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.

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.

Objective To investigate the distribution characteristics of pathogens causing infections within 90 days after liver transplantation and the influencing factors of infection. Methods Clinical data of 176 recipients who underwent liver transplantation at the Liver Transplant Center of Beijing Friendship Hospital Affiliated to Capital Medical University from September 2021 to August 2024 were retrospectively analyzed. Patients were divided into the infection group (n=124) and the non-infection group (n=52) based on whether they developed infection within 90 days after transplantation. The distribution characteristics of pathogens in infected patients were analyzed. Univariate and multivariate logistic regression analyses were used to explore the influencing factors of infection. Results Among the 176 liver transplant recipients, 124 cases developed 243 episodes of 518 bacterial, fungal, viral or mycoplasma infections within 90 days after transplantation, with an overall infection rate of 70.5% (124/176). The composition of pathogens was mainly Gram-negative bacteria (38.6%, 200/518), followed by Gram-positive bacteria (32.2%, 167/518) and viruses (15.4%, 80/518), and fungi accounted for 13.1% (68/518). Among Gram-negative bacteria, the main pathogen was Klebsiella pneumoniae (6.8%, 35/518), and among Gram-positive bacteria, the main pathogen was Enterococcus faecalis (8.5%, 44/518). Viruses included Epstein-Barr virus (3.7%, 19/518) and cytomegalovirus (3.7%, 19/518), and fungi were mainly Candida albicans (6.8%, 35/518). The most common infection site among the 243 episodes was pulmonary infection (42.0%, 102/243), followed by abdominal infection (22.6%, 55/243) and bloodstream infection (18.1%, 44/243). The infections mainly occurred within 2 weeks after transplantation (60.9%, 148/243). Multivariate logistic regression analysis indicated that preoperative infection within 2 weeks, a high preoperative model for end-stage liver disease (MELD) score, and preoperative sarcopenia were independent risk factors for infection within 90 days after liver transplantation (all odds ratio>1, P<0.05). After multivariate correction, the levels of CD4⁺T cells and CD8⁺T cells within 90 days after surgery were independently associated with the occurrence of infection. Low levels of CD4⁺T cells and CD8⁺T cells might be related to an increased risk of infection. Conclusions The infection rate after liver transplantation is high, and the pathogens are mainly Gram-negative bacteria. The lungs are the most common infection site. Preoperative MELD score, preoperative sarcopenia and preoperative infection within 2 weeks are independent risk factors for infection within 90 days after liver transplantation. Regular monitoring of immune indicators CD4⁺T cells and CD8⁺T cells levels after transplantation is helpful to reduce the occurrence of post-transplantation infection.

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.

Acute kidney injury (AKI) is a prevalent and life-threatening clinical syndrome characterised by a rapid decline in renal function and diverse pathological etiologies. The condition has been demonstrated to be associated with elevated mortality rates and an increased risk of progression to chronic kidney disease. At present, clinicians depend heavily on conventional functional markers, such as serum creatinine and urine output, for the diagnosis and staging of the disease. It is evident that these conventional indicators characteristically manifest a considerable temporal delay and only undergo modification subsequent to considerable tissue damage. This severely restricts the timeframe for early detection and timely therapeutic intervention. Furthermore, standard markers fail to provide specific biological information regarding the underlying cellular injury mechanisms. The utilisation of advanced probe technologies in molecular imaging offers a robust alternative to overcome these inherent diagnostic limitations.This comprehensive review systematically evaluates recent progress in the design and application of two primary categories of molecular imaging tools for acute kidney disease, specifically reactive probes and enzyme-activated probes. Reactive probes are engineered to specifically interact with redox-active chemical species, including hydrogen peroxide, peroxynitrite, hypochlorous acid, and sulfur dioxide. Because oxidative stress constitutes a primary early event in acute renal tubular damage, these probes enable researchers and clinicians to visualize early cellular injury and radical accumulation well before global renal functional decline becomes evident. We discuss the application of these reactive probes across multiple imaging modalities including fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and photoacoustic techniques. Photoacoustic imaging combines high spatial resolution with deep tissue penetration and has successfully demonstrated the ability to provide diagnostic alerts up to 12 h before any detectable rise in serum creatinine levels. Additionally, specific reactive probes have shown promising translational potential when tested by high-throughput screening in clinical human urine samples. Enzyme-activated probes target the specific catalytic activity of disease-relevant enzymes. These include well-documented renal tubular structural biomarkers such as NAG, GGT, and ALP, along with apoptosis-related caspases and specific nitroreductases. By responding only to enzymatic cleavage, these tools provide highly specific and pathology-directed imaging readouts. Recent structural design strategies in this field have advanced significantly beyond single-enzyme detection. Researchers are now focusing on sophisticated dual-target recognition to minimize background noise, multimodal integration to cross-validate imaging signals, and theranostic applications where probes simultaneously deliver diagnostic feedback and therapeutic agents to injured tissues. Nanotechnology serves as a fundamental enabler for realizing these advanced probe functions. By precisely optimizing nanoparticle parameters such as hydrodynamic size, surface charge, and targeting ligands, researchers can achieve amplified signal output, highly precise kidney delivery, and protection against premature degradation in the systemic circulation. For example, modifying surface charges can significantly enhance the active uptake of nanoprobes by damaged renal tubular epithelial cells.While preclinical probe development has progressed rapidly, moving these technologies into routine clinical practice remains a major challenge. We analyze the translational feasibility and current obstacles from biological, technological, and regulatory perspectives. Although biological targets such as KIM-1, FAP, and ALP have been validated in extensive patient cohorts, practical barriers severely limit their immediate clinical application. These obstacles involve complex changes in in vivo pharmacokinetics. During an acute injury episode, the extreme drop in the glomerular filtration rate alters probe clearance and can cause unwanted systemic accumulation or confusing background imaging signals. Other major hurdles include a lack of comprehensive long-term toxicity data and the absence of standardized manufacturing protocols to ensure batch-to-batch consistency. Future successful translation will require rigorous multi-center clinical studies to confirm the true diagnostic value of these probes over traditional markers. Researchers must also establish strict standardization of imaging procedures and comprehensive safety evaluations. Ultimately, this review provides a thorough reference framework for designing clinically translatable molecular probes and building a precision diagnostic imaging system for acute kidney injury.

