In vivo autophagy quantification: Measuring LC3 and P62 puncta in 3D image system from zebrafish larvae

Nanotechnology for microglial targeting and inhibition of neuroinflammation underlying Alzheimer's pathology

BACKGROUND

Alzheimer's disease (AD) is considered to have a multifactorial etiology. The hallmark of AD is progressive neurodegeneration, which is characterized by the deepening loss of memory and a high mortality rate in the elderly. The neurodegeneration in AD is believed to be exacerbated following the intercoupled cascades of extracellular amyloid beta (Aβ) plaques, uncontrolled microglial activation, and neuroinflammation. Current therapies for AD are mostly designed to target the symptoms, with limited ability to address the mechanistic triggers for the disease. In this study, we report a novel nanotechnology based on microglial scavenger receptor (SR)-targeting amphiphilic nanoparticles (NPs) for the convergent alleviation of fibril Aβ (fAβ) burden, microglial modulation, and neuroprotection.

METHODS

We designed a nanotechnology approach to regulate the SR-mediated intracellular fAβ trafficking within microglia. We synthesized SR-targeting sugar-based amphiphilic macromolecules (AM) and used them as a bioactive shell to fabricate serum-stable AM-NPs via flash nanoprecipitation. Using electron microscopy, in vitro approaches, ELISA, and confocal microscopy, we investigated the effect of AM-NPs on Aβ fibrilization, fAβ-mediated microglial inflammation, and neurotoxicity in BV2 microglia and SH-SY5Y neuroblastoma cell lines.

RESULTS

AM-NPs interrupted Aβ fibrilization, attenuated fAβ microglial internalization via targeting the fAβ-specific SRs, arrested the fAβ-mediated microglial activation and pro-inflammatory response, and accelerated lysosomal degradation of intracellular fAβ. Moreover, AM-NPs counteracted the microglial-mediated neurotoxicity after exposure to fAβ.

CONCLUSIONS

The AM-NP nanotechnology presents a multifactorial strategy to target pathological Aβ aggregation and arrest the fAβ-mediated pathological progression in microglia and neurons.

Exosomal microRNA profiling revealed enhanced autophagy suppression and anti-tumor effects of a combination of compound Phyllanthus urinaria and lenvatinib in hepatocellular carcinoma

BACKGROUND

Compound Phyllanthus urinaria (CP), a traditional Chinese herbal remedy, possesses strong anti-cancer effects and is extensively employed in the clinical management of hepatocellular carcinoma (HCC). While lenvatinib and other oral tyrosine kinase inhibitors have been authorized as initial treatments for advanced unresectable HCC, the survival of patients is ultimately restricted due to the gradual development of drug resistance. Fortunately, the co-administration of CP and lenvatinib holds promise for anti-cancer applications.

PURPOSE

Our objective was to understand the molecular-level mechanisms of bioactive phytocompounds in CP, in order to explore the anti-HCC effects of combining CP and lenvatinib treatment and reveal the underlying mechanisms. Furthermore, we discovered new miRNAs associated with autophagy that are common to both HepG2-derived exosomes and HepG2 cells. These miRNAs play a role in the advancement of HCC and were identified through the utilization of CP and lenvatinib.

METHODS

To assess the anti-HCC effects of CP in combination with lenvatinib, both an in vitro CCK-8 assay and an in vivo xenograft model assay were performed. TEM, NTA, and nano-flow cytometry were employed for the identification of isolated exosomes. To ascertain the miRNA expression patterns in HepG2 cells and HepG2-derived exosomes, miRNA-sequencing analysis was conducted. Further investigation involved the use of real-time PCR, examination of the fusion protein GFP-mRFP-LC3, TEM analysis, and western blotting.

RESULTS

In vitro and in vivo, the combination of CP and lenvatinib showed a stronger and more powerful impact on HCC compared to either CP or lenvatinib alone. The combination of CP and lenvatinib had a significant impact on autophagy-related miRNAs in HepG2-derived exosomes and HepG2 cells, as demonstrated by cellular and exosomal miRNA sequencing. Additional tests indicated that the increased inhibition of autophagy in HepG2 cells subjected to CP treatment, as well as the combination of CP and lenvatinib, was accomplished through the regulation of Beclin-1, LC3-II, and P62 expression.

