Ability of Local Clearance of Senescent Cells in Ipsilateral Hemisphere to Mitigate Acute Ischemic Brain Injury in Mice.

Senolytic treatment has potential therapeutic efficacy for acute ischemic stroke (AIS). However, the systemic treatment of senolytics may produce off-target side effects and a toxic profile, which affect analysis of the role of acute senescence of neuronal cells in pathogenesis of AIS. We constructed a novel lenti-INK-ATTAC viral vector to introduce INK-ATTAC genes to the ipsilateral brain and locally eliminate senescent brain cells by administering AP20187 to activate caspase-8 apoptotic cascade. In this study, we have found that acute senescence is triggered by middle cerebral artery occlusion (MCAO) surgery, particularly in astrocytes and cerebral endothelial cells (CECs). The upregulation of p16INK4a and senescence-associated secretory phenotype (SASP) factors including matrix metalloproteinase-3, interleukin-1 alpha and -6 were observed in oxygen-glucose deprivation-treated astrocytes and CECs. The systemic administration of a senolytic, ABT-263, prevented the impairment of brain activity from hypoxic brain injury in mice, and significantly improved the neurological severity score, rotarod performance, locomotor activity, and weight loss. The treatment of ABT-263 reduced senescence of astrocytes and CECs in MCAO mice. Furthermore, the localized removal of senescent cells in the injured brain through the stereotaxical injection of lenti-INK-ATTAC viruses generates neuroprotective effects, protecting against acute ischemic brain injury in mice. The content of SASP factors and mRNA level of p16INK4a in the brain tissue of MCAO mice were significantly reduced by the infection of lenti-INK-ATTAC viruses. These results indicate that local clearance of senescent brain cells is a potential therapy on AIS, and demonstrate the correlation between neuronal senescence and pathogenesis of AIS.

Aging-Associated Thyroid Dysfunction Contributes to Oxidative Stress and Worsened Functional Outcomes Following Traumatic Brain Injury.

The incidence of traumatic brain injury (TBI) increases dramatically with advanced age and accumulating evidence indicates that age is one of the important predictors of an unfavorable prognosis after brain trauma. Unfortunately, thus far, evidence-based effective therapeutics for geriatric TBI is limited. By using middle-aged animals, we first confirm that there is an age-related change in TBI susceptibility manifested by increased inflammatory events, neuronal death and impaired functional outcomes in motor and cognitive behaviors. Since thyroid hormones function as endogenous regulators of oxidative stress, we postulate that age-related thyroid dysfunction could be a crucial pathology in the increased TBI severity. By surgically removing the thyroid glands, which recapitulates the age-related increase in TBI-susceptible phenotypes, we provide direct evidence showing that endogenous thyroid hormone-dependent compensatory regulation of antioxidant events modulates individual TBI susceptibility, which is abolished in aged or thyroidectomized individuals. The antioxidant capacity of melatonin is well-known, and we found acute melatonin treatment but not liothyronine (T3) supplementation improved the TBI-susceptible phenotypes of oxidative stress, excitotoxic neuronal loss and promotes functional recovery in the aged individuals with thyroid dysfunction. Our study suggests that monitoring thyroid function and acute administration of melatonin could be feasible therapeutics in the management of geriatric-TBI in clinic.

Attenuation of indoxyl sulfate-induced cell damage by cinchonidine-a Cinchona alkaloid-through the downregulation of p53 signaling pathway by promoting MDM2 cytoplasmic-nuclear shuttling in endothelial cells.

