Glioblastoma (GB) is the most common and highly malignant brain tumor characterized by aggressive growth and resistance to alkylating chemotherapy. Autophagy induction is one of the hallmark effects ...of anti-GB therapies with temozolomide (TMZ). However, the non-classical form of autophagy, autophagy-based unconventional secretion, also called secretory autophagy and its role in regulating the sensitivity of GB to TMZ remains unclear. There is an urgent need to illuminate the mechanism and to develop novel therapeutic targets for GB.
Cancer genome databases and paired-GB patient samples with or without TMZ treatment were used to assess the relationship between HMGB1 mRNA levels and overall patient survival. The relationship between HMGB1 protein level and TMZ sensitivity was measured by immunohistochemistry, ELISA, Western blot and qRT-PCR. GB cells were engineered to express a chimeric autophagic flux reporter protein consisting of mCherry, GFP and LC3B. The role of secretory autophagy in tumor microenvironment (TME) was analyzed by intracranial implantation of GL261 cells. Coimmunoprecipitation (Co-IP) and Western blotting were performed to test the RAGE-NFκB-NLRP3 inflammasome pathway.
The exocytosis of HMGB1 induced by TMZ in GB is dependent on the secretory autophagy. HMGB1 contributed to M1-like polarization of tumor associated macrophages (TAMs) and enhanced the sensitivity of GB cells to TMZ. Mechanistically, RAGE acted as a receptor for HMGB1 in TAMs and through RAGE-NFκB-NLRP3 inflammasome pathway, HMGB1 enhanced M1-like polarization of TAMs. Clinically, the elevated level of HMGB1 in sera may serve as a beneficial therapeutic-predictor for GB patients under TMZ treatment.
We demonstrated that enhanced secretory autophagy in GB facilitates M1-like polarization of TAMs to enhance TMZ sensitivity of GB cells. HMGB1 acts as a key regulator in the crosstalk between GB cells and tumor-suppressive M1-like TAMs in GB microenvironment and may be considered as an adjuvant for the chemotherapeutic agent TMZ.
Diatoms are important primary producers in the marine ecosystem. Currently it is difficult to genetically transform diatoms due to the technical limitations of existing methods. The ...promoter/terminator of the nitrate reductase gene of the model diatom Phaeodactylum tricornutum was cloned and used to drive chloramphenicol acetyltransferase (CAT) reporter gene expression. The construct was transferred by electroporation into P. tricornutum grown in medium lacking silicon. CAT expression was induced in transformed diatoms in the presence of nitrate, enabling growth in selective medium, and was repressed when ammonium was the only nitrogen source. Expression of CAT transcript and protein were demonstrated by RT-PCR and Western blot analysis, respectively. Our study is the first to report a successful genetic transformation of diatom by electroporation in an economical and efficient manner and provides a tightly regulated inducible gene expression system for diatom.
Graphene, a 2-dimensional carbon nanomaterial, has attracted wide attention in biomedical applications, owing to its intrinsic physical and chemical properties. In this work, a photosensitizer ...molecule, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-alpha (HPPH or Photochlor®), is loaded onto polyethylene glycol (PEG)-functionalized graphene oxide (GO) via supramolecular π-π stacking. The obtained GO-PEG-HPPH complex shows high HPPH loading efficiency. The in vivo distribution and delivery were tracked by fluorescence imaging as well as positron emission tomography (PET) after radiolabeling of HPPH with (64)Cu. Compared with free HPPH, GO-PEG-HPPH offers dramatically improved photodynamic cancer cell killing efficacy due to the increased tumor delivery of HPPH. Our study identifies a role for graphene as a carrier of PDT agents to improve PDT efficacy and increase long-term survival following treatment.
African classical swine fever virus (ASFV) has spread seriously around the world and has dealt with a heavy blow to the pig breeding industry due to the lack of vaccines. In this study, we produced ...recombinant
Lactobacillus plantarum
(
L. plantarum
) expressing an ASFV p54 and porcine IL-21 (pIL-21) fusion protein and evaluated the immune effect of NC8-pSIP409-pgsA'-p54-pIL-21 in a mouse model. First, we verified that the ASFV p54 protein and p54-pIL-21 fusion protein were anchored on the surface of
L. plantarum
NC8 by flow cytometry, immunofluorescence and Western blotting. Then, the results were verified by flow cytometry, ELISA and MTT assays. Mouse-specific humoral immunity and mucosal and T cell-mediated immune responses were induced by recombinant
L. plantarum
. The results of feeding mice recombinant
L. plantarum
showed that the levels of serum IgG and mucosal secreted IgA (SIgA), the number of CD4 and CD8 T cells, and the expression of IFN-γ in CD4 and CD8 T cells increased significantly, and lymphocyte proliferation occurred under stimulation with the ASFV p54 protein. Our data lay a foundation for the development of oral vaccines against ASFV in the future.
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•Membrane protein assembly has been overlooked in earlier studies of NP-membrane interactions.•Three types of protein assemblage are designed to investigate NP-membrane interactions ...under membrane confinement.•We demonstrate the size dependent membrane wrapping on NPs regulated by the protein assemblage.•The protein assemblage either promotes or suppresses membrane wrapping on NPs.•Protein assemblage triggers membrane protrusions that wrap NPs from the top side.
