Abstract: Optical coherence tomography (OCT) is a non-invasive imaging technique that uses visible and near-infrared light to provide detailed cross-sectional images of human tissue, widely used for the examination of fundus diseases. Currently, OCT is mainly divided into two types: time-domain and Fourier-domain, with the Fourier-domain further divided into spectral-domain and swept-source types. These types of OCT each have their own characteristics in terms of image acquisition methods, scanning speed, axial and lateral resolution, and imaging range. Swept-source OCT (SS-OCT) often uses scanning light sources with wavelengths of 1 050 nm or 1 300 nm, which have strong tissue penetration capabilities. Combined with faster scanning speeds and a wider scanning range, it can clearly display the deep structures of the retina and choroid, demonstrating unique advantages in the quantitative assessment of the fundus. Based on recent research advances, this paper will review the application of SS-OCT in ocular diseases, aiming to provide a reference for early diagnosis, elucidation of pathological mechanisms, and evaluation of therapeutic effects in ophthalmology.
Key words: swept-source optical coherence tomography; fundus diseases; choroidal vessel volume index; non-invasive imaging technology; fundus disease examination
（Acta Laser Biology Sinica, 2025, 34(6): 481-488）

Abstract: Telomeres are specialized structures at the ends of chromosomes, composed of repetitive DNA sequences and associated proteins. Their primary role is to maintain chromosomal stability and integrity by preventing progressive loss of chromosome ends and unwanted chromosomal rearrangements. Changes in telomere length are closely linked to a variety of diseases, including cancer, aging, and cardiovascular disorders. Therefore, measuring telomere length holds significant biological importance. Driven by technological advances, a diverse array of methods for telomere-length assessment has emerged, forming a rich technical landscape. Each method carries distinct advantages and limitations, making it suitable for particular research goals and application contexts. This review summarizes current findings on all major telomere-measurement techniques and offers recommendations for future technological development, emphasizing the potential of integrating innovative approaches to enhance disease diagnosis and treatment strategies, providing researchers and clinicians with a guide for selecting optimal methods and facilitating the translation of telomere biology into precise diagnostics and personalized therapies.
Key words: telomere length; detection methods; cellular senescence; biomarker; accurate diagnosis
（Acta Laser Biology Sinica, 2025, 34(6): 496-503）

Abstract: Nasopharyngeal carcinoma (NPC) is a highly prevalent malignant tumor in Southeast Asia and Southern China, with a strong association with Epstein-Barr virus (EBV) infection. Although early-stage NPC exhibits favorable local control with chemoradiotherapy, recurrence, metastasis, and drug resistance remain major clinical challenges. Immune cells play a critical role in tumor progression, among which macrophages — originating from bone marrow hematopoietic stem cells (differentiated via monocytes) — serve as core components of innate immunity, widely distributed in tissues to regulate inflammation and tissue repair. Tumor-associated macrophages (TAMs), a central constituent of the tumor microenvironment, are recruited and differentiated from monocytes by tumor-secreted cytokines, displaying high plasticity with two primary subtypes: pro-tumor M2 and anti-tumor M1. M2-type TAMs drive tumor progression by promoting proliferation, invasion, angiogenesis, and immunosuppression, e. g. , overexpressing programmed death-ligand 1 (PD-L1) and secreting interleukin-10 (IL-10). In contrast, M1-type TAMs exert direct anti-tumor effects through antibody-dependent cellular cytotoxicity (ADCC), reactive oxygen species/nitric oxide (ROS/NO)-induced apoptosis, and activation of adaptive immunity via enhanced antigen presentation and CD8+ T-cell infiltration. Clinical studies indicate that high infiltration of M2-type TAMs correlates with reduced patient survival, chemoradiotherapy resistance, and diminished immunotherapy response, highlighting their potential as prognostic biomarkers and therapeutic targets. Current therapeutic strategies targeting TAMs include: inhibiting M2 recruitment by blocking the CCL2-CCR2/CSF-1R signaling axis; enhancing M1 function via epigenetic regulation or CD40 bispecific antibodies; depleting pro-tumor TAMs using clodronate liposomes or photothermal/photodynamic therapy; and combining with chemoradiotherapy or immunotherapy. This article systematically reviews the origin, classification, functions, and clinical relevance of TAMs in NPC, summarizes advancements in targeted therapeutic strategies, and provides theoretical and practical insights for individualized NPC treatment.
Key words: nasopharyngeal carcinoma; tumor-associated macrophages; tumor microenvironment; macrophage polarization; targeted therapy
（Acta Laser Biology Sinica, 2025, 34(6): 504-514）

