Manganese Dioxide-Based Nanomaterials for Medical Applications.

Manganese dioxide (MnO2) nanomaterials can react with trace hydrogen peroxide (H2O2) to produce paramagnetic manganese (Mn2+) and oxygen (O2), which can be used for magnetic resonance imaging and alleviate the hypoxic environment of tumors, respectively. MnO2 nanomaterials also can oxidize glutathione (GSH) to produce oxidized glutathione (GSSG) to break the balance of intracellular redox reactions. As a consequence of the sensitivity of the tumor microenvironment to MnO2-based nanomaterials, these materials can be used as multifunctional diagnostic and therapeutic platforms for tumor imaging and treatment. Importantly, when MnO2 nanomaterials are implanted along with other therapeutics, synergetic tumor therapy can be achieved. In addition to tumor treatment, MnO2-based nanomaterials display promising prospects for tissue repair, organ protection, and the treatment of other diseases. Herein, we provide a thorough review of recent progress in the use of MnO2-based nanomaterials for biomedical applications, which may be helpful for the design and clinical translation of next-generation MnO2 nanomaterials.

Targeted delivery of Fc-fused PD-L1 for effective management of acute and chronic colitis.

The PD-1/PD-L1 pathway in mucosal immunity is currently actively explored and considered as a target for inflammatory bowel disease (IBD) treatment. However, systemic PD-L1 administration may cause unpredictable adverse effects due to immunosuppression. Here we show that reactive oxygen species (ROS)-responsive nanoparticles enhance the efficacy and safety of PD-L1 in a mouse colitis model. The nanoparticles control the accumulation and release of PD-L1 fused to Fc (PD-L1-Fc) at inflammatory sites in the colon. The nanotherapeutics shows superiority in alleviating inflammatory symptoms over systemic PD-L1-Fc administration and mitigates the adverse effects of PD-L1-Fc administration. The nanoparticles-formulated PD-L1-Fc affects production of proinflammatory and anti-inflammatory cytokines, attenuates the infiltration of macrophages, neutrophils, and dendritic cells, increases the frequencies of Treg, Th1 and Tfh cells, reshapes the gut microbiota composition; and increases short-chain fatty acid production. In summary, PD-L1-Fc-decorated nanoparticles may provide an effective and safe strategy for the targeted treatment of IBD.

Nanotherapeutics for prostate cancer treatment: A comprehensive review.

Prostate cancer (PCa) is the most prevalent solid organ malignancy and seriously affects male health. The adverse effects of prostate cancer therapeutics can cause secondary damage to patients. Nanotherapeutics, which have special targeting abilities and controlled therapeutic release profiles, may serve as alternative agents for PCa treatment. At present, many nanotherapeutics have been developed to treat PCa and have shown better treatment effects in animals than traditional therapeutics. Although PCa nanotherapeutics are highly attractive, few successful cases have been reported in clinical practice. To help researchers design valuable nanotherapeutics for PCa treatment and avoid useless efforts, herein, we first reviewed the strategies and challenges involved in prostate cancer treatment. Subsequently, we presented a comprehensive review of nanotherapeutics for PCa treatment, including their targeting methods, controlled release strategies, therapeutic approaches and mechanisms. Finally, we proposed the future prospects of nanotherapeutics for PCa treatment.

Roxithromycin and rhEGF Co-loaded Reactive Oxygen Species Responsive Nanoparticles for Accelerating Wound Healing.

