Potassium 2-(l-hydroxypentyl)-benzoate attenuates neuroinflammatory responses and upregulates heme oxygenase-1 in systemic lipopolysaccharide-induced inflammation in mice

PHPB ameliorates memory deficits and reduces oxidative injury in Alzheimer's disease mouse model by activating Nrf2 signaling pathway

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia in elderly people and substantially affects patient quality of life. Oxidative stress is considered a key factor in the development of AD. Nrf2 plays a vital role in maintaining redox homeostasis and regulating neuroinflammatory responses in AD. Previous studies show that potassium 2-(1-hydroxypentyl)-benzoate (PHPB) exerts neuroprotective effects against cognitive impairment in a variety of dementia animal models such as APP/PS1 transgenic mice. In this study we investigated whether PHPB ameriorated the progression of AD by reducing oxidative stress (OS) damage. Both 5- and 13-month-old APP/PS1 mice were administered PHPB (100 mg·kg-1·d-1, i.g.) for 10 weeks. After the cognition assessment, the mice were euthanized, and the left hemisphere of the brain was harvested for analyses. We showed that 5-month-old APP/PS1 mice already exhibited impaired performance in the step-down test, and knockdown of Nrf2 gene only slightly increased the impairment, while knockdown of Nrf2 gene in 13-month-old APP/PS1 mice resulted in greatly worse performance. PHPB administration significantly ameliorated the cognition impairments and enhanced antioxidative capacity in APP/PS1 mice. In addition, PHPB administration significantly increased the p-AKT/AKT and p-GSK3β/GSK3β ratios and the expression levels of Nrf2, HO-1 and NQO-1 in APP/PS1 mice, but these changes were abolished by knockdown of Nrf2 gene. In SK-N-SH APPwt cells and primary mouse neurons, PHPB (10 μM) significantly increased the p-AKT/AKT and p-GSK3β/GSK3β ratios and the level of Nrf2, which were blocked by knockdown of Nrf2 gene. In summary, this study demonstrates that PHPB exerts a protective effect via the Akt/GSK3β/Nrf2 pathway and it might be a promising neuroprotective agent for the treatment of AD.

Microglia in neuroimmunopharmacology and drug addiction

Drug addiction is a chronic and debilitating disease that is considered a global health problem. Various cell types in the brain are involved in the progression of drug addiction. Recently, the xenobiotic hypothesis has been proposed, which frames substances of abuse as exogenous molecules that are responded to by the immune system as foreign "invaders", thus triggering protective inflammatory responses. An emerging body of literature reveals that microglia, the primary resident immune cells in the brain, play an important role in the progression of addiction. Repeated cycles of drug administration cause a progressive, persistent induction of neuroinflammation by releasing microglial proinflammatory cytokines and their metabolic products. This contributes to drug addiction via modulation of neuronal function. In this review, we focus on the role of microglia in the etiology of drug addiction. Then, we discuss the dynamic states of microglia and the correlative and causal evidence linking microglia to drug addiction. Finally, possible mechanisms of how microglia sense drug-related stimuli and modulate the addiction state and how microglia-targeted anti-inflammation therapies affect addiction are reviewed. Understanding the role of microglia in drug addiction may help develop new treatment strategies to fight this devastating societal challenge.

Minimally invasive vagus nerve stimulation modulates mast cell degranulation via the microbiota-gut-brain axis to ameliorate blood-brain barrier and intestinal barrier damage following ischemic stroke

Mast cells (MCs) play a significant role in various diseases, and their activation and degranulation can trigger inflammatory responses and barrier damage. Several studies have indicated that vagus nerve stimulation (VNS) exerts ameliorates neurological injury, and regulates gut MC degranulation. However, there is limited research on the modulatory effect of VNS on MCs in both the gut and brain in brain ischemia-reperfusion (I/R) injury in this process. We aim to develop a minimally invasive, targeted and convenient VNS approach to assess the impact of VNS and to clarify the relationship between VNS and MCs on the prognosis of acute ischemic stroke. We utilized middle cerebral artery occlusion/reperfusion (MCAO/r) to induce brain I/R injury. After the experiment, the motor function and neurofunctional impairments of the rats were detected, and the gastrointestinal function, blood-brain barrier (BBB) and intestinal barrier damage, and systemic and local inflammation were evaluated by Nissl, TTC staining, Evans blue, immunofluorescence staining, transmission electron microscopy, western blot assays, ELISA, and fecal 16S rRNA sequencing methods. Our research confirmed that our minimally invasive VNS method is a novel approach for stimulating the vagus nerve. VNS alleviated motor deficits and gastrointestinal dysfunction while also suppressing intestinal and neuroinflammation. Additionally, VNS ameliorated gut microbiota dysbiosis in rats. Furthermore, our analysis indicated that VNS reduces chymase secretion by modulating MCs degranulation and improves intestinal and BBB damage. Our results showed that VNS treatment can alleviate the damage of BBB and colonic barrier after cerebral I/R by modulating mast cell degranulation, and alleviates systemic inflammatory responses.