Abstract: Lactate has long been regarded as a metabolic byproduct of glycolysis. Recent studies, however, have revealed its pivotal role in regulating the tumor immune microenvironment (TIME). Excess lactate accumulation disrupts metabolic balance, suppresses the activity of T cells and NK cells, and induces the polarization of immunosuppressive cells, thereby reshaping the immune landscape of TIME. Meanwhile, lactylation, as a novel post-translational protein modification, mediates the regulation of epigenetic events by metabolic signals, promoting the expression of immune-related genes, such as PD-L1, IL-10, and Arg1, and further enhancing immune evasion. This review focuses on the metabolic-epigenetic coordination of lactate and lactylation in TIME, elaborating on lactate production and shuttling, immune-cell metabolic interactions, and the clinical potential of targeting lactate homeostasis. A deeper understanding of the lactate-lactylation axis may provide novel molecular targets and research directions for future tumor immunotherapy.
Key words: lactate; lactylation; tumor metabolism; immune regulation; therapeutic resistance
（Acta Laser Biology Sinica, 2025, 34(6): 515-522）

Abstract: To evaluate the efficacy differences of Portulaca oleracea extract, intense pulsed light, and their combination in treating hormone-dependent dermatitis (HDD) in guinea pigs, and to explore their mechanisms of action, this study selected 30 guinea pigs and randomly divided them into 5 groups (6 per group). One group served as the control, while the remaining four groups developed an HDD model using 0.05% clobetasol propionate ointment. After the model was established, one group was designated as the model group, and the other three groups received three treatments: topical application of Portulaca oleracea extract, 590 nm intense pulsed light therapy and the combination of the two. Changes in skin lesions were directly observed, and histopathological alterations were assessed via haematoxylin-eosin staining. Enzyme-linked immunosorbent assay (ELISA) was employed to measure tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), cysteinyl aspartate specific proteinase-14 (Caspase-14) and loricrin (LOR) expression levels in the lesion tissues. The ELISA results revealed elevated IL-6 and TNF-α expression alongside reduced Caspase-14 and LOR expression in the lesion tissues of guinea pigs in the model group (P<0.05). In addition, IL-6 and TNF-α levels were reduced and Caspase-14 and LOR levels were increased in the three treatment groups, and the effect was more significant in the combination group (P<0.05). The study indicates that Portulaca oleracea extract improves guinea pig HDD through anti-inflammatory effects and skin barrier repair, with synergistic enhancement when combined with intense pulsed light. This study aimed to investigate the synergistic therapeutic effects of Portulaca oleracea extract and intense pulsed light in a guinea pig HDD model and elucidate its potential mechanisms of action, thereby providing a reference for clinical treatment.
Key words: hormone-dependent dermatitis; Portulaca oleracea; intense pulsed light; guinea pig; collaborative therapeutic mechanism
（Acta Laser Biology Sinica, 2025, 34(6): 523-529）

