Acetylation of late expression factor 4 is crucial for the transcription and proliferation of Bombyx mori nucleopolyhedrovirus.

Late expression factor 4 (LEF4), RNA polymerase subunit of Bombyx mori nucleopolyhedrovirus (BmNPV), plays an enzymatic role to enhance the capping of pre-mRNA of late and very late genes. Lysine acetylation is a post-translational modification process having many important functions associated with the regulation of a gene expression. Our previous study on lysine acetylome in BmNPV infected BmN cells showed that LEF 4 was acetylated at lysine 76 (K76). However, it is still unclear whether the modification of K76 residue contributes to the modulation of viral gene transcription. To elucidate the role played by acetylation or deacetylation of LEF4 K76 in the transcription of viral genes, we constructed acetylation mimicking and deacetylation mimicking mutant virus, K76Q and K76R, respectively. We then transfected BmN cells with these mutants and analyzed the level of pre-mRNA at different times. The K76R showed a significant decrease in the mRNA transcription level of vp39 and p10 genes at 48 and 72 h post-transfection, while K76Q did not show any significant changes compared with lef4-Wt. We further detected the virus titer of lef4-Wt, K76Q [et] K76R, and it was found that K76R impaired the virus infectivity ability at 72 and 96 h, while K76Q did not affect the virus infectivity. Moreover, the yeast two hybrid technique (Y2H) showed that both mutants (K76Q [et] K76R) affected the association of LEF 4 with the P47 protein. Taken together, these results indicated that acetylation modification of K76 is important for the proper transcription of late and very late genes, and the effectiveness of viral infection. Keywords: BmNPV lef4 gene; lysine acetylation, late genes transcription; BmNPV p47 gene; infectivity.

Acetylation of nucleopolyhedrovirus P35 is crucial for its anti-apoptotic activity in silkworm, Bombyx mori.

Apoptosis is a characteristic feature of a nucleopolyhedrovirus infected insect cells. This defensive strategy of the insect cells also affects the viral infectivity. On the contrary, the P35 baculovirus apoptosis inhibitor impedes the insect cell apoptosis induced by viral infection. Our previous investigation of the Bombyx mori nucleopolyhedrovirus (BmNPV) acetylome showed that 3 lysine (K) (70, 127 and 256) sites of P35 were acetylated during infection. How these modifications affect the interaction between the insect cells and BmNPV is still unknown. In order to explore the underlying mechanism of P35 lysine acetylation, mutants with glutamine or arginine substitution were constructed to mimic the acetylated (Q) and deacetylated (R) state. ELISA and DNA fragmentation assay were used to ascertain the acetylation effects on apoptosis. Subsequently the results showed that acetylation of K70 upregulated the anti-apoptotic activity, thereby preventing apoptosis induced by insect cells. Caspase 1 activity assay further confirmed that, acetylated K70 exhibited a strong anti-apoptotic activity in cell lines infected with BmNPV. Intriguingly, an examination with the yeast 2 hybrid (Y2H) assay revealed an interaction with the silkworm caspase 1. Taken together, we demonstrated that acetylation of P35 is crucial for an interaction with caspase 1 and the upregulation of anti-apoptotic activity. Keywords: Bombyx mori; BmNPV; P35; acetylation; anti-apoptotic; caspase 1.

Wnt/ß-catenin signaling regulates brain-derived neurotrophic factor release from spinal microglia to mediate HIV1 gp120-induced neuropathic pain.

HIV-associated neuropathic pain (HNP) is a common complication for AIDS patients. The pathological mechanism governing HNP has not been elucidated, and HNP has no effective analgesic treatment. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophic factor family related to the plasticity of the central nervous system. BDNF dysregulation is involved in many neurological diseases, including neuropathic pain. However, to the best of our knowledge, the role and mechanism of BDNF in HNP have not been elucidated. In this study, we explored this condition in an HNP mouse model induced by intrathecal injection of gp120. We found that Wnt3a and ß-catenin expression levels increased in the spinal cord of HNP mice, consequently regulating the expression of BDNF and affecting hypersensitivity. In addition, the blockade of Wing-Int/ß-catenin signaling, BDNF/TrkB or the BDNF/p75NTR pathway alleviated mechanical allodynia. BDNF immunoreactivity was colocalized with spinal microglial cells, which were activated in HNP mice. Inhibition of spinal microglial cell activation by minocycline relieved mechanical allodynia in HNP mice. This study helped to elucidate the role of the Wing-Int/ß-catenin/BDNF signaling axis in HNP and may establish a foundation for further research investigating the Wing-Int/ß-catenin/BDNF signaling axis as a target for HNP treatment.

Acetylation of BmAtg8 inhibits starvation-induced autophagy initiation.

