1.The role of PKMYT1 in glucocorticoid-induced osteoblast apoptosis
Chengyou YANG ; Hong LUO ; Tao WANG ; Zhihong XIE ; Liang LIANG ; Fanchao LI ; Jianhua WU ; Fei ZHANG ; Wuxun PENG
Chinese Journal of Sports Medicine 2025;44(5):381-393
Objective To investigate the role of membrane-associated tyrosine/threonine-protein ki-nase 1(PKMYT1)in glucocorticoid(GC)-induced osteoblast(OB)apoptosis,providing a theoretical basis and potential therapeutic targets for early-stage steroid-induced avascular necrosis of the femoral head(SANFH).Methods(1)Mouse calvarial osteoblastic cells(MC3T3-E1)were selected for the study.The control group was cultured in standard medium,while the experimental group was subject-ed to osteogenic induction culture,with osteogenic capacity verified by alkaline phosphatase(ALP)and Alizarin Red S(ARS)staining.Then,mouse osteoblasts(mOB)were treated with different con-centrations of GC.After that,apoptosis was detected by using Annexin V-FITC/PI double staining as-say,while cell proliferation was assessed by using Cell Counting Kit-8(CCK8).Moreover,the expres-sions of anti-apoptotic protein B-cell lymphoma/leukemia-2(BCL-2),pro-apoptotic proteins cleaved caspase-3andcleavedcaspase-9(cleavedcaspase 3/9)weredetectedbyusing Westernblotting(WB).Meanwhile,proteomic analysis was employed to identify molecules potentially regulating GC-in-duced apoptosis in mOBs.What's more,quantitative real-time PCR(qPCR)and WB were used to further analyze PKMYT1 expression.(2)mOBs were treated with PKMYT1 inhibitor GSK-1520489A of different concentrations to screen the optimal one,and all subjects were then further divided into a control,a GC,a GSK-1520489A,and a GC+GSK-1520489A group.Later,the expression of PK-MYT1 and apoptosis-related proteins BCL-2 and cleaved caspase 3/9 of all groups were detected us-ing WB,and cell viability and cytotoxicity were evaluated by CCK8 assay,with cell proliferation by using 5-ethynyl-2'-deoxyuridine(EDU)assay and apoptosis by cell live/dead staining and Annexin V-FITC/PI double staining.(3)mOBs were infected with PKMYT1 overexpression lentiviral vectors,and its efficiency was verified by using immunofluorescence,qPCR,and WB.After successful overexpres-sion of PKMYT1,all cells were divided into the control,GC,PKMYT1 overexpression(OE),and OE+GC groups,whose cell proliferation was detected by EDU assay,and apoptosis was assessed by Annexin V-FITC/PI double staining and cell live/dead staining.(4)To verify the changes in PKMYT1 expression in human osteoblasts(hOB),hOBs extracted from human femoral heads of healthy individu-als were chosen into the control group,while those from patients with hormone-induced avascular ne-crosis of the femoral head(hSANFH)were selected into the hSANFH group.Then,PKMYT1 expres-sion in both groups was detected by using qPCR and WB.Results(1)After inducing the differentia-tion of mouse calvarial osteoblastic cells(MC3T3-E1)into mature osteoblasts,under the action of GC,compared with the control group,with the increase of GC concentration,the experimental group showed increased mOB apoptosis(P<0.01)and expression of cleaved caspase 3/9(P<0.01),but de-creased cell viability(P<0.01)and expressionof apoptosis-relatedprotein BCL-2(P<0.01).More-over,according to the proteomic sequencing,significant decrease was observed in the PKMYT1 expres-sion in mature mOBs treated with GC.(2)As to treatment of mOBs with different concentrations of PKMYT1 inhibitor GSK-1520489A,with the increase of concentration,cell viability decreased and cy-totoxicity increased(P<0.001).Moreover,compared with the control group,mOBs proliferation de-creased(P<0.001)and apoptosis increased(P<0.001)in the GSK-1520489A group.Meanwhile,com-pared with the GC group,mOB proliferation decreased(P<0.05)and apoptosis increased significantly(P<0.01)in the GC+GSK-1520489A group.(3)After overexpression of PKMYT1,in comparison with the control group,mOB proliferation increased(P<0.001)but apoptosis did not increase significantly(P>0.05)in the OE group.Moreover,compared with the GC group,mOB proliferation increased(P<0.001)but apoptosis decreased(P<0.001)significantly in the OE+GC group.(4)In hOBs extracted from human femoral head tissues,qPCR and WB results showed that PKMYT1 expression of the hSANFH group was significantly lower than the control group(P<0.001).Conclusion Down regulation of PKMYT1 expression promotes GC-induced apoptosis of mOBs.Conversely,over expression of PK-MYT1 inhibits GC-induced apoptosis of mOBs.Therefore,PKMYT1 may serve as a potential target for the early treatment of SANFH.
