1.The Regulatory Effects and Mechanisms of Piezo1 Channel on Chondrocytes and Bone Metabolic Dysregulation in Osteoarthritis
Yan LI ; Tao LIU ; Yu-Biao GU ; Hui-Qing TIAN ; Lei ZHANG ; Bi-Hui BAI ; Zhi-Jun HE ; Wen CHEN ; Jin-Peng LI ; Fei LI
Progress in Biochemistry and Biophysics 2026;53(3):564-576
Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca2+, K+, and Na+, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca2+ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca2+ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca2+ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.
2.Modified Huangqi Jianzhong Decoction Alleviates Gastric Precancerous Conditions in Mice by Regulating Mitochondrial Function via FoxO3/ROS Signaling Pathway
Yueqiang WEN ; Li ZHOU ; Dan LUO ; Maoyuan ZHAO ; Jun HAN ; Xueyi LI ; Jianguo LI ; Zhelin HE ; Tao SHEN ; Jinhao ZENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(14):216-225
ObjectiveTo investigate the therapeutic effects and mechanisms of modified Huangqi Jianzhong decoction (HQJZ) on gastric precancerous conditions (GPC). MethodsIn the cell experiment, human gastric mucosal epithelial cells underwent malignant transformation induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) for the modeling of GPC (MC cells). The cells were allocated into four groups: control , model, low-dose HQJZ (HQJZ-L), and high-dose HQJZ (HQJZ-H). The control and model groups were cultured with the complete medium, while HQJZ-L and HQJZ-H groups received additional interventions with HQJZ at low (0.5 g·L-1) and high (1.0 g·L-1) doses, respectively. Cell counting kit-8 (CCK-8) assay was used to evaluate cytotoxicity, Transwell assay to assess cell invasion, Annexin V-FITC/PI staining to detect apoptosis, immunofluorescence assay to analyze reactive oxygen species (ROS) expression and mitochondrial autophagy, and Western blot to verify expression of proteins in key pathways. In the animal experiment, the GPC model was established in healthy BALB/c mice through MNNG induction. Twenty-four mice were allocated into four groups: control, model, HQJZ-L, and HQJZ-H. Control and model groups received normal saline (10 mL·kg-1·d-1) orally, while HQJZ-L and HQJZ-H groups were administrated with low-dose (6.24 g·kg-1·d-1) and high-dose (12.48 g·kg-1·d-1) HQJZ, respectively. After treatment, hematoxylin‑eosin (HE) staining and AB-PAS staining were performed to observe histopathological changes in the gastric tissue. Immunofluorescence assay was used to detect reactive oxygen species (ROS) and microtubule-associated protein 1 light chain 3 (LC3) levels in the gastric mucosa, TdT-mediated dUTP nick-end labeling (TUNEL) staining to assess apoptosis rates, and Western blotting and immunohistochemistry (IHC) to analyze the expression levels of Ki67, proliferating cell nuclear antigen (PCNA), and foxhead box O3 (FoxO3). ResultsCell viability assays showed that HQJZ dose-dependently reduced MC cell viability compared with the control group (P<0.05, P<0.01). Transwell assays revealed that the model group exhibited enhanced cell invasion compared with the control group (P<0.05). Compared with the model group, HQJZ treatment attenuated the cell invasion (P<0.05). Gastric mucosal pathology in mice demonstrated that compared with the control group, the model group showed elevated HE and AB-PAS pathological scores (P<0.05), while HQJZ treatment reduced these scores (P<0.05). Transmission electron microscopy revealed increased mitochondrial number and volume in the model group compared with the control group. HQJZ treatment resulted in abnormal mitochondrial structure and significant alterations in rough endoplasmic reticulum morphology and distribution, presenting as dilated and hollow forms. Mitochondrial and apoptosis assessments indicated that compared with the control group, the model group exhibited enhanced Mito Tracker Green fluorescence (P<0.05), no significant change in DCFH-DA fluorescence, Mito Tracker Red CMXRos fluorescence, ROS immunofluorescence, or malondialdehyde (MDA) level, increased GSH level (P<0.05), enhanced LC3 fluorescence (P<0.05), no significant change in apoptosis rate, and elevated ATP content in cells and mouse serum (P<0.05). Compared with the model group, HQJZ treatment reduced Mito Tracker Green fluorescence (P<0.05), increased DCFH-DA fluorescence, Mito Tracker Red fluorescence, MDA level, LC3 fluorescence, and apoptosis rate (P<0.05), and decreased cellular ATP content (P<0.05). The HQJZ-L group showed no significant change in ROS immunofluorescence or GSH level, whereas the HQJZ-H group demonstrated enhanced ROS immunofluorescence and glutathione (GSH) level (P<0.05). Immunohistochemistry and Western blotting revealed that compared with the control group, the model group exhibited increased numbers of PCNA- and Ki67-positive cells (P<0.05) and elevated protein levels of FoxO3, sirtuin 1 (SIRT1), and B-cell lymphoma 6 (Bcl-6) (P<0.05). HQJZ treatment reduced the numbers of PCNA- and Ki67-positive cells (P<0.05) and lowered the protein levels of FoxO3, SIRT1, and Bcl-6 (P<0.05). ConclusionHQJZ alleviates the progression of gastric precancerous lesions by regulating mitochondrial function via the FoxO3/ROS pathway and promoting apoptosis of GPC-malignant cells.
3.Statistical analysis of vector monitoring in port areas of Shandong Province from 2017 to 2023
Huan-mei HAN ; Tao ZHANG ; Zhi-ping SU ; Rong-jun YAN ; Wei HUANG ; Wen-wen ZHANG
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):121-127
Objective To provide a scientific basis for vector prevention and control in port areas, vector monitoring has been conducted continuously to characterize the composition, density, and seasonal fluctuations of vectors across 21 port-areas of Shandong province from 2017 to 2023. Methods In accordance with the Regional Vector Monitoring Plan for Frontier Ports, vector surveillance of mosquitoes, flies, cockroaches, rodents, and other disease vectors was performed. Data were analyzed to describe vector community composition and identify seasonal fluctuations. Results A total of 601 rodents belonging to 1 family, 4 genera, and 4 species were captured. Three dominant rodent species inhabit port areas. In addition, 88 104 mosquitoes were captured and classified into 3 subfamilies, 4 genera, and 12 species; 38 959 flies were trapped and classified into 8 families,31 genera, and 51 species, including 9 dominant fly species in port-areas; and 54 672 captured cockroaches were classified into 2 families,4 genera, and 4 species, with Blattella germanica as the dominant species. Conclusions Significant vector community changes(P<0.005)have been identified after the epidemic. To improve the pertinence and efficacy of port health quarantine work, continuous and strong attention should be paid to vector compositions and population densities at Shandong ports.
4.Relationship between shear wave elastography parameters and APRI and Child-Pugh grading in patients with hepatitis B cirrhosis
Wen ZHAO ; Mengsi XU ; Chunfeng YU ; Jun CHEN
Chinese Journal of Radiological Health 2026;35(3):433-438
Objective To investigate the associations of shear wave elastography (SWE) parameters and AST-to-platelet ratio index (APRI) with Child-Pugh grade in patients with hepatitis B cirrhosis. Methods The clinical data of 103 patients with hepatitis B cirrhosis who underwent SWE and APRI testing between July 2022 and October 2024 were retrospectively analyzed. These patients comprised the observation group. The clinical data of 99 non-cirrhotic patients were retrospectively analyzed and the patients were enrolled as control group. Liver stiffness (LS), spleen stiffness (SS), APRI and Child-Pugh score were compared in the two groups. According to Child-Pugh grading, the 103 cirrhosis patients were divided into three groups: Group A (grade A, 5-6 points, n=35), Group B (grade B, 7-9 points, n=38), and Group C (grade C, 10-15 points, n=30). SWE parameters and APRI were compared among the three groups. Pearson correlation analysis was used to examine the correlations of LS, SS, and APRI with Child-Pugh score. Results SWE parameters, APRI, and Child-Pugh scores were significantly higher in the observation group than in the control group (P<0.05). Among the three cirrhosis groups, SWE parameters and APRI were highest in Group C, followed by Group B, and lowest in Group A (P<0.05). SWE parameters and APRI were significantly positively correlated with Child-Pugh score (P<0.05). Conclusion SWE parameters and APRI are positively correlated with Child-Pugh grade and are useful for assessing the severity of liver cirrhosis.