BACKGROUND: Bacterial infection can delay wound healing and is therefore a major threat to public health. Although various strategies have been developed to treat bacterial infections, antibiotics remain the best option to combat infections. The inclusion of growth factors in the treatment approach can also accelerate wound healing. The co-delivery of antibiotics and growth factors for the combined treatment of wounds needs further investigation. OBJECTIVE: Here we aimed to develop antibiotic and growth factor co-loaded nanoparticles (NPs) to treat Staphylococcus aureus-infected wounds. METHODS: By using our previously prepared reactive oxygen species-responsive material (Oxi-αCD), roxithromycin (ROX)-loaded NPs (ROX/Oxi-αCD NPs) and recombinant human epidermal growth factor (rhEGF)/ROX co-loaded NPs (rhEGF/ROX/Oxi-αCD NPs) were successfully fabricated. The in vivo efficacy of this prepared nanomedicine was evaluated in mice with S. aureus-infected wounds. RESULTS: ROX/Oxi-αCD NPs and rhEGF/ROX/Oxi-αCD NPs had a spherical structure and their particle sizes were 164 ± 5 nm and 190 ± 8 nm, respectively. The in vitro antibacterial experiments showed that ROX/Oxi-αCD NPs had a lower minimum inhibitory concentration than ROX. The in vivo animal experiments demonstrated that rhEGF/ROX/Oxi-αCD NPs could significantly accelerate the healing of S. aureus-infected wounds as compared to the free ROX drug and ROX/Oxi-αCD NPs (P < 0.05). CONCLUSION: ROX and rhEGF co-loaded NPs can effectively eliminate bacteria in wounds and accelerate wound healing. Our present work could provide a new strategy to combat bacteria-infected wounds.

Selective modulation of alkali metal ions on acetylcholinesterase.

Acetylcholinesterase (AChE) is an important hydrolase in cholinergic synapses and a candidate target in the treatment of Alzheimer's disease. The lithium treatment widely used in neurological disorders can alter the AChE activity, yet the underlying mechanism of how the ion species regulate the enzymatic activity remains unclear. In this work, we performed combined quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) simulations and well-tempered metadynamics to understand the modulation of human AChE (hAChE) activity using three alkali metal ions (Li+, Na+, and K+) in different concentrations. Our simulations show that the binding affinity and catalytic activity are affected by different ion species through allosteric ion coordination geometries on the hAChE complex and distant electrostatic screening effect. A Li+ cluster involving D330, E393, and D397 residues and three Li+ ions was found to be highly conserved and can be critical to the enzyme activity. Binding energy calculations indicate that the electrostatic screening from allosterically bound cations can affect the key residues at the catalytic site and active-site gorge, including E199. Furthermore, an increase in ion concentration can lead to lower reactivity, especially for Li+ ions, which exhibit more cation-hAChE contacts than Na+ and K+. The selective ion binding and their preferred modulation on hAChE are highly related to ion species. This work provides a molecular perspective on selective modulation by different ion species of the enzyme catalytic processes.

Cyclosporine A-Encapsulated pH/ROS Dual-Responsive Nanoformulations for the Targeted Treatment of Colitis in Mice.

Inflammatory bowel disease (IBD) is a frequently occurring disease that seriously influences the patient's quality of life. To decrease adverse effects and improve efficacy of therapeutics, nanomedicines have been widely used to treat IBD. However, how to thoroughly release payloads under an inflammatory microenvironment and synergistic therapy of IBD need to be further investigated. To address this issue, cyclosporine A (CsA)-loaded, folic acid (FA)-modified, pH and reactive oxygen species (ROS) dual-responsive nanoparticles (FA-CsA NPs) were fabricated using pH/ROS-responsive material as carrier. The prepared FA-CsA NPs had spherical shape and uniform size distribution and could smartly release their payloads under acid and/or ROS microenvironment. In vitro experiments demonstrated that FA-CsA NPs can be effectively internalized by activated macrophages, and the internalized NPs could down-regulate the expression of proinflammatory cytokines compared to free drug or nontargeted NPs. In vivo experiments verified that FA-CsA NPs significantly accumulated at inflammatory colon tissues and the accumulated NPs obviously improved the symptoms of colitis in mice without obvious adverse effects. In conclusion, our results provided a candidate for the targeted treatment of IBD.

Docetaxel-loaded pH/ROS dual-responsive nanoparticles with self-supplied ROS for inhibiting metastasis and enhancing immunotherapy of breast cancer.