Renocardiac syndromes are a critical concern among patients with chronic kidney disease (CKD). High level of indoxyl sulfate (IS), a protein-bound uremic toxin, in plasma is known to promote the pathogenesis of cardiovascular diseases by impairing endothelial function. However, the therapeutic effects of the adsorbent of indole, a precursor of IS, on renocardiac syndromes is still debated. Therefore, novel therapeutic approaches should be developed to treat IS-associated endothelial dysfunction. In the present study, we have found that cinchonidine, a major Cinchona alkaloid, exhibited superior cell-protective effects among the 131 test compounds in IS-stimulated human umbilical vein endothelial cells (HUVECs). IS-induced cell death, cellular senescence, and impairment of tube formation in HUVECs were substantially reversed after treatment with cinchonidine. Despite the cinchonidine did not alter reactive oxygen species formation, cellular uptake of IS and OAT3 activity, RNA-Seq analysis showed that the cinchonidine treatment downregulated p53-modulated gene expression and substantially reversed IS-caused G0/G1 cell cycle arrest. Although the mRNA levels of p53 were not considerably downregulated by cinchonidine in IS-treated HUVECs, the treatment of cinchonidine promoted the degradation of p53 and the cytoplasmic-nuclear shuttling of MDM2. Cinchonidine exhibited cell-protective effects against the IS-induced cell death, cellular senescence, and impairment of vasculogenic activity in HUVECs through the downregulation of p53 signaling pathway. Collectively, cinchonidine may be a potential cell-protective agent to rescue IS-induced endothelial cell damage.

Advances in Antibody-Based Therapeutics for Cerebral Ischemia.

Cerebral ischemia is an acute disorder characterized by an abrupt reduction in blood flow that results in immediate deprivation of both glucose and oxygen. The main types of cerebral ischemia are ischemic and hemorrhagic stroke. When a stroke occurs, several signaling pathways are activated, comprising necrosis, apoptosis, and autophagy as well as glial activation and white matter injury, which leads to neuronal cell death. Current treatments for strokes include challenging mechanical thrombectomy or tissue plasminogen activator, which increase the danger of cerebral bleeding, brain edema, and cerebral damage, limiting their usage in clinical settings. Monoclonal antibody therapy has proven to be effective and safe in the treatment of a variety of neurological disorders. In contrast, the evidence for stroke therapy is minimal. Recently, Clone MTS510 antibody targeting toll-like receptor-4 (TLR4) protein, ASC06-IgG1 antibody targeting acid sensing ion channel-1a (ASIC1a) protein, Anti-GluN1 antibodies targeting N-methyl-D-aspartate (NMDA) receptor associated calcium influx, GSK249320 antibody targeting myelin-associated glycoprotein (MAG), anti-High Mobility Group Box-1 antibody targeting high mobility group box-1 (HMGB1) are currently under clinical trials for cerebral ischemia treatment. In this article, we review the current antibody-based pharmaceuticals for neurological diseases, the use of antibody drugs in stroke, strategies to improve the efficacy of antibody therapeutics in cerebral ischemia, and the recent advancement of antibody drugs in clinical practice. Overall, we highlight the need of enhancing blood-brain barrier (BBB) penetration for the improvement of antibody-based therapeutics in the brain, which could greatly enhance the antibody medications for cerebral ischemia in clinical practice.

Mechanisms of TQ-6, a Novel Ruthenium-Derivative Compound, against Lipopolysaccharide-Induced In Vitro Macrophage Activation and Liver Injury in Experimental Mice: The Crucial Role of p38 MAPK and NF-κB Signaling.

Several studies have reported that metal complexes exhibit anti-inflammatory activities; however, the molecular mechanism is not well understood. In this study, we used a potent ruthenium (II)-derived compound, [Ru(η6-cymene)2-(1H-benzoimidazol-2-yl)-quinoline Cl]BF4 (TQ-6), to investigate the molecular mechanisms underlying the anti-inflammatory effects against lipopolysaccharide (LPS)-induced macrophage activation and liver injury in mice. Treating LPS-stimulated RAW 264.7 cells with TQ-6 suppressed nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in a concentration-dependent manner. The LPS-induced expression of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) were reduced in TQ-6-treated cells. TQ-6 suppressed, LPS-stimulated p38 MAPK phosphorylation, IκBα degradation, and p65 nuclear translocation in cells. Consistent with the in vitro studies, TQ-6 also suppressed the expression of iNOS, TNF-α, and p65 in the mouse model with acute liver injury induced by LPS. The present study showed that TQ-6 could protect against LPS-induced in vitro inflammation in macrophage and in vivo liver injury in mice, and suggested that NF-κB could be a promising target for protecting against LPS-induced inflammation and liver injury by TQ-6. Therefore, TQ-6 can be a potential therapeutic agent for treating inflammatory diseases.

