Comparison of Immune Microenvironment Between Colon and Liver Metastatic Tissue in Colon Cancer Patients with Liver Metastasis.

BACKGROUND: Liver metastasis is an indicator of unfavorable responses to immunotherapy in colorectal cancer patients. However, the difference of immune microenvironment between primary tumors and liver metastases has not been well understood. PATIENTS AND METHODS: Fifty-four colon cancer with liver metastasis patients who received resection of both primary and metastasis lesions have been analyzed. The immune score is based on the density of infiltrating immune cells (CD3+ cell, CD8+ cell, CD11b+ cell, CD11c+ cell, and CD33+ cell) in the center and margin of the tumor. The expression of immune markers between the primary tumor and hepatic metastases was analyzed using Wilcoxon's signed rank test. RESULTS: All the five markers had higher expression in tumor margins than center tumor in both primary tumor and hepatic metastases lesions. The expression of CD11c and CD11b had no difference between metastatic lesions and primary tumor. In tumor margins, except CD11b, all the other 4 markers expressed significantly higher in hepatic metastases than in primary tumor. Intra-tumor, CD3 had higher expression in primary tumor than in hepatic metastases, while CD33 had higher expression in hepatic metastases than in primary tumor. CD8+ CD3+ cells of the total CD8+ cell population in primary tumor was significantly higher than in hepatic metastases (36.42% vs. 24.88%, p = 0.0069). CONCLUSIONS: The immune microenvironment between primary tumor and hepatic metastasis is different. More immunosuppressing cells in liver may partially explain why immunotherapy in colon cancer is less effective with liver metastatic disease.

Role of Systemic Treatment for Advanced/Metastatic Gastric Carcinoma in the Third-Line Setting: A Bayesian Network Analysis.

Background: Increasing evidences from phase II or III trials have proved that salvage systematic therapy, including chemotherapy, target therapy, or checkpoint inhibitor therapy can prolong survival in patients who do not succeed with second line therapy, yet there are no guidelines for the optimum third-line treatments. To compare the effectiveness and safety of current third-line therapies for metastatic Gastric Cancer (mGC), we conducted this network analysis. Methods: Literature up to Sep 30, 2019 were systematically searched and analyzed by a Bayesian fixed-effect model. Results: This study included seven randomized clinical trails which involved 2,655 patients. It turns out that for overall survival, nivolumab has the highest probability to be the optimal choice for overall survival (OS). For patients with no peritoneal metastases, the network meta-analysis showed that Nivolumab (HR:0.64; 95% CI: 0.48-0.85) and Trifluridine/tipiacil (HR:0.66; 95% CI: 0.51-0.86) were associated with significantly higher improvement in OS than placebo. However, patients with peritoneal metastases could not benefit from nivolumab, ramucirumab, or Trifluridine/tipiacil, when compared with a placebo. For progression-free survival, apatinib (850 mg) was the most likely candidate, followed by ramucirumab. Statistically, Apatinib (850 mg), Trifluridine/tipiacil, and SLC had higher incidences of high-grade adverse events (AEs) than placebo. Conclusion: Our findings demonstrate that nivolumab has the best balance between acceptability and effectiveness in the third line therapy for mGC.

Arginine is neuroprotective through suppressing HIF-1α/LDHA-mediated inflammatory response after cerebral ischemia/reperfusion injury.

Neuroinflammation is a secondary response following ischemia stroke. Arginine is a non-essential amino acid that has been shown to inhibit acute inflammatory reaction. In this study we show that arginine treatment decreases neuronal death after rat cerebral ischemia/reperfusion (I/R) injury and improves functional recovery of stroke animals. We also show that arginine suppresses inflammatory response in the ischemic brain tissue and in the cultured microglia after OGD insult. We further provide evidence that the levels of HIF-1α and LDHA are increased after rat I/R injury and that arginine treatment prevents the elevation of HIF-1α and LDHA after I/R injury. Arginine inhibits inflammatory response through suppression of HIF-1α and LDHA in the rat ischemic brain tissue and in the cultured microglia following OGD insult, and protects against ischemic neuron death after rat I/R injury by attenuating HIF-1α/LDHA-mediated inflammatory response. Together, these results indicate a possibility that arginine-induced neuroprotective effect may be through the suppression of HIF-1α/LDHA-mediated inflammatory response in microglia after cerebral ischemia injury.

Sex-dependent effects of GPER activation on neuroinflammation in a rat model of traumatic brain injury.

