Aging has emerged as a cutting edge and hotspot in global life science field， with anti-aging and geriatric disease prevention and treatment becoming critical issues urgently demanding solutions in international medical communities. In the face of the challenge of accelerating global population aging， in-depth exploration of aging mechanisms and the development of effective intervention strategies hold significant scientific and clinical value. This study supported by the national key research and development program of China， employed the essence-Qi-spirit theory of Qiluo doctrine as its guiding framework， focusing on the key scientific issue of the core traditional Chinese pathogenesis of aging， namely "depletion of kidney essence， deficiency of primordial Qi， and impairment of body and spirit". The treatment principle of "tonifying the kidney to replenish essence， harmonizing Yin and Yang， warming and invigorating primordial Qi， and nourishing the body and spirit" was established. Centered on holistic aging， systemic aging， and aging-related diseases， the research integrated multidisciplinary research approaches to construct multi-modal aging models and a multi-dimensional evaluation system， and it utilized multi-omics technologies to deeply analyze aging mechanisms. By systematically reviewing historical kidney-tonifying and anti-aging formulas and combining big data with artificial intelligence technologies， an information database of anti-aging traditional Chinese medicine substance was developed to reveal the differences and synergistic effects of various treatment methods and formulas on anti-aging. Based on this treatment method， the research integrated two millennia of kidney-tonifying medicinal experience to develop the innovative anti-aging traditional Chinese medicine， namely Bazhi Bushen capsules. It was validated that this capsule can delay holistic and systemic aging through multiple targets and mechanisms， thereby elucidating the scientific connotation of the essence-Qi-spirit theory of Qiluo doctrine in guiding anti-aging research from multiple dimensions and providing robust support for leveraging the advantages of traditional Chinese medicine to occupy the commanding heights of international anti-aging research.

Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Spermatogenesis is a highly ordered and spatiotemporally regulated developmental process in the male reproductive system, during which spermatogonial stem cells (SSCs), supported by the seminiferous tubule microenvironment, sequentially undergo mitosis, meiosis, and spermiogenesis to ultimately generate structurally intact spermatozoa. This complex process is accompanied by extensive transcriptional reprogramming, chromatin remodeling, and finely tuned post-transcriptional regulation. Precise control of RNA fate is therefore essential for maintaining the continuity and fidelity of spermatogenesis, and its disruption represents a major molecular basis of male infertility. N⁶-methyladenosine (m⁶A), the most abundant internal RNA modification in eukaryotes, has emerged as a critical regulator of post-transcriptional gene expression. m⁶A methyltransferases (“writers”) catalyze the addition of a methyl group to the N⁶ position of adenosine, m⁶A demethylases (“erasers”) remove the modification, and m⁶A-binding proteins (“readers”) recognize m⁶A-modified transcripts. Through the coordinated actions of these factors, m⁶A regulates transcript fate at multiple levels, including RNA splicing, nuclear export, stability, translation, and decay. Emerging evidence indicates that m⁶A-mediated regulation is essential across multiple stages of spermatogenesis, including SSC self-renewal and differentiation, meiotic progression, maintenance of chromosomal stability, and sperm morphogenesis. Beyond its intrinsic functions in germ cells, m⁶A also contributes to the regulation of the testicular microenvironment. In sertoli cells, m⁶A is involved in maintaining blood-testis barrier integrity, RNA processing, and paracrine signaling, thereby providing structural and metabolic support for germ cell development. In Leydig cells, m⁶A regulates steroidogenesis, particularly testosterone synthesis, and participates in cellular stress responses and metabolic homeostasis. Through these mechanisms, m⁶A indirectly influences spermatogenesis by modulating the functional state of testicular somatic cells, highlighting an integrated regulatory mode that combines cell-intrinsic and microenvironment-mediated effects. Notably, distinct classes of m⁶A regulators exhibit pronounced stage-specific functions and coordinated division of labor, collectively forming a multilayered and dynamic regulatory network. Writers often display dosage- and temporal window-dependent effects; erasers contribute to stage-specific demethylation and functional compensation; while readers function through a “switch-buffer” dual-layer architecture, and RNA-binding proteins (RBPs) participate in substrate selection and post-transcriptional regulation. Importantly, emerging evidence suggests that some m⁶A-related proteins can function through noncanonical mechanisms independent of m⁶A recognition, such as intrinsic RNA-binding activity, helicase function, or ribonucleoprotein complex assembly, thereby expanding the functional landscape of the m⁶A regulatory system. Dysregulation of m⁶A machinery can lead to multiple spermatogenic defects, including impaired SSC self-renewal, meiotic arrest, abnormal chromatin remodeling, and defective sperm formation, ultimately resulting in male infertility. Despite substantial advances, several critical questions remain unresolved, including the distinction between m⁶A-dependent and -independent mechanisms, the spatiotemporal dynamics of m⁶A modifications at single-cell resolution, and the coordination and antagonism among different regulatory factors. In this review, we systematically summarize the dual regulation of spermatogenesis by germ cell-intrinsic mechanisms and the testicular microenvironment, and delineate the molecular mechanisms and stage-specific functions of the dynamic m⁶A regulatory network. We further discuss the current limitations in the field and propose feasible experimental strategies for future investigation. Collectively, this work aims to provide a comprehensive framework for understanding the epitranscriptomic regulation of spermatogenesis and to offer theoretical insights into the pathogenesis and clinical management of male infertility.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Yi and Gui,its physiological characteristics and pathological manifestations are closely related to the lumbar spine.The intervertebral disc,chamber of arthrosis,requires nourishment from qi and blood circulation,as well as support from liver and kidney functions to maintain its health.Chinese medicine master Shi Qi has based on the pathological manifestations of discogenic low back pain patients at different stages and followed the guidelines of the Visceral manifestation theory.Combining more than 60 years of experience in traditional Chinese medicine diagnosis and treatment,he has used external observations to infer internal conditions and examined causes to find solutions.By entering the body from the outside and focusing on the"Homology of Yi and Gui"as a benchmark,he emphasizes the distinctive characteristic of traditional Chinese medicine in medical treatment.He states that"visceral pattern is fundamental"and"qi-blood is first,"emphasizing the importance of treating liver and kidney together.This article aims to draw on the wisdom of Taishan to provide a bridge for colleagues.

