ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription （ZJSP） on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy （DCM）， with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase （AMPK）/forkhead box protein O1 （FoxO1）/cluster of differentiation 36 （CD36） signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin （STZ） while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group， the low-dose（14.43 g·kg^-1）and high-dose（28.86 g·kg^-1） ZJSP groups， and the metformin group （0.25 g·kg^-1）， with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks， fasting blood glucose （FBG） and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin （FINS） and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin （HE） staining， and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of AMPK， FoxO1， and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK， p-AMPK， FoxO1， p-FoxO1， and CD36. ResultsCompared with the control group， the model group showed significantly increased levels of FBG and FINS （P<0.01）， elevated levels of triglycerides （TG）， total cholesterol （TC）， and low-density lipoprotein cholesterol （LDL-C） （P<0.01）， and significantly decreased left ventricular ejection fraction （EF） and fractional shortening （FS） values （P<0.01）. HE staining revealed marked cardiomyocyte hypertrophy， disarray， and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased， while FoxO1 and CD36 mRNA expressions were significantly increased （P<0.01）. The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced， while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased （P<0.01）. Compared with the model group， all treatment groups exhibited significantly reduced FBG （P<0.01）， decreased FINS and blood lipid levels （TG， TC， LDL-C） （P<0.05， P<0.01）， improved cardiac function （P<0.05）， noticeable amelioration of myocardial histopathological morphology and lipid deposition， increased AMPK mRNA expression （P<0.01）， with significantly downregulated FoxO1 and CD36 mRNA expressions （P<0.01）， elevated p-AMPK/AMPK protein expression levels in myocardial tissue （P<0.05）， significantly decreased p-FoxO1/FoxO1 ratios （P<0.01）， and downregulated CD36 protein expression levels （P<0.05， P<0.01）. ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice， and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.

ObjectiveTo investigate the ameliorative effects and related mechanisms of the Zuogui Jiangtang Shuxin prescription （ZJSP） on glucose and lipid metabolism disorders in MKR mice with diabetic cardiomyopathy （DCM）， with a focus on elucidating its regulatory role on the adenosine monophosphate-activated protein kinase （AMPK）/forkhead box protein O1 （FoxO1）/cluster of differentiation 36 （CD36） signaling pathway and lipid deposition. MethodsFifty 8-week-old male MKR mice were fed a high-fat diet for four weeks and then intraperitoneally injected with streptozotocin （STZ） while maintaining a high-fat diet to establish a DCM model. The mice were randomly divided into the model group， the low-dose（14.43 g·kg^-1）and high-dose（28.86 g·kg^-1） ZJSP groups， and the metformin group （0.25 g·kg^-1）， with age-matched FVB mice as a normal control group. Each group received intragastric administration of normal saline or corresponding concentrations of ZJSP at equal volumes. After four weeks， fasting blood glucose （FBG） and cardiac function were measured. Blood was collected from the eyeballs under anesthesia to detect fasting insulin （FINS） and blood lipid levels. Myocardial tissue morphology was observed by hematoxylin-eosin （HE） staining， and lipid deposition in the heart was assessed using oil red O staining. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of AMPK， FoxO1， and CD36 in myocardial tissues. Western blot was employed to detect the protein expression levels of AMPK， p-AMPK， FoxO1， p-FoxO1， and CD36. ResultsCompared with the control group， the model group showed significantly increased levels of FBG and FINS （P<0.01）， elevated levels of triglycerides （TG）， total cholesterol （TC）， and low-density lipoprotein cholesterol （LDL-C） （P<0.01）， and significantly decreased left ventricular ejection fraction （EF） and fractional shortening （FS） values （P<0.01）. HE staining revealed marked cardiomyocyte hypertrophy， disarray， and widened intercellular spaces in myocardial tissues. Oil Red O staining showed extensive red deposition areas and fine lipid droplet accumulation in the myocardial tissue. AMPK mRNA expression was decreased， while FoxO1 and CD36 mRNA expressions were significantly increased （P<0.01）. The p-AMPK/AMPK protein expression ratio in myocardial tissues was significantly reduced， while the p-FoxO1/FoxO1 protein expression ratio and CD36 protein expression levels were significantly increased （P<0.01）. Compared with the model group， all treatment groups exhibited significantly reduced FBG （P<0.01）， decreased FINS and blood lipid levels （TG， TC， LDL-C） （P<0.05， P<0.01）， improved cardiac function （P<0.05）， noticeable amelioration of myocardial histopathological morphology and lipid deposition， increased AMPK mRNA expression （P<0.01）， with significantly downregulated FoxO1 and CD36 mRNA expressions （P<0.01）， elevated p-AMPK/AMPK protein expression levels in myocardial tissue （P<0.05）， significantly decreased p-FoxO1/FoxO1 ratios （P<0.01）， and downregulated CD36 protein expression levels （P<0.05， P<0.01）. ConclusionZJSP exerts a protective effect on the heart in type 2 DCM of MKR mice， and its mechanism may be associated with the regulation of the AMPK/FoxO1/CD36 signaling pathway.

