1.Translational Research of Electromagnetic Fields on Diseases Related With Bone Remodeling: Review and Prospects
Peng SHANG ; Jun-Yu LIU ; Sheng-Hang WANG ; Jian-Cheng YANG ; Zhe-Yuan ZHANG ; An-Lin LI ; Hao ZHANG ; Yu-Hong ZENG
Progress in Biochemistry and Biophysics 2025;52(2):439-455
Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.
2.Effect of auricular therapy on sleep improvement and the GABAergic system pathway in an insomnia rat model
Hao CHEN ; Xifen ZHANG ; Xuesong WANG ; Yuanbo GAO ; Xuxin LI ; Xihui ZHENG ; Yu WANG ; Xiaojun ZHENG ; Haiping LI ; Yanfen SHE
Journal of Beijing University of Traditional Chinese Medicine 2025;48(1):138-148
Objective:
To investigate the effect of auricular therapy on sleep improvement and the GABAergic system pathway in a rat model of insomnia and to explore its possible mechanism.
Methods:
According to the random number table, 60 male SD rats were randomly divided into blank control, model, auricular point sticking, auricular bloodletting, and auricular bloodletting combined with sticking groups, with 12 rats per group. Insomnia was induced by intraperitoneal injection of p-chlorophenylalanine. After establishing the insomnia model, 36 rats were treated once a day with auricular point sticking or bloodletting for 5 consecutive days. After the intervention, the general condition and body weight of rats were observed; the righting reflex test was used to detect the sleep latency and duration; HE staining was used to observe the morphology of hypothalamic neuron cells; and an enzyme-linked immunosorbent assay was used to detect the GABA and glutamate content in rat serum. Immunohistochemistry(IHC) and real-time fluorescence quantitative PCR were used to detect GABA ARα1 and GABA ARγ2 protein and mRNA expression in the hypothalamus of rats, and Western blotting(WB) was used to detect GABA ARα1, GABA ARγ2, GAD65/67, GAT-1, and GABA-T protein expression in the hypothalamus of rats.
Results:
Compared with the blank control group, the model group had a lower body weight, a significantly shorter sleep duration (P<0.05), severe damage to the morphological structure of hypothalamic neurons with disordered cell arrangement, larger intercellular gaps, enlarged cell bodies, and a vacuolated appearance. All the intervention groups had significantly higher body weight and longer sleep duration than the model group (P<0.05). Compared with the other intervention groups, the auricular point sticking group had a longer sleep duration (P<0.05), and the hypothalamic neuron cells in all intervention groups improved, with the auricular point sticking group showing more apparent improvement. The model group had a lower GABA and higher glutamate contents, and GABA ARα1, GABA ARγ2, and GAD65/67 protein expression in the hypothalamus were lower than in the blank control group. In contrast, GAT-1 and GABA-T protein expression was higher, and GABA ARα1 and GABA ARγ2 mRNA expression was lower (P<0.05). The serum GABA content in the auricular point sticking and auricular bloodletting groups was higher, and the serum glutamate content in the auricular point sticking and auricular bloodletting combined sticking groups was lower than in the model group. GABA ARα1 mRNA expression in the hypothalamus of each intervention group was significantly increased, and GABA ARγ2 mRNA expression in the hypothalamus of the auricular point sticking and auricular bloodletting combined sticking groups increased. GABA ARα1(IHC, WB), GABA ARγ2(WB), and GAD65/67 protein expression in the hypothalamus of the auricular point sticking group increased, whereas GAT-1 and GABA-T protein expression decreased. GABA ARα1 and GABA ARγ2 protein expression(IHC, WB) in the hypothalamus of the auricular bloodletting group increased, whereas GABA-T protein expression decreased. GABA ARγ1(IHC) and GABA ARγ2(WB) protein expression in the hypothalamus of the auricular bloodletting combined sticking group increased, whereas GAT-1 and GABA-T protein expression decreased (P<0.05). Compared with in the inventation groups, the serum GABA content in the auricular point sticking group increased, the serum glutamate content decreased, GABA ARα1 and GABA ARγ2 mRNA expression in the hypothalamus increased, and GABA ARα1(IHC), GAD65/67 protein expression increased. In contrast, GABA-T protein expression decreased (P<0.05), and GABA ARγ2 protein expression(IHC) in the hypothalamus of the auricular bloodletting group increased (P<0.05).