The G protein-coupled estrogen receptor (GPER) plays a role in estrogen-mediated neuroprotection and has been considered a potential therapeutic target for treating various neurological diseases. It is increasingly recognized that sex is a biological variable affecting treatment outcomes and efficacy, and that neuroinflammation is a key secondary injury mechanism following brain injury, though it is unknown whether the neuroprotective effects exerted by GPER involve modulation of inflammatory processes. The aim of this study was to investigate whether activation of GPER has a sex-dependent effect on neuroinflammation following traumatic brain injury (TBI), a sexually dimorphic disease. In male and ovariectomized (OVX) female rats, the GPER agonist, G1, inhibited the upregulated expression of pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α), increased the expression of the anti-inflammatory cytokine IL-4, and shifted microglia/macrophage polarization toward the M2 phenotype. In gonadally-intact females, G1 caused more pro-inflammatory (IL-6 and TNF-α) and less anti-inflammatory cytokine (IL-4) production, without altering microglia/macrophage polarization. Estradiol supplementation blocked the effects of G1 in OVX females. We also found that post-injury GPER expression was increased in males and OVX females but not in intact females. G1 administration increased Akt phosphorylation in males and OVX females, but had no significant effect in intact females, while Akt inhibition blocked the effects of G1 in males and OVX females. These results indicate that G1 exerts anti-inflammatory effects in males and OVX females but not in intact females; these sex-specific effects are dependent on circulating estrogen levels and are partially mediated through Akt signaling. Future studies are needed to elucidate the relevant molecular mechanisms, especially in females. A better understanding of the sex differences in treatment efficacy with GPER agonists may help improve personalized therapeutic strategies for males and pre- and postmenopausal females with TBI.

l-lysine confers neuroprotection by suppressing inflammatory response via microRNA-575/PTEN signaling after mouse intracerebral hemorrhage injury.

l-lysine is a basic amino acid that has been shown to exert neuroprotective effect. However, the underlying mechanism remains to be elucidated. In this study, we investigate how l-lysine exerts its neuroprotective effect in hemin-insulted mouse cortical neurons in vitro and the mouse model of intracerebral hemorrhage (ICH) in vivo. We demonstrate that l-lysine treatment promotes M2 microglial polarization and reduces inflammatory response both in vitro and in vivo, suggesting that l-lysine may play a neuroprotective role in ICH injury. Indeed, we show that l-lysine treatment reduces cortical neuronal death after hemin insult in vitro and decrease the number of degenerating neurons after ICH in vivo. l-lysine also improves the functional recovery of ICH animals in neurobehavioral tests. Consistent with the role of PTEN in regulating inflammatory response, we find that PTEN inhibition promotes M2 microglial polarization and suppresses pro-inflammatory response in mouse ICH injury, which contribute to the neuroprotective effect of l-lysine. Moreover, our results reveal that microRNA-575 directly suppressed PTEN to promote M2 microglial polarization and mediate the neuroprotective effect of l-lysine in ICH injury. Together, our results suggest that l-lysine confers neuroprotection after ICH injury through enhancing M2 microglial polarization and reducing inflammatory response, which is mediated by microRNA-575 upregulation and subsequent PTEN downregulation.

BpV(pic) confers neuroprotection by inhibiting M1 microglial polarization and MCP-1 expression in rat traumatic brain injury.

Traumatic brain injury (TBI) is a major cause of motor and cognitive impairment in young adults. It is associated with high mortality rates and very few effective treatment options. Bisperoxovanadium (pyridine-2-carboxyl) [bpV(pic)] is an commercially available inhibitor of Phosphatase and tensin homolog (PTEN). Previous studies have shown that bpV(pic) has protective effects in central nervous system. However, the role of bpV(pic) in TBI is unclear. In this study we aimed to investigate the neuroprotective role of bpV(pic) in rat TBI model. We found that injection of bpV(pic) significantly reduces brain edema and neurological dysfunction after TBI and this is mediated by AKT pathway. TBI is known to promote the M1 pro-inflammatory phenotype of microglial polarization and this effect is inhibited by bpV(pic) treatment which, instead promotes M2 microglial polarization in vivo and in vitro. We also found evidence of bpV(pic)-regulated neuroinflammation mediated by AKT activation and NF-κB p65 inhibition. BpV(pic) treatment also suppressed microglia in the peri-TBI region. MCP-1 is known to recruit monocytes and macrophages to promote inflammation, we show that bpV(pic) can inhibit TBI-induced up-regulation of MCP-1 via the AKT/NF-κB p65 signaling pathway. Taken together, our findings demonstrate that bpV(pic) plays a neuroprotective role in rat TBI, which may be achieved by inhibiting M1 microglia polarization and MCP-1 expression by modulating AKT/NF-κB p65 signaling pathway.