5.Effectiveness Evaluation of Pre-Service Training for Laboratory Animal Practitioners Based on the "Three-Separation" Model
Fuli WEN ; Yongjun XU ; Yunfeng FU ; Laien XUE ; Linlin CUI ; Junzhu WANG ; Jun LU ; Heping ZHENG
Laboratory Animal and Comparative Medicine 2026;46(5):771-778
ObjectiveTo summarize the application experience of the "Three-Separation" model in the pre-service training of laboratory animal practitioners and scientifically evaluate its training effectiveness. MethodsA retrospective analysis was conducted on 8 009 practitioners who participated in pre-service training at the Fujian Provincial Laboratory Animal Training Base from January 2010 to December 2025. Among them, 1 250 trainees from January 2010 to December 2017 were included in the control group (traditional training model), and 6 759 trainees from January 2018 to December 2025 were included in the evaluation group ("Three-Separation" model, based on separating job requirements, differentiating exam content, and categorizing exam methods). Meanwhile, a questionnaire survey was conducted to evaluate training effectiveness, yielding 1 624 valid questionnaires (585 from the control group and 1 039 from the evaluation group). The "Three-Separation" model simultaneously optimized fee structures to improve affordability and inclusiveness. The comprehensive competencies and training satisfaction of the two groups after training were compared and analyzed using the independent sample t-test, χ² test, and Wilcoxon rank-sum test. ResultsThe overall satisfaction rate of the evaluation group was 92.49% (961/1 039), significantly higher than that of the control group (77.78%, 455/585), with a highly significant difference (χ²=72.50, P<0.001). The evaluation group showed a more favorable distribution of positive, neutral, and negative ratings in dimensions such as course pertinence, time flexibility, assessment rationality, and reasonableness of fees, and the positive rating rates were highly significantly higher than those in the control group (P<0.001). The comprehensive pass rate of the evaluation group (95.53%) was significantly higher than that of the control group (86.24%), with a highly significant difference (P<0.001). ConclusionThe scientific application of the "Three-Separation" model can accurately match the competency requirements of different positions, optimize the training and assessment system, reduce participation barriers by making training fees more affordable and accessible, effectively improve the comprehensive quality and training satisfaction of laboratory animal practitioners, achieve better teaching outcomes, and provide replicable and promotable practical references for the standardized upgrading of the training system in the laboratory animal industry and other industries.
6.Mechanistic Interplay Between Remodeling of The Peritubular Capillary Microenvironment and Renal Fibrosis
Qi-Fa QIN ; Wen-Hui HUANG ; Jun-Yue HUANG ; Guang-Run ZHANG ; Rong XUE ; Rui QIAN ; Li-Li XU ; Li-Ting DONG
Progress in Biochemistry and Biophysics 2026;53(10):2647-2664
Renal fibrosis is the common pathological endpoint of many forms of chronic kidney disease (CKD), yet the mechanisms determining effective repair versus persistent fibrotic remodeling remain incompletely understood. Peritubular capillaries (PTCs) are not merely passive targets of fibrotic injury, but form a dynamic vascular microenvironment linking regional perfusion, oxygen delivery, tubular metabolism, endothelial barrier integrity, pericyte support, immune-cell trafficking, and extracellular matrix (ECM) remodeling. We propose that PTC abnormalities should not be interpreted simply as reduced capillary density, but as a multidimensional disturbance of microvascular structure and function. Structural vascular preservation does not necessarily indicate effective microcirculation: anatomically detectable capillaries may still exhibit impaired perfusion, barrier dysfunction, abnormal endothelial-pericyte interactions, disturbed oxygen metabolism, or reduced network connectivity. Conversely, increased angiogenesis does not necessarily signify successful vascular repair if vessels remain immature, poorly perfused, or inadequately integrated into the existing network. To organize these abnormalities, we conceptualize PTC remodeling into four predominant but nonexclusive states: endothelial barrier disruption with inflammatory adhesion; endothelial-pericyte