Abstract: The GCN2-eIF2α pathway regulates cell growth and serves as a key component of the integrated stress response (ISR). In malignant tumors, cancer cells reside in a microenvironment characterized by chronic hypoxia and nutrient deprivation. Under such conditions, the level of amino acid catabolism increases, which activates the GCN2-eIF2α pathway and inhibits protein synthesis to maintain the cellular homeostasis of cancer cells. In this study, a total of 9 pairs of tissue samples, including cancerous tissues and their matched adjacent normal tissues, were collected from patients diagnosed with non-small cell lung cancer (NSCLC). A combined analysis using histology, transcriptomics, qRT-PCR, and Western blotting was performed to investigate the molecular mechanism by which the GCN2-eIF2α pathway regulates cancer cell proliferation. Results of paraffin sections showed that in the tumor tissues of lung cancer patients, alveolar cells were densely packed, alveolar septa were narrow, and nuclear staining was heterogeneous, exhibiting typical malignant histopathological features. Transcriptomic studies revealed that the enriched pathways and differentially expressed genes among samples were identified based on gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment results from the transcriptome, which confirmed that the GCN2-eIF2α pathway plays an important role in lung carcinogenesis. Further screening was performed to select key genes for validation at the molecular and protein levels. qRT-PCR results demonstrated that these genes were expressed in both cancerous and normal tissue cells, with their expression levels mostly upregulated in cancerous tissue cells (P<0.05), which was consistent with the gene abundance analysis results in the transcriptome. At the protein level, the expression levels of general control nonderepressible 2 kinase (GCN2) and eukaryotic translation initiation 2α (eIF2α) in cancerous tissues were significantly higher than those in adjacent normal tissues, indicating that the GCN2-eIF2α pathway is implicated in lung carcinogenesis. This study can provide a reference for eIF2α and GCN2 to serve as new therapeutic targets for tumors, and also propose the possibility of inhibiting cancer cell progression by suppressing GCN2-mediated phosphorylation of eIF2α, thereby offering a solution to address the limitations of current anti-tumor therapies.
Key words: lung cancer; GCN2-eIF2α pathway; transcriptomics; cancer pathogenesis; targeted tumor therapy
（Acta Laser Biology Sinica, 2025, 34(6): 530-540）

Abstract: In the monitoring, diagnosis, and clinical management of fundus diseases, the visualization of fundus vascular structures is recognized as of paramount importance for accurate pathological assessment. Laser speckle contrast imaging, a well-established non-invasive optical imaging technique, is capable of achieving vessel visualization and real-time dynamic blood flow monitoring, as contrast agents are not required. However, significant noise is inevitably introduced by the conventional contrast calculation method that employs a fixed-size sliding window. In the present study, laser speckle contrast images are aligned and fused with vascular structural images acquired via LED light illumination. Subsequent to fusion, the composite images are segmented into regional subsets, and region-specific optimal pixels are selected based on the variance criterion to perform contrast computation. Within the vascular boundary region, the geometry and dimensions of the analysis window are dynamically adjusted to adapt to the local vascular morphology. The results indicate that the contrast has been enhanced by 67.61%. Moreover, in deeper vascular imaging, the proposed method is found to yield superior noise reduction performance and enhanced image quality, thereby providing support for the diagnosis and management of ocular diseases.
Key words: laser speckle contrast imaging; fundus; blood flow; image registration; adaptive window
（Acta Laser Biology Sinica, 2025, 34(6): 541-550）

Abstract: To investigate the therapeutic efficacy and underlying mechanisms of cylindrin combined with metronidazole for traumatic oral ulcers, we randomly assigned 36 SD rats to different groups. After successful modeling, the rats received respective drug treatments for 7 days. General conditions of each group were observed and recorded. Pathological changes in oral mucosa were examined via hematoxylin-eosin staining, while plasma levels of IL-1 and IL-6 were detected using ELISA. The results showed that the rats in each group exhibited symptoms after successful modeling, such as hunching and curling, reduced behaviors and lethargy, as well as decreased appetite. After drug intervention, these symptoms improved, for one example, the weight of the high-dose group of combined medication is the closest to the blank control group. It was observed that the oral ulcer wounds in the high-dose group of combined medication showed the best effect by treatment. The result of hematoxylin-eosin staining revealed pathological changes in the epithelial structure of the modeling group, while the high-dose group of combined medication showed the best recovery after treatment. Compared to the cylindrin group and the metronidazole group, the results of ELISA indicated that the expression levels of IL-1 and IL-6 were significantly reduced in both the high and low-dose groups of combined medication (P<0.001). This study demonstrated that the mixed solution of cylindrin and metronidazole suppresses the expression of inflammatory factors IL-1 and IL-6, which contributes a more excellent therapeutic influence than single-agent on traumatic oral ulcers. It is expected to provide a better strategy for the clinical treatment of oral ulcers.
Key words: traumatic oral ulcer; cylindrin; metronidazole solution; combination therapy; inflammatory factor
（Acta Laser Biology Sinica, 2025, 34(6): 551-560）