Conclusion
Auricular therapy, particularly auricular point sticking, may have modulated the GABAergic system pathway by upregulating hypothalamic GABA ARα1, GABA ARγ2, and GAD65/67 protein expression while downregulating GAT-1 and GABA-T protein expression to alleviate symptoms in an insomnia rat model.
3.Effect of Shenxiong Huanglian Jiedu Decoction on Neuronal Damage and Aβ Clearance in Mice Model of Alzheimer's Disease
Jing LIU ; Kang CHEN ; Yushun ZHOU ; Zhezuo ZHANG ; Guran YU ; Hao LI
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(7):43-52
ObjectiveTo investigate the effects of Shenxiong Huanglian Jiedu decoction on the clearance of amyloid β-protein (Aβ) and neuronal damage in the mouse model of Alzheimer's disease (AD). MethodsA total of 36 SPF-grade 2-month-old C57BL/6J mice were used in this study, and the modeling was performed by bilateral hippocampal injection of Aβ oligomers in C57BL/6J mice. The experiment was conducted with a blank group, a sham operation group, a model group, low- and high-dose (3.27,6.54 g·kg-1, respectively) Shenxiong Huanglian Jiedu decoction groups, and a positive control (donepezil hydrochloride, 0.65 mg·kg-1) group. At the end of the drug intervention, the learning and memory abilities and the activities of mice were evaluated by the Morris water maze and open field tests. Brain histopathology was examined by hematoxylin-eosin and Nissl staining. Additionally, in vivo imaging was employed to measure the metabolism of fluorescent Aβ in the cerebrospinal fluid, and staining of ionized calcium-binding adapter molecule-1 (Iba-1) was employed to assess microglial activation in the hippocampal tissue. Additionally, neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) levels in the brain tissue and serum were determined by the immunofluorescence assay and enzyme-linked immunosorbent assay. Western blot was conducted to determine the expression of inflammation and pathway-related proteins in the hippocampal tissue. ResultsCompared with the blank group and the sham operation group, the escape latency of the mice in the model group was prolonged, the platform residence time was shortened, the hippocampal tissue showed pathological manifestations such as neuronal pyknosis, Nissl body dissolution, and microglia activation. The metabolic rate of fluorescent Aβ through cerebrospinal fluid was slowed down, and the expression levels of BDNF, NT-3, and interleukin-10 (IL-10) in the hippocampus were significantly decreased (P<0.01). The expression levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and phosphorylated nuclear transcription factor-κB (p-NF-κB p65) in hippocampus were significantly increased (P<0.05, P<0.01). Compared with the model group, the escape latency of mice in the low and high dose groups of Chinese medicine and donepezil group was shortened, and the platform residence time was prolonged. Neuronal karyopyknosis, Nissl body dissolution and microglia activation in hippocampus were improved. Fluorescence Aβ was metabolized faster by cerebrospinal fluid. The expression of BDNF and NT-3 in hippocampus was increased (P<0.01), and the expression of TLR4, MyD88 and p-NF-κB p65 was significantly decreased (P<0.05, P<0.01). The expression of TNF-α in the hippocampus of the high-dose group was significantly decreased (P<0.05), and the expression of IL-10 was significantly increased (P<0.05). The expression of TNF-α, IL-6 and IL-1β in the hippocampus of the donepezil group was significantly decreased (P<0.05, P<0.01). ConclusionShenxiong Huanglian Jiedu decoction may mitigate neuronal damage and enhance cerebrospinal fluid flow in the mouse model of AD, thereby promoting the clearance of Aβ and improving the learning and memory abilities. These beneficial effects are likely mediated through the inhibition of microglial activation, reduction of inflammation, and modulation of the TLR4/MyD88/NF-κB signaling pathway.
