood disorders and can upregulate Wnt/β‐catenin signaling.

Methods

We evaluated the protective effect of lithium on the BBB in a mouse model of collagenase IV‐induced ICH. Furthermore, we assessed the effect and dependency of lithium on Wnt/β‐catenin signaling in mice with endothelial deletion of the Wnt7 coactivator Gpr124.

Results

Lithium treatment (3 mmol/kg) significantly decreased the hematoma volume (11.15 ± 3.89 mm³ vs. 19.97 ± 3.20 mm³ in vehicle controls, p = 0.0016) and improved the neurological outcomes of mice following ICH. Importantly, lithium significantly increased the BBB integrity, as evidenced by reductions in the levels of brain edema (p = 0.0312), Evans blue leakage (p = 0.0261), and blood IgG extravasation (p = 0.0009) into brain tissue around the hematoma. Mechanistically, lithium upregulated the activity of endothelial Wnt/β‐catenin signaling in mice and increased the levels of tight junction proteins (occludin, claudin‐5 and ZO‐1). Furthermore, the protective effect of lithium on cerebral damage and BBB integrity was abolished in endothelial Gpr124 knockout mice, suggesting that its protective effect on BBB function was mainly dependent on Gpr124‐mediated endothelial Wnt/β‐catenin signaling.

Conclusion

Our findings indicate that lithium may serve as a therapeutic candidate for treating BBB breakdown and brain edema following ICH.

Traditional Chinese medicine use in the pathophysiological processes of intracerebral hemorrhage and comparison with conventional therapy

Intracerebral hemorrhage (ICH) refers to hemorrhage caused by non-traumatic vascular rupture in the brain parenchyma, which is characterized by acute onset, severe illness, and high mortality and disability. The influx of blood into the brain tissue after cerebrovascular rupture causes severe brain damage, including primary injury caused by persistent hemorrhage and secondary brain injury (SBI) induced by hematoma. The mechanism of brain injury is complicated and is a significant cause of disability after ICH. Therefore, it is essential to understand the mechanism of brain injury after ICH to develop drugs to prevent and treat ICH. Studies have confirmed that many traditional Chinese medicines (TCM) can reduce brain injury by improving neurotoxicity, inflammation, oxidative stress (OS), blood-brain barrier (BBB), apoptosis, and neurological dysfunction after ICH. Starting from the pathophysiological process of brain injury after ICH, this paper summarizes the mechanisms by which TCM improves cerebral injury after ICH and its comparison with conventional western medicine, so as to provide clues and a reference for the clinical application of TCM in the prevention and treatment of hemorrhagic stroke and further research and development of new drugs.

Progesterone attenuates neurological deficits and exerts a protective effect on damaged axons via the PI3K/AKT/mTOR-dependent pathway in a mouse model of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating event with high disability and fatality rates. However, there is a lack of effective treatments for this condition. We aimed to investigate the neuroprotective and axonal regenerative effects of progesterone after ICH. For this purpose, an ICH model was established in adult mice by injecting type VII collagenase into the striatum; the mice were then treated with progesterone (8 mg/kg). Hematoma absorption, neurological scores, and brain water content were evaluated on days one, three, and seven after the ICH. The effect of progesterone on inflammation and axonal regeneration was examined on day three after the ICH using western blotting, immunohistochemistry, immunofluorescence, as well as hematoxylin-eosin, Nissl, and Luxol fast blue staining. In addition, we combined progesterone with the phosphoinositide 3-kinase/serine/threonine-specific protein kinase (PI3K/AKT) inhibitor, LY294002, to explore its potential neuroprotective mechanisms. Administration of progesterone attenuated the neurological deficits and expression of inflammatory cytokines and promoted axonal regeneration after ICH, this effect was blocked by LY294002. Collectively, these results suggest that progesterone could reduce axonal damage and produced partial neuroprotective effects after ICH through the PI3K/AKT/mTOR pathway, providing a new therapeutic target and basis for the treatment of ICH.

Revisiting Minocycline in Intracerebral Hemorrhage: Mechanisms and Clinical Translation

Intracerebral hemorrhage (ICH) is an important subtype of stroke with an unsatisfactory prognosis of high mortality and disability. Although many pre-clinical studies and clinical trials have been performed in the past decades, effective therapy that meaningfully improve prognosis and outcomes of ICH patients is still lacking. An active area of research is towards alleviating secondary brain injury after ICH through neuroprotective pharmaceuticals and in which minocycline is a promising candidate. Here, we will first discuss new insights into the protective mechanisms of minocycline for ICH including reducing iron-related toxicity, maintenance of blood-brain barrier, and alleviating different types of cell death from preclinical data, then consider its shortcomings. Finally, we will review clinical trial perspectives for minocycline in ICH. We hope that this summary and discussion about updated information on minocycline as a viable treatment for ICH can facilitate further investigations.

