Loss of LncRNA DUXAP8 synergistically enhanced sorafenib induced ferroptosis in hepatocellular carcinoma via SLC7A11 de-palmitoylation.

BACKGROUND: Ferroptosis is an important iron-dependent form of cell death in hepatocellular carcinoma (HCC). Sorafenib, a potent ferroptosis inducer, is used to treat advanced HCC but its efficacy is limited by the development of drug resistance. METHODS: The effects of DUXAP8 expression on HCC progression were evaluated by TCGA database, Kaplan-Meier analysis, and in situ hybridization analysis. Sorafenib resistant HCC cell lines were modeled in vitro to study the regulation of DUXAP8 on ferroptosis in HCC induced by sorafenib. We used RNA pull-down, immunofluorescence assays, acyl-biotinyl exchange assay and mass spectrometry analysis to assess the molecular mechanism of ferroptosis regulation by DUXAP8. Syngeneic subcutaneous and orthotopic CDX models were used to assess whether DUXAP8 inhibition improves HCC in vivo. RESULTS: LncRNA DUXAP8, which is highly expressed in liver cancer and associated with poor prognosis, contributes to sorafenib resistance through suppression of ferroptosis. In vitro tests revealed that DUXAP8 reduced the sensitivity of HCC to sorafenib-induced ferroptosis by acting on SLC7A11, a subunit of the amino acid antiporter system xc-. DUXAP8 facilitates SLC7A11 palmitoylation and impedes its lysosomal degradation, thereby enhancing SLC7A11 action and suppressing ferroptosis. RNA pull-down and immunofluorescence assays confirmed that DUXAP8 decreased membrane translocation and promoted sorting of de-palmitoylated SLC7A11 to lysosomes by binding of DUXAP8 to SLC7A11. In addition, mass spectrometric analysis found that the Cys414 residue of SLC7A11 might be the predominant mutant site responsible for molecular masking of SLC7A11 lysosomal sorting. Further, the antitumor effect of DUXAP8 knockdown was verified in orthotopic and subcutaneous CDX models. CONCLUSIONS: Our findings suggest that a novel translational strategy combining sorafenib with DUXAP8 silencing to overcome drug resistance may improve treatment efficacy in patients with advanced HCC.

Distilling universal activity descriptors for perovskite catalysts from multiple data sources via multi-task symbolic regression.

Developing activity descriptors via data-driven machine learning (ML) methods can speed up the design of highly active and low-cost electrocatalysts. Despite the fact that a large amount of activity data for electrocatalysts is stored in the literature, data from different publications are not comparable due to different experimental or computational conditions. In this work, an interpretable ML method, multi-task symbolic regression, was adopted to learn from data in multiple experiments. A universal activity descriptor to evaluate the oxygen evolution reaction (OER) performance of oxide perovskites free of calculations or experiments was constructed and reached high accuracy and generalization ability. Utilizing this descriptor with Bayesian-optimized parameters, a series of compelling double perovskites with excellent OER activity were predicted and further evaluated using first-principles calculations. Finally, the two ML-predicted nickel-based perovskites with the best OER activity were successfully synthesized and characterized experimentally. This work opens a new way to extend machine-learning material design by utilizing multiple data sources.

Facilitating charge transfer through an atomic coherent interface of a novel direct Z-scheme BiVO4@Cu3SnS4 heterojunction to boost photocatalytic performance.

Direct Z-scheme photocatalytic systems are very promising composite photocatalysts, and their photocatalytic performance is highly associated with the quality of the interface within them. Herein, a novel direct Z-scheme heterojunction with a coherent interface has been presented for the first time. Specifically, the heterojunction was constructed by dispersing pre-prepared BiVO4 crystals into the reaction system to synthesize Cu3SnS4, followed by a hydrothermal reaction. It is shown that Cu3SnS4 was deposited on the surface of each pre-prepared BiVO4 crystal as a thin layer via heterogeneous nucleation to acquire a core-shell heterojunction. The BiVO4@Cu3SnS4 heterojunction was found to possess an atomic coherent interface, which is formed through the bonding between the (121) plane of BiVO4 and the (112) plane of Cu3SnS4, originating from the matching in the crystalline lattice between the two planes. The coherent interface facilitated the charge transfer from Cu3SnS4 to BiVO4 owing to the difference in their Fermi levels, thereby forming a built-in electric field pointing from Cu3SnS4 to BiVO4. Reduced fluorescence emission and a shortened carrier lifetime reveal an obvious reduction in the inter-band charge recombination for the optimal BVO@CTS-0.19 sample. Consequently, BVO@CTS-0.19 shows remarkably enhanced photocatalytic performance in MO degradation, Cr6+ reduction and oxygen evolution. The Z-scheme charge transfer mechanism for BVO@CTS-0.19 was verified by a suite of techniques. This work provides a universal strategy for building a coherent interface to develop high-performance direct Z-scheme heterojunctions.