Long-Term Triclocarban Exposure Induced Enterotoxicity by Triggering Intestinal AhR-Mediated Inflammation and Disrupting Microbial Community in Mice

Exposure to triclocarban (TCC), a commonly used antibacterial agent, has been shown to induce significant intestine injuries and colonic inflammation in mice. However, the detailed mechanisms by which TCC exposure triggered enterotoxicity remain largely unclear. Herein, intestinal toxicity effects of long-term and chronic TCC exposure were investigated using a combination of histopathological assessments, metagenomics, targeted metabolomics, and biological assays. Mechanically, TCC exposure caused induction of intestinal aryl hydrocarbon receptor (AhR) and its transcriptional target cytochrome P4501A1 (Cyp1a1) leading to dysfunction of the gut barrier and disruption of the gut microbial community. A large number of lipopolysaccharides (LPS) are released from the gut lumen into blood circulation owing to the markedly increased permeability and gut leakage. Consequently, toll-like receptor-4 (TLR4) and NF-κB signaling pathways were activated by high levels of LPS. Simultaneously, classic macrophage phenotypes were switched by TCC, shown with marked upregulation of macrophage M1 and downregulation of macrophage M2 that was accompanied by striking upregulation of proinflammatory factors such as Il-1β, Il-6, Il-17, and Tnf-α in the intestinal lamina propria. These findings provide new evidence for the TCC-induced enterotoxicity.

Agomelatine improves memory and learning impairments in a rat model of LPS-induced neurotoxicity by modulating the ERK/SorLA/BDNF/TrkB pathway

The mutual interplay between neuroinflammation, synaptic plasticity, and autophagy has piqued researchers' interest, particularly when it comes to linking their impact and relationship to cognitive deficits. Being able to reduce inflammation and apoptosis, melatonin has shown to have positive neuroprotective effects; that is why we thought to check the possible role of agomelatine (AGO) as a promising candidate that could have a positive impact on cognitive deficits. In the current study, AGO (40 mg/kg/day, p.o., 7 days) successfully ameliorated the cognitive and learning disabilities caused by lipopolysaccharide (LPS) in rats (250 μg/kg/day, i.p., 7 days). This positive impact was supported by improved histopathological findings and improved spatial memory as assessed using Morris water maze. AGO showed a strong ability to control BACE1 activity and to rein in the hippocampal amyloid beta (Aβ) deposition. Also, it improved neuronal survival, neuroplasticity, and neurogenesis by boosting BDNF levels and promoting its advantageous effects and by reinforcing the pTrkB expression. In addition, it upregulated the pre- and postsynaptic neuroplasticity biomarkers resembled in synapsin I, synaptophysin, and PSD-95. Furthermore, AGO showed a modulatory action on Sortilin-related receptor with A-type repeats (SorLA) pathway and adjusted autophagy. It is noteworthy that all of these actions were abolished by administering PD98059 a MEK/ERK pathway inhibitor (0.3 mg/kg/day, i.p., 7 days). In conclusion, AGO administration significantly improves memory and learning disabilities associated with LPS administration by modulating the ERK/SorLA/BDNF/TrkB signaling pathway parallel to its capacity to adjust the autophagic process.

Agomir-331 Suppresses Reactive Gliosis and Neuroinflammation after Traumatic Brain Injury

Traumatic brain injury usually triggers glial scar formation, neuroinflammation, and neurodegeneration. However, the molecular mechanisms underlying these pathological features are largely unknown. Using a mouse model of hippocampal stab injury (HSI), we observed that miR-331, a brain-enriched microRNA, was significantly downregulated in the early stage (0-7 days) of HSI. Intranasal administration of agomir-331, an upgraded product of miR-331 mimics, suppressed reactive gliosis and neuronal apoptosis and improved cognitive function in HSI mice. Finally, we identified IL-1β as a direct downstream target of miR-331, and agomir-331 treatment significantly reduced IL-1β levels in the hippocampus after acute injury. Our findings highlight, for the first time, agomir-331 as a pivotal neuroprotective agent for early rehabilitation of HSI.

