1.The Mechanism of Blue Light in Inactivating Microorganisms and Its Applications in The Food and Medical Fields
Ruo-Hong BI ; Rong-Qian WU ; Yi LÜ ; Xiao-Fei LIU
Progress in Biochemistry and Biophysics 2025;52(5):1219-1228
		                        		
		                        			
		                        			Blue light inactivation technology, particularly at the 405 nm wavelength, has demonstrated distinct and multifaceted mechanisms of action against both Gram-positive and Gram-negative bacteria, offering a promising alternative to conventional antibiotic therapies. For Gram-positive pathogens such as Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus (MRSA), the bactericidal effects are primarily mediated by endogenous porphyrins (e.g., protoporphyrin III, coproporphyrin III, and uroporphyrin III), which exhibit strong absorption peaks between 400-430 nm. Upon irradiation, these porphyrins are photoexcited to generate cytotoxic reactive oxygen species (ROS), including singlet oxygen, hydroxyl radicals, and superoxide anions, which collectively induce oxidative damage to cellular components. Early studies by Endarko et al. revealed that (405±5) nm blue light at 185 J/cm² effectively inactivated L. monocytogenes without exogenous photosensitizers, supporting the hypothesis of intrinsic photosensitizer involvement. Subsequent work by Masson-Meyers et al. demonstrated that 405 nm light at 121 J/cm² suppressed MRSA growth by activating endogenous porphyrins, leading to ROS accumulation. Kim et al. further elucidated that ROS generated under 405 nm irradiation directly interact with unsaturated fatty acids in bacterial membranes, initiating lipid peroxidation. This process disrupts membrane fluidity, compromises structural integrity, and impairs membrane-bound proteins, ultimately causing cell death. In contrast, Gram-negative bacteria such as Salmonella, Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Acinetobacter baumannii exhibit more complex inactivation pathways. While endogenous porphyrins remain central to ROS generation, studies reveal additional photodynamic contributors, including flavins (e.g., riboflavin) and bacterial pigments. For instance, H. pylori naturally accumulates protoporphyrin and coproporphyrin mixtures, enabling efficient 405 nm light-mediated inactivation without antibiotic resistance concerns. Kim et al. demonstrated that 405 nm light at 288 J/cm² inactivates Salmonella by inducing genomic DNA oxidation (e.g., 8-hydroxy-deoxyguanosine formation) and disrupting membrane functions, particularly efflux pumps and glucose uptake systems. Huang et al. highlighted the enhanced efficacy of pulsed 405 nm light over continuous irradiation for E. coli, attributing this to increased membrane damage and optimized ROS generation through frequency-dependent photodynamic effects. Environmental factors such as temperature, pH, and osmotic stress further modulate susceptibility, sublethal stress conditions (e.g., high salinity or acidic environments) weaken bacterial membranes, rendering cells more vulnerable to subsequent ROS-mediated damage. The 405 nm blue light inactivates drug-resistant Pseudomonas aeruginosa through endogenous porphyrins, pyocyanin, and pyoverdine, with the inactivation efficacy influenced by bacterial growth phase and culture medium composition. Intriguingly, repeated 405 nm exposure (20 cycles) failed to induce resistance in A. baumannii, with transient tolerance linked to transient overexpression of antioxidant enzymes (e.g., superoxide dismutase) or stress-response genes (e.g., oxyR). For Gram-positive bacteria, porphyrin abundance dictates sensitivity, whereas in Gram-negative species, membrane architecture and accessory pigments modulate outcomes. Critically, ROS-mediated damage is nonspecific, targeting DNA, proteins, and lipids simultaneously, thereby minimizing resistance evolution. The 405 nm blue light technology, as a non-chemical sterilization method, shows promise in medical and food industries. It enhances infection control through photodynamic therapy and disinfection, synergizing with red light for anti-inflammatory treatments (e.g., acne). In food processing, it effectively inactivates pathogens (e.g., E. coli, S. aureus) without altering food quality. Despite efficacy against multidrug-resistant A. baumannii, challenges include device standardization, limited penetration in complex materials, and optimization of photosensitizers/light parameters. Interdisciplinary research is needed to address these limitations and scale applications in healthcare, food safety, and environmental decontamination. 
		                        		
		                        		
		                        		
		                        	
2.Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development.
Tianyong XU ; Yunying WU ; Yi ZHANG ; Xi-Nian ZUO ; Feiyan CHEN ; Changsong ZHOU
Neuroscience Bulletin 2024;40(1):50-64
		                        		
		                        			
		                        			The organization of the brain follows a topological hierarchy that changes dynamically during development. However, it remains unknown whether and how cognitive training administered over multiple years during development can modify this hierarchical topology. By measuring the brain and behavior of school children who had carried out abacus-based mental calculation (AMC) training for five years (starting from 7 years to 12 years old) in pre-training and post-training, we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology. We observed the development-induced emergence of the default network, AMC training-promoted shifting, and regional changes in cortical gradients. Moreover, the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy. We found that gradient-based features can predict the math ability within groups. Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.
		                        		