uncoupling with no-reflow; dysregulated angiogenesis with network simplification; and capillary rarefaction with fibrotic matrix locking. These states are not sequential stages of CKD. They may coexist within the same kidney, overlap within the same anatomical region, and vary with disease etiology, injury phase, vascular compartment, and treatment exposure. We further propose six dimensions for evaluating PTC status—structural presence, functional perfusion, barrier integrity, pericyte coupling, oxygen metabolism, and network connectivity—so that vascular quantity, function, and reparative capacity are assessed separately rather than inferred from a single endothelial marker or capillary-density measurement. Mechanistically, these states converge on a bidirectional microvascular-fibrotic feedback loop. Barrier disruption facilitates leukocyte recruitment and alters vascular paracrine signaling. Endothelial-pericyte uncoupling compromises capillary stability, whereas abnormal pericyte contraction may increase local vascular resistance and contribute to no-reflow before overt capillary loss. Dysregulated angiogenesis may generate vessels that fail to mature or connect to an effective perfusion network. Progressive capillary rarefaction compromises oxygen delivery, while sustained tubular transport demand and mitochondrial dysfunction may aggravate regional oxygen supply-demand mismatch. Injured tubules, immune cells, endothelial cells, pericytes, and fibroblasts communicate through soluble mediators, extracellular vesicles, direct cell contact, and cell-matrix signaling. Importantly, fibrosis is not merely a downstream consequence of microvascular injury. Altered ECM may increase diffusion distance, modify mechanotransduction, impair endothelial survival and migration, and restrict capillary reopening and regeneration. We use the term matrix locking to describe this sustained constraint on vascular repair, while emphasizing that current evidence does not establish irreversible disease in humans. This framework also has therapeutic implications. PTC-directed treatment should not be reduced to increasing vessel number or uniformly promoting angiogenesis. Instead, intervention should be matched to the dominant and potentially reversible abnormality: preserving endothelial barrier function; restoring endothelial-pericyte stability and reducing pathological microvascular resistance; normalizing angiogenesis so that vascular growth is accompanied by maturation, barrier competence, network integration, and effective perfusion; and, in advanced rarefaction, relieving matrix-related constraints while supporting vascular regeneration. The context- and time-dependent effects of signaling through VEGF, Tie2, PDGF-B/PDGFRβ, eNOS/NO, and related pathways indicate that the same molecular signal may exert different effects depending on disease context and timing. Therapeutic efficacy should therefore be evaluated by restoration of effective microcirculation and tissue function rather than by isolated molecular changes or capillary counts alone. Despite increasing mechanistic evidence, the translational basis for this framework remains limited. Most causal and interventional data derive from animal or cell models, whereas human evidence is largely limited to pathological observations, patient-sample associations, and prognostic studies. Currently available circulating and urinary candidate biomarkers generally lack sufficient specificity for PTC injury or state assignment, and no standardized quantitative thresholds have been externally validated. The four-state model should therefore be regarded as a hypothesis-generating analytical framework rather than a clinicopathological classification system. Future studies should integrate spatially resolved tissue phenotyping, blood and urine biomarkers, and dynamic microcirculatory assessment in longitudinal cohorts. They should test reproducibility, assess prognostic value beyond conventional pathology, estimated glomerular filtration rate, and proteinuria, and determine whether changes in PTC status precede or mediate therapeutic benefit. Linking reproducible microvascular phenotypes to defined mechanisms, treatment response, and long-term renal outcomes will be essential to determine whether state-directed assessment and restoration of the PTC microenvironment can ultimately inform patient stratification and therapeutic decision-making.