Mesenchymal Stem Cell-Derived Neuron-Like Cell Transplantation Combined with Electroacupuncture Improves Synaptic Plasticity in Rats with Intracerebral Hemorrhage via mTOR/p70S6K Signaling

Previous studies have shown that the combination of mesenchymal stem cell (MSC) transplantation and electroacupuncture (EA) stimulation is a neuroprotective strategy for treating intracerebral hemorrhage (ICH). However, the underlying mechanisms by which the combined treatment promotes neuroprotection remain unclear. This study was designed to investigate the effects of the combined treatment on synaptic plasticity and elucidate their underlying mechanisms. Therefore, rat ICH models were established by injecting collagenase and heparin, and the animals were randomly divided into model control (MC), EA stimulation (EA), MSC-derived neuron-like cell transplantation (MSC-dNLCs), and MSC-dNLC transplantation combined with EA stimulation (MSC-dNLCs+EA) groups. We observed the ultrastructure of the brain and measured the brain water content (BWC) and the levels of the microtubule-associated protein 2 (MAP2), galactocerebrosidase (GALC), and glial fibrillary acidic protein (GFAP) proteins. We also measured the levels of the phosphorylated mammalian target of rapamycin (mTOR) and 70 kDa ribosomal protein S6 kinase (p70S6K) proteins, as well as the expression of synapse-related proteins. The BWC increased in rats after ICH and decreased significantly in ICH rats treated with MSC-dNLC transplantation, EA stimulation, or combined therapy. Meanwhile, after ICH, the number of blood vessels increased more evidently, but only the combined treatment reduced the number of blood vessels among rats receiving the three treatments. Moreover, the levels of MAP2, GALC, postsynaptic density 95 (PSD95), and synaptophysin (SYP) proteins, as well as the levels of the phosphorylated mTOR and p70S6k proteins, increased in the MSC-dNLCs+EA group compared with those in the MSC-dNLCs and EA groups. Compared with the MC group, GFAP expression was significantly reduced in the MSC-dNLCs, EA, and MSC-dNLCs+EA groups, but the differences among the three treatment groups were not significant. In addition, the number of synapses increased only in the MSC-dNLCs+EA group compared to the MC group. Based on these data, the combination of MSC-dNLC transplantation and EA stimulation exerts a synergistic effect on improving the consequences of ICH by relieving cerebral edema and glial scarring, promoting the survival of neurons and oligodendrocytes, and activating mTOR/p70S6K signaling to enhance synaptic plasticity.

Hippocampal Activated Microglia May Contribute to Blood–Brain Barrier Impairment and Cognitive Dysfunction in Post-Traumatic Stress Disorder-Like Rats

Post-traumatic stress disorder (PTSD)-associated cognitive dysfunction significantly disturbs patients’ quality of life and will to live. However, its underlying mechanism is as yet unknown. Recent researches indicate that blood–brain barrier (BBB) breakdown is responsible for early cognitive dysfunction. Microglia might participate in remodeling of BBB-associated tight junction and regulating BBB integrity. Nevertheless, it is unclear whether microglia activation and BBB injury involve in PTSD-associated cognitive dysfunction. Hence, we established an animal model of PTSD, single prolonged stress (SPS), and investigated permeability changes in the hippocampus and further explored the effects of microglia on BBB remodeling. The Y maze was used to assess the changes of cognitive function. The sodium fluorescein (NaFlu) assay and western blotting analysis were employed to detect BBB integrity changes. Minocycline was administered to inhibit microglial activation. Immunofluorescence stains were used to assess the activation states in microglia. The results showed that SPS-exposed rats exhibited poorer cognitive performance, higher passage of NaFlu, and lower expression of tight junction proteins (occludin and claudin 5) in the hippocampus on the day after SPS, but no difference on the 7th day. Inhibition of microglial activation by minocycline attenuated poor cognitive performance and BBB impairment including the extravasation of NaFlu and protein levels of the tight junction. Taken together, the present study indicates that BBB impairment may underlie the shared pathological basis of PTSD and cognitive dysfunction. Microglial activation may involve in BBB remodeling at the early stage of SPS.