miR-124-3p Combined with ANGPTL2 Has High Diagnostic Values for Obese and Nonobese Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a hormonal disorder that affects 5-20% of women of reproductive age. Interestingly, serum miR-124-3p and ANGPTL2 are differentially expressed in PCOS patients. Accordingly, this study set out to explore the clinical roles of serum miR-124-3p/ANGPTL2 in PCOS. Firstly, miR-124-3p/ANGPTL2 expression patterns were detected in the serum of 102 PCOS patients and 100 healthy subjects. miR-124-3p or/and ANGPTL2 diagnostic efficacy on PCOS was further analyzed, in addition to the measurement of lipid metabolism, glucose metabolism, sex hormone indexes, and inflammation levels. Correlations between serum miR-124-3p/ANGPTL2 expressions and age, BMI, Ferriman-Gallwey score, lipid metabolism, glucose metabolism, sex hormone indexes, TNF-α, and IL-6 in PCOS patients were determined. The expression correlation and binding relationship of ANGPTL2 and miR-124-3p were identified. In addition, miR-124-3p was downregulated and ANGPTL2 was upregulated in the serum of obese and nonobese PCOS patients. miR-124-3p expression was found to be negatively correlated with Ferriman-Gallwey score and serum total testosterone (T), and negatively related to prolactin (PRL). ANGPTL2 expression was positively correlated with FNS and inversely linked with PRL. TNF-α and IL-6 were negatively correlated with miR-124-3p, but positively correlated with ANGPTL2. Furthermore, there was a negative correlation and a targeting relationship between ANGPTL2 and miR-124-3p expression in the serum of obese and nonobese PCOS patients. Collectively, our findings indicated that miR-124-3p might target ANGPTL2 expression in obese and nonobese PCOS patients, and further underscored the diagnostic value of their combination.

From pure water to hydrogen peroxide on a novel 2,5,8-triamino-tri-s-triazine (melem)-derived photocatalyst with a high apparent quantum efficiency.

Photocatalytic hydrogen peroxide (H2O2) production is a green process but remains a great challenge. Herein, a novel photocatalyst with high activity for H2O2 production, is developed based on 2,5,8-triamino-tri-s-triazine (melem) by linking it with 2, 3-naphthalene dicarboxylic anhydride (NDA). The obtained melem/NDA hybrid not only exhibited narrowed band gap and obviously enhanced visible light absorption, but also showed reduced charge recombination originated from its spatial distribution in HOMO and LUMO induced by the introduction of NDA as verified by DFT calculations. More significantly, the sufficient LUMO and HOMO positions for the optimal sample, melem/NDA0.5, ensured efficient H2O2 production from pure water via both the oxygen reduction reactions mainly through the two-step one-electron path and the water oxidation reaction through the one-step two-electron path. Consequently, melem/NDA0.5 achieves an apparent quantum efficiency of as high as 6.9 % at 420 nm. This work sheds light on developing high-performance organic photocatalysts for boosting photocatalytic H2O2 production.

ZIC2 promotes colorectal cancer growth and metastasis through the TGF-ß signaling pathway.

ZIC2 is involved in the tumor progression of many types of cancers. The role of ZIC2 in the metastasis of colorectal cancer and its mechanism are not yet clear. In this study, we found that high ZIC2 expression was not only associated with poor prognosis, relapse-free survival and advanced metastasis but was also an independent prognostic factor in colorectal cancer patients. Moreover, ZIC2 knockdown inhibited cell proliferation, migration and invasion, while the upregulation of ZIC2 had the opposite effect in vitro. ZIC2 overexpression induced TGF-ß1 expression and increased Smad3 phosphorylation. The carcinogenic effects of elevated ZIC2 expression can be eliminated by interfering with the TGF-ß1 receptor with inhibitors. This further verified the promoting effect of ZIC2 on the TGF-ß signaling pathway. In vivo experiments have also confirmed that ZIC2 can promote liver metastases of colorectal cancer. The results suggest that ZIC2 is associated with poor prognosis and relapse-free survival in colorectal cancer patients. Moreover, ZIC2 promoted colorectal cancer progression and metastasis by activating the TGF-ß signaling pathway. Hence, ZIC2 is expected to be a new therapeutic and prognostic target for colorectal cancer in the future.