7.The Mechanisms of Quercetin in Improving Alzheimer’s Disease
Yu-Meng ZHANG ; Yu-Shan TIAN ; Jie LI ; Wen-Jun MU ; Chang-Feng YIN ; Huan CHEN ; Hong-Wei HOU
Progress in Biochemistry and Biophysics 2025;52(2):334-347
Alzheimer’s disease (AD) is a prevalent neurodegenerative condition characterized by progressive cognitive decline and memory loss. As the incidence of AD continues to rise annually, researchers have shown keen interest in the active components found in natural plants and their neuroprotective effects against AD. Quercetin, a flavonol widely present in fruits and vegetables, has multiple biological effects including anticancer, anti-inflammatory, and antioxidant. Oxidative stress plays a central role in the pathogenesis of AD, and the antioxidant properties of quercetin are essential for its neuroprotective function. Quercetin can modulate multiple signaling pathways related to AD, such as Nrf2-ARE, JNK, p38 MAPK, PON2, PI3K/Akt, and PKC, all of which are closely related to oxidative stress. Furthermore, quercetin is capable of inhibiting the aggregation of β‑amyloid protein (Aβ) and the phosphorylation of tau protein, as well as the activity of β‑secretase 1 and acetylcholinesterase, thus slowing down the progression of the disease.The review also provides insights into the pharmacokinetic properties of quercetin, including its absorption, metabolism, and excretion, as well as its bioavailability challenges and clinical applications. To improve the bioavailability and enhance the targeting of quercetin, the potential of quercetin nanomedicine delivery systems in the treatment of AD is also discussed. In summary, the multifaceted mechanisms of quercetin against AD provide a new perspective for drug development. However, translating these findings into clinical practice requires overcoming current limitations and ongoing research. In this way, its therapeutic potential in the treatment of AD can be fully utilized.
8.The Use of Speech in Screening for Cognitive Decline in Older Adults
Si-Wen WANG ; Xiao-Xiao YIN ; Lin-Lin GAO ; Wen-Jun GUI ; Qiao-Xia HU ; Qiong LOU ; Qin-Wen WANG
Progress in Biochemistry and Biophysics 2025;52(2):456-463
Alzheimer’s disease (AD) is a chronic neurodegenerative disorder that severely affects the health of the elderly, marked by its incurability, high prevalence, and extended latency period. The current approach to AD prevention and treatment emphasizes early detection and intervention, particularly during the pre-AD stage of mild cognitive impairment (MCI), which provides an optimal “window of opportunity” for intervention. Clinical detection methods for MCI, such as cerebrospinal fluid monitoring, genetic testing, and imaging diagnostics, are invasive and costly, limiting their broad clinical application. Speech, as a vital cognitive output, offers a new perspective and tool for computer-assisted analysis and screening of cognitive decline. This is because elderly individuals with cognitive decline exhibit distinct characteristics in semantic and audio information, such as reduced lexical richness, decreased speech coherence and conciseness, and declines in speech rate, voice rhythm, and hesitation rates. The objective presence of these semantic and audio characteristics lays the groundwork for computer-based screening of cognitive decline. Speech information is primarily sourced from databases or collected through tasks involving spontaneous speech, semantic fluency, and reading, followed by analysis using computer models. Spontaneous language tasks include dialogues/interviews, event descriptions, narrative recall, and picture descriptions. Semantic fluency tasks assess controlled retrieval of vocabulary items, requiring participants to extract information at the word level during lexical search. Reading tasks involve participants reading a passage aloud. Summarizing past research, the speech characteristics of the elderly can be divided into two major categories: semantic information and audio information. Semantic information focuses on the meaning of speech across different tasks, highlighting differences in vocabulary and text content in cognitive impairment. Overall, discourse pragmatic disorders in AD can be studied along three dimensions: cohesion, coherence, and conciseness. Cohesion mainly examines the use of vocabulary by participants, with a reduction in the use of nouns, pronouns, verbs, and adjectives in AD patients. Coherence assesses the ability of participants to maintain topics, with a decrease in the number of subordinate clauses in AD patients. Conciseness evaluates the information density of participants, with AD patients producing shorter texts with less information compared to normal elderly individuals. Audio information focuses on acoustic features that are difficult for the human ear to detect. There is a significant degradation in temporal parameters in the later stages of cognitive impairment; AD patients require more time to read the same paragraph, have longer vocalization times, and produce more pauses or silent parts in their spontaneous speech signals compared to normal individuals. Researchers have extracted audio and speech features, developing independent systems for each set of features, achieving an accuracy rate of 82% for both, which increases to 86% when both types of features are combined, demonstrating the advantage of integrating audio and speech information. Currently, deep learning and machine learning are the main methods used for information analysis. The overall diagnostic accuracy rate for AD exceeds 80%, and the diagnostic accuracy rate for MCI also exceeds 80%, indicating significant potential. Deep learning techniques require substantial data support, necessitating future expansion of database scale and continuous algorithm upgrades to transition from laboratory research to practical product implementation.