VSIG4 Attenuates NLRP3 and Ameliorates Neuroinflammation via JAK2-STAT3-A20 Pathway after Intracerebral Hemorrhage in Mice

Intracerebral hemorrhage (ICH) is a fatal cerebrovascular disease. Neuroinflammation plays an important pathological role in brain injury after ICH. NLRP3 contributes to the pathogenesis of ICH, but the underlying mechanisms regulating of NLRP3 remain elusive. V-set and immunoglobulin domain containing 4 (VSIG4), specifically expressed in resting tissue-resident macrophages, can deliver anti-inflammatory signals into various inflammatory diseases. However, the interaction between VSIG4 and NLRP3, as well as the underlying mechanisms after ICH have not been reported. C57BL/6 mice were subjected to the autologous blood injection ICH model. VSIG4 and NLRP3 levels of macrophages were detected following ICH. Ad-VSIG4 or controls were administered via intracerebroventricular (i.c.v) injection before ICH induction. STAT3 inhibitor (S31-201), JAK2 inhibitor (TG101348), or Ad-A20 RNAi was administered to investigate the role of JAK2-STAT3-A20 pathway in VSIG4-mediated neuroinflammation after ICH. Pro-inflammatory cytokine production, BBB disruption, brain water content, and neurological test were examined in ICH mice. VSIG4 levels were significantly decreased, and NLRP3 levels were significantly increased in the perihematomal brain tissues after ICH. Ad-VSIG4 attenuated NLRP3 levels and inhibited inflammation, as well as improved neurological function and reduced BBB disruption and brain water content. Furthermore, Ad-VSIG4 increased the protein levels of phosphorylated JAK2 and STAT3, and A20 levels at 24 h after ICH. STAT3 inhibitor, JAK2 inhibitor, and A20 RNAi abolished the beneficial effects of Ad-VSIG4 after ICH. In summary, these data suggested that VSIG4 attenuated NLRP3 and ameliorated neuroinflammation via JAK2-STAT3-A20 pathway after intracerebral hemorrhage in mice. VSIG4 might be an ideal therapeutic target for ICH patients.

Minocycline improves the functional recovery after traumatic brain injury via inhibition of aquaporin-4

Traumatic brain injury (TBI) is one of the main concerns worldwide as there is still no comprehensive therapeutic intervention. Astrocytic water channel aquaporin-4 (AQP-4) system is closely related to the brain edema, water transport at blood-brain barrier (BBB) and astrocyte function in the central nervous system (CNS). Minocycline, a broad-spectrum semisynthetic tetracycline antibiotic, has shown anti-inflammation, anti-apoptotic, vascular protection and neuroprotective effects on TBI models. Here, we tried to further explore the underlying mechanism of minocycline treatment for TBI, especially the relationship of minocycline and AQP4 during TBI treatment. In present study, we observed that minocycline efficaciously reduces the elevation of AQP4 in TBI mice. Furthermore, minocycline significantly reduced neuronal apoptosis, ameliorated brain edema and BBB disruption after TBI. In addition, the expressions of tight junction protein and astrocyte morphology alteration were optimized by minocycline administration. Similar results were found after treating with TGN-020 (an inhibitor of AQP4) in TBI mice. Moreover, these effects were reversed by cyanamide (CYA) treatment, which notably upregulated AQP4 expression level in vivo. In primary cultured astrocytes, small-interfering RNA (siRNA) AQP4 treatment prevented glutamate-induced astrocyte swelling. To sum up, our study suggests that minocycline improves the functional recovery of TBI through reducing AQP4 level to optimize BBB integrity and astrocyte function, and highlights that the AQP4 may be an important therapeutic target during minocycline treating for TBI.

Microglia Phenotype and Intracerebral Hemorrhage: A Balance of Yin and Yang

Intracerebral hemorrhage (ICH) features extremely high rates of morbidity and mortality, with no specific and effective therapy. And local inflammation caused by the over-activated immune cells seriously damages the recovery of neurological function after ICH. Fortunately, immune intervention to microglia has provided new methods and ideas for ICH treatment. Microglia, as the resident immune cells in the brain, play vital roles in both tissue damage and repair processes after ICH. The perihematomal activated microglia not only arouse acute inflammatory responses, oxidative stress, excitotoxicity, and cytotoxicity to cause neuron death, but also show another phenotype that inhibit inflammation, clear hematoma and promote tissue regeneration. The proportion of microglia phenotypes determines the progression of brain tissue damage or repair after ICH. Therefore, microglia may be a promising and imperative therapeutic target for ICH. In this review, we discuss the dual functions of microglia in the brain after an ICH from immunological perspective, elaborate on the activation mechanism of perihematomal microglia, and summarize related therapeutic drugs researches.