Gelsemium elegans cyclic peptide induces human cervical carcinoma cells apoptosis through intrinsic and extrinsic pathways.

Four novel Gelsemium elegans cyclic peptides (GEPs) were isolated in an antihuman cervical carcinoma activity tracking method, and their amino acid sequences were identified. The GEP-1 cyclic-(Trp-Leu-His-Val)-peptide inhibited HeLa cell proliferation in a dose- and time-dependent manner. GEP-1 induced intracellular reactive oxygen species (ROS) overproduction and induced HeLa cells apoptosis in a caspase-dependent manner. GEP-1 also induced collapse of the mitochondrial membrane potential and promoted the mitochondrial release of cytochrome c (cyt c), apoptosis-inducing factor (AIF), and endonuclease G (Endo G) in HeLa cells. Furthermore, GEP-1 triggered the extrinsic death receptor-dependent pathway, which was characterized by activating Fas and FADD. Notably, GEP-1 is a potential antihuman cervical carcinoma peptide.

Noradrenergic innervations of the medial prefrontal cortex mediate empathy for pain in rats via the α1 and ß receptors.

Empathy involves integrated affective and cognitive processes to share the emotional state of others. This evolutionarily conserved ability has also been identified in nonhuman primates and rodents. Our previous work demonstrated that social interaction with a cagemate rat in pain induces mechanical pain hypersensitivity in cagemate observer (CO) rats. Moreover, we also demonstrated that the medial prefrontal cortex (mPFC) and the locus coeruleus-norepinephrine (LC-NE) system are involved in this process. The LC sends noradrenergic innervations throughout the brain, and its innervation of the prefrontal cortex plays important roles in working memory and attention. The present study seeks to study the roles of the LC-to-mPFC pathway in pain empathy in rats. Selective ablation of the noradrenergic innervations of the mPFC through bilateral injections of the axonally transported catecholamine immunotoxin, saporin-conjugated antiserum to dopamine-ß-hydroxylase into the mPFC diminished mechanical pain hypersensitivity in CO rats. Bilateral intra-mPFC applications of the adrenergic α1 receptor antagonist prazosin and the ß receptor antagonist propranolol, but not the adrenergic α2 antagonist yohimbine, eliminated mechanical pain hypersensitivity in CO rats. In contrast, intra-mPFC applications of prazosin, yohimbine or propranolol did not affect the mechanical pain sensitivity of rats per se. Our results indicate that noradrenergic innervations in the mPFC mediate empathy for pain in rats via the α1 and ß receptors.

Gut microbiome alteration as a diagnostic tool and associated with inflammatory response marker in primary liver cancer.

BACKGROUND: Primary liver cancer has high mortality and morbidity worldwide. However, the characteristic of gut microbiota profile and its correlation with inflammation status in liver cancer patients remains largely unknown, and a gut microbiome-based diagnostic model for liver cancer is still absent. METHODS: Here, we provided a comprehensive analysis based on fecal 16S rRNA sequencing and clinical data in a cohort consisting of 40 healthy volunteers, 143 hepatocellular carcinoma (HCC) patients, and 46 cholangiocarcinoma (CCA) patients. RESULTS: Our results indicated a distinct shift of gut microbiota composition between two primary liver cancer types and compared with healthy volunteers. Based on the diversity constitute of gut microbiome taxonomy and random forest algorithm, eight genera with mean abundance above 0.1% were selected to construct the classification model with half of the randomly selected cohort. Based on this signature, high diagnostic accuracy in the validation cohort to classify liver cancer types (AUC = 0.989, 0.967, 0.920 for Control, HCC, CCA separately) was achieved. Further analysis showed increased Gram-negative bacteria and elevated inflammatory response markers in CCA group versus HCC group. The correlation analysis between inflammatory response markers and composition of gut microbiome revealed decreased potentially beneficial genus and increased opportunistic pathogens positively correlated with adverse prognostic inflammatory response markers. CONCLUSION: Generally, our study established the gut microbiome-based signature for liver cancer prediction and screening and revealed that gut microbiome characteristic in primary liver cancer was correlated with adverse inflammatory response markers in liver cancer.