BACKGROUND: Although stimuli-responsive nanoplatforms were developed to deliver immunogenic cell death (ICD) inducers to enhance cancer immunotherapy, the complete release of ICD inducers into the tumor microenvironment (TME) was limited by the inadequate supplementation of endogenous stimulus (e.g., reactive oxygen species (ROS)). To address this issue, we synthesized a self-responsive nanomaterial with self-supplied ROS, which mainly consists of a ROS responsive moiety HPAP and cinnamaldehyde (CA) as the ROS-generating agent. The endogenous ROS can accelerate the degradation of HPAP in materials to release docetaxel (DTX, an ICD inducer). In intracellular acidic environment, the pH-sensitive acetal was cleaved to release CA. The released CA in turn induces the generation of more ROS through mitochondrial damage, resulting in amplified DTX release. Using this self-cycling and self-responsive nanomaterial as a carrier, DTX-loaded pH/ROS dual-responsive nanoparticles (DTX/FA-CA-Oxi-αCD NPs) were fabricated and evaluated in vitro and in vivo. RESULTS: In vitro experiments validated that the NPs could be effectively internalized by FA-overexpressed cells and completely release DTX in acidic and ROS microenvironments to induce ICD effect. These NPs significantly blocked 4T1 cell migration and decreased cell invasion. In vivo experiments demonstrated that the tumor-targeted NPs significantly inhibited tumor growth and blocked tumor metastasis. More importantly, these NPs significantly improved immunotherapy through triggering effector T-cell activation and relieving the immunosuppressive state of the TME. CONCLUSIONS: Our results demonstrated that DTX/FA-CA-Oxi-αCD NPs displayed great potential in preventing tumor metastasis, inhibiting tumor growth, and improving the efficacy of anti-PD-1antibody.

A novel skeleton alkaloid from Portulaca oleracea L. and its bioactivities.

A novel skeleton alkaloid was obtained from Portulaca oleracea L., which was identified as 10,11-dihydroxybenzo[5',6'] pentaleno[1',2':3,4]pyrrolo[2,1-b]oxazol-7(11bH)-one, named oleracone M, and its structure was determined using UHPLC-ESI-QTOF/MS, 1D NMR and 2D NMR spectroscopy, and circular dichroism. Then the bioactivities of the compound were investigated including the anti-inflammatory, anti-acetylcholinesterase and antioxidant activities. The results showed that the novel skeleton alkaloid exhibited the potent effect on inhibiting the secretion of IL-1ß at 10 µM, anticholinesterase activity with IC50 value of 49.58 µM, and antioxidant activity with IC50 value of 66.43 µM.

Glucocorticoid nanoformulations relieve chronic pelvic pain syndrome and may alleviate depression in mice.

BACKGROUND: Chronic pelvic pain syndrome (CPPS) is a typical symptom of chronic prostatitis (CP) in males that may cause abnormal urination, sexual dysfunction, or depression and significantly affect the quality of life of the patient. Currently, there is no effective treatment for CPPS due to its recurrence and intractability. For synergistic CPPS therapy, we developed pH/reactive oxygen species (ROS) dual-responsive dexamethasone (Dex) nanoformulations using a ROS-responsive moiety and phytochemical modified α-cyclodextrin (α-CD) as the carrier. RESULTS: Dex release from the nanoformulations can be controlled in acidic and/or ROS-rich microenvironments. The fabricated Dex nanoformulations can also be efficiently internalized by lipopolysaccharide (LPS)-stimulated macrophages, prostatic epithelial cells, and stromal cells. Moreover, the levels of proinflammatory factors (e.g., TNF-α, IL-1ß, and IL-17 A) in these cells were significantly decreased by Dex nanoformulations treatment through the release of Dex, phytochemical and elimination of ROS. In vivo experiments demonstrated notable accumulation of the Dex nanoformulations in prostate tissue to alleviate the symptoms of CPPS through the downregulation of proinflammatory factors. Interestingly, depression in mice may be relieved due to alleviation of their pelvic pain. CONCLUSION: We fabricated Dex nanoformulations for the effective management of CPPS and alleviation of depression in mice.