Neuroprotection of minocycline by inhibition of extracellular matrix metalloproteinase inducer expression following intracerebral hemorrhage in mice

Intracerebral hemorrhage (ICH) is a severe neurological dysfunction and a medical emergency with a high mortality rate. Minocycline ameliorates deficits in rodent models of acute and chronic neurological diseases. However, the role of minocycline in ICH remains unclear. The extracellular matrix metalloproteinase inducer (EMMPRIN) is a key inflammatory mediator in some neurological diseases, triggering matrix metalloproteinases (MMPs) production. In this study, we aimed to use minocycline to inhibit EMMPRIN and thus the activity of MMPs. Male adult C57BL/6 mice were injected with collagenase type VII or saline into the right basal ganglia and euthanized at different time points. The minocycline was intraperitoneally injected once every 12 h for three days to block the expression of EMMPRIN from two hours after ICH. We found that breakdown of the BBB was most severe 3 days after ICH. The minocycline treatment significantly decreased EMMPRIN and MMP-9 expression, reduced zonula occludens-1 and occludin, and alleviated BBB disruption. Moreover, minocycline treatment displayed a lower brain water content, lesser neurological dysfunction, and smaller injury volume on day 3 than those of the vehicle-treated group. Minocycline also inhibited the activation of microglia/macrophages, infiltration of neutrophils, and production of inflammatory mediators, including tumor necrosis factor alpha and interleukin-1beta. The current study shows that minocycline exhibits protective roles in ICH by decreasing EMMPRIN and MMP-9 expression, alleviating BBB disruption, inhibiting neuroinflammation, areducing neuronal degeneration and death.

rhFGF20 promotes angiogenesis and vascular repair following traumatic brain injury by regulating Wnt/β-catenin pathway

The pathology of cerebrovascular disorders takes an important role in traumatic brain injury (TBI) by increasing intracranial pressure. Fibroblast growth factor 20 (FGF20) is a brain-derived neurotrophic factor, that has been shown to play an important role in the survival of dopaminergic neurons and the treatment of Parkinson's disease (PD). However, little is known about the role of FGF20 in the treatment of TBI and its underlying mechanism. The purpose of this study was to evaluate the protective effect of recombinant human FGF20 (rhFGF20) on protecting cerebral blood vessels after TBI. In this study, we indicated that rhFGF20 could reduce brain edema, Evans blue penetration and upregulated the expression of blood-brain barrier (BBB)-related tight junction (TJ) proteins, exerting a protective effect on the BBB in vivo after TBI. In the TBI repair phase, rhFGF20 promoted angiogenesis, neurological and cognitive function recovery. In tumor necrosis factor-α (TNF-α)-induced human brain microvascular endothelial cells (hCMEC/D3), an in vitro BBB disruption model, rhFGF20 reversed the impairment in cell migration and tube formation induced by TNF-α. Moreover, in both the TBI mouse model and the in vitro model, rhFGF20 increased the expression of β-catenin and GSK3β, which are the two key regulators in the Wnt/β-catenin signaling pathway. In addition, the Wnt/β-catenin inhibitor IWR-1-endo significantly reversed the effects of rhFGF20. These results indicate that rhFGF20 may prevent vascular repair and angiogenesis through the Wnt/β-catenin pathway.

Roles of Crosstalk between Astrocytes and Microglia in Triggering Neuroinflammation and Brain Edema Formation in 1,2-Dichloroethane-Intoxicated Mice