2.AMP-activated protein kinase mediates macrophage fatty acid oxidation:an approach to prevent and treat atherosclerosis with traditional Chinese medicine
Panxia CAO ; Zining PENG ; Shanshan LIU ; Tiantian FEI ; Tengyun LIANG ; Mengwen ZHANG ; Hong WU
Chinese Journal of Tissue Engineering Research 2025;29(18):3906-3914
BACKGROUND:The energy metabolism and polarization state of macrophages play a crucial role in the progression of atherosclerosis.Traditional Chinese Medicine(TCM)has shown significant therapeutic potential for prevention and treatment of atherosclerosis by regulating macrophage metabolic pathways.OBJECTIVE:To review the research progress in AMP-activated protein kinase regulation of macrophage energy metabolism and polarization and explore the mechanism of TCM in the prevention and treatment of atherosclerosis.METHODS:A computerized search was conducted on the databases including Web of Science,PubMed,and CNKI,covering relevant literature up to June 2024.The search terms were"AMPK,fatty acid oxidation,macrophage polarization,Traditional Chinese Medicine,atherosclerosis,coronary heart disease"in Chinese and English.A total of 62 articles were finally included for review.RESULTS AND CONCLUSION:The shiftin macrophage energy metabolism from oxidative phosphorylation to glycolysis plays a key role in the progression of atherosclerosis.The activation of AMP-activated protein kinase in macrophages promotes fatty acid oxidation and M2 polarization,exerting anti-inflammatory effects and stabilizing arterial plaques.TCM monomers(such as ginseng,astragalus,and polygonatum)and compounds(such as Huanglian Jiedu Decoction,Yangxin Shumai Granules,and Tiaogan Daozhuo Formula)influence macrophage metabolism and cellular function by regulating the AMP-activated protein kinase pathway and intervening in multiple signaling pathways,such as nuclear factor-κB,peroxisome proliferator-activated receptor γ,and mammalian target of rapamycin,thereby achieving therapeutic effects.Future research should focus on the interactions between AMP-activated protein kinase,metabolism,and polarization pathways,as well as how TCM exerts its therapeutic effects through these pathways,providing new strategies for the treatment of atherosclerosis.
3.Application of PLIBEL and REBA for identifying and assessing the risk of work-related musculoskeletal disorders among medical staff
Tongsu ZHANG ; Ruijie LING ; Jingzhi SUN ; Zhongxu WANG ; Ning JIA ; Chuansha WU ; Yan YANG ; Fei LIU ; Hong YIN
China Occupational Medicine 2025;52(6):618-623
Objective To identify potential ergonomic risk factors of works and quickly assess their risks of developing work-related musculoskeletal disorders (WMSDs) in the medical staff. Methods A total of 188 medical staff were selected as the research objects using a two-stage random sampling method. The method for the identification of musculoskeletal stress factors (PLIBEL) was used to analyze the adverse ergonomic factors in the work process, and the rapid entire body assessment (REBA) was used to quickly assess the whole-body posture load. Results The PLIBEL assessment results showed that various adverse ergonomic factors affected different parts of the body during the work process of medical staff. Specifically, 18 adverse ergonomic factors were identified in the neck, shoulders, and upper back, while 10 adverse ergonomic factors were identified in the elbow, forearm, hand, and lower back. Rehabilitation therapists and nurses engaged in patient handling in general wards and medication preparation and blood collection were exposed to ≥35 adverse ergonomic factors. The REBA assessment showed that the REBA score was 3-12 points for medical staff during their work process. Rehabilitation therapists were classified as having an extremely high ergonomic risk. High-risk occupations included ward housekeeping nurses, surgery assistant nurses, operating-room instrument nurses, and surgeons. Medium-risk occupations included general ward nurses (medication preparation and blood collection, venipuncture/infusion, and patient handling), intensive care unit (ICU) nurses, internal medicine residents, and dentists. Low-risk occupations included administrative front-desk nurses, outpatient internal medicine physicians, and technicians/physicians in ultrasonography, laboratory medicine, physical examination, and occupational health departments. Conclusion Adverse ergonomic factors of medical staff predominantly affect the neck, shoulders, upper back, elbows, forearms, hands, and the lower back during the work process. Rehabilitation therapists, ward housekeeping nurses, ICU nurses, operating-room instrument nurses, and surgeons are high-risk groups for WMSDs. Attention should be paid to the management and control of adverse ergonomic factors for medical staff to prevent the occurrence of WMSDs.