Hesperetin ameliorates spinal cord injury by inhibiting NLRP3 inflammasome activation and pyroptosis through enhancing Nrf2 signaling

Neuroinflammation is a prominent feature of traumatic spinal cord injuries (SCIs). Hesperetin exhibits anti-inflammatory effects in neurological disorders; however, the potential neuroprotective effects of hesperetin in cases of SCI remain unclear. Sprague-Dawley rats with C5 hemi-contusion injuries were used as an SCI model. Hesperetin was administered to the experimental rats in order to investigate its neuroprotective effects after SCI, and BV2 cells were pretreated with hesperetin or silencing of nuclear factor erythroid 2-related factor 2 (siNrf2), and then stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP). The therapeutic impact and molecular mechanism of hesperetin were elucidated in a series of in vivo and in vitro investigations conducted using a combination of experiments. The results of the present in vivo experiment indicated that hesperetin improved functional recovery and protected spinal cord tissue after SCI. Hesperetin attenuated oxidative stress and microglial activation, lowered malondialdehyde (MDA) levels, and elevated catalase (CAT), glutathione (GSH)-Px, and superoxide dismutase (SOD) levels. Moreover, hesperetin downregulated the expression of advanced oxygenation protein products (AOPPs), ionized calcium-binding adapter molecule 1 (Iba-1), NOD-like receptor protein 3 (NLRP3), and interleukin-1 beta (IL-1β), but increased the expression of Nrf2. In vitro studies have shown that hesperetin inhibits the generation of reactive oxygen species (ROS), as well as the neuroinflammation associated with the upregulation of Nrf2 and heme oxygenase-1 (HO-1) in BV2 cells. The results of the present study indicated that hesperetin inhibited BV2 cell pyroptosis and significantly blocked the expression of NLRP3 inflammasome proteins (NLRP3 Caspase-1 p10 apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain [ASC]) and pro-inflammatory mediators (IL-18, IL-1β). Furthermore, the silencing of Nrf2 by small interfering ribonucleic acid (siRNA) partially abolished its antioxidant effect in the aforementioned cell experiments. Collectively, these findings illustrate that through an increase in Nrf2 signaling hesperetin reduces oxidative stress and neuroinflammation by suppressing NLRP3 inflammasome activation and pyroptosis.

Structural characterization of polysaccharide purified from Hericium erinaceus fermented mycelium and its pharmacological basis for application in Alzheimer's disease: Oxidative stress related calcium homeostasis

The purified polysaccharides from Hericium erinaceus fermented mycelium entitled with PHEB was analyzed and it was mainly composed of six glycosidic bonds. It has been confirmed to show the relieving activity against Alzheimer's Disease (AD)- just as behaviors of B6C3-Tg (APPswePSEN1d E9)/Nju double transgenic [Genotype: (Appswe)T, (Psen1) T] (APP/PS1) mice. Six-week PHEB administration significantly improved the cognitive behavior of mice. Brain injury, amyloid beta deposition and tau hyperphosphorylation were alleviated in PHEB-treated AD mice without changes in other tissues. PHEB alleviated the oxidative stress in brains of AD mice via regulation the Nrf2 and its downstream kinase, which further improved the cholinergic system function. Proteomics and bioinformatics analysis showed that the therapeutic effect of PHEB is achieved by regulating calcium homeostasis mediated by oxidative stress. Furthermore, PHEB regulated the CaMK II/IV to achieve the calcium homeostasis in brains; and ultimately to show the anti-AD property.

Salvianolic acid B ameliorates vascular endothelial dysfunction through influencing a bone morphogenetic protein 4-ROS cycle in diabetic mice

AIM

This study investigated the roles of bone morphogenetic protein-4 (BMP4) and ROS in diabetic endothelial dysfunction and explored whether Salvianolic acid B (Sal B) improved endothelial function by affecting BMP4-ROS in diabetic mice.

MAIN METHODS

db/db mice were orally administrated with Sal B (10 mg/kg/day) for one week while db/m + mice were injected with adenoviral vectors delivering BMP4 (3 × 10⁸ pfu) and then received one week-Sal B treatment. ROS levels were assayed by DHE staining. Protein expression and phosphorylation were evaluated by Western blot. Aortic rings were suspended in myograph for force measurement. Flow-mediated dilatations in the second-order mesenteric arteries were determined by pressure myograph.