CME-1, a novel polysaccharide, suppresses iNOS expression in lipopolysaccharide-stimulated macrophages through ceramide-initiated protein phosphatase 2A activation.

CME-1, a novel water-soluble polysaccharide purified from Ophiocordyceps sinensis mycelia, has anti-oxidative, antithrombotic and antitumour properties. In this study, other major attributes of CME-1, namely anti-inflammatory and immunomodulatory properties, were investigated. Treating lipopolysaccharide (LPS)-stimulated RAW 264.7 cells with CME-1 concentration-dependently suppressed nitric oxide formation and inducible nitric oxide synthase (iNOS) expression. In the CME-1-treated RAW 264.7 cells, LPS-induced IκBα degradation and the phosphorylation of p65, Akt and mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38, were reduced. Treatment with a protein phosphatase 2A (PP2A)-specific inhibitor, significantly reversed the CME-1-suppressed iNOS expression; IκBα degradation; and p65, Akt and MAPK phosphorylation. PP2A activity up-regulation and PP2A demethylation reduction were also observed in the cells. Moreover, CME-1-induced PP2A activation and its subsequent suppression of LPS-activated RAW 264.7 cells were diminished by the inhibition of ceramide signals. LPS-induced reactive oxygen species (ROS) and hydroxyl radical formation were eliminated by treating RAW 264.7 cells with CME-1. Furthermore, the role of ceramide signalling pathway and anti-oxidative property were also demonstrated in CME-1-mediated inhibition of LPS-activated primary peritoneal macrophages. In conclusion, CME-1 suppressed iNOS expression by up-regulating ceramide-induced PP2A activation and reducing ROS production in LPS-stimulated macrophages. CME-1 is a potential therapeutic agent for treating inflammatory diseases.

The Influence of Hepatitis B Viral Load and Pre-S Deletion Mutations on Post-Operative Recurrence of Hepatocellular Carcinoma and the Tertiary Preventive Effects by Anti-Viral Therapy.

BACKGROUND: Whether or not hepatitis B virus (HBV) genotypes, mutations, and viral loads determine outcomes for patients with HBV-induced hepatocellular carcinoma (HCC) remains controversial. AIMS: To study the influence of HBV viral factors on prognoses for patients with HBV-induced HCC after resection surgery and investigate if antiviral therapy could counteract the adverse effects of viral factors. METHODS: A total of 333 HBV-related HCC patients who underwent tumor resection were enrolled retrospectively. Serum HBV DNA levels, mutations, anti-viral therapy, and other clinical variables were analyzed for their association with post-operative recurrence. RESULTS: After a median follow-up of 45.9 months, 208 patients had HCC recurrence after resection. The 5-year overall survival and recurrence-free survival rates were 55.4% and 35.3%, respectively. Multivariate analysis showed indocyanine green retention rate at 15 minutes >10%, gamma-glutamyltransferase (GGT) level >60 U/L, macroscopic and microscopic venous invasion, and the absence of anti-viral therapy were significant risk factors for recurrence. Anti-viral therapy could decrease recurrence in patients with early stage HCC, but the effect was less apparent in those with the Barcelona-Clinic Liver Cancer stage C HCC. For patients without antiviral therapy after resection, serum HBV DNA levels >10(6) copies/mL, GGT >60 U/L, and macroscopic and microscopic venous invasion were significant risk factors predicting recurrence. Among the 216 patients without anti-viral therapy but with complete HBV surface gene mapping data, 73 were with pre-S deletion mutants. Among patients with higher serum HBV DNA levels, those with pre-S deletion had significantly higher rates of recurrence. Moreover, multivariate analysis showed multi-nodularity, macroscopic venous invasion, cirrhosis, advanced tumor cell differentiation, and pre-S deletion were significant risk factors predictive of recurrence. CONCLUSIONS: Ongoing HBV viral replication and pre-S deletion are crucial for determining post-operative tumor recurrence. Anti-viral therapy can help reduce recurrence and improve prognosis, especially for those with early stage HCC.