SENP3 attenuates foam cell formation by deSUMOylating NLRP3 in macrophages stimulated with ox-LDL.

SUMO-specific protease 3 (SENP3) participates in the removal of SUMOylation and maintains the balance of the SUMO system, which ensures normal functioning of substrates and cellular activities. In the present study, we found that SENP3 expression was significantly reduced in ox-LDL-stimulated macrophages. SENP3 overexpression suppressed and SENP3 knockdown promoted macrophage foam cell formation. Moreover, SENP3 inhibited cholesterol uptake, CD36 expression, and NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome activation in ox-LDL-stimulated macrophages. Ox-LDL-stimulated NLRP3 SUMOylation was reduced by SENP3. Blocking NLRP3 SUMOylation inhibited foam cell formation and NLRP3 inflammasome activation. Thus, this study revealed that SENP3 inhibits macrophage foam cell formation by deSUMOylating NLRP3 and regulating NLRP3 inflammasome activation, which may provide a potentially innovative approach to treatment of atherosclerosis.

The SUMOylation of Human Cytomegalovirus Capsid Assembly Protein Precursor (UL80.5) Affects Its Interaction with Major Capsid Protein (UL86) and Viral Replication.

Human Cytomegalovirus Capsid Assembly Protein Precursor (pAP, UL80.5) plays a key role in capsid assembly by forming an internal protein scaffold with Major Capsid Protein (MCP, UL86) and other capsid subunits. In this study, we revealed UL80.5 as a novel SUMOylated viral protein. We confirmed that UL80.5 interacted with the SUMO E2 ligase UBC9 (58-93aa) and could be covalently modified by SUMO1/SUMO2/SUMO3 proteins. 371Lysine located within a ψKxE consensus motif on UL80.5 carboxy-terminal was the major SUMOylation site. Interestingly, the SUMOylation of UL80.5 restrained its interaction with UL86 but had no effects on translocating UL86 into the nucleus. Furthermore, we showed that the removal of the 371lysine SUMOylation site of UL80.5 inhibited viral replication. In conclusion, our data demonstrates that SUMOylation plays an important role in regulating UL80.5 functions and viral replication.

Cortex Mori Radicis Attenuates Streptozotocin-induced Diabetic Renal Injury in Mice via Regulation of Transient Receptor Potential Canonical Channel 6.

OBJECTIVE: Cortex Mori Radicis (CMR) has been reported to possess antipyretic, anticonvulsant, anti-allergic, anti-inflammatory, and anti-diabetic effects. In this study, we aimed to investigate the effect of CMR on streptozotocin (STZ)-induced diabetic renal injury in mice and explore the underlying mechanism. METHODS: Mice were gavaged with different doses of CMR for continuous 7 days. Then, STZ (50 mg/kg) was applied to induce renal injury associated with type 1 diabetes. Firstly, blood glucose levels and metabolic parameters were evaluated, including weight, food intake, and excrement. HE and PAS staining were performed to examine renal histological changes. Renal inflammation, fibrosis, and oxidative stress were assayed by real-time PCR and ELISA, separately. Additionally, podocyte- related markers, such as nephrin and wilms' tumor-1 (WT-1), were detected by immunohistochemical staining and Western blot separately. Lastly, expression of transient receptor potential canonical channel 6 (TRPC6) and activation of MAPK signaling pathways were assayed. RESULTS: CMR pretreatment significantly lowered the blood glucose levels, suppressed renal inflammation, fibrosis, and oxidative stress, and relieved renal pathological injury, accompanying the inhibition of nephrin and WT-1 expression in STZ-induced diabetic mice. Moreover, CMR decreased the expression of TRPC6 and suppressed the phosphorylation of ERK, but not P38 MAPK and JNK. Notably, the application of hyperforin, a specific activator of TRPC6, significantly abrogated the hypoglycemic effect of CMR and reversed the suppression of CMR on TRPC6 expression and ERK activation in the diabetic mice. CONCLUSION: Our findings indicated that CMR attenuated early renal injury in STZ-induced diabetic mice by inhibiting ERK signaling via regulation of TRPC6, suggesting that CMR can be considered as a promising candidate for the management of diabetes-related renal complications.

Electroacupuncture Pretreatment Attenuates Cerebral Ischemia-Reperfusion Injury in Rats Through Transient Receptor Potential Vanilloid 1-Mediated Anti-apoptosis via Inhibiting NF-κB Signaling Pathway.

Our previous study showed that electroacupuncture (EA) pretreatment elicited protective effect on cerebral ischemia-reperfusion injury (CIRI) in rats, at least partly, which was associated with transient receptor potential vanilloid 1 (TRPV1)-regulated anti-oxidant stress and anti-inflammation. In this study, we further investigated the possible contribution of TRPV1-mediated anti-apoptosis in EA pretreatment-evoked neuroprotection in CIRI. After EA pretreatment at Baihui (GV20), bilateral Shenshu (BL23) and Sanyinjiao (SP6) acupoints, transient focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion for 6 h in rats. Then, infarct volume, nerve cell injury, neuronal apoptosis, NF-κB signaling activation, and expression of TRPV1 were evaluated by TTC staining, Hematoxylin-Eosin staining, transmission electron microscopy, immunochemistry, immunofluorescence, and Western blot, respectively. The presented data showed that EA pretreatment significantly reduced infarct volume, relieved nerve cell injury, decreased the expression of pro-apoptotic proteins Bax and cleaved caspase-3, increased the level of anti-apoptotic protein Bcl-2, inhibited NF-κB (p65) transcriptional activity, and curbed TRPV1 expression in MCAO rats. By contrast, enhancement of TRPV1 expression accompanying capsaicin application, the specific TRPV1 agonists, markedly accelerated nerve cell damage, aggravated neuronal apoptosis, prompted nuclear translocation of NF-κB (p65), resulting in the reversion of EA pretreatment-evoked neuroprotective effect in MCAO rats. Thus, we conclude that EA pretreatment-induced downregulation of neuronal TRPV1 expression plays an anti-apoptosis role through inhibiting NF-κB signaling pathway, thereby protecting MCAO rats from cerebral ischemia-reperfusion injury.