KEY FINDINGS

We first revealed the existence of a BMP4-ROS cycle in db/db mice, which stimulated p38 MAPK/JNK/caspase 3 and thus participated in endothelial dysfunction. One week-treatment or 24 h-incubation with Sal B disrupted the cycle, suppressed p38 MAPK/JNK/caspase 3 cascade, and improved endothelium-dependent relaxations (EDRs) in db/db mouse aortas. Importantly, in vivo Sal B treatment also improved flow-mediated dilatation in db/db mouse second order mesenteric arteries. Furthermore, in vivo BMP4 overexpression induced oxidative stress, stimulated p38 MAPK/JNK/caspase 3, and impaired EDRs in db/m + mouse aortas, which were all reversed by Sal B.

SIGNIFICANCE

The present study demonstrates that Sal B ameliorates endothelial dysfunction through breaking the BMP4-ROS cycle and subsequently inhibiting p38 MAPK/JNK/caspase 3 in diabetic mice and provides evidence for the additional new mechanism underlying the benefit of Sal B against diabetic vasculopathy.

PDPOB Exerts Multiaspect Anti-Ischemic Effects Associated with the Regulation of PI3K/AKT and MAPK Signaling Pathways

The discovery of new therapeutic agents for ischemic stroke remains an urgent need. Here, we identified a novel phenyl carboxylic acid derivative, n-pentyl 4-(3,4-dihydroxyphenyl)-4-oxobutanoate (PDPOB), with anti-ischemic activities. The in vitro anti-ischemic neuroprotective and anti-inflammatory capacities of PDPOB were investigated using neuronal cells suffering from oxygen-glucose deprivation/reperfusion (OGD/R) and microglial cells stimulated by lipopolysaccharide (LPS). PDPOB attenuated the OGD/R-evoked cellular damage of SH-SY5Y cells and primary cortical neurons in a concentration-dependent manner. Likewise, PDPOB displayed protective roles against OGD/R-evoked multiaspect neuronal deterioration in SH-SY5Y cells, as evidenced by alleviated mitochondrial dysfunction, oxidative stress, and apoptosis. A further study unveiled the accelerated phosphorylation of protein kinase B (AKT) by PDPOB treatment, while blockade of phosphoinositide 3-kinase (PI3K)/AKT signaling substantially diminished the neuroprotective capacities of PDPOB. Additionally, the PDPOB pretreatment dampened the LPS-evoked neuroinflammation in BV2 cells, characterized by the suppressed secretion of nitric oxide (NO) and proinflammatory cytokines, as well as normalized expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Western blotting further revealed that PDPOB abated the overabundant phosphorylation of the extracellular signal-regulated kinase (ERK), c-Jun-N-terminal kinase (JNK), and p38 in LPS-exposed BV2 cells. The intravenous application of PDPOB (30 mg/kg, single dose) attenuated ipsilateral cerebral infarction in middle cerebral artery occlusion (MCAO) rats, accompanied by recovered neurological behaviors. Collectively, the above observations provided substantial evidence for the favorable properties and mechanistic explanations of PDPOB in the regulation of ischemia-associated neuronal injury and microglial inflammation, which may furnish ideas for the discovery of new therapeutic strategies against cerebral ischemia.

MAPK: A Key Player in the Development and Progression of Stroke

Conclusion:

Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.

Dihydrolipoic acid protects against lipopolysaccharide-induced behavioral deficits and neuroinflammation via regulation of Nrf2/HO-1/NLRP3 signaling in rat

Background

Recently, depression has been identified as a prevalent and severe mental disorder. However, the mechanisms underlying the depression risk remain elusive. The neuroinflammation and NLRP3 inflammasome activation are known to be involved in the pathology of depression. Dihydrolipoic acid (DHLA) has been reported as a strong antioxidant and exhibits anti-inflammatory properties in various diseases, albeit the direct relevance between DHLA and depression is yet unknown. The present study aimed to investigate the preventive effect and potential mechanism of DHLA in the lipopolysaccharide (LPS)-induced sickness behavior in rats.