Silkworm (Bombyx mori) is not only a model organism for scientific studies, but also a commercial insect for agricultural production. BmAtg8 (a B. mori homolog of yeast Atg8) plays crucial roles in macroautophagy (hereafter referred to autophagy), which is helpful for silkworm metamorphosis. Relevant mechanism about BmAtg8 currently remains ambiguous. Based on our previous acetylome of B. mori after BmNPV infection, we focused on that acetylation of BmAtg8 K13 was changed upon virus challenge. Subsequently, anti-BmAtg8 antibody was generated, and EBSS-induced BmN cellular autophagy model was established. Next, by constructing acetylation-mimic K13Q or deacetylation-mimic K13R mutant BmAtg8, we further examined that K13 of BmAtg8 was acetylated after BmNPV infection and chose 3 h as an appropriate point after EBSS treatment for autophagy initiation. Furthermore, acetylation of BmAtg8 K13 significantly reduced BmAtg8-PE formation in the presence of EBSS, thereby interfering autophagy initiation. Interestingly, acetylated K13 of BmAtg8 contributed to weaken interaction with Atg7, which may influence BmAtg8-PE conjugation. Eventually, acetylation of BmAtg8 K13 is critical for attenuating cell rescue through impaired autophagy initiation. Taken together, our data support an acetylated molecular function for BmAtg8 during starvation-induced autophagy, and provide insights into the modulating mechanisms that potentially reveal the LC3 (a mammalian homolog of Atg8) function in mammal.

KAN0438757, a novel PFKFB3 inhibitor, prevent the progression of severe acute pancreatitis via the Nrf2/HO-1 pathway in infiltrated macrophage.

Acute pancreatitis (AP) is a non-infectious pancreatic enzyme-induced disorder, a life-threatening inflammatory condition that can cause multi-organ dysfunction, characterized by high morbidity and mortality. Several therapies have been employed to target this disorder; however, few happen to be effectively employable even in the early phase. PFKFB3(6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-3) is a critical regulator of glycolysis and is upregulated under inflammatory, mitogenic, and hypoxia conditions. Essential information on the targeting of the inflammatory pathway will present the termination of the disorder and recovery. Herein we investigated the protective function of KAN0438757, a potent inhibitor of PFKFB3, and its mechanism of impeding AP induced in mice. KAN0438757 was confirmed to activate the Nrf2/HO-1 inflammatory signaling pathways in response to caerulein induced acute pancreatitis (CAE-AP) and fatty acid ethyl ester induced severe acute pancreatitis (FAEE-SAP). Additionally, KAN0438757 alleviated the inflammatory process in infiltrated macrophage via the Nrf2/HO-1 inflammatory signaling pathway and demonstrated a significant effect on the growth of mice with induced AP. And more importantly, KAN0438757 displayed negligible toxicity in vivo. Taken together our data suggest KAN0438757 directly suppresses the inflammatory role of PFKFB3 and induces a protective role via the Nrf2/HO-1 pathway, which could prove as an excellent therapeutic platform for SAP amelioration.

The CuO and AgO co-modified ZnO nanocomposites for promoting wound healing in Staphylococcus aureus infection.

Bacterial has become a common pathogen of humans owing to their drug-resistant effects and evasion of the host immune system, with their ability to form biofilm and induce severe infections, a condition which has become a primary public health concern globally. Herein, we report on CuO@AgO/ZnO NPs antibacterial activity enhanced by near-infrared (NIR) light which was effective in the elimination of Staphylococcus aureus and the Pseudomonas aeruginosa. The CuO@AgO/ZnO NPs under NIR significantly eradicated S. aureus and its biofilm and P. aeruginosa in vitro, and subsequently exhibited such phenomenon in vivo, eliminating bacteria and healing wound. This demonstrated the combined intrinsic antibacterial potency of the Cu and Ag components of the CuO@AgO/ZnO NPs was enhanced tremendously to achieve such outcomes in vitro and in vivo. Considering the above advantages and facile preparation methods, the CuO@AgO/ZnO NPs synthesized in this work may prove as an important antibacterial agent in bacterial-related infection therapeutics and for biomedical-related purposes.

Polydopamine, harness of the antibacterial potentials-A review.

Antibiotic resistance is one of the major causes of morbidity and mortality, triggered by the adhesion of microbes and to some extent the formation of biofilms. This condition has been quite challenging in the health and industrial sector. Conditions and processes required to foil these infectious and resistance are of much concern. The synthesis of PDA material, inspired by the Mytilus edulis foot protein (MEFP)5 possesses unique characteristics that allow for, adhesion, photothermal therapy, synergistic effects with other materials, biocompatibility process, etc. Therefore, their usage holds great potential for dealing with both the infectious nature and the antibiotic resistance processes. Hence, this review provides an overview of the mechanism involved in accomplishing and eradicating bacteria, the recently harnessed antibacterial effect of the PDA through other properties they possess, a way forward in tapping the benefit embedded in the PDA, and the future perspective.