CONCLUSION

In conclusion, our results indicate that the combination of CP and lenvatinib can effectively inhibit HCC by promoting the exosome-mediated suppression of autophagy. This novel therapeutic option is highly efficient and durable, making it a promising treatment for HCC. Moreover, the miRNAs that are differentially expressed and associated with exosome-mediated autophagy, which have been discovered in this study, could potentially be targeted for clinical treatment of HCC.

Antioxidants and azd0156 Rescue Inflammatory Response in Autophagy-Impaired Macrophages

Autophagy is a lysosomal degradation system that eliminates and recycles damaged intracellular organelles and proteins. Inflammatory macrophages play a critical role in the development of various age-related inflammatory illnesses such as abdominal aortic aneurysm, atherosclerosis, and rheumatoid arthritis; therefore, identifying the mechanisms that cause macrophage inflammation is crucial for a better understanding of and developing therapeutics for inflammatory diseases. Previous research has linked autophagy to macrophage inflammation; Atg16L1-deficient macrophages increase IL-1 and IL-18 production via inflammasome activation. In this study, however, we show an alternative pathway of macrophage inflammation in an autophagy-deficient environment. We found that inhibiting autophagy in THP1 macrophages progressively increased the expression of p65-mediated inflammatory genes. This effect was reversed by treatment with antioxidants or azd0156, an ataxia telangiectasia mutated (ATM) inhibitor. In addition, our results showed that M1 macrophages inhibit autophagy and induce DNA damage, whereas M2 macrophages activate autophagy and reduce DNA damage. Importantly, the chemical activation of autophagy or ATM inhibition during M1 polarization reduced the M1 phenotype and inflammation, whereas inhibiting autophagy during M2 polarization also reduced the M2 phenotype. Thus, our findings highlight the importance of the autophagy-ATM pathway in driving macrophage inflammation.

Elsinochrome A induces cell apoptosis and autophagy in photodynamic therapy

Elsinochrome A (EA) is a perylene quinone natural photosensitizer, photosensitizer under light excitation generates reactive oxygen species (ROS) to induce apoptosis, so can be used for treating tumors, that is so-called photodynamic therapy (PDT). However, the molecular mechanism, especially related to apoptosis and autophagy, is still unclear. In this study, we aimed to explore the mechanism of EA-PDT-induced B16 cells apoptosis and autophagy. The action of EA-PDT on mitochondrial permeability transition pore (MPTP), mitochondrial membrane potential (MMP) and the mitochondrial function were researched by fluorescence technique and Extracellular Flux Analyzer. Illumina sequencing, tandem mass tags Quantitative Proteomics and Western Blot studied the mechanism at the gene and protein levels. The results indicated that EA-PDT had excellent phototoxicity in vitro. EA could bind to the mitochondria. EA-PDT for 5 min caused MPTP opening, MMP decreasing and abnormal mitochondrial function with a concentration-dependent characteristic. EA-PDT resulted in an increase intracellular ROS and the number of autophagosomes. Caspase2, caspase9 and tnf were upregulated, and bcl2, prkn, atg2, atg9 and atg10 were downregulated. Our results indicated that EA-PDT induced cell apoptosis and autophagy through the mediation of ROS/Atg/Parkin. This study can provide enlightenment for exploring potential targets of drug development for the PDT of melanoma.

Resveratrol induces proliferation and differentiation of mouse pre-osteoblast MC3T3-E1 by promoting autophagy

BACKGROUND

In mouse, it was discovered that resveratrol (Res) enhanced osteoporosis (OP) by boosting osteogenesis. Besides, Res can also have an impact on MC3T3-E1 cells, which are crucial for the control of osteogenesis and thus increase osteogenesis. Although some articles have discovered that Res enhanced autophagy to promote the value-added differentiation of MC3T3, it is unclear exactly how this affects the process of osteogenesis in mouse. Therefore, we will show that Res encourages MC3T3-E1 proliferation and differentiation in mouse pre-osteoblasts and further investigate the autophagy-related mechanism for this impact.