Methods

Adult male Sprague–Dawley rats were utilized. LPS and DHLA were injected intraperitoneally every 2 days and daily, respectively. Fluoxetine (Flu) was injected intraperitoneally daily. PD98059, an inhibitor of ERK, was injected intraperitoneally 1 h before DHLA injection daily. Small interfering ribonucleic acid (siRNA) for nuclear factor erythroid 2-like (Nrf2) was injected into the bilateral hippocampus 14 days before the DHLA injection. Depression-like behavior tests were performed. Western blot and immunofluorescence staining detected the ERK/Nrf2/HO-1/ROS/NLRP3 pathway-related proteins.

Results

The DHLA and fluoxetine treatment exerted preventive effects in LPS-induced sickness behavior rats. The DHLA treatment increased the expression of ERK, Nrf2, and HO-1 but decreased the ROS generation levels and reduced the expression of NLRP3, caspase-1, and IL-1β in LPS-induced sickness behavior rats. PD98059 abolished the effects of DHLA on preventive effect as well as the levels of Nrf2 and HO-1 proteins. Similarly, Nrf2 siRNA reversed the preventive effect of DHLA administration via the decreased expression of HO-1.

Conclusions

These findings suggested that DHLA exerted a preventive effect via ERK/Nrf2/HO-1/ROS/NLRP3 pathway in LPS-induced sickness behavior rats. Thus, DHLA may serve as a potential therapeutic strategy for depression.

Probiotics modulate the microbiota-gut-brain axis and improve memory deficits in aged SAMP8 mice

ProBiotic-4 is a probiotic preparation composed of Bifidobacterium lactis, Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus acidophilus. This study aims to investigate the effects of ProBiotic-4 on the microbiota–gut–brain axis and cognitive deficits, and to explore the underlying molecular mechanism using senescence-accelerated mouse prone 8 (SAMP8) mice. ProBiotic-4 was orally administered to 9-month-old SAMP8 mice for 12 weeks. We observed that ProBiotic-4 significantly improved the memory deficits, cerebral neuronal and synaptic injuries, glial activation, and microbiota composition in the feces and brains of aged SAMP8 mice. ProBiotic-4 substantially attenuated aging-related disruption of the intestinal barrier and blood–brain barrier, decreased interleukin-6 and tumor necrosis factor-α at both mRNA and protein levels, reduced plasma and cerebral lipopolysaccharide (LPS) concentration, toll-like receptor 4 (TLR4) expression, and nuclear factor-κB (NF-κB) nuclear translocation in the brain. In addition, not only did ProBiotic-4 significantly decreased the levels of γ-H2AX, 8-hydroxydesoxyguanosine, and retinoic-acid-inducible gene-I (RIG-I), it also abrogated RIG-I multimerization in the brain. These findings suggest that targeting gut microbiota with probiotics may have a therapeutic potential for the deficits of the microbiota–gut–brain axis and cognitive function in aging, and that its mechanism is associated with inhibition of both TLR4-and RIG-I-mediated NF-κB signaling pathway and inflammatory responses.

Cerebrolysin Ameliorates Focal Cerebral Ischemia Injury Through Neuroinflammatory Inhibition via CREB/PGC-1α Pathway

Neuroinflammation is one of the important factors aggravating brain injury after ischemic stroke. We aimed to investigate the effects of cerebrolysin (CBL) on neuroinflammation in vivo and in vitro and the underlying mechanisms. The gene expressions of pro-inflammatory factors and anti-inflammatory factors were analyzed by real time PCR in rat transient middle cerebral artery occlusion (tMCAO) model, lipopolysaccharides-induced neuroinflammatory mice model and LPS-treated mouse primary microglia cells. The neuroprotective effects of CBL were evaluated by infarct size, Longa test and Rotarod test for long-term functional recovery in rats subjected to ischemia. The role of CREB/PGC-1α pathway in anti-neuroinflammatory effect of CBL was also determined by real time PCR and Western blotting. In the tMCAO model, administration of CBL at 3 h post-ischemia reduced infarct volume, promoted long-term functional recovery, decreased the gene expression of pro-inflammatory factors and increased the gene expression of anti-inflammatory factors. Correspondingly, in LPS-induced neuroinflammatory mice model, CBL treatment attenuated sickness behavior, decreased the gene expression of pro-inflammatory factors, and increased the gene expression of anti-inflammatory factors. In in vitro and in vivo experiments, CBL increased the protein expression levels of PGC-1α and phosphorylated CREB to play anti-inflammatory effect. Additionally, the application of the specific CREB inhibitor, 666-15 compound could effectively reverse the anti-inflammatory effect of CBL in primary mouse microglia cells and anti-ischemic brain injury of CBL in rats subjected to tMCAO. In conclusion, CBL ameliorated cerebral ischemia injury through reducing neuroinflammation partly via the activation of CREB/PGC-1α pathway and may play a therapeutic role as anti-neuroinflammatory agents in the brain disorders associated with neuroinflammation.