We have previously reported that the activation of astrocytes and microglia may lead to the overproduction of proinflammatory mediators, which could induce neuroinflammation and cause brain edema in 1,2-dichloroethane (1,2-DCE)-intoxicated mice. In this research, we further hypothesized that astrocyte–microglia crosstalk might trigger neuroinflammation and contribute to brain edema in 1,2-DCE-intoxicated mice. The present research revealed, for the first time, that subacute intoxication with 1,2-DCE might provoke the proinflammatory polarization of microglia, and pretreatment with minocycline, a specific inhibitor of microglial activation, may attenuate the enhanced protein levels of ionized calcium-binding adapter molecule1 (Iba-1), cluster of differentiation 11b (CD11b), glial fibrillary acidic protein (GFAP), soluble calcium-binding protein 100B (S100B), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), inducible nitric oxide synthase (iNOS), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase-9 (MMP-9), Toll-like receptor 4 (TLR4), MyD88, and p-p65, and ameliorate the suppressed protein expression levels of occludin and claudin 5; we also observed changes in water content and made pathological observations on edema in the brains of 1,2-DCE-intoxicated mice. Moreover, pretreatment with fluorocitrate, an inhibitor of reactive astrocytes, could also reverse the alteration in protein expression levels of GFAP, S100B, Iba-1, CD11b, TNF-α, IL-6, iNOS, VCAM-1, ICAM-1, MMP-9, occludin, and claudin 5 in the brain of 1,2-DCE intoxicated mice. Furthermore, pretreatment with melatonin, a well-known anti-inflammatory drug, could also attenuate the above-mentioned changes in the brains of 1,2-DCE-intoxicated mice. Altogether, the findings from this research indicated that microglial activation might play an important role in triggering neuroinflammation, and hence may contribute to brain edema formation; additionally, the findings suggested that molecular crosstalk between reactive astrocytes and activated microglia may amplify the neuroinflammatory reaction, which could induce secondary brain injury in 1,2-DCE-intoxicated mice.

The combination of deferoxamine and minocycline strengthens neuroprotective effect on acute intracerebral hemorrhage in rats

Objectives: Intracerebral hemorrhage (ICH) is a devastating type of strokes that carries high mortality rates, but effective therapeutic options are still lacking. Here, the adult rat model of ICH was used to investigate the efficacy of a combinational therapy of deferoxamine (DFX) and minocycline.Methods: The ICH was induced by stereotaxic infusion of collagenase into striatum of adult rats. After the induction of ICH, rats were treated with intraperitoneal injection of deferoxamine (50 mg/kg), minocycline (45 mg/kg), or both agents, at 2 hours after ICH and then every 12 hours for up to 3 days. The vehicle group were treated with phosphate-buffered saline (PBS) only. Rats were killed at 1, 2, and 3 day(s) for examination of iron deposition, neuronal death, neurological deficits, the area of brain damage, activation of microglia/macrophages.Results: Our data revealed that the systemic administration of DFX and/or minocycline decreased iron accumulation. And immunofluorescence staining results indicated that drug-treated group significantly decreased the neuronal degeneration, the number of activated microglia/macrophages and the amount of cell death after ICH. In addition, neurological deficits caused by ICH were improved in the presence of DFX and/or minocycline compare with vehicle group. Furthermore, the combination treatment showed better effects in neuroprotection and anti-inflammation when compared to the monotherapy groups.Conclusions: The combination therapy significantly reduces the number of neuronal deaths, suppresses of the activation of microglia/macrophages, decreases iron accumulation in the area around the hematoma, lessening the brain damage area, and improving neurological deficits in ICH.

In schizophrenia, immune-inflammatory pathways are strongly associated with depressive and anxiety symptoms, which are part of a latent trait which comprises neurocognitive impairments and schizophrenia symptoms

BACKGROUND

The aim is to examine whether biomarkers of the immune-inflammatory response (IRS) and endogenous opioid (EOS) systems are associated with affective symptoms in schizophrenia.

METHODS

We recruited 115 schizophrenia patients and 43 healthy controls and assessed the Hamilton Depression (HDRS) and Anxiety (HAM-A) rating Scale scores as well as serum levels of interleukin (IL)-6, IL-10, eotaxin (CCL11), high mobility group box 1 (HMGB1), Dickkopf-related protein 1 (DKK1), and mu (MOR) and kappa (KOR) opioid receptors.

RESULTS

The HDRS and HAM-A scores are significantly and positively correlated with a) psychosis, hostility, excitation, mannerism, negative symptoms, psychomotor retardation, and formal thought disorders; and b) lowered scores on semantic and episodic memory, executive functions, and attention tests as measured with the Brief Assessment of Cognition in Psychiatry. Both HDRS and HAM-A are significantly increased in non-responders to treatment as compared with partial responders. Both affective scores are strongly associated with a latent vector extracted from all symptoms, reflecting overall severity of schizophrenia symptoms (OSOS), and neurocognitive test scores, reflecting a generalized cognitive decline (G-CoDe). The HDRS score was strongly and positively associated with IL-6, HMGB1, KOR, and MOR levels, and the HAM-A score with IL-6, IL-10, CCL11, HMGB1, KOR, and MOR levels. A single latent trait may be extracted from OSOS, G-CoDe, and the HDRS and HAMA scores, and this latent vector score is strongly predicted by HMGB1, MOR, and DKK1.