4.Effect of Shenxiong Huanglian Jiedu Decoction on Neuronal Damage and Aβ Clearance in Mice Model of Alzheimer's Disease
Jing LIU ; Kang CHEN ; Yushun ZHOU ; Zhezuo ZHANG ; Guran YU ; Hao LI
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(7):43-52
ObjectiveTo investigate the effects of Shenxiong Huanglian Jiedu decoction on the clearance of amyloid β-protein (Aβ) and neuronal damage in the mouse model of Alzheimer's disease (AD). MethodsA total of 36 SPF-grade 2-month-old C57BL/6J mice were used in this study, and the modeling was performed by bilateral hippocampal injection of Aβ oligomers in C57BL/6J mice. The experiment was conducted with a blank group, a sham operation group, a model group, low- and high-dose (3.27,6.54 g·kg-1, respectively) Shenxiong Huanglian Jiedu decoction groups, and a positive control (donepezil hydrochloride, 0.65 mg·kg-1) group. At the end of the drug intervention, the learning and memory abilities and the activities of mice were evaluated by the Morris water maze and open field tests. Brain histopathology was examined by hematoxylin-eosin and Nissl staining. Additionally, in vivo imaging was employed to measure the metabolism of fluorescent Aβ in the cerebrospinal fluid, and staining of ionized calcium-binding adapter molecule-1 (Iba-1) was employed to assess microglial activation in the hippocampal tissue. Additionally, neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) levels in the brain tissue and serum were determined by the immunofluorescence assay and enzyme-linked immunosorbent assay. Western blot was conducted to determine the expression of inflammation and pathway-related proteins in the hippocampal tissue. ResultsCompared with the blank group and the sham operation group, the escape latency of the mice in the model group was prolonged, the platform residence time was shortened, the hippocampal tissue showed pathological manifestations such as neuronal pyknosis, Nissl body dissolution, and microglia activation. The metabolic rate of fluorescent Aβ through cerebrospinal fluid was slowed down, and the expression levels of BDNF, NT-3, and interleukin-10 (IL-10) in the hippocampus were significantly decreased (P<0.01). The expression levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and phosphorylated nuclear transcription factor-κB (p-NF-κB p65) in hippocampus were significantly increased (P<0.05, P<0.01). Compared with the model group, the escape latency of mice in the low and high dose groups of Chinese medicine and donepezil group was shortened, and the platform residence time was prolonged. Neuronal karyopyknosis, Nissl body dissolution and microglia activation in hippocampus were improved. Fluorescence Aβ was metabolized faster by cerebrospinal fluid. The expression of BDNF and NT-3 in hippocampus was increased (P<0.01), and the expression of TLR4, MyD88 and p-NF-κB p65 was significantly decreased (P<0.05, P<0.01). The expression of TNF-α in the hippocampus of the high-dose group was significantly decreased (P<0.05), and the expression of IL-10 was significantly increased (P<0.05). The expression of TNF-α, IL-6 and IL-1β in the hippocampus of the donepezil group was significantly decreased (P<0.05, P<0.01). ConclusionShenxiong Huanglian Jiedu decoction may mitigate neuronal damage and enhance cerebrospinal fluid flow in the mouse model of AD, thereby promoting the clearance of Aβ and improving the learning and memory abilities. These beneficial effects are likely mediated through the inhibition of microglial activation, reduction of inflammation, and modulation of the TLR4/MyD88/NF-κB signaling pathway.
5.Microscopic Mechanism of Chronic Liver Disease and Novel Thinking of Medicine Management Based on Theory of "Yang Transforming Qi While Yin Constituting Form-sweat Pore"
Yuying XU ; Changpu ZHAO ; Rongzhi LI ; Yu ZHANG ; Fei WANG ; Chenyuan HAO ; Guangjie SHU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(4):244-255
The theory of "Yang transforming Qi while Yin constituting form" in the Huangdi's Internal Classic is derived from the application, transformation, movement, and balance of Tao. It is highly condensed, revealing the true meaning of Tao and guiding the changes and progress of all natural things, including diseases. Therefore, the appearance of various physical diseases is the manifestation of Yin-Yang Qi transformation. Sweat pore, formed by the Qi transformation of Yin and Yang, is the nourishing and regulating system. It serves as the hub and channel, assisting in the flow and transformation of Qi, facilitating the exchange of material, energy, and information with the outside world. With sweat pore as the hub and based on the macro-control and holistic thinking of "Yang transforming Qi while Yin constituting form", this paper explores the microscopic mechanisms underlying chronic liver disease. In combination with the roles of mitochondria, exosomes, and the ultraliver sieve structure in the formation and progression of chronic liver disease, this paper elucidates the close internal relationship between the disease's initial quality, symptom signs, and its physiological and pathological functions under the guidance of this theory. Modern studies have shown that autophagy, intestinal flora disorders, glucose and lipid metabolism disturbances, activation of inflammatory factors, ferroptosis, and other microscopic pathological mechanisms are involved in the occurrence and development of chronic liver disease. The common connotation of the Yin-Yang concept in traditional Chinese medicine (TCM) and the pathological mechanisms in modern medicine is deeply analyzed. The corresponding relevant microscopic mechanisms and the guiding role of the theory of "Yang transforming Qi while Yin constituting form-sweat pore" in the management of chronic liver disease are summarized. Wind medicine promotes growth and transformation through sweat pore. The combination of pungent and sweet medicines facilitates Yang and disperse Yin. The formulas, combining the characteristics of wind medicine and pungent and sweet medicines, fit the principle of "Yang transforming Qi while Yin constituting form-sweat pore". This paper combines both macro and micro perspectives to explain the scientific connotation and microscopic mechanisms of chronic liver disease based on the theory of "Yang transforming Qi while Yin constituting form-sweat pore", and explore the prevention and treatment of chronic liver disease through the principles, methods, prescriptions, and medicines featured by combination of pungent and sweet medicines, facilitating Yang, activating sweat pore, and dispersing Yin, providing new ideas and reference for the clinical treatment of chronic liver disease.