		                        		
		                        		
		                        			Child
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		                        			Humans
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		                        			Cognitive Training
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		                        			Magnetic Resonance Imaging
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		                        			Brain
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		                        			Brain Mapping
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		                        			Motor Cortex
		                        			
		                        		
		                        	
3.Combination of AAV-delivered tumor suppressor PTEN with anti-PD-1 loaded depot gel for enhanced antitumor immunity.
Yongshun ZHANG ; Lan YANG ; Yangsen OU ; Rui HU ; Guangsheng DU ; Shuang LUO ; Fuhua WU ; Hairui WANG ; Zhiqiang XIE ; Yu ZHANG ; Chunting HE ; Cheng MA ; Tao GONG ; Ling ZHANG ; Zhirong ZHANG ; Xun SUN
Acta Pharmaceutica Sinica B 2024;14(1):350-364
		                        		
		                        			
		                        			Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene in cancer cells may be associated with immunosuppressive tumor microenvironment (TME) and poor response to immune checkpoint blockade (ICB) therapy. Therefore, efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy. Here, we screened an adeno-associated virus (AAV) capsid for efficient PTEN gene delivery into B16F10 tumor cells. We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death (ICD) and increasing immune cell infiltration. Moreover, we developed an anti-PD-1 loaded phospholipid-based phase separation gel (PPSG), which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo. In order to effectively inhibit the recurrence of melanoma, we further applied a triple therapy based on AAV6-PTEN, PPSG@anti-PD-1 and CpG, and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory, which completely rejected tumor recurrence. We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.
		                        		
		                        		
		                        		
		                        	
5.MGMT activated by Wnt pathway promotes cisplatin tolerance through inducing slow-cycling cells and nonhomologous end joining in colorectal cancer
Zhang HAOWEI ; Li QIXIN ; Guo XIAOLONG ; Wu HONG ; Hu CHENHAO ; Liu GAIXIA ; Yu TIANYU ; Hu XIAKE ; Qiu QUANPENG ; Guo GANG ; She JUNJUN ; Chen YINNAN
Journal of Pharmaceutical Analysis 2024;14(6):863-877
		                        		
		                        			
		                        			Chemotherapy resistance plays a pivotal role in the prognosis and therapeutic failure of patients with colorectal cancer(CRC).Cisplatin(DDP)-resistant cells exhibit an inherent ability to evade the toxic chemotherapeutic drug effects which are characterized by the activation of slow-cycle programs and DNA repair.Among the elements that lead to DDP resistance,O6-methylguanine(O6-MG)-DNA-meth-yltransferase(MGMT),a DNA-repair enzyme,performs a quintessential role.In this study,we clarify the significant involvement of MGMT in conferring DDP resistance in CRC,elucidating the underlying mechanism of the regulatory actions of MGMT.A notable upregulation of MGMT in DDP-resistant cancer cells was found in our study,and MGMT repression amplifies the sensitivity of these cells to DDP treatment in vitro and in vivo.Conversely,in cancer cells,MGMT overexpression abolishes their sensi-tivity to DDP treatment.Mechanistically,the interaction between MGMT and cyclin dependent kinase 1(CDK1)inducing slow-cycling cells is attainted via the promotion of ubiquitination degradation of CDK1.Meanwhile,to achieve nonhomologous end joining,MGMT interacts with XRCC6 to resist chemotherapy drugs.Our transcriptome data from samples of 88 patients with CRC suggest that MGMT expression is co-related with the Wnt signaling pathway activation,and several Wnt inhibitors can repress drug-resistant cells.In summary,our results point out that MGMT is a potential therapeutic target and predictive marker of chemoresistance in CRC.
		                        		
		                        		
		                        		
		                        	
6.Effect of pulsed electric field on reactive oxygen species generation in pancreatic cancer cells
Zhixuan ZHANG ; Zhuoqun LI ; Xuan HAN ; Chu ZHANG ; Hairuo YANG ; Zheng WU ; Yi LYU ; Nana ZHANG
Chinese Journal of Hepatobiliary Surgery 2023;29(10):753-759
		                        		
		                        			
		                        			Objective:To investigate the changes of reactive oxygen species (ROS) in pancreatic cancer cells under the effect of pulsed electric fields (PEF).Methods:Murine-derived pancreatic cancer cells Panc02 were treated with PEF at electric field strengths of 0, 250, 500, 750, and 1 000 V/cm, respectively. The intracellular ROS generation patterns under the different field strengths and at different times after the PEF were investigated in vitro by flow cytometry and immunofluorescence, meanwhile exploring the apoptosis of murine and human pancreatic cancer cells under different field strengths. Twenty 6- to 8-week-old male C57BL/6 SPF mice were prepared as orthotopic pancreatic cancer models and divided into five groups of four mice each: 250 V/cm PEF group, 500 V/cm PEF group, 750 V/cm PEF group, 1 000 V/cm PEF group, and sham operation group. ROS expression in the residual tumor tissues of mice in each group was detected by immunofluorescence.Results:Under the 500 V/cm, 750 V/cm and 1 000 V/cm electric field strength, the proportion of cells with intracellular ROS expression was decreased after 6 h, 12 h, 24 h and 48 h of the PEF compared with 2 h after the PEF, and the differences were statistically significant (all P<0.05). Compared with 0 V/cm PEF group, ROS expression increased in Panc02 cells treated with 500 V/cm and 750 V/cm PEF groups, and the differences were statistically significant (all P<0.05). Compared with 250 V/cm PEF group under the same time, ROS in Panc02 cells treated with 500 V/cm and 750 V/cm electric field strengths increased, and the differences were statistically significant (all P<0.05). The proportions of apoptosis of both Panc02 cells and MIA-PaCa-2 cells increased with rising field strength and peaked at the field strength of 750 V/cm. Compared with the sham-operated group, the expression of ROS was increased in pancreatic cancer tissues of mice in the 500 V/cm PEF-treated group (16.65±6.01 vs. 2.38±1.21, t=-6.53) and 750 V/cm PEF-treated group (16.54±4.41 vs. 2.38±1.21, t=-6.48), and the differences were statistically significant in both cases (both P<0.001). Conclusion:PEF treatment was able to increase the level of ROS in both pancreatic cancer cells and tissues, and more ROS were produced when the electric field strength was 500 and 750 V/cm.
		                        		
		                        		
		                        		
		                        	
7.Distribution characteristics of tumor infiltrating lymphocytes in EBV-associated lymphoepithelioma-like carcinoma and their clinical significance.
J Y JIN ; Y Q LYU ; T T LU ; W J YIN ; Y X WU ; X Y LIU ; Y YANG ; C Q WU ; X H NI ; D SU
Chinese Journal of Pathology 2023;52(8):814-819
		                        		
		                        			
		                        			Objective: To investigate the association between the distribution of tumor infiltrating lymphocytes (TIL) in EBV associated lymphoepitheliomatoid carcinoma (LELC) and the pathological subtypes of LELC, as well as the clinical significance of TIL distribution. Methods: The LELC patients with sufficient tumor tissues, complete clinical data and positive EBER, who visited Zhejiang Cancer Hospital, Hangzhou, China from January 2006 to October 2018, were selected. Various immunohistochemical markers (CD20, CD138, CD4, CD8, CD56 and FOXP3) were examined for TIL typing. Two pathologists reviewed the hematoxylin and eosin (HE) staining sections and interpreted the immunohistochemical results. Correlation analysis was used to evaluate the relationship between the distribution of TIL subgroups and LELC's pathological characteristics. Survival analyses were conducted to study the prognostic values of TIL subgrouping. Results: A total of 102 patients with EBV related LELC were included. 46 of them were classic LELC (c-LELC) with rich interstitial TIL, and 56 were non-classic LELC (n-LELC) with relatively fewer interstitial TIL. The results of TIL analysis showed that all subtypes of c-LELC were rich in TIL, with B lymphocytes as the dominant subgroup. The number of TIL in n-LELC was fewer than that in c-LELC, with T lymphocytes as the dominant subgroup. There was no significant difference in the distribution of plasma cells between the two groups. Survival analysis showed that the total number of TIL, and the infiltrations of CD20+B cells, CD4+T cells, and FOXP3+Treg cells were associated with better overall survivals (P=0.004, 0.003, 0.008 and 0.025, respectively) and disease-free survivals (P=0.011, 0.003, 0.038 and 0.041, respectively) in patients with LELC. Conclusions: The morphologic subtypes of EBV-related LELC have different tumor immune characteristics. The total number of TIL in the stroma of c-LELC is significantly higher than that of n-LELC. Interestingly, B lymphocytes are the dominant TIL in c-LELC, while T lymphocytes are the dominant TIL in n-LELC. The infiltration of TIL, CD20+B cells, CD4+T cells and FOXP3+Treg cells in LELC may suggest a better prognosis.
		                        		
		                        		
		                        		
		                        			Humans
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		                        			Lymphocytes, Tumor-Infiltrating
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		                        			Herpesvirus 4, Human
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		                        			Clinical Relevance
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		                        			Prognosis
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		                        			Carcinoma, Squamous Cell/pathology*
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		                        			Forkhead Transcription Factors
		                        			
		                        		
		                        	
8.Oligosarcoma: report of a case.
S XING ; X J QI ; Y XIA ; J WU ; W W FU
Chinese Journal of Pathology 2023;52(8):850-852
            
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