CONCLUSION

Immune-inflammatory and EOS pathways contribute to the phenome of schizophrenia, which comprises OSOS, affective, and physiosomatic symptoms, and G-CoDe.

Microglia: A Double-Edged Sword in Intracerebral Hemorrhage From Basic Mechanisms to Clinical Research

Microglia are the resident immune cells of the central nervous system (CNS). It is well established that microglia are activated and polarized to acquire different inflammatory phenotypes, either pro-inflammatory or anti-inflammatory phenotypes, which act as a critical component in the neuroinflammation following intracerebral hemorrhage (ICH). Microglia produce pro-inflammatory mediators at the early stages after ICH onset, anti-inflammatory microglia with neuroprotective effects appear to be suppressed. Previous research found that driving microglia towards an anti-inflammatory phenotype could restrict inflammation and engulf cellular debris. The principal objective of this review is to analyze the phenotypes and dynamic profiles of microglia as well as their shift in functional response following ICH. The results may further the understanding of the body's self-regulatory functions involving microglia following ICH. On this basis, suggestions for future clinical development and research are provided.

Minocycline improves the recovery of nerve function and alleviates blood-brain barrier damage by inhibiting endoplasmic reticulum in traumatic brain injury mice model

Traumatic brain injury (TBI) is a clinical emergency with a very high incidence, disability, and fatality rate. Minocycline, a widely used semisynthetic second-generation tetracycline antibiotic, has anti-inflammatory and bactericidal effects. However, minocycline has not been explored as a therapeutic drug in TBI and if effective, the related molecular mechanism is also unclear. In this study, we examined the neuroprotective effect and possible mechanism of minocycline, in mice TBI model by studying the trauma-related functional and morphological changes. Also, in vitro cell studies were carried out to verify the animal model data. We found that minocycline significantly improved the neurobehavioral score, inhibited apoptosis, repaired the blood-brain barrier, and reduced the levels of inflammatory factors Interleukin-6 and tumor necrosis factor-α in TBI mice. In vitro, upon oxygen and glucose deprivation, minocycline reduced the levels of cellular inflammatory factors and increased the levels of tight junction and adherens junction proteins, thereby significantly improving the cell viability. Moreover, Mino treatment prevented the loss of tight junction and adherens junction proteins which were markedly reversed by an ER stress activator (tunicamycin) both in vivo and in vitro. Our findings set an effective basis for the clinical use of Mino to treat Traumatic brain injury-induced neurological deficits.

Sphingosine-1-phosphate receptor 3 is implicated in BBB injury via the CCL2-CCR2 axis following acute intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is a catastrophic cerebrovascular disease with high morbidity and mortality. Evidence demonstrated that sphingosine-1-phosphate receptor (S1PR) plays a vital role in inflammatory damage via the upregulation of CCL2 expression. However, whether S1PR3 is involved in blood-brain barrier (BBB) breakdown via CCL2 activation after ICH has not been described.

METHODS

We investigated the expression profiles of all S1PRs using high-throughput RNA-seq analysis and RT-PCR. The potential role of S1PR3 and interaction between S1PR3 and CCL2 were evaluated via Western blotting, immunofluorescence, and flow cytometry. BBB disruption was examined via magnetic resonance imaging, transmission electron microscopy, and Evans blue extravasation. Microglial activation, proliferation, and polarization were assessed via histopathological analysis. The expression levels of CCL2, p-p38 MAPK, ICAM-1, and ZO-1 were examined in vitro and in vivo.

RESULTS

The present results showed that the levels of S1PR3 and its ligand, sphingosine 1-phosphate (S1P), were dramatically increased following ICH, which regulated the expression of CCL2 and p38MAPK. Moreover, reductions in brain edema volume, amelioration of BBB integrity, and improvements in behavioral deficits were achieved after the administration of CAY10444, an S1PR3 antagonist, to rats. Remarkably increased CCL2, p-p38MAPK, and ICAM-1 expression and decreased ZO-1 expression were observed in cocultured human astrocytes (HAs) and hCMEC/D3 cells after S1P stimulation. However, the expression levels of CCL2, p-p38 MAPK, and ICAM-1 were decreased and ZO-1 expression was increased after S1PR3 inhibition. In addition, microglial proliferation and M1 polarization were attenuated after CAY10444 administration.