RNA Folding Based on 5 Beads Model and Multiscale Simulation.

RNA folding prediction is very meaningful and challenging. The molecular dynamics simulation (MDS) of all atoms (AA) is limited to the folding of small RNA molecules. At present, most of the practical models are coarse grained (CG) model, and the coarse-grained force field (CGFF) parameters usually depend on known RNA structures. However, the limitation of the CGFF is obvious that it is difficult to study the modified RNA. Based on the 3 beads model (AIMS_RNA_B3), we proposed the AIMS_RNA_B5 model with three beads representing a base and two beads representing the main chain (sugar group and phosphate group). We first run the all atom molecular dynamic simulation (AAMDS), and fit the CGFF parameter with the AA trajectory. Then perform the coarse-grained molecular dynamic simulation (CGMDS). AAMDS is the foundation of CGMDS. CGMDS is mainly to carry out the conformation sampling based on the current AAMDS state and improve the folding speed. We simulated the folding of three RNAs, which belong to hairpin, pseudoknot and tRNA respectively. Compared to the AIMS_RNA_B3 model, the AIMS_RNA_B5 model is more reasonable and performs better.

Glucocorticoid-loaded pH/ROS dual-responsive nanoparticles alleviate joint destruction by downregulating the NF-κB signaling pathway.

Rheumatoid arthritis (RA) is an autoimmune disease causing severe symptoms that are difficult to treat. Nano-drug delivery system is recognized as a promising strategy for management of RA. However, how to thoroughly release payloads from nanoformulations and synergistic therapy of RA needs to be further investigated. To address this issue, a pH and reactive oxygen species (ROS) dual-responsive, methylprednisolone (MPS)-loaded and arginine-glycine-aspartic acid (RGD)-modified nanoparticles (NPs) was fabricated using phytochemical and ROS-responsive moiety co-modified α-cyclodextrin (α-CD) as a carrier. In vitro and in vivo experiments verified that the pH/ROS dual-responsive nanomedicine could be efficiently internalized by activated macrophages and synovial cells, and the released MPS could promote transformation of M1-type macrophages into M2 phenotype, thereby down-regulating pro-inflammatory cytokines. In vivo experiments demonstrated that the pH/ROS dual-responsive nanomedicine was remarkably accumulated in the inflamed joints of mice with collagen-induced arthritis (CIA). The accumulated nanomedicine could obviously relieve joint swelling and cartilage destruction without obvious adverse effects. Importantly, the expression of interleukin-6 and tumor necrosis factor-α in the joints of CIA mice were significantly inhibited by the pH/ROS dual-responsive nanomedicine in comparison with free drug and non-targeted counterparts. In addition, the expression of the NF-κB signaling pathway molecule P65 was also significantly decreased by nanomedicine-treatment. Our results reveal that MPS-loaded pH/ROS dual-responsive NPs can effectively alleviate joint destruction via down-regulation of the NF-κB signaling pathway. STATEMENT OF SIGNIFICANCE: Nanomedicine is recognized as an attractive method for the targeting treatment of rheumatoid arthritis (RA). To thorough release of payloads from nanoformulations and synergistic therapy of RA, herein, a phytochemical and ROS-responsive moiety co-modified α-cyclodextrin was used as a pH/ROS dual-responsive carrier to encapsulate methylprednisolone to manage RA. The fabricated nanomedicine can effectively release its payloads under pH and/or ROS microenvironment, and the released drugs dramatically promote transformation of M1-type macrophages into M2 phenotype to reduce the release of pro-inflammatory cytokines. The prepared nanomedicine also obviously decreased the NF-κB signaling pathway molecule P65 expression in the joints, thereby down-regulating pro-inflammatory cytokines expression to alleviate joint swelling and cartilage destruction. We provided a candidate for the targeting treatment of RA.

Phytic acid-modified manganese dioxide nanoparticles oligomer for magnetic resonance imaging and targeting therapy of osteosarcoma.