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.

Objective To analyze the relationship between the expression of ferroptosis markers in the tumor microenvironment(TME)and the prognosis of transcatheter arterial chemoembolization(TACE)for hepatocellular carcinoma(HCC).Methods This prospective observational study included 100 HCC patients who received TACE treatment at Langfang Hospital of Traditional Chinese Medicine from March 2019 to June 2021 as the study subjects.The levels of 8-isoprostaglandin F2α(8-iso-PGF2α),4-hydroxy-2-nonenal(4-HNE),8-hydroxy-2'deoxyguanosine(8-OH-dG)and hepcidin in plasma were evaluated by ELISA kit at baseline(1 day before TACE),1 day after TACE and 4～8 weeks.The changes of ferroptosis related markers during TACE treatment were compared.The difference between the level of 8-iso-PGF2α,4-HNE and the baseline 1 day after TACE treatment was recorded as △8-iso-PGF2α,△4-HNE.Results Compared with the baseline,the levels of 8-iso-PGF2α and 4-HNE increased significantly and the level of hepcidin decreased significantly one day after TACE treatment,and the differences were statistically significant(t=8.03,16.29,2.92,all P<0.05).Compared with 1 day after treatment,the levels of 8-iso-PGF2α,4-HNE decreased and the level of 8-OH-dG increased at 4～8 weeks after TACE treatment,and the differences were statistically significant(t=9.12,17.17,2.63,all P<0.05).Multivariate COX analysis showed that △8-iso-PGF2α,△4-HNE and 8-iso-PGF2α 1 day after TACE treatment were independent factors affecting the overall survival after TACE(Wald χ2=5.205,13.801,6.054,all P<0.05).The survival time of patients with △4-HNE>2.01 μg/ml was significantly longer than that of patients with △4-HNE≤2.01 μg/ml(Log-rank=5.718,P=0.017),and that of patients with△8-iso-PGF2α>1.75ng/ml was sig-nificantly longer than that of patients with△8-iso-PGF2≤1.75ng/ml(Log-rank=4.163,P=0.041).Conclusion The prognosis of HCC patients who are in a state of high ferroptosis(4-HNE and 8-iso-PGF2 increased)at 1 day after TACE treatment is better,which indicate that ferroptosis mediated HCC death induced by TACE treatment.

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.

The red blood cell membrane is an important place for signaling,material transport,energy exchange and other life activities inside and outside the erythrocyte,and its function is mainly realized by the protein complexes on the membrane sur-face.Glycoproteins,integrins,signaling proteins,channel pro-teins and other proteins that constitute the erythrocyte membrane protein complexes interact with each other through direct physi-cal effects or regulatory factor-mediated mechanisms,playing a role in regulating oxygen transport,maintaining cellular morphol-ogy and stability,participating in the regulation of signaling,as well as supporting the cytoskeleton and other functions.Hemo-globin is the mediator of oxygen transport and delivery in blood erythrocytes,and regulating its conformational changes can in-crease the efficiency of oxygen supply to alleviate hypoxia in plateau hypoxia.This review describes the composition,func-tion,interaction mechanism,and adaptive regulation of hemoglo-bin to hypoxia in erythrocyte membrane protein complexes,with the aim of providing new reference for the prevention of hypoxia symptoms,the formulation of therapeutic regimens and the devel-opment of anti-hypoxia drugs.

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.