9.A Fitting Method for Photoacoustic Pump-probe Imaging Based on Phase Correction
Zhuo-Jun XIE ; Hong-Wen ZHONG ; Run-Xiang LIU ; Bo WANG ; Ping XUE ; Bin HE
Progress in Biochemistry and Biophysics 2025;52(2):525-532
ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.
10.Role of Innate Trained Immunity in Diseases
Chuang CHENG ; Yue-Qing WANG ; Xiao-Qin MU ; Xi ZHENG ; Jing HE ; Jun WANG ; Chao TAN ; Xiao-Wen LIU ; Li-Li ZOU
Progress in Biochemistry and Biophysics 2025;52(1):119-132
The innate immune system can be boosted in response to subsequent triggers by pre-exposure to microbes or microbial products, known as “trained immunity”. Compared to classical immune memory, innate trained immunity has several different features. Firstly, the molecules involved in trained immunity differ from those involved in classical immune memory. Innate trained immunity mainly involves innate immune cells (e.g., myeloid immune cells, natural killer cells, innate lymphoid cells) and their effector molecules (e.g., pattern recognition receptor (PRR), various cytokines), as well as some kinds of non-immune cells (e.g., microglial cells). Secondly, the increased responsiveness to secondary stimuli during innate trained immunity is not specific to a particular pathogen, but influences epigenetic reprogramming in the cell through signaling pathways, leading to the sustained changes in genes transcriptional process, which ultimately affects cellular physiology without permanent genetic changes (e.g., mutations or recombination). Finally, innate trained immunity relies on an altered functional state of innate immune cells that could persist for weeks to months after initial stimulus removal. An appropriate inducer could induce trained immunity in innate lymphocytes, such as exogenous stimulants (including vaccines) and endogenous stimulants, which was firstly discovered in bone marrow derived immune cells. However, mature bone marrow derived immune cells are short-lived cells, that may not be able to transmit memory phenotypes to their offspring and provide long-term protection. Therefore, trained immunity is more likely to be relied on long-lived cells, such as epithelial stem cells, mesenchymal stromal cells and non-immune cells such as fibroblasts. Epigenetic reprogramming is one of the key molecular mechanisms that induces trained immunity, including DNA modifications, non-coding RNAs, histone modifications and chromatin remodeling. In addition to epigenetic reprogramming, different cellular metabolic pathways are involved in the regulation of innate trained immunity, including aerobic glycolysis, glutamine catabolism, cholesterol metabolism and fatty acid synthesis, through a series of intracellular cascade responses triggered by the recognition of PRR specific ligands. In the view of evolutionary, trained immunity is beneficial in enhancing protection against secondary infections with an induction in the evolutionary protective process against infections. Therefore, innate trained immunity plays an important role in therapy against diseases such as tumors and infections, which has signature therapeutic effects in these diseases. In organ transplantation, trained immunity has been associated with acute rejection, which prolongs the survival of allografts. However, trained immunity is not always protective but pathological in some cases, and dysregulated trained immunity contributes to the development of inflammatory and autoimmune diseases. Trained immunity provides a novel form of immune memory, but when inappropriately activated, may lead to an attack on tissues, causing autoinflammation. In autoimmune diseases such as rheumatoid arthritis and atherosclerosis, trained immunity may lead to enhance inflammation and tissue lesion in diseased regions. In Alzheimer’s disease and Parkinson’s disease, trained immunity may lead to over-activation of microglial cells, triggering neuroinflammation even nerve injury. This paper summarizes the basis and mechanisms of innate trained immunity, including the different cell types involved, the impacts on diseases and the effects as a therapeutic strategy to provide novel ideas for different diseases.


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