4.Establishment and application of ultra-fast real-time PCR for Brucella detection
Zhen-na XU ; Zhi-peng WU ; Wei-bin HONG ; Zhi-shen GUAN ; Qi-ming LIN ; Zuan-lan MO ; Yi-fei YE ; Hai-yan XIE ; Min LI ; Yan-qiu ZHU ; Xiao-jun LI ; Xian-peng ZHANG
Chinese Journal of Zoonoses 2025;41(3):278-283
This study was aimed at establishing a method of ultra-fast quantitative PCR for Brucella detection.We used an exogenous recombinant plasmid as the internal reference and targeted the T4SS secretion system,an important Brucella viru-lence factor,to design specific primers and probes.The sensitivity,specificity,and repeatability of this method were evaluated,and a standard curve was constructed.The coincidence rate of detection findings with this method versus quantitative PCR was determined.This method markedly decreased the detection time to only 10 minutes.The standard curve demonstrated a good linear relationship(Y=-3.410 7x+38.357,R2=0.998 5)with a low minimum detection limit of 10 copies/μL.The method exhibited good specificity and did not specifically amplify several common clinical bacteria other than Brucella.The de-tection of three concentrations of positive plasmids yielded coefficients of variation(CVs)of 0.20%to 0.91%,thus demonstra-ting the method's excellent repeatability.Furthermore,140 clinical samples were analyzed concurrently with the fluorescence PCR method,which yielded a 100%compliance rate and consistent results.Our findings indicated that the Brucella ultra-fast quantitative PCR was ultrafast;had high sensitivity,high specificity,and good specificity;and can be used for the clinical de-tection of Brucella and emergency investigation of epidemics.Therefore,this method is valuable for the early diagnosis of Bru-cella.
5.Association of Chinese visceral adiposity index and high-sensitivity C-reactive protein with the risk of digestive malignancies
Shuqing CUI ; Chao MA ; Jiaxing LI ; Yunpeng LI ; Ze WANG ; Fei TIAN ; Hong JI ; Xinyu GE ; Shouling WU ; Xiangming MA
Journal of Clinical Hepatology 2025;41(7):1380-1387
Objective To investigate the association of Chinese visceral adiposity index(CVAI)and high-sensitivity C-reactive protein(hs-CRP)with the risk of digestive malignancies in the Kailuan study population,and to provide a basis for the prevention and control of digestive malignancies in the population.Methods A prospective cohort study was conducted,and a total of 94 377 Kailuan workers who participated in the 2006 health examination,had no history of cancer,and had complete data on CVAI,CRP,and related covariates were selected as the observation cohort.According to the levels of CVAI and CRP,the subjects were divided into low CVAI+CRP≤3 mg/L group[CVAI(-)CRP(-)group],low CVAI+CRP>3 mg/L group[CVAI(-)CRP(+)group],high CVAI+CRP≤3 mg/L group[CVAI(+)CRP(-)group],and high CVAI+CRP>3 mg/L group[CVAI(+)CRP(+)group].An analysis of variance was used for comparison of normally distributed continuous data between groups,and the non-parametric Kruskal-Wallis H test was used for comparison of continuous data with skewed distribution between groups;the chi-square test was used for comparison of categorical data between groups.The Cox proportional-hazards regression model was used to assess the impact of CVAI and CRP alone or in combination on the risk of digestive malignancies.Results There were significant differences between the four groups in age,male/female ratio,total cholesterol,triglycerides,high-density lipoprotein cholesterol,systolic blood pressure,diastolic blood pressure,fasting blood glucose,high-sensitivity C-reactive protein,waist circumference,body mass index,marital status,alcohol consumption,smoking,reported income,and physical exercise(all P<0.05).During a mean follow-up time of 14.08±2.76 years,2 043 new-onset cases of digestive malignancies were identified by the end of follow-up on December 31,2021.The Cox proportional-hazards regression model showed that after adjustment for CRP and other factors,compared with the low CVAI group,the high CVAI group had a hazard ratio(HR)of 1.34(95%confidence interval[CI]:1.23-1.47)for the risk of digestive malignancies.After adjustment for CVAI and other factors,compared with the CRP≤3 mg/L group,the CRP>3 mg/L group had an HR of 1.14(95%CI:1.02-1.28)for the risk of digestive malignancies.Compared with the CVAI(-)CRP(-)group(n=40 978),the CVAI(-)CRP(+)group(n=6 210),the CVAI(+)CRP(-)group(n=36 502),and the CVAI(+)CRP(+)group(n=10 687)had an HR of 1.05(95%CI:1.01-1.09,P<0.05),1.32(95%CI:1.20-1.45,P<0.05),and 1.48(95%CI:1.28-1.70,P<0.05),respectively,for the risk of digestive malignancies.As for digestive malignancies at specific locations,the CVAI(+)CRP(+)group had an increased risk of liver cancer,gastric cancer,pancreatic cancer,colorectal cancer,and small intestinal cancer with an HR of 1.35(95%CI:1.05-1.81,P<0.05),1.48(95%CI:1.09-2.00,P<0.05),1.60(95%CI:1.07-2.41,P<0.05),1.76(1.40-2.21,P<0.05),and 3.85(95%CI:1.43-10.33,P<0.05),respectively.Conclusion A high level of CVAI,a high level of CRP,and high levels of CVAI and CRP in combination can all increase the risk of digestive malignancies,among which the high levels of CVAI and CRP in combination may lead to a higher risk.