Abstract: To investigate the effects of propofol (Pro) on hypoxia/reoxygenation (H/R) injury in H9C2 cardiomyocytes via regulation of the silent information regulator 1(SIRT1)/p53 signaling pathway-mediated ferroptosis, an in vitro H9C2 cell H/R model was established. Cells were divided into the following groups: Control group, H/R group, H/R+Pro group, H/R+Pro+erastin group, H/R+Pro+si-NC group, and H/R+Pro+si-SIRT1 group. The cytotoxic effect of Pro on H9C2 cells was assessed using the cell counting kit-8 (CCK-8) assay. Intracellular reactive oxygen species (ROS) levels were measured using the 2', 7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe. Mitochondrial ultrastructure was examined by transmission electron microscopy (TEM). Oxidative stress markers were quantified using corresponding assay kits. Expression levels of ferroptosis-related proteins were detected by Western blot. Results demonstrated that compared to the Control group, the H/R group exhibited significantly reduced cell viability, elevated levels of ROS and malondialdehyde (MDA), decreased levels of catalase (CAT) and superoxide dismutase (SOD), nuclear membrane rupture, increased mitochondrial membrane density, loss of mitochondrial cristae, swelling and rupture of mitochondria, increased Fe2+ content and lactate dehydrogenase (LDH) activity, elevated levels of acyl-CoA synthetase long-chain family member 4 (ACSL4) and p53, and reduced levels of glutathione peroxidase 4 (GPX4) and SIRT1 (P<0.05). Pro treatment significantly ameliorated H/R injury, increasing cell viability and elevating SOD, CAT, GPX4, and SIRT1 levels, while reducing Fe2+ content, ROS, MDA, ACSL4, and p53 levels, and restoring mitochondrial structure (P<0.05). Erastin partially reversed the protective effects of Pro (P<0.05). Conversely, si-SIRT1 completely abolished the effects of Pro, resulting in decreased GPX4 levels and increased Fe2+ content and ACSL4 levels (P<0.05). This study revealed that Propofol likely protects cardiomyocytes against H/R injury by activating the SIRT1/p53 pathway to inhibit ferroptosis. This finding provides crucial mechanistic insight into Propofol-mediated cardioprotection and suggests a potential novel strategy for the prevention and treatment of myocardial ischemia-reperfusion injury.
Key words: propofol; silent information regulator 1/p53 signaling pathway; ferroptosis; cardiomyocytes; hypoxia/reoxygenation injury
（Acta Laser Biology Sinica, 2025, 34(6): 561-568）

Abstract: The purpose of this study was to investigate the effects of bone marrow mesenchymal stem cells (BMSCs) on motor function recovery, neurotrophic factor expression and PI3K/AKT/GSK-3β/β-catenin signaling pathway in rats with spinal injury. Thirty SD rats were randomly divided into normal group, model group and BMSCs group. After the spinal injury model was established in the model group and the BMSCs group, the BMSCs group was locally injected with BMSCs suspension, and the normal group and the model group were injected with the same amount of normal saline. BBB score and inclined plate test were used to evaluate the behavioral function. Hematoxylin-eosin (HE) staining was used to observe the histopathological changes. The levels of serum neurotrophic factor-3 (NT-3), nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were detected by enzyme-linked immunosorbent assay. The expression levels of pathway proteins were detected by Western blotting. The results showed that compared with the model group, BMSCs treatment significantly improved the motor function score and inclined plate angle of rats, reduced edema, necrosis and inflammatory response of spinal cord tissue, and up-regulated the level of neurotrophic factors and the expression of PI3K/AKT/GSK-3β/β-catenin pathway protein. The results showed that BMSCs transplantation could promote the release of neurotrophic factors by activating the PI3K/AKT/GSK-3β/β-catenin pathway, thereby improving the recovery of motor function after spinal injury. Motor dysfunction and insufficient nerve repair after spinal injury are clinical problems. This study focused on the repair effect of BMSCs, explored its effect on the recovery of motor function and the expression of neurotrophic factors in rats, and the regulatory mechanism of PI3K/AKT/GSK-3β/β-catenin pathway, so as to provide experimental basis for revealing the neural repair potential of BMSCs and developing targeted therapy strategies for spinal injury.
Key words: bone marrow mesenchymal stem cells; spinal injury; motor function; neurotrophic factor; pI3K/AKT/GSK-3β/β-catenin pathway
（Acta Laser Biology Sinica, 2025, 34(6): 569-576）