Hydrogen gas reduces HMGB1 release in lung tissues of septic mice in an Nrf2/HO-1-dependent pathway

BACKGROUND

Lung injury is a vital contributor of mortality in septic patients. Our previous studies have found that molecular hydrogen (H₂), which has anti-oxidant, anti-inflammatory, and anti-apoptosis effects, had a therapeutic effect on a septic animal model through increasing expression of nuclear factor-erythroid 2-related factor 2 (Nrf2). The aim of this research was to investigate the effects of 2% H₂ gas inhalation on sepsis-induced lung injury and its underlying mechanisms.

METHODS

Male wild-type (WT) and Nrf2-knockout (Nrf2-KO) ICR mice underwent sham or cecal ligation and puncture (CLP) operation. Two percent of H₂ gas was inhaled for 60 min beginning at both 1 h and 6 h after sham or CLP surgery. To assess the severity of septic lung injury, the 7-day survival rate, wet/dry (W/D) weight ratio of lung tissue, lung histopathologic score, pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), high-mobility group box 1 (HMGB1)), anti-inflammatory cytokine (interleukin 10 (IL-10)), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and heme oxygenase 1 (HO-1)), and an oxidative product (malondialdehyde (MDA)) were detected after sham or CLP operation. The histopathologic changes were observed in lung tissues by hematoxylin and eosin (HE) staining, and pro-inflammatory cytokines (TNF-α and IL-6), anti-inflammatory cytokine (IL-10), antioxidant enzymes (SOD and CAT), and MDA were detected in lung tissues by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results indicated that 2% H₂ gas treatment increased the survival rates, decreased the W/D weight ratio and the lung injury score, alleviated the injuries caused by oxidative stress and inflammation, and induced HO-1 level but reduced HMGB1 level in WT but not Krf2-KO mice. These data reveal that H₂ gas could suppress lung injury in septic mice through regulation of HO-1 and HMGB1 expression and that Nrf2 plays a main role in the protective effects of H₂ gas on lung damage caused by sepsis.

Potassium 2-(1-hydroxypentyl)-benzoate improves depressive-like behaviors in rat model

Potassium 2-(1-hydroxypentyl)-benzoate (PHPB) is a novel drug candidate for acute ischemic stroke. PHPB has been also shown to be beneficial for some neurodegenerative diseases. In this study, we demonstrated that PHPB improved depressive-like behaviors induced by chronic unpredictable mild stress (CUMS) in rats. Male SD rats were subjected to the stress for five weeks. PHPB (30 and 100 mg/kg) or fluoxetine (FLX 10 mg/kg, as positive control) was administered orally from the third week in CUMS procedure. The behavioral tests were applied and then the biochemical studies were carried out. PHPB or FLX treatment rescued the behavioral deficiency in CUMS-exposed rats. Meanwhile, PHPB normalized the enhanced level of serum corticosterone, improved hippocampal and serum BDNF levels, as well as p-CREB level in hippocampus. In addition, PHPB could reverse the reduced level of extracellular 5-HT and its metabolite 5-HIAA in prefrontal cortex (PFC) of depressed rats. In summary, our results showed that PHPB improved depression-like behaviors in CUMS-exposed rats. The mechanisms might relate to the reverse of neurotrophic disturbance in the brain, reducing excessive HPA axis response and facilitating the release of 5-HT.

3D tissue engineering, an emerging technique for pharmaceutical research

Tissue engineering and the tissue engineering model have shown promise in improving methods of drug delivery, drug action, and drug discovery in pharmaceutical research for the attenuation of the central nervous system inflammatory response. Such inflammation contributes to the lack of regenerative ability of neural cells, as well as the temporary and permanent loss of function associated with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and traumatic brain injury. This review is focused specifically on the recent advances in the tissue engineering model made by altering scaffold biophysical and biochemical properties for use in the treatment of neurodegenerative diseases. A portion of this article will also be spent on the review of recent progress made in extracellular matrix decellularization as a new and innovative scaffold for disease treatment.