The prognostic value of sarcopenia combined with preoperative fibrinogen-albumin ratio in patients with intrahepatic cholangiocarcinoma after surgery: A multicenter, prospective study.

BACKGROUND: To explore the prognostic value of the fibrinogen-albumin ratio (FAR) combined with sarcopenia in intrahepatic cholangiocarcinoma (ICC) patients after surgery and to develop a nomogram for predicting the survival of ICC patients. MATERIALS AND METHODS: In this prospective cohort study, 116 ICC patients who underwent radical surgery were enrolled as the discovery cohort and another independent cohort of 68 ICC patients was used as the validation cohort. Kaplan-Meier method was used to analyze prognosis. The independent predictor of overall survival (OS) and recurrence-free survival (RFS) was evaluated by univariable and multivariable Cox regression analyses, then developing nomograms. The performance of nomograms was evaluated by concordance index (C-index), calibration curve, receiver operating characteristic curve analysis (ROC), and decision curve analysis (DCA). RESULTS: Patients with high FAR had lower OS and RFS. FAR and sarcopenia were effective predictors of OS and RFS. Patients with high FAR and sarcopenia had a poorer prognosis than other patients. OS nomogram was constructed based on age, FAR, and sarcopenia. RFS nomogram was constructed based on FAR and sarcopenia. C-index for the nomograms of OS and RFS was 0.713 and 0.686. Calibration curves revealed great consistency between actual survival and nomogram prediction. The area under ROC curve (AUC) for the nomograms of OS and RFS was 0.796 and 0.791 in the discovery cohort, 0.823 and 0.726 in the validation cohort. The clinical value of nomograms was confirmed by the DCA. CONCLUSIONS: ICC patients with high FAR and sarcopenia had a poor prognosis, the nomograms developed based on these two factors were accurate and clinically useful in ICC patients who underwent radical resection.

Ryk receptors on unmyelinated nerve fibers mediate excitatory synaptic transmission and CCL2 release during neuropathic pain induced by peripheral nerve injury.

Background Neuropathic pain is a major pathology of the central nervous system associated with neuroinflammation. Ryk (receptor-like tyrosine kinase) receptors act as repulsive axon-guidance molecules during development of central nervous system and neural injury. Increasing evidence suggests the potential involvement of Wnt/Ryk (wingless and Int) signaling in the pathogenesis of neuropathic pain. However, its underlying mechanism remains unknown. Results The expression and location of Ryk receptor as well as its ligand Wnt1 were detected by qPCR, Western blot, and immunohistochemistry. We found that Ryk, a specific Wnt receptor, was expressed in IB4+ (Isolectin B4) and CGRP+ (calcitonin gene-related peptide) dorsal root ganglia neurons and their ascending unmyelinated fibers in the dorsal horn of the spinal cord. Ryk was upregulated after spinal nerve ligation surgery. Wnt1 was also increased in activated astrocytes in the dorsal horn after spinal nerve ligation. The presynaptic mechanism of Ryk in regulation of neuropathic pain was determined by electrophysiology in spinal slice. Spinal nerve ligation model was established, and the therapeutic potential of inhibiting Ryk receptor was determined. Spine-specific blocking of the Wnt/Ryk receptor signaling attenuated the spinal nerve ligation-induced mechanical allodynia but not thermal hyperalgesia. Further, it also blocked Ca2+-dependent signals including CaMKII and PKCγ, subsequent release of CCL2 (CCR-like protein) in the dorsal horn. An in vitro study showed that inactivating Ryk receptors with anti-Ryk antibodies or lentiviral Ryk shRNA led to the inactivation of Wnt1 for excitatory synaptic transmission in spinal slices and subsequent decrease in CCL2 expression in the dorsal root ganglia neurons. Conclusion These studies demonstrate the existence of critical crosstalk between astrocytes and unmyelinated fibers, which indicate the presynaptic mechanism of Ryk in cytokine transmission of neuropathic pain and the therapeutic potential for Wnt/Ryk signaling pathway in the treatment of neuropathic pain.

Enhanced RAGE Expression in the Dorsal Root Ganglion May Contribute to Neuropathic Pain Induced by Spinal Nerve Ligation in Rats.