CONCLUSION

To the best of our knowledge, this is the first demonstration of the neuroprotective role of S1PR3 modulation in maintaining BBB integrity by inhibiting the S1PR3-CCL2 axis after ICH, providing a novel treatment for ICH by targeting S1PR3.

Neurovascular Units and Neural-Glia Networks in Intracerebral Hemorrhage: from Mechanisms to Translation

Intracerebral hemorrhage (ICH), the most lethal type of stroke, often leads to poor outcomes in the clinic. Due to the complex mechanisms and cell-cell crosstalk during ICH, the neurovascular unit (NVU) was proposed to serve as a promising therapeutic target for ICH research. This review aims to summarize the development of pathophysiological shifts in the NVU and neural-glia networks after ICH. In addition, potential targets for ICH therapy are discussed in this review. Beyond cerebral blood flow, the NVU also plays an important role in protecting neurons, maintaining central nervous system (CNS) homeostasis, coordinating neuronal activity among supporting cells, forming and maintaining the blood-brain barrier (BBB), and regulating neuroimmune responses. During ICH, NVU dysfunction is induced, along with neuronal cell death, microglia and astrocyte activation, endothelial cell (EC) and tight junction (TJ) protein damage, and BBB disruption. In addition, it has been shown that certain targets and candidates can improve ICH-induced secondary brain injury based on an NVU and neural-glia framework. Moreover, therapeutic approaches and strategies for ICH are discussed.

JLX001 attenuates blood-brain barrier dysfunction in MCAO/R rats via activating the Wnt/β-catenin signaling pathway

JLX001, a new dihydrochloride of Cyclovirobuxine D (CVB-D), has bioactivities against ischemia injury. The blood-brain barrier (BBB) disruption is involved in the pathogeneses of ischemic stroke. This study was designed to explore the effect and potential mechanism of JLX001 on the BBB after ischemic stroke. Rats were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) to mimic cerebral ischemia in vivo. In vitro, rat primary brain microvascular endothelial cells (PBMECs) were cultured and exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). Posttreatment of JLX001 for 15 days after MCAO/R improved the behavior, learning and memory ability. Pretreatment of JLX001 for 3 days significantly attenuated infarct volume, lessened brain edema, mitigated BBB disruption and decreased the neurological deficit score in MCAO/R rats. Moreover, JLX001 increased cell viability and reduced sodium fluorescein leakage after OGD/R injury. In addition, JLX001 increased the expressions of Claudin-5 and Occludin, decreased the expression of MMP-9 both in vivo and in vitro. Moreover, immunofluorescence staining and western immunoblotting results showed that JLX001 increased the expressions of tight junction proteins via activating Wnt/β-catenin signal pathway in vivo and in vitro, which may be associated with the activation of PI3K/Akt signaling. Besides, XAV939 (an inhibitor of the Wnt/β-catenin pathway) proved the connection of JLX001 and Wnt/β-catenin pathway. These results suggest that JLX001 alleviates BBB disruption after MCAO/R and OGD/R possibly by alleviating MMP-9 and activating the Wnt/β-catenin signaling pathway.

Wnt Pathway: An Emerging Player in Vascular and Traumatic Mediated Brain Injuries

The Wnt pathway, which comprises the canonical and non-canonical pathways, is an evolutionarily conserved mechanism that regulates crucial biological aspects throughout the development and adulthood. Emergence and patterning of the nervous and vascular systems are intimately coordinated, a process in which Wnt pathway plays particularly important roles. In the brain, Wnt ligands activate a cell-specific surface receptor complex to induce intracellular signaling cascades regulating neurogenesis, synaptogenesis, neuronal plasticity, synaptic plasticity, angiogenesis, vascular stabilization, and inflammation. The Wnt pathway is tightly regulated in the adult brain to maintain neurovascular functions. Historically, research in neuroscience has emphasized essentially on investigating the pathway in neurodegenerative disorders. Nonetheless, emerging findings have demonstrated that the pathway is deregulated in vascular- and traumatic-mediated brain injuries. These findings are suggesting that the pathway constitutes a promising target for the development of novel therapeutic protective and restorative interventions. Yet, targeting a complex multifunctional signal transduction pathway remains a major challenge. The review aims to summarize the current knowledge regarding the implication of Wnt pathway in the pathobiology of ischemic and hemorrhagic stroke, as well as traumatic brain injury (TBI). Furthermore, the review will present the strategies used so far to manipulate the pathway for therapeutic purposes as to highlight potential future directions.