Osteosarcoma is the most common malignant tumor in the skeletal system with high mortality. Phytic acid (PA) is a natural compound extracted from plant seeds, which shows certain antitumor activity and good bone targeting ability. To develop a novel theranostics for magnetic resonance imaging (MRI) and targeting therapy of osteosarcoma, we employed PA to modify manganese dioxide nanoparticles (MnO2@PA NPs) for osteosarcoma treatment. The MnO2 NPs oligomer was formed by PA modification with uniformed size distribution and negative zeta potential. Fourier-transform infrared spectroscopy, X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis demonstrated that PA has been successfully modified on MnO2 NPs, and the structure of MnO2@PA NPs is amorphous. In vitro experiments demonstrated that MnO2@PA NPs oligomer can be efficiently internalized by tumor cell, and the internalized NPs can react with H2O2 under acid microenvironment to produce Mn2+ and O2. In vivo experiments demonstrated that MnO2@PA NPs oligomer can passively accumulate in tumor tissue, and the accumulated NPs can produce Mn2+ and O2 for MRI and targeting therapy of osteosarcoma. In conclusion, we prepared a novel bone-targeting nano theranostics for MRI and therapy of osteosarcoma.

Ribonucleic Acid Folding Prediction Based on Iterative Multiscale Simulation.

RNA folding prediction is a challenge. Currently, many RNA folding models are coarse-grained (CG) with the potential derived from the known RNA structures. However, this potential is not suitable for modified and entirely new RNA. It is also not suitable for the folding simulation of RNA in the real cellular environment, including many kinds of molecular interactions. In contrast, our proposed model has the potential to address these issues, which is a multiscale simulation scheme based on all-atom (AA) force fields. We fit the CG force field using the trajectories generated by the AA force field and then iteratively perform molecular dynamics (MD) simulations of the two scales. The all-atom molecular dynamics (AAMD) simulation is mainly responsible for the correction of RNA structure, and the CGMD simulation is mainly responsible for efficient conformational sampling. On the basis of this scheme, we can successfully fold three RNAs belonging to a hairpin, a pseudoknot, and a four-way junction.

Antibiotic-loaded reactive oxygen species-responsive nanomedicine for effective management of chronic bacterial prostatitis.

Chronic bacterial prostatitis (CBP) occurs frequently in the male population and significantly influences quality of life. Antibiotics are the main strategy for managing chronic bacterial prostatitis; however, most antibiotics have low efficacy due to their poor penetration of prostate tissues. To overcome this challenge, we fabricated cefpodoxime proxetil (CPD)-loaded reactive oxygen species (ROS)-responsive nanoparticles (NPs) for targeted treatment of CBP. These NPs were modified with folic acid (FA) and could be effectively internalized by bacteria-infected macrophages and prostatic epithelial cells because of the high expression of folate receptors (FRs) in these cells. In vitro cellular assays demonstrated that the CPD-loaded nanomedicine can obviously reduce proinflammatory cytokine expression in cells since the nanomedicine can efficiently eradicate cellular bacteria. In vivo imaging results verified that FA-modified nanomedicines can penetrate the prostatic epithelium and accumulate in the glandular lumen because FRs overexpression was also observed in the prostate tissues of CBP mice. Animal experiments demonstrated that FA-modified nanomedicine can remarkably relieve pelvic pain in CBP mice and dramatically decrease proinflammatory cytokine expression in prostate tissues via eradication of bacteria and scavenging of ROS. Our results provide a new strategy to deliver antibiotics for targeted therapy of CBP. STATEMENT OF SIGNIFICANCE: To overcome poor penetration of antibiotics in prostatic tissues, we developed an antibiotics-loaded ROS-responsive NPs for targeted treatment of CBP. We demonstrated that both bacteria-infected macrophages and prostatic epithelial cells have FRs overexpression, thus FA-modified NPs can be efficiently internalized by these cells. FA-modified NPs can penetrate the prostatic epithelium and accumulate in the glandular lumen via FRs-mediated endocytosis, and the accumulated NPs can smartly release their payload under high ROS microenvironment. A distinguished therapy outcome was obtained in murine CBP model since CPD-loaded NPs can efficiently eradicate the resident bacteria in prostate tissues and downregulate proinflammatory cytokine expression. Our work provides a practicable strategy to expand the application of antibiotics for management of CBP.