Diabetic cardiomyopathy （DCM） is one of the most common complications of diabetes mellitus and is a major threat to global health. As a key mechanism in the occurrence and progression of DCM， the inflammatory response persists throughout the entire course of the DCM. The Gaozhuo theory suggests that the basic pathogenesis of inflammatory injury in DCM is the Qi deficiency of spleen and kidney and Gaozhuo invasion， and divides the pathological process into three phases： Gaozhuo invasion， turbid heat damage to the channels， and turbid blood stasis and heat junction. Among them， the Qi deficiency of spleen and kidney and the endogenous formation of Gaozhuo represent the process of inflammatory factor formation induced by glucose metabolism disorders. Turbid heat damage to the channels refers to the process of myocardial inflammatory injury mediated by inflammatory factors， and turbid blood stasis and heat junction are the process of myocardial injury developing toward myocardial fibrosis and ventricular remodeling. As the disease continues to progress， it eventually develops into a depletion of the heart Yang， leading to the ultimate regression of heart failure. According to the theory of Gaozhuo， traditional Chinese medicine （TCM） should regulate inflammatory injury in DCM by strengthening the spleen and tonifying the kidney to address the root cause， and resolving dampness and lowering turbidity to treat the symptoms. If the turbidity has been stored for a long time and turns into heat， strengthening the spleen and tonifying the kidney， and clearing heat and resolving turbidity should be the therapy. If the turbidity， stasis， and heat are knotted in the heart and collaterals， strengthening the spleen and tonifying the kidney， and resolving stasis and lowering turbidity should be the therapy. TCM compounds and monomers can regulate the inflammatory response in DCM. TCM compounds can be divided into the categories for benefiting Qi to resolve turbidity， benefiting Qi and clearing heat to resolve turbidity， and benefiting Qi and activating blood to reduce turbidity. The compounds can inhibit upstream signals of inflammation and expression of inflammatory factors， improve the inflammatory damage to myocardium and blood vessels， myocardial fibrosis， and cardiac systole and diastole， and thus slow down the onset and progression of DCM.

Non-alcoholic fatty liver disease （NAFLD） is one of the most common complications of type 2 diabetes mellitus （T2DM）， and hepatic stellate cell （HSC） activation is the key link in the progression of NAFLD to liver fibrosis. According to the theory of "Gaozhuo"， spleen deficiency and Qi stagnation， along with Gaozhuo invasion， are the causes of NAFLD progression to liver fibrosis， which reveals the pathogenesis essence of HSC activation in traditional Chinese medicine （TCM）. Among them， spleen deficiency and Qi stagnation are the root causes of the endogenous formation of Gaozhuo. Spleen deficiency indicates the insulin sensitivity decrease and glucose metabolism disorders， and Qi stagnation means the dysregulation of hepatic glucose and lipid metabolism， which creates the preconditions for HSC activation. Gaozhuo invasion is the direct cause of HSC activation， including three stages： Internal retention of Gaozhuo， turbidity and stasis stagnation， and toxic stasis and consolidation. Internal retention of Gaozhuo refers to the abnormal metabolism and deposition of hepatic lipids， as well as the microcirculatory disorders. Turbidity and stasis stagnation is the process by which lipotoxicity stimulates the transformation of HSC into myofibroblast （MFB）， and toxic stasis and consolidation represent the secretion of a large amount of extracellular matrix （ECM） by MFB to promote the fibrosis. According to the theory of Gaozhuo and the activation process of HSC， syndromes for T2DM combined