A combination of inhibiting microglia activity and remodeling gut microenvironment suppresses the development and progression of experimental autoimmune uveitis

Noninfectious (autoimmune and immune-mediated) uveitis is an ocular inflammatory disease which can lead to blindness in severe cases. Due to the potential side effects of first-line drugs for clinical uveitis, novel drugs and targets against uveitis are still urgently needed. In the present study, using rat experimental autoimmune uveitis (EAU) model, we first found that minocycline treatment can substantially inhibit the development of EAU and improve the retinal function by suppressing the retinal microglial activation, and block the infiltration of inflammatory cells, including Th17, into the retina by decreasing the major histocompatibility complex class II (MHC II) expression in resident and infiltrating cells. Moreover, we demonstrated that minocycline treatment can remodel the gut microenvironment of EAU rats by restoring the relative abundance of Ruminococcus bromii, Streptococcus hyointestinalis, and Desulfovibrio sp. ABHU2SB and promoting a functional shift in the gut via reversing the levels of L-proline, allicin, aceturic acid, xanthine, and leukotriene B4, and especially increasing the production of propionic acid, histamine, and pantothenic acid. At last, we revealed that minocycline treatment can significantly attenuate the progression of EAU after inflammation onset, which may be explained by the role of minocycline in the remodeling of the gut microenvironment since selective elimination of retinal microglia on the later stages of EAU was shown to have little effect. These data clearly demonstrated that inhibition of microglial activation and remodeling of the gut microenvironment can suppress the development and progression of experimental autoimmune uveitis. Considering the excellent safety profile of minocycline in multiple clinical experiments, we suggest that minocycline may have therapeutic implications for clinical uveitis.

JAK3 restrains inflammatory responses and protects against periodontal disease through Wnt3a signaling

Homeostasis between pro- and anti- inflammatory responses induced by bacteria is critical for the maintenance of health. In the oral cavity, pro-inflammatory mechanisms induced by pathogenic bacteria are well-established; however, the anti-inflammatory responses that act to restrain innate responses remain poorly characterized. Here, we demonstrate that infection with the periodontal pathogen Porphyromonas gingivalis enhances the activity of Janus kinase 3 (JAK3) in innate immune cells, and subsequently phospho-inactivates Nedd4-2, an ubiquitin E3 ligase. In turn, Wingless-INT (Wnt) 3 (Wnt3) ubiquitination is decreased, while total protein levels are enhanced, leading to a reduction in pro-inflammatory cytokine levels. In contrast, JAK3 or Wnt3a inhibition robustly enhances nuclear factor kappa-light-chain-enhancer of activated B cells activity and the production of pro-inflammatory cytokines in P. gingivalis-stimulated innate immune cells. Moreover, using gain- and loss-of-function approaches, we demonstrate that downstream molecules of Wnt3a signaling, including Dvl3 and β-catenin, are responsible for the negative regulatory role of Wnt3a. In addition, using an in vivo P. gingivalis-mediated periodontal disease model, we show that JAK3 inhibition enhances infiltration of inflammatory cells, reduces expression of Wnt3a and Dvl3 in P. gingivalis-infected gingival tissues, and increases disease severity. Together, our results reveal a new anti-inflammatory role for JAK3 in innate immune cells and show that the underlying signaling pathway involves Nedd4-2-mediated Wnt3a ubiquitination.

A Combined Proteomics and Bioinformatics Approach Reveals Novel Signaling Pathways and Molecular Targets After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a non-traumatic cerebrovascular disorder with very high morbidity and mortality and regarded as one of the deadliest stroke subtypes. Notably, there is no effective treatment for ICH. Despite an overall increase in preclinical studies, the pathophysiology of ICH is complex and remains enigmatic. To this end, ICH was induced in male CD-1 mice and the ipsilateral brain tissue was characterized in an unbiased manner using a combination of proteomics and bioinformatics approaches. A total of 4833 proteins were revealed by quantitative proteomic analysis. Of those, 207 proteins exhibited significantly altered expression after ICH in comparison to sham. It was found that 46 proteins were significantly upregulated and 161 proteins were significantly downregulated after ICH compared to sham. The quantitative proteomics approach combined with bioinformatics revealed several novel molecular targets (cyclin-dependent-like kinase 5, E3 ubiquitin-protein ligase, protein phosphatase 2A-alpha, protein phosphatase 2A-beta, serine/threonine-protein kinase PAK1, alpha-actinin-4, calpain-8, axin-1, NCK1, and septin-4), and related signaling pathways, which could play roles in secondary brain injury and long-term neurobehavioral outcomes after ICH warranting further investigation.