6.Shikonin attenuates blood–brain barrier injury and oxidative stress in rats with subarachnoid hemorrhage by activating Sirt1/ Nrf2/HO-1 signaling
Guanghu LI ; Yang'e YI ; Sheng QIAN ; Xianping XU ; Hao MIN ; Jianpeng WANG ; Pan GUO ; Tingting YU ; Zhiqiang ZHANG
The Korean Journal of Physiology and Pharmacology 2025;29(3):283-291
Subarachnoid hemorrhage (SAH) is a serious intracranial hemorrhage characterized by acute bleeding into the subarachnoid space. The effects of shikonin, a natural compound from the roots of Lithospermum erythrorhizon, on oxidative stress and blood–brain barrier (BBB) injury in SAH was evaluated in this study. A rat model of SAH was established by endovascular perforation to mimic the rupture of intracranial aneurysms. Rats were then administered 25 mg/kg of shikonin or dimethylsulfoxide after surgery. Brain edema, SAH grade, and neurobehavioral scores were measured after 24 h of SAH to evaluate neurological impairment. Concentrations of the oxidative stress markers superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA) in the brain cortex were determined using the corresponding commercially available assay kits. Evans blue staining was used to determine BBB permeability. Western blotting was used to quantify protein levels of tight junction proteins zonula occludens-1, Occludin, and Claudin-5. After modeling, the brain water content increased significantly whereas the neurobehavioral scores of rats with SAH decreased prominently. MDA levels increased and the levels of the antioxidant enzymes GSH and SOD decreased after SAH. These changes were reversed after shikonin administration. Shikonin treatment also inhibited Evans blue extravasation after SAH. Furthermore, reduction in the levels of tight junction proteins after SAH modeling was rescued after shikonin treatment. In conclusion, shikonin exerts a neuroprotective effect after SAH by mitigating BBB injury and inhibiting oxidative stress in the cerebral cortex.
7.Effect of surface treatment on dentin rebonding after laser non-destructive removal of zirconia prosthesis
LI Xiaoting ; JIANG Lei ; LU Zhicen ; CAI Chunyan ; YU Hao
Journal of Prevention and Treatment for Stomatological Diseases 2025;33(3):195-202
Objective:
To investigate the changes of dentin surface and the effects of different surface treatments on the rebonding effect following non-destructive restoration removal by an Er:YAG laser and to provide reference for oral clinical operation
Methods:
This study was approved by the ethics review committee of the unit. Using computer-aided design and computer-aided manufacturing (CAD/CAM) technology, 102 zirconia specimens (4 mm × 4 mm × 1.5 mm) were fabricated. In total, 110 impacted third molar teeth were extracted, and 102 dentine blocks (4 mm × 4 mm × 2 mm) were prepared. The zirconia specimen and dentin blocks were bonded with resin cement before removal with an Er: YAG laser. Three disassembled dentin blocks were randomly selected, and the components of dentin surface elements were analyzed by energy dispersive X-ray spectroscopy (EDX). The removed dentin blocks were randomly divided into three groups (n = 33) based on the different surface treatments: control group (no treatment), sandblasting group (50 μm, Al2O3 sandblasting), and laser irradiation group (Er: YAG laser irradiation, parameters were set to 10 Hz, 60 mJ, 0.6 W). Three dentin blocks were randomly selected in each group for scanning electron microscopy (SEM) observation, and the residual resin on dentin surface of remaining 30 dentin blocks in each group were observed under an optical microscope at 20 times magnification. Scores were obtained using the adhesive remnant index (ARI) method. Three groups of dentin blocks (n = 30) that underwent different surface treatments were rebonded with resin cement according to standard procedures and then divided into two subgroups for aging (n = 15). One subgroup was subjected to a 37 ℃ water bath for 24 h, and the other subgroup was subjected to 5 000 thermal cycles after a 37 ℃ water bath for 24 h, and the micro-shear bonding strength of each group was measured. The microshear bonding strength of each group was measured, and fracture modes were analyzed. The differences of dentine surface ARI between the three groups, as well as the inter-group differences in fracture mode, and bonding strength, and the intra-group differences before and after aging were compared between the three groups.