Glycine Exhibits Neuroprotective Effects in Ischemic Stroke in Rats through the Inhibition of M1 Microglial Polarization via the NF-κB p65/Hif-1α Signaling Pathway.

Glycine is a simple nonessential amino acid known to have neuroprotective properties. Treatment with glycine results in reduced infarct volume of the brain, neurologic function scores, and neuronal and microglial death in ischemic stroke injury. Neuroinflammation has been considered a major contributor to cerebral ischemia-induced brain damage. However, the role of glycine in neuroinflammation following ischemic stroke is unclear. The present study aimed to determine whether neuroinflammation is involved in the neuroprotective effects of glycine in cerebral ischemia injury. Ischemic stroke promotes M1 microglial polarization. Interestingly, we found that the injection of glycine in rats after injury can inhibit ischemia-induced inflammation and promote M2 microglial polarization in vivo (Sprague-Dawley rats) and in vitro (cortical microglia and BV-2 cells). We show that glycine suppresses Hif-1α by inhibiting the upregulation of NF-κB p65 after ischemia-reperfusion injury, resulting in the inhibition of proinflammatory activity. The activation of AKT mediates the inhibition of NF-κB p65/Hif-1α signaling by glycine. Moreover, we confirm that glycine-regulated AKT activation is mediated by the inhibition of PTEN in a PTEN depletion cell line, U251 cells. Glycine modulates microglial polarization after ischemic stroke, which indirectly inhibits ischemia-induced neuronal death and functional recovery. Taken together, our findings provide a new understanding of glycine in neuroprotection by inhibiting M1 microglial polarization and promoting anti-inflammation by suppressing NF-κB p65/Hif-1α signaling.

DJ-1 Suppresses Cytoplasmic TDP-43 Aggregation in Oxidative Stress-Induced Cell Injury.

DJ-1 (also called PARK7) is a multifunctional redox-sensitive protein that is protective against oxidative stress-induced cell death. TAR DNA-binding protein 43 (TDP-43) is a major protein component of pathological inclusions in amyotrophic lateral sclerosis and frontotemporal dementia. Reducing aberrant aggregation of TDP-43 is a potential approach to prevent cell death. To investigate whether DJ-1 might inhibit TDP-43 aggregation to exert a protective effect in oxidative stress-induced injury, we tested the protein level and subcellular localization of TDP-43 and DJ-1 in SH-SY5Y cells transfected with wild-type DJ-1, DJ-1 mutant (L166P) cDNA, or DJ-1 siRNA. We show that oxidative stress induced by paraquat leads to the formation of cytosolic TDP-43 aggregation in SH-SY5Y cells. DJ-1 overexpression decreases paraquat-induced cytoplasmic accumulation of TDP-43 in SH-SY5Y cells and protects against paraquat-induced cell death. Transfection of DJ-1 L166P mutant or DJ-1 siRNA leads to increased cytosolic aggregation of TDP-43 in paraquat-treated SH-SY5Y cells and promotes cell death. These data suggest that DJ-1 may protect against oxidative stress-induced cell death through the suppression of cytoplasmic TDP-43 aggregation.

Effects of estrogen receptor GPR30 agonist G1 on neuronal apoptosis and microglia polarization in traumatic brain injury rats.

PURPOSE: To investigate the effects of estrogen G protein-coupled receptor 30 (GPR30) agonist G1 on hippocampal neuronal apoptosis and microglial polarization in rat traumatic brain injury (TBI). METHODS: Male SD rats were randomly divided into sham group, TBI + vehicle group, TBI + G1 group. Experimental moderate TBI was induced using Feeney's weigh-drop method. G1 (100µg/kg) or vehicle was intravenously injected from femoral vein at 30 min post-injury. Rats were sacrificed at 24 h after injury for detection of neuronal apoptosis and microglia polarization. Neuronal apoptosis was assayed by immunofluorescent staining of active caspase-3. M1 type microglia markers (iNOS and IL-1ß) and M2 type markers (Arg1 and IL-4) were examined by immunoblotting or ELISA. Total protein level of Akt and phosphorylated Akt were assayed by immunoblotting. RESULTS: G1 significantly reduced active caspase-3 positive neurons in hippocampus. Meanwhile G1 increased the ratio of Arg1/iNOS. IL-1ß production was decreased but IL-4 was increased after G1 treatment. G1 treatment also increased the active form of Akt. CONCLUSIONS: GPR30 agonist G1 inhibited neuronal apoptosis and favored microglia polarization to M2 type.