OBJECTIVE: There is some evidence implicating receptor for advanced glycation end products (RAGE) signaling in the pathogenesis of neuropathic pain (NP). The objective was to investigate whether RAGE signaling in the dorsal root ganglion (DRG) might contribute to NP following peripheral nerve injury. DESIGN: Experimental study before and after spinal nerve ligation (SNL) surgery. SETTING: Caged in a controlled environment. SUBJECTS: Male Sprague-Dawley rats. METHODS: A SNL rat model of NP was used. Mechanical hyperalgesia was measured by the paw withdrawal threshold (PWT) to mechanical stimuli (1.4-15 g). Protein expressions of RAGE (immunofluorescence and western blotting), glial fibrillary acidic protein (GFAP; satellite glial cell [SGC] activation marker), IL-1ß (ELISA), TNF-α (ELISA), and NF-κB (western blotting) in the DRG were determined. RAGE signaling was inhibited by intrathecal injection of anti-RAGE antibody. RESULTS: After 7 days, SNL surgery reduced the PWT and upregulated the protein expression of RAGE, GFAP, NF-κB, TNF-α, and IL-1ß. Intrathecal injection of RAGE-neutralizing antibody attenuated the SNL-induced mechanical hyperalgesia, activation of SGCs, and upregulation of NF-κB, TNF-α, and IL-1ß in the DRG. CONCLUSION: RAGE signaling may contribute to the pain hypersensitivity observed in the rat SNL model of NP. Although the precise mechanism remains to be established, NF-κB, TNF-α, and IL-1ß likely play a role, together with the activation of SGCs.

Molecular hydrogen suppresses reactive astrogliosis related to oxidative injury during spinal cord injury in rats.

AIMS: Spinal cord injury (SCI) can induce excessive astrocyte activation. Hydrogen has been deemed as a novel antioxidant. We investigated whether molecular hydrogen could act as an antiastrogliosis agent during SCI and oxidative injury in experimental rats and cultured astrocytes. METHODS: Hydrogen-rich saline (HS, 8 mL/kg, i.p.) was injected every 12 h after SCI in rats. The expression of STAT3, p-STAT3, and glial fibrillary acidic protein (GFAP); the release of IL-1ß, IL-6, and TNF-α; and astrogliosis, along with the BBB score, were evaluated. Culturing astrocytes with hydrogen-rich medium, the intracellular reactive oxygen species (ROS), astrogliosis, and the release of proinflammatory cytokines were assessed after H2O2-induced injury. RESULTS: In the HS group, the expression of STAT3, p-STAT3, and GFAP and the proinflammatory cytokines were decreased in local spinal cord on postoperation day (POD) 3; on PODs 7 and 14, reactive astrogliosis was suppressed, and the locomotor function was also improved. Furthermore, hydrogen-rich medium attenuated the intracellular production of ROS (especially HO•), astrogliosis, and the secretion of proinflammatory cytokines in astrocytes 12 h after H2O2-induced injury. CONCLUSIONS: Molecular hydrogen could suppress reactive astrogliosis after contusive SCI and reduce the release of proinflammatory cytokines produced by active astrocytes related to oxidative injury. Thus, molecular hydrogen is potential to be a neuroprotective agent.

Role of glia in neuropathic pain.

Neuropathic pain is experienced as a result of disease or physical injury affecting the somatosensory system. It can be associated with abnormal sensations (dysesthesia) or evoked by normally nonpainful stimuli. Glia has emerged as key regulators of neuropathic pain perception and potential targets for drug development. Glia are activated upon peripheral nerve damage and secrete a number of proinflammatory factors. This process involves many mechanisms including neuroinflammation, ion channel activation, and ligand-receptor interactions. This review describes recent advances in the understanding of neuropathic pain, including the role of glia and their targeting by current treatment approaches.

Generalized green synthesis and formation mechanism of sponge-like ferrite micro-polyhedra with tunable structure and composition.

This paper describes a green versatile glucose-engineered precipitation-sintering process that allows for the selective and mass preparation of spongy porous ferrite (M = Fe, Zn, Co, Ni, Mn, etc.) micro-polyhedra with tunable morphology, texture, and composition. Some kinetic factors, such as the molar ratio of glucose to metal nitrates, reaction temperature, sintering temperature and time, and type of metal nitrates, can be expediently employed to modulate their aspect ratio, shape, size, composition, and textural properties. In this protocol, glucose functions as a reductant, protecting agent, structure-directing agent, and a sacrificial template to guide the assembly of sheet-like nuclei into polyhedral precursors and the formation of spongy porous structures. Owing to larger EM parameters, multiresonant behavior, and dissipative current, spongy porous Fe3O4 polyhedra exhibited enhanced microwave-absorbing properties. This endows them with important potential applications in magnetic devices, catalysis, sorption, photoluminescence, electromagnetic wave absorbing materials, anode materials, and so on. Meanwhile, this general approach can be extended to synthesize other porous sponges with regular geometric configuration because it is simple, inexpensive, environmentally benign, and suitable for extensive production.