Results:
When zirconia was removed by Er: YAG laser, there was no obvious damage on the dentin surface, but C and Si elements in dentin increased significantly. After different surface treatments, the ARI scores of the sandblasting and laser irradiation groups were lower than those of the control group (P<0.05), while ARI was not significantly different between the sandblasting and laser irradiation groups (P>0.05). The dentin surface morphology was also different. There was a large amount of residual resin on the dentin surface of the control group. In the sandblasting group, the residual resin was lower, the dentin surface was rough, and the dentin tubules were visible. A large amount of residual resin was observed on the dentin surface of the laser irradiation group. After 24 h of water bath at 37 ℃, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (6.13 ± 2.40) MPa, (9.39 ± 2.00) MPa, and (5.85 ± 1.44) MPa, respectively, and the bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). After being subjected to 24 h of water bath at 37 ℃ and 5 000 thermal cycles, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (5.39 ± 0.83) MPa, (8.45 ± 1.20) MPa and (4.84 ± 1.43) MPa, respectively. The bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). There was no significant difference between the control group, sandblasting group, and laser irradiation group before and after 5 000 thermal cycles following 24 h of water bath at 37 ℃ (P>0.05). In the control group, sandblasting group, and laser irradiation group, cohesive fracture was not observed. The fracture mode was mainly adhesive fracture. Before and after 5 000 thermal cycles, the frequency of mixed fracture in the sandblasting group was significantly higher than that in the other two groups (P<0.05).
Conclusion
Er: YAG laser removal of zirconia does not damage dentin, but a large amount of resin remains on the dentin surface after removal. The sandblasting process can effectively remove these residual resins, thereby improving the dentine rebonding effect.
8.Effects of honey-processed Astragalus on energy metabolism and polarization of RAW264.7 cells
Hong-chang LI ; Ke PEI ; Wang-yang XIE ; Xiang-long MENG ; Zi-han YU ; Wen-ling LI ; Hao CAI
Acta Pharmaceutica Sinica 2025;60(2):459-470
In this study, RAW264.7 cells were employed to investigate the effects of honey-processed
9.The effect of rutaecarpine on improving fatty liver and osteoporosis in MAFLD mice
Yu-hao ZHANG ; Yi-ning LI ; Xin-hai JIANG ; Wei-zhi WANG ; Shun-wang LI ; Ren SHENG ; Li-juan LEI ; Yu-yan ZHANG ; Jing-rui WANG ; Xin-wei WEI ; Yan-ni XU ; Yan LIN ; Lin TANG ; Shu-yi SI
Acta Pharmaceutica Sinica 2025;60(1):141-149
Metabolic-associated fatty liver disease (MAFLD) and osteoporosis (OP) are two very common metabolic diseases. A growing body of experimental evidence supports a pathophysiological link between MAFLD and OP. MAFLD is often associated with the development of OP. Rutaecarpine (RUT) is one of the main active components of Chinese medicine Euodiae Fructus. Our previous studies have demonstrated that RUT has lipid-lowering, anti-inflammatory and anti-atherosclerotic effects, and can improve the OP of rats. However, whether RUT can improve both fatty liver and OP symptoms of MAFLD mice at the same time remains to be investigated. In this study, we used C57BL/6 mice fed a high-fat diet (HFD) for 4 months to construct a MAFLD model, and gave the mice a low dose (5 mg·kg-1) and a high dose (15 mg·kg-1) of RUT by gavage for 4 weeks. The effects of RUT on liver steatosis and bone metabolism were then evaluated at the end of the experiment [this experiment was approved by the Experimental Animal Ethics Committee of Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences (approval number: IMB-20190124D303)]. The results showed that RUT treatment significantly reduced hepatic steatosis and lipid accumulation, and significantly reduced bone loss and promoted bone formation. In summary, this study shows that RUT has an effect of improving fatty liver and OP in MAFLD mice.
10.In situ Analytical Techniques for Membrane Protein Interactions
Zi-Yuan KANG ; Tong YU ; Chao LI ; Xue-Hua ZHANG ; Jun-Hui GUO ; Qi-Chang LI ; Jing-Xing GUO ; Hao XIE
Progress in Biochemistry and Biophysics 2025;52(5):1206-1218
Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.


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