ERK 1/2 Activation Mediates the Neuroprotective Effect of BpV(pic) in Focal Cerebral Ischemia-Reperfusion Injury.

Bisperoxovanadium (pyridine-2-carboxyl) [bpV(pic)] is a commercially available PTEN inhibitor. Previous studies from us and others have shown that bpV(pic) confers neuroprotection in cerebral ischemia injury. We set up to determine whether ERK 1/2 activation plays a role in bpV(pic)-induced neuroprotective effect in cerebral ischemia injury. We found that the phosphorylation levels of Akt (p-AKT) and ERK1/2 (p-ERK 1/2) were down-regulated after cerebral ischemia-reperfusion injury. The injection of bpV(pic) after injury not only increased the level of p-AKT but also the level of p-ERK 1/2. While the inhibition of PTEN mediated the up-regulatation of p-AKT and p-ERK 1/2 by bpV(pic). Interestingly, the ERK 1/2 activation induced by bpV(pic) was also independent of the inhibition of PTEN. Our results indicate that bpV(pic) protects against OGD-induced neuronal death and promotes the functional recovery of stroke animals through PTEN inhibition and ERK 1/2 activation, respectively. This study suggests that the effect of bpV(pic) on ERK 1/2 signaling should be considered while using bpV(pic) as a PTEN inhibitor.

Glioblastoma recurrence correlates with NLGN3 levels.

Glioblastoma (GBM) is the most aggressive glioma in the brain. Recurrence of GBM is almost inevitable within a short term after tumor resection. In a retrospective study of 386 cases of GBM collected between 2013 and 2016, we found that recurrence of GBM mainly occurs in the deep brain regions, including the basal ganglia, thalamus, and corpus callosum. But the mechanism underlying this phenomenon is not clear. Previous studies suggest that neuroligin-3 (NLGN3) is necessary for GBM growth. Our results show that the levels of NLGN3 in the cortex are higher than those in the deep regions in a normal human brain, and similar patterns are also found in a normal mouse brain. In contrast, NLGN3 levels in the deep brain regions of GBM patients are high. We also show that an increase in NLGN3 concentration promotes the growth of U251 cells and U87-MG cells. Respective use of the cortex neuron culture medium (C-NCM) and basal ganglia neuron culture medium (BG-NCM) with DMEM to cultivate U251, U87-MG and GBM cells isolated from patients, we found that these cells grew faster after treatment with C-NCM and BG-NCM in which the cells treated with C-NCM grew faster than the ones treated with BG-NCM group. Inhibition of NLGN3 release by ADAM10i prevents NCM-induced cell growth. Together, this study suggests that increased levels of NLGN3 in the deep brain region under the GBM pathological circumstances may contribute to GBM recurrence in the basal ganglia, thalamus, and corpus callosum.

Glycine confers neuroprotection through PTEN/AKT signal pathway in experimental intracerebral hemorrhage.

Glycine has been shown to protect against ischemic stroke through various mechanisms. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) which antagonize Akt-dependent cell survival has been linked to neuronal damage. However, whether glycine has a neuroprotective property in intracerebral hemorrhage (ICH) was unknown. This study aimed to determine the protective effect of glycine in rats ICH. Adult male Sprague-Dawley (SD) rats were subjected to left striatum infusion of autologous blood. ICH animals received glycine (0.2-3 mg/kg, icv) at 1 h after ICH with or without pre-injection of Akt Inhibitor IV (100 µM, 2 µl, icv) 0.5 h prior to glycine treatment. Our results showed that in the perihematomal area PTEN was up-regulated in the early stage after ICH. However, glycine treatment decreased PTEN protein level and increased the phosphorylation level of AKT (p-AKT) in the perihematomal area. With the administration of glycine, neuronal death was significantly reduced and Evans blue leakage was alleviated as well as the brain edema after ICH. Moreover, hematoma volume was decreased and neurobehavioral outcome was improved. Nevertheless, Akt Inhibitor IV abolished the neuroprotective effects of glycine after ICH. Together, our findings demonstrate, for the first time, the protective role of glycine on ICH rats, and suggest that the neuroprotective effect of glycine was mediated through PTEN/Akt signal pathway.