METHODS

(1) MC3T3-E1 cells were separated into blank control group and various concentrations (0.01, 0.1, 1, 10, 100µmol/L) of group in order to determine the ideal Res concentration. In the Res group, Cell Counting Kit-8 (CCK-8) was used to measure the proliferation activity of pre-osteoblasts in mice in each group after resveratrol intervention. Alkaline Phosphatase (ALP) and alizarin red staining were used to gauge the degree of osteogenic differentiation, and RT-qPCR was used to measure the expression levels of Runx2 and OCN in the osteogenic differentiation ability of the cells. (2) In the experiment, four groups were set up: the control group, 3MA group, Res group, and Res + 3MA group. To examine cell mineralization, ALP and alizarin red staining were utilized. RT-qPCR and Western blot detection of cell autophagy activity levels and osteogenic differentiation capacity in each group following intervention.

RESULTS

(1) Resveratrol might increase the number of mice pre-osteoblast, with the impact being most pronounced at 10µmol/L (P < 0.05). The nodules developed substantially more often than in the blank control group, and Runx2 and OCN expressions significantly increased (P < 0.05). (2) In contrast to the Res group, after 3MA purine blocked autophagy, the Res + 3MA group's alkaline phosphatase staining and the development of mineralized nodules were reduced. Runx2, OCN, LC3II / LC3I expression decreased, p62 expression increased (P < 0.05).

CONCLUSION

The present study partially or indirectly demonstrated that Res may, through increased autophagy, induce osteogenic differentiation of MC3T3-E1 cells.

Brucella BtpB Manipulates Apoptosis and Autophagic Flux in RAW264.7 Cells

Brucella transfers effectors into host cells, manipulating cellular processes to its advantage; however, the mechanism by which effectors regulate cellular processes during infection is poorly understood. A growing number of studies have shown that apoptosis and autophagy are critical mechanisms for target cells to cope with pathogens and maintain cellular homeostasis. BtpB is a Brucella type IV secretion system effector with a complex mechanism for manipulating host infection. Here, we show that the ectopic expression of BtpB promoted DNA fragmentation. In contrast, an isogenic mutant strain, ΔbtpB, inhibited apoptosis compared to the wild-type strain B. suis S2 in RAW264.7 cells. In addition, BtpB inhibited autophagy, as determined by LC3-II protein levels, the number of LC3 puncta, and p62 degradation. We also found that BtpB reduced autophagolysosome formation and blocked the complete autophagic flux. Moreover, our results revealed that the autophagy inhibitor, chloroquine, reduces Brucella's intracellular survival. Overall, our data unveil new mechanisms of virulence implicating the effector BtpB in regulating host intracellular infection.

Engineering Multifunctional Hydrogel-Integrated 3D Printed Bioactive Prosthetic Interfaces for Osteoporotic Osseointegration

3D printed porous titanium alloy implants is an advanced orthopedic material for joint replacement. However, the high risk of aseptic loosening and periprosthetic infection is difficult to avoid, and the declined autophagy of osteoporosis-derived bone marrow mesenchymal stem cells (OP-BMSCs) further severely impairs the osseointegration under the osteoporotic circumstance. It is thus becoming urgently significant to develop orthopedic materials with autophagy regulation and antibacterial bioactivity. In this regard, a novel class of multifunctional hydrogel-integrated 3D printed bioactive prosthetic interfaces is engineered for in situ osseointegration in osteoporosis. The hydrogel is fabricated from the dynamic crosslinking of synthetic polymers, natural polymers, and silver nanowires to deliver autophagy-regulated rapamycin. Therefore, the resultant soft material exhibits antibacterial ability, biocompatibility, degradability, conductive, self-healing, and stimuli-responsive abilities. In vitro experiments demonstrate that the hydrogel-integrated 3D printed bioactive prosthetic interfaces can restore the declined cellular activities of OP-BMSCs by upregulating the autophagy level and show excellent antibacterial activity against S. aureus and MRSA. More remarkably, the multifunctional 3D printed bioactive prosthetic interfaces significantly improve osseointegration and inhibit infection in osteoporotic environment in vivo. This study provides an efficient strategy to develop novel prosthetic interfaces to reduce complications after arthroplasty for patients with osteoporosis.