The mechanism of Bai He Gu Jin Tang against non-small cell lung cancer revealed by network pharmacology and molecular docking.

BACKGROUND: Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related burden and deaths, thus effective treatment strategies with lower side effects for NSCLC are urgently needed. To systematically analyze the mechanism of Bai He Gu Jin Tang (BHGJT) against NSCLC by network pharmacology and molecular docking. METHODS: The active compounds of BHGJT were obtained by searching the Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine and Encyclopaedia of Traditional Chinese Medicine. Search tool for interactions of chemicals was used for acquiring the targets of BHGJT. The component-target network was mapped by Cytoscape. NSCLC-related genes were obtained by searching Genecards, DrugBank and Therapeutic Target Database. The protein-protein interaction network of intersection targets was established based on Search Tool for Recurring Instances of Neighboring Genes (STRING), and further, the therapeutic core targets were selected by topological parameters. The hub targets were transmitted to Database for Annotation, Visualization and Integrated Discovery for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Finally, AutoDock Vina and MglTools were employed for molecular docking validation. RESULTS: Two hundred fifty-six compounds and 237 putative targets of BHGJT-related active compounds as well as 1721potential targets of NSCLC were retrieved. Network analysis showed that 8 active compounds of BHGJT including kaempferol, quercetin, luteolin, isorhamnetin, beta-sitosterol, stigmasterol, mairin and liquiritigenin as well as 15 hub targets such as AKR1B10 and AKR1C2 contribute to the treatment of BHGJT against NSCLC. GO functional enrichment analysis shows that BHGJT could regulate many biological processes, such as apoptotic process. Three modules of the endocrine related pathways including the inflammation, hypoxia related pathways as well as the other cancer related pathways based on Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis might explain the biological mechanisms of BHGJT in treating BHGJT. The results of molecular docking verified that AKR1B10 and AKR1C2 had the strongest binding activity with the 8 key compounds of NSCLC. CONCLUSION: Our study reveals the mechanism of BHGJT in treating NSCLC involving multiple components, multiple targets and multiple pathways. The present study laid an initial foundation for the subsequent research and clinical application of BHGJT and its active compounds against NSCLC.

SUMO1 SUMOylates and SENP3 deSUMOylates NLRP3 to orchestrate the inflammasome activation.

The NLRP3 inflammasome regulates innate immune and inflammatory responses by promoting caspase1-dependent induction of pro-inflammatory cytokines. However, aberrant inflammasome activation causes diverse diseases, and thus inflammasome activity must be tightly controlled. Here, we reveal a molecular mechanism underlying the regulation of NLRP3 inflammasome. NLRP3 interacts with SUMO-conjugating enzyme (UBC9), which subsequently promotes small ubiquitin-like modifier 1 (SUMO1) to catalyze NLRP3 SUMOylation at residue Lys204. SUMO1-catalyzed SUMOylation of NLRP3 facilitates ASC oligomerization, inflammasome activation, and interleukin-1ß secretion. Moreover, this study also reveals that SUMO-specific protease 3 (SENP3) is required for the deSUMOylation of NLRP3. Interestingly, SENP3 deSUMOylates NLRP3 to attenuate ASC recruitment and speck formation, the NLRP3 inflammasome activation, as well as IL-1ß cleavage and secretion. In conclusion, we reveal that SUMO1-catalyzed SUMOylation and SENP3-mediated deSUMOylation of NLRP3 orchestrate the inflammasome activation.

Inhibition of herpes simplex virus 1 gene expression and replication by RNase P-associated external guide sequences.

An external guide sequence (EGS) is a RNA sequence which can interact with a target mRNA to form a tertiary structure like a pre-tRNA and recruit intracellular ribonuclease P (RNase P), a tRNA processing enzyme, to degrade target mRNA. Previously, an in vitro selection procedure has been used by us to engineer new EGSs that are more robust in inducing human RNase P to cleave their targeted mRNAs. In this study, we constructed EGSs from a variant to target the mRNA encoding herpes simplex virus 1 (HSV-1) major transcription regulator ICP4, which is essential for the expression of viral early and late genes and viral growth. The EGS variant induced human RNase P cleavage of ICP4 mRNA sequence 60 times better than the EGS generated from a natural pre-tRNA. A decrease of about 97% and 75% in the level of ICP4 gene expression and an inhibition of about 7,000- and 500-fold in viral growth were observed in HSV infected cells expressing the variant and the pre-tRNA-derived EGS, respectively. This study shows that engineered EGSs can inhibit HSV-1 gene expression and viral growth. Furthermore, these results demonstrate the potential for engineered EGS RNAs to be developed and used as anti-HSV therapeutics.