Self-Illuminating Triggered Release of Therapeutics from Photocleavable Nanoprodrug for the Targeted Treatment of Breast Cancer.

Photocleavable biomaterials and bioconjugates have been widely researched for tissue engineering, cell culture, and therapeutics delivery. However, most in vivo applications of these materials or conjugates require external irradiation, and some of the light sources used such as ultraviolet (UV) light have poor tissue penetration. To address these key limitations, we synthesized a photocleavable nanoprodrug using luminol (a luminescent donor), chlorambucil (CHL, i.e., an antitumor drug with a photocleavable linker), and polyethylene glycol-folic acid conjugates (a targeted moiety) loaded onto polyamidoamine (PAMAM). The synthesized nanoprodrug can smartly release its payloads through photocleavage of photoresponsive linker by UV light, which was produced in situ by reacting luminol with pathological reactive oxygen species (ROS). The luminescence performance and absorption spectrum of this nanoprodrug was characterized in detail. In vitro cellular assays verified that the nanoprodrugs could be efficiently internalized by 4T1 and MDA-MB-231 cells, and the CHL released from the nanoprodrugs could distinctly decrease cell viability through the damage of DNA in cells. In vivo animal experiments demonstrated that the nanoprodrugs were mainly accumulated at tumor sites, and the antitumor drug CHL could be smartly released from the nanoprodrugs through cleavage of photosensitive linkers at a high level of ROS. The released CHL significantly inhibited the growth of tumors without any obvious adverse effects. Our results provide a practicable strategy to expand the in vivo application of photocleavable biomaterials and bioconjugates.

Multiscale simulations of large complexes in conjunction with cryo-EM analysis.

The cellular environment is highly crowded with most proteins and RNA/DNA forming homomeric and heteromeric complexes. Essential questions regarding how these complexes switch between functional, rest, and abnormal states with regulators or modifications remain challenging and complicated. Here, we review the recent progress integrating cryoelectron microscopy and multiscale molecular modeling to understand the dynamics and function-related mechanism in protein-RNA/DNA complexes, protein-protein complexes/assemblies, and membrane protein complexes. One future direction of multiscale simulations will be to interpret the large complex multibody regulation in assembly-induced function enhancement in conjunction with advanced atomic resolution structural-biology techniques and specialized computing architectures.

Recent advances in nanotherapeutics for the treatment of burn wounds.

Moderate or severe burns are potentially devastating injuries that can even cause death, and many of them occur every year. Infection prevention, anti-inflammation, pain management and administration of growth factors play key roles in the treatment of burn wounds. Novel therapeutic strategies under development, such as nanotherapeutics, are promising prospects for burn wound treatment. Nanotherapeutics, including metallic and polymeric nanoformulations, have been extensively developed to manage various types of burns. Both human and animal studies have demonstrated that nanotherapeutics are biocompatible and effective in this application. Herein, we provide comprehensive knowledge of and an update on the progress of various nanoformulations for the treatment of burn wounds.

Folic acid-modified ROS-responsive nanoparticles encapsulating luteolin for targeted breast cancer treatment.