Objectives:To investigate the predictive value of Murray's law-based quantitative flow ratio(μQFR)in side branches for long-term clinical prognosis in patients with non-left main bifurcation lesions who underwent simple main branch stenting,and to provide a potential functional assessment standard for intervention decision-making on coronary bifurcation lesions.Methods:A retrospective analysis was conducted in 408 patients with non-left main bifurcation lesions who underwent simple main branch stenting at Lianyungang First People's Hospital and Nanjing First Hospital between July 2018 and January 2021.The study utilized third-generation QFR software to analyze pre-and post-procedure anatomical and functional parameters of the target lesion's main branch and key branches.The primary endpoint was target vessel failure(TVF)events during the 3-year follow-up.Patients were stratified into TVF and non-TVF groups.Baseline characteristics,procedural data,and pre-/post-procedural parameters of target vessels were compared between groups.Multivariable Cox regression was performed to identify predictors of TVF.Diagnostic efficacy of predictors was evaluated using area under the receiver operating characteristic(ROC)curve(AUC)with DeLong's method for comparison.Patients were dichotomized based on the optimal cutoffof post-procedural side branch μQFR,with TVF incidence rates compared via Cox regression and Kaplan-Meier analysis.Results:During 3-year follow-up,54 patients(13.2%)experienced TVF(TVF group),data were compared with 354 patients(86.76%)without TVF(non-TVF group).The TVF group showed higher post-procedural side branch diameter stenosis([32.93±17.80]%vs.[22.62±11.96]%,P<0.001)and lower μQFR(0.80±0.10 vs.0.89±0.07,P<0.001).Multivariate Cox regression identified higher post-procedural side branch μQFR as an independent protective factor against 3-year TVF(per 0.01 increase:HR=0.903,95%CI:0.850-0.959,P<0.001).ROC curves indicated that post-procedural side branch μQFR had moderate diagnostic efficacy for predicting 3-year TVF(AUC=0.769,95%CI:0.678-0.861,P<0.001),with a significantly higher AUC value than post-operative side branch area stenosis and minimal lumen diameter(both P<0.001),the optimal cutoffvalue was 0.84.Multivariate Cox regression and Kaplan-Meier survival analysis revealed markedly higher 3-year TVF rates in patients with μQFR≤0.84 compared to patients with μQFR>0.84(HR=4.007,95%CI:2.342-6.855,P<0.001;28.3%vs.7.9%,log-rank P<0.001).Conclusions:For patients with bifurcation lesions not involving the left main,the immediate post-procedural side branch μQFR could better predict 3-year TVF than anatomical indices.Maintaining post-stenting side branch μQFR>0.84 may optimize clinical outcomes when using a single-stent strategy.