Activating transcription factor 4 modulates BDNF release from microglial cells.

Pathogenic pain is a common sign of many diseases. The mechanism is unclear. Activating transcription factor 4 (ATF4) plays a critical role in cell activation. Brain-derived neurotrophic factor (BDNF) is an important molecule in pathogenic pain. This study aims to investigate the role of ATF4 in inducing BDNF release from microglial cells. In this study, mouse microglial cells were cultured. The levels of BDNF in the culture medium were determined by enzyme-linked immunosorbent assay. Overexpression of ATF4 in microglial cells was performed by gene transfection. The apoptosis of microglial cells was assessed by flow cytometry. The results showed that microglial cells expressed ATF4 and protease-activated receptor-2 (PAR2). BDNF was detectable in the culture medium of microglial cells, which was significantly increased in the ATF4-overexpressing microglial cells. The ATF4-overexpressing microglial cells showed a high frequency of apoptotic cells, which could be inhibited by exposure to the PAR2 agonist tryptase in the culture. The tryptase-treated ATF4-overexpressing microglial cells kept higher secretion of BDNF. We conclude that the activation of ATF4 can increase BDNF release from microglial cells.

Enhanced reactive oxygen species (ROS) yields and antibacterial activity of spongy ZnO/ZnFe2O4 hybrid micro-hexahedra selectively synthesized through a versatile glucose-engineered co-precipitation/annealing process.

In this study, sponge-like ZnO/ZnFe2O4 hybrid micro-hexahedra with diverse textures and compositions were fabricated by the thermal decomposition of hexahedral zinc/iron oxalate precursors, starting from a glucose-engineered co-precipitation process. The resulting ZnO/ZnFe2O4 micro-hexahedra were systematically characterized by X-ray powder diffraction, Fourier-transform infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy (TEM), high-resolution TEM, and surface area analysis. Moreover, modulation in crystal size, composition, and textural properties of spongy ZnO/ZnFe2O4 micro-hexahedra was easily achieved by varying the Zn2+/Fe3+ feeding ratio and the annealing temperature. The antibacterial property of the products was analyzed by testing ATP (adenosine triphosphate) and inhibition zones. Results showed that oxidative stress was the governing mechanism for the antibacterial activity of ZnO/ZnFe2O4 hybrid materials. Moreover, we found that the higher reactive oxygen species yields and the resulting antibacterial activity were exhibited by the ZnO/ZnFe2O4 micro-hexahedra formed at lower sintering temperatures rather than the pure ZnO and Fe2O3. The enhanced antibacterial properties were likely caused by the spongy ZnO/ZnFe2O4 heterostructures, improving the probability of photoinduced charge separation and broadening the visible-light absorption.

Transient early neurotrophin release and delayed inflammatory cytokine release by microglia in response to PAR-2 stimulation.

Activated microglia exerts both beneficial and deleterious effects on neurons, but the signaling mechanism controlling these distinct responses remain unclear. We demonstrated that treatment of microglial cultures with the PAR-2 agonist, 2-Furoyl-LIGRLO-NH2, evoked early transient release of BDNF, while sustained PAR-2 stimulation evoked the delayed release of inflammatory cytokines (IL-1 ß and TNF-α) and nitric oxide. Culture medium harvested during the early phase (at 1 h) of microglial activation induced by 2-Furoyl-LIGRLO-NH2 (microglial conditioned medium, MCM) had no deleterious effects on cultured neurons, while MCM harvested during the late phase (at 72 h) promoted DNA fragmentation and apoptosis as indicated by TUNEL and annexin/PI staining. Blockade of PAR-1 during the early phase of PAR-2 stimulation enhanced BDNF release (by 11%, small but significant) while a PAR-1 agonist added during the late phase (24 h after 2-Furoyl-LIGRLO-NH2 addition) suppressed the release of cytokines and NO. The neuroprotective and neurotoxic effects of activated microglial exhibit distinct temporal profiles that are regulated by PAR-1 and PAR-2 stimulation. It may be possible to facilitate neuronal recovery and repair by appropriately timed stimulation and inhibition of microglial PAR-1 and PAR-2 receptors.