Understanding how nanoparticles (NPs) interact with cell membranes is of essential importance for developing nanomedicine and nanosafety evaluation. Such delicate process is regulated by the engineered NP properties and surface coatings, but also involves membrane-associated proteins that have been overlooked and yet to be elucidated. Given ubiquity and diversity of protein assembly occurring on the cell membrane, here we design three types of protein assemblage associated with the membrane, including the one-dimensional filament, two-dimensional mesh, and three-dimensional cage. Dissipative particle dynamics simulations are performed to investigate the NP-membrane interactions under different membrane confinement. Our results show the size dependent membrane wrapping on NPs regulated by the protein assemblage. Depending on the relative size, geometry and mobility of the protein assemblage, the induced membrane confinement either promotes or suppresses the membrane wrapping on NPs through competition of rigidifying the local membrane patch and inducing non-zero membrane curvature. When the normal wrapping is prohibited, membrane protrusions are triggered by the protein assemblage that assists the membrane wrapping on NPs from the top side. Then the NPs are trapped inside the membrane with failed internalization. This study will aid our understanding of the molecular mechanisms underlying the regulatory role of protein assemblage in the NP-cell membrane interactions.
Plastic phenotype convention between glioma stem cells (GSCs) and non-stem tumor cells (NSTCs) significantly fuels glioblastoma heterogeneity that causes therapeutic failure. Recent progressions ...indicate that glucose metabolic reprogramming could drive cell fates. However, the metabolic pattern of GSCs and NSTCs and its association with tumor cell phenotypes remain largely unknown. Here we found that GSCs were more glycolytic than NSTCs, and voltage-dependent anion channel 2 (VDAC2), a mitochondrial membrane protein, was critical for metabolic switching between GSCs and NSTCs to affect their phenotypes. VDAC2 was highly expressed in NSTCs relative to GSCs and coupled a glycolytic rate-limiting enzyme platelet-type of phosphofructokinase (PFKP) on mitochondrion to inhibit PFKP-mediated glycolysis required for GSC maintenance. Disruption of VDAC2 induced dedifferentiation of NSTCs to acquire GSC features, including the enhanced self-renewal, preferential expression of GSC markers, and increased tumorigenicity. Inversely, enforced expression ofVDAC2 impaired the self-renewal and highly tumorigenic properties of GSCs. PFK inhibitor clotrimazole compromised the effect of VDAC2 disruption on glycolytic reprogramming and GSC phenotypic transition. Clinically, VDAC2 expression inversely correlated with glioma grades (Immunohistochemical staining scores of VDAC2 were 4.7 ± 2.8, 3.2 ± 1.9, and 1.9 ± 1.9 for grade II, grade III, and IV, respectively, p < 0.05 for all) and the patients with high expression of VDAC2 had longer overall survival than those with low expression of VDAC2 (p = 0.0008). In conclusion, we demonstrate that VDAC2 is a new glycolytic regulator controlling the phenotype transition between glioma stem cells and non-stem cells and may serves as a new prognostic indicator and a potential therapeutic target for glioma patients.
This work reports the surface coating of Li
1.2
Mn
0.54
Ni
0.13
Co
0.13
O
2
cathode material with nano-CeO
2
by a versatile hydrothermal method. Thus, obtained nano-CeO
2
-coated Li
1.2
Mn
0.54
Ni
...0.13
Co
0.13
O
2
material was characterized by XRD, SEM, and TEM. It is revealed that the synthesized nano-CeO
2
material has rich oxygen vacancies, and a spinel-phase layer is formed on the surface of host material. The electrochemical testing results show that Li
1.2
Mn
0.54
Ni
0.13
Co
0.13
O
2
with 4 wt% CeO
2
coating (denoted as C3) has good rate capability and enhanced cyclic stability, enhanced initial discharge capacity of 298.5 mA h g
−1
(0.05 C) compared to 281.9 mAh g
−1
, and excellent initial coulombic efficiency of 86.94% compared to 77.28% for the pristine one in the potential range 2.0–4.8 V (vs. Li/Li
+
). It is worth noting that this modified strategy greatly reduces the irreversible capacity loss (ICR) of the first cycle of active materials, the ICR of the C3 (44.8 mAh g
−1
) is markedly lower than pristine material (82.9 mAh g
−1
) at the current density of 12.5 mA g
−1
(0.05 C). Such improvements are mainly ascribed to the oxygen vacancies in nano-CeO
2
coating layer, which are responsible for the promoted activation of Li
2
MnO
3
. Moreover, the formation of the spinel structure is beneficial to stabilize the crystal lattice of the bulk material and facilitate Li
+
diffusion by unique 3D transport channels.
Although the tumorigenic potential of glioma stem cells (GSCs) is associated with multiple molecular alterations, the gene amplification status of GSCs has not been elucidated. Overexpression of ...HomeoboxA5 (HOXA5) is associated with increased glioma malignancy. In this study, we identify the gene amplification and protein overexpression of HOXA5 in GSCs and its function in regulating GSC maintenance and the downstream transcriptional effector, to explore the significance of HOXA5 amplification/overexpression for GSC identification and prognostic determination. The HOXA5 gene is significantly amplified in glioblastoma (GBM) and is an independent prognostic factor for predicting worse patient outcomes. Specifically, HOXA5 gene amplification and the resultant protein overexpression are correlated with increased proportions of GSCs and enhanced self-renewal/invasiveness of these cells. Disruption of HOXA5 expression impairs GSC survival and GBM tumor propagation. Mechanistically, HOXA5 directly binds to the promoter region of protein tyrosine phosphatase receptor type Z1 (PTPRZ1), thereby upregulating this gene for GSC maintenance. Suppression of PTPRZ1 largely compromises the pro-tumoral effect of HOXA5 on GSCs. In summary, HOXA5 amplification serves as a genetic biomarker for predicting worse GBM outcome, by enhancing PTPRZ1-mediated GSC survival.
•HOXA5 is amplified in GBM and predicts poor patient prognosis.•HOXA5 transcriptionally activates PTPRZ1 to enhance GSC self-renewal and invasiveness.•HOXA5 gene amplification could help for personalized molecular diagnosis and targeted therapy.
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