Objective To screen and analyze key genes in rabbit corneal alkali burns based on transcriptomics se-quencing technology and bioinformatics techniques.Methods Thirty healthy male New Zealand rabbits were randomly di-vided into 2 groups(n=15 per group):The control group received no intervention,while the alkali burn group underwent corneal alkali burn modeling.Histological evaluation of corneal tissues was performed via hematoxylin-eosin(HE)stai-ning.Transcriptome sequencing was conducted for library construction and sequencing.Differentially expressed genes(DEGs)were identified using DESeq2,followed by Gene Ontology(GO)functional enrichment analysis and Kyoto Ency-clopedia of Genes and Genomes(KEGG)pathway analysis.A protein-protein interaction(PPI)network was constructed to screen hub genes,and RT-PCR was employed to validate mRNA expression levels of key genes.Results HE staining revealed orderly arranged corneal stromal layers and scattered stromal cells in the control group,whereas the alkali burn group exhibited stromal edema,thickened collagen fibers with loose/disorganized alignment,and increased fibroblast and inflammatory cell infiltration.Compared to the control group,1 827 significant DEGs were identified in the alkali burn group,including 1 495 upregulated and 332 downregulated genes.GO analysis showed biological processes such as immune response,plasma membrane,and identical protein binding.KEGG analysis indicated that DEGs were enriched in pathways related to cancer,lipid and atherosclerosis,and neuroactive ligand-receptor interaction.The PPI network screened 11 key genes:neutrophil cytosolic factor 1(NCF1),neutrophil cytosolic factor 2(NCF2),matrix metallopeptidase 2(MMP2),ma-trix metallopeptidase 9(MMP9),interleukin-1α(IL-1α),interleukin-1β(IL-1β),interleukin-6(IL-6),interleukin-8(CXCL8),cluster of differentiation 4(CD4),C-C motif ligand 2(CCL2)and tumor necrosis factor(TNF).RT-PCR valida-tion revealed that the mRNA expression levels of key genes in the corneal tissues of the alkali burn group were significantly higher than those in the control group(all P＜0.05),consistent with the transcriptomic sequencing results.Conclusion Based on the rabbit corneal alkali burn model,this study identified 11 key genes(NCF1,NCF2,MMP2,MMP9,IL-1α,IL-1β,IL-6,CXCL8,CD4,CCL2 and TNF)through transcriptomics and bioinformatics analysis.

AIM:To investigate the mechanism by which interleukin-13(IL-13)influences vascular smooth muscle cell(VSMC)phenotypic transformation and subsequently contributes to vascular intimal hyperplasia in rats.METHODS:A total of 32 male SD rats,aged 5～7 weeks and weighing 330～360 g,were randomly divided into 4 groups(n=8 per group):normal(Nor)group,normal treatment(Nor+IL-13 neutralizing antibody,Nor+IL-13Nab)group,inju-ry(Inj)group,and injruy treatment(Inj+IL-13Nab)group.A 2F balloon catheter was used to induce mechanical injury in the left common carotid artery of SD rats to establish a vascular intimal hyperplasia model.Hematoxylin-eosin staining was performed to observe vascular structural changes.Enzyme-linked immunosorbent assay(ELISA)kits were used to measure IL-13 and transforming growth factor-β1(TGF-β1)levels.Human aortic smooth muscle cells(HA-SMCs)were cultured in vitro.Flow cytometry was conducted to assess peripheral blood CD4+IL-13+T cell content.Real-time quantita-tive PCR(RT-qPCR)was employed to evaluate gene expression levels of α-smooth muscle actin,osteopontin,calponin,collagen type Ⅰ/Ⅲ,proliferating cell nuclear antigen and Ki-67 antigen.Transwell and scratch wound assays were per-formed to assess cell migration.RESULTS:Compared with the model group,administration of IL-13Nab significantly in-hibited vascular intimal hyperplasia induced by mechanical vascular injury by antagonizing high plasma IL-13 levels(P<0.01).Immunofluorescence and mRNA analysis showed that neutralizing high plasma IL-13 suppressed collagen accumu-lation(P<0.01)and VSMC phenotypic transformation(P<0.01)in the injured vessels but did not inhibit peripheral blood CD4+IL-13+T cell activation.Incubation of HA-SMCs with recombinant human IL-13(rhIL-13)promoted cell pro-liferation and migration(P<0.01)as well as phenotypic transformation(P<0.01).Additional evidence suggested that rhIL-13-induced HA-SMC phenotypic transformation was associated with the regulation of TGF-β1 secretion by HA-SMCs.CONCLUSION:Interleukin-13 promotes vascular intimal hyperplasia by regulating VSMC phenotypic transformation through TGF-β1 secretion in rat models.

Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38％)and primary myocardial cells(the inhibition rate was 49.7％,with P＜0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P＜0.01),decreasing the hy-drated particle size(P＜0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.