Luteolin (Lut) is a natural flavonoid polyphenolic compound with multiple pharmacological activities, such as anti-oxidant, anti-inflammatory, and anti-tumor effects. However, the poor aqueous solubility and low bioactivity of Lut restrict its clinical translation. Herein, we developed a reactive oxygen species (ROS)-responsive nanoplatforms to improve the bioactivity of Lut. Folic acid (FA) was employed to decorate the nanoparticles (NPs) to enhance its targeting ability. The size of Lut-loaded ROS-responsive nanoparticles (Lut/Oxi-αCD NPs) and FA-modified Lut/Oxi-αCD NPs (Lut/FA-Oxi-αCD NPs) is 210.5 ± 6.1 and 196.7 ± 1.8 nm, respectively. Both Lut/Oxi-αCD NPs and Lut/FA-Oxi-αCD NPs have high drug loading (14.83 ± 3.50 and 16.37 ± 1.47%, respectively). In vitro cellular assays verified that these NPs could be efficiently internalized by 4T1 cells and the released Lut from NPs could inhibit tumor cells proliferation significantly. Animal experiments demonstrated that Lut/Oxi-αCD NPs, especially Lut/FA-Oxi-αCD NPs obviously accumulated at tumor sites, and inhibited tumor growth ∼3 times compared to the Lut group. In conclusion, the antitumor efficacy of Lut was dramatically improved by targeting delivery with the ROS-responsive nanoplatforms.

A double bilayer to study the nonequilibrium environmental response of GIRK2 in complex states.

G protein-gated inwardly rectifying potassium (GIRK) channels play essential roles in electrical signaling in neurons and muscle cells. Nonequilibrium environments provide crucial driving forces behind many cellular events. Here, we apply the antiparallel alignment double bilayer model to study GIRK2 in response to the time-dependent membrane potential. Using molecular dynamics and umbrella sampling, we examined the time-dependent environmental impact on the ion conduction, energy basis, and primary motions of GIRK2 in different complex states with phosphatidylinositol-4,5-bisphosphate (PIP2) and G-protein ßγ subunits (Gßγ). The antiparallel alignment double bilayer model enables us to study the transport performance in inward and outward K+ and mixed K+ and Na+. We obtained the recoverable discharge process of GIRK2 complexed with both PIP2 and Gßγ, compared with occasional conduction under PIP2-only regulation. Calculations of potential of mean force suggest different regulation by the helix bundle crossing (HBC) gate and G-loop gate regarding different complex states and under a membrane potential. In a nonequilibrium environment, distinct functional rocking motions of GIRK2 were identified under strengthened correlations between the transmembrane helices and downstream cytoplasmic domains with binding of PIP2, cations, and Gßγ. The findings suggest the potential domain motions and dynamics associated with a nonequilibrium environment and highlight the application of the antiparallel alignment double bilayer model to investigate factors in an asymmetric environment.

Prostatic fluid exosome-mediated microRNA-155 promotes the pathogenesis of type IIIA chronic prostatitis.

BACKGROUND: The latest research has shown that exosomes play an important role in cell-to-cell communication and are closely related to the occurrence of many chronic inflammatory diseases. However, no studies have clarified whether exosomes are involved in the pathogenesis of aseptic inflammation, type IIIA chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS-A). This study aimed to explore the relationship between prostatic fluid exosomes and CP/CPPS-A and reveal new pathogenesis. METHODS: Our group collected prostatic fluid samples from CP/CPPS-A patients and normal adult men. Electron microscope, quantitative PCR (qPCR), Western Blot, nanoparticle tracking analysis, hematoxylin-and-eosin (HE) staining, immunofluorescence staining and miRNA-155 functional analysis were used to verify the role of exosomes in CP/CPPS-A in vivo and in vitro. RESULTS: Exosomes were abundantly enriched in the prostatic fluid of CP/CPPS-A patients and selectively overloaded with microRNA-155 (miRNA-155). These exosomes were taken up by prostatic stromal cells in large quantities. They activated interleukin (IL)-8 and tumor necrosis factor-alpha (TNF-α) expression in vitro, and the integrity of the exosomes' plasma membrane is a necessary condition for information transmission by exosomes. In in vivo experiments, histological results showed that prostatic fluid exosomes induced prostatitis in rats. Also, immunofluorescence staining showed excessive activation of IL-8, TNF-α, and inducible nitric oxide synthase (iNOS). CONCLUSIONS: Exosomes in the prostatic fluid and the miRNA-155 contained therein were may be involved with the pathogenesis of CP/CPPS-A.