Multifunctional phototheranostic agent ZnO@Ag for anti-infection through photothermal/photodynamic therapy.

To overcome the limitations of traditional therapeutics, nanotechnology offers a synergistic therapeutic approach for the treatment of bacterial infection and biofilms that has attracted attention. Herein, we report on a ZnO@Ag nanocomposite with good biocompatibility synthesized by doping ZnO NPs with silver nanoparticles (Ag NPs). ZnO@Ag nanocomposites were synthesized with varying ratios of Ag NPs (0.5%, 2%, 8%). Under the same experimental conditions, ZnO@8%Ag exhibited outstanding properties compared to the other nanocomposites and the pristine ZnO NPs. ZnO@8%Ag demonstrated excellent photothermal and photodynamic properties. Also, ZnO@8%Ag demonstrated over 99% inhibition of Staphylococcus aureus (S. aureus) under photothermal therapy (PTT) or photodynamics therapy (PDT) as a result of the excessive generation of reactive oxygen species (ROS) by the Ag+ released, while the pristine ZnO showed an insignificant inhibition rate compared to the PBS group (control). Furthermore, ZnO@8%Ag completely disrupted S. aureus biofilm under a combined PTT/PDT treatment, a synergetic trimodal therapy, although the molecular mechanism of biofilm inhibition remains unclear. Hence, the excellent photothermal, photodynamic, biocompatibility, and bactericidal properties of ZnO@8%Ag present it as an appropriate platform for bacterial and biofilm treatment or other biomedically related applications.

Genomic Variability and Post-translational Protein Processing Enhance the Immune Evasion of Mycoplasma hyopneumoniae and Its Interaction With the Porcine Immune System.

Mycoplasma hyopneumoniae (M. hyopneumoniae, Mhp) is a geographically widespread and economically devastating pathogen that colonizes ciliated epithelium; the infection of Mhp can damnify the mucociliary functions as well as leading to Mycoplasma pneumonia of swine (MPS). MPS is a chronic respiratory infectious disease with high infectivity, and the mortality can be increased by secondary infections as the host immunity gets down-regulated during Mhp infection. The host immune responses are regarded as the main driving force for the disease development, while MPS is prone to attack repeatedly in farms even with vaccination or other treatments. As one of the smallest microorganisms with limited genome scale and metabolic pathways, Mhp can use several mechanisms to achieve immune evasion effect and derive enough nutrients from its host, indicating that there is a strong interaction between Mhp and porcine organism. In this review, we summarized the immune evasion mechanisms from genomic variability and post-translational protein processing. Besides, Mhp can induce the immune cells apoptosis by reactive oxygen species production, excessive nitric oxide (NO) release and caspase activation, and stimulate the release of cytokines to regulate inflammation. This article seeks to provide some new points to reveal the complicated interaction between the pathogen and host immune system with Mhp as a typical example, further providing some new strategies for the vaccine development against Mhp infection.

HN1L is essential for cell growth and survival during nucleopolyhedrovirus infection in silkworm, Bombyx mori.

Hematological and neurological expressed 1-like (HN1L) protein is an evolutionarily conserved protein that plays an important role in embryonic development. It has been reported that HN1L is involved in the process of cell growth and cancer formation and that cell cycle arrest occurs during suppression of HN1L expression. Previous studies have demonstrated that the expression levels of the Bombyx mori HN1L protein were significantly downregulated in Bombyx mori Nucleopolyhedrovirus (BmNPV) infected silkworm cells. Transient transfections were performed with plasmids for pIEX-1-HN1L expression in Bombyx mori ovarian cells (BmN) in order to explore the effect of the HN1L protein on the growth of silkworm cells and its regulatory role in the process of viral infection. Cellular localization analysis revealed that HN1L was localized in the cytoplasm and that its upregulation could significantly enhance cellular activity. Furthermore, HN1L could promote G1/S phase conversion, thereby contributing to cell proliferation. Upon infection of BmN cells with BmNPV, the induction of apoptosis increased, although HN1L overexpression could inhibit DNA fragmentation, suggesting that the HN1L protein could inhibit cell apoptosis induced by viral invasion. In addition, Western blotting indicated that the HN1L protein inhibited the activation of caspase-9 zymogen and the expression of Bax protein, although it promoted Bcl-2 expression. Flow cytometry analysis further confirmed that overexpression of HN1L significantly inhibited apoptosis induced by BmNPV infection. Consequently, we demonstrated that BmN HN1L is a protein with multiple functions, which enhanced cell activity, regulated the cell cycle and induced an anti-apoptotic response by BmNPV infection.