6.Psychological experience during subsequent pregnancy in women with fetal loss: a meta-synthesis
Fei ZHANG ; Weitao LI ; Liping WU ; Hong LU
Chinese Journal of Modern Nursing 2025;31(10):1357-1363
Objective:To systematically evaluate the psychological experience of women with fetal loss during subsequent pregnancy and to inform future care for women with fetal loss during subsequent pregnancy.Methods:Qualitative studies on the psychological experience of women with fetal loss during subsequent pregnancy was electronically searched in Chinese and English databases such as VIP, China Biology Medicine disc, China National Knowledge Infrastructure, Wanfang Database, Cochrane Library, PubMed, Embase, Web of Science, PsycINFO. The search period was from database establishment to August 15, 2024. Literature quality was assessed using the quality evaluation criteria for qualitative research of the Australia Joanna Briggs Institute Evidence-Based Health Care Center, and data integration and analysis was performed using the aggregative synthesis approach.Results:A total of 11 articles were included. Thirty-four findings were distilled, similar findings were grouped into nine new categories, and three integrative findings were consolidated for the coexistence of positive and negative emotions, the need for multifaceted social support, and strategies to cope with negative emotions during subsequent pregnancy.Conclusions:Women with fetal loss have a complex psychological experience during subsequent pregnancy. Medical and nursing staff should focus on this group of people, identify the psychological state of women in a timely and accurate manner, and provide them with targeted support to help them get through their pregnancy.
7.Dimeric natural product panepocyclinol A inhibits STAT3 via di-covalent modification.
Li LI ; Yuezhou WANG ; Yiqiu WANG ; Xiaoyang LI ; Qihong DENG ; Fei GAO ; Wenhua LIAN ; Yunzhan LI ; Fu GUI ; Yanling WEI ; Su-Jie ZHU ; Cai-Hong YUN ; Lei ZHANG ; Zhiyu HU ; Qingyan XU ; Xiaobing WU ; Lanfen CHEN ; Dawang ZHOU ; Jianming ZHANG ; Fei XIA ; Xianming DENG
Acta Pharmaceutica Sinica B 2025;15(1):409-423
Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.
8.Clinical Efficacy of Xiaoji Hufei Formula in Protecting Children with Close Contact Exposure to Influenza: A Multicenter,Prospective, Non-randomized, Parallel, Controlled Trial
Jing WANG ; Jianping LIU ; Tiegang LIU ; Hong WANG ; Yingxin FU ; Jing LI ; Huaqing TAN ; Yingqi XU ; Yanan MA ; Wei WANG ; Jia WANG ; Haipeng CHEN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Liqun WU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):223-230
ObjectiveTo evaluate the efficacy and safety of Xiaoji Hufei Formula in protecting children with close contact exposure to influenza, and to provide reference and evidence-based support for better clinical prevention and treatment of influenza in children. MethodsA multicenter, prospective, non-randomized, parallel, controlled trial was conducted from October 2021 to May 2022 in five hospitals, including Dongfang Hospital of Beijing University of Chinese Medicine. Confirmed influenza cases and influenza-like illness (ILI) cases were collected, and eligible children with close contact exposure to these cases were recruited in the outpatient clinics. According to whether the enrolled close contacts were willing to take Xiaoji Hufei formula for influenza prevention, they were assigned to the observation group (108 cases) or the control group (108 cases). Follow-up visits were conducted on days 7 and 14 after enrollment. The primary outcomes were the incidence of ILI and the rate of laboratory-confirmed influenza. Secondary outcomes included traditional Chinese medicine (TCM) symptom score scale for influenza, influenza-related emergency (outpatient) visit rate, influenza hospitalization rate, and time to onset after exposure to influenza cases. ResultsA total of 216 participants were enrolled, with 108 in the observation group and 108 in the control group. Primary outcomes: (1) Incidence of ILI: The incidence was 12.0% (13/108) in the observation group and 23.1% (25/108) in the control group, with the observation group showing a significantly lower incidence (χ2=4.6, P<0.05). (2) Influenza confirmation rate: 3.7% (4/108) in the observation group and 4.6% (5/108) in the control group, with no statistically significant difference. Secondary outcomes: (1) TCM symptom score scale: after onset, nasal congestion and runny nose scores differed significantly between the two groups (P<0.05), while other symptoms such as fever, sore throat, and cough showed no significant differences. (2) Influenza-related emergency (outpatient) visit rate: 84.6% (11 cases) in the observation group and 96.0% (24 cases) in the control group, with no significant difference. (3) Time to onset after exposure: The median onset time after exposure to index patients was 7 days in the observation group and 4 days in the control group, with a statistically significant difference (P<0.05). ConclusionIn previously healthy children exposed to infectious influenza cases under unprotected conditions, Xiaoji Hufei formula prophylaxis significantly reduced the incidence of ILI. Xiaoji Hufei Formula can be recommended as a specific preventive prescription for influenza in children.
9.Clinical Efficacy of Xiaoji Hufei Formula in Protecting Children with Close Contact Exposure to Influenza: A Multicenter,Prospective, Non-randomized, Parallel, Controlled Trial
Jing WANG ; Jianping LIU ; Tiegang LIU ; Hong WANG ; Yingxin FU ; Jing LI ; Huaqing TAN ; Yingqi XU ; Yanan MA ; Wei WANG ; Jia WANG ; Haipeng CHEN ; Yuanshuo TIAN ; Yang WANG ; Chen BAI ; Zhendong WANG ; Qianqian LI ; He YU ; Xueyan MA ; Fei DONG ; Liqun WU ; Xiaohong GU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(21):223-230
ObjectiveTo evaluate the efficacy and safety of Xiaoji Hufei Formula in protecting children with close contact exposure to influenza, and to provide reference and evidence-based support for better clinical prevention and treatment of influenza in children. MethodsA multicenter, prospective, non-randomized, parallel, controlled trial was conducted from October 2021 to May 2022 in five hospitals, including Dongfang Hospital of Beijing University of Chinese Medicine. Confirmed influenza cases and influenza-like illness (ILI) cases were collected, and eligible children with close contact exposure to these cases were recruited in the outpatient clinics. According to whether the enrolled close contacts were willing to take Xiaoji Hufei formula for influenza prevention, they were assigned to the observation group (108 cases) or the control group (108 cases). Follow-up visits were conducted on days 7 and 14 after enrollment. The primary outcomes were the incidence of ILI and the rate of laboratory-confirmed influenza. Secondary outcomes included traditional Chinese medicine (TCM) symptom score scale for influenza, influenza-related emergency (outpatient) visit rate, influenza hospitalization rate, and time to onset after exposure to influenza cases. ResultsA total of 216 participants were enrolled, with 108 in the observation group and 108 in the control group. Primary outcomes: (1) Incidence of ILI: The incidence was 12.0% (13/108) in the observation group and 23.1% (25/108) in the control group, with the observation group showing a significantly lower incidence (χ2=4.6, P<0.05). (2) Influenza confirmation rate: 3.7% (4/108) in the observation group and 4.6% (5/108) in the control group, with no statistically significant difference. Secondary outcomes: (1) TCM symptom score scale: after onset, nasal congestion and runny nose scores differed significantly between the two groups (P<0.05), while other symptoms such as fever, sore throat, and cough showed no significant differences. (2) Influenza-related emergency (outpatient) visit rate: 84.6% (11 cases) in the observation group and 96.0% (24 cases) in the control group, with no significant difference. (3) Time to onset after exposure: The median onset time after exposure to index patients was 7 days in the observation group and 4 days in the control group, with a statistically significant difference (P<0.05). ConclusionIn previously healthy children exposed to infectious influenza cases under unprotected conditions, Xiaoji Hufei formula prophylaxis significantly reduced the incidence of ILI. Xiaoji Hufei Formula can be recommended as a specific preventive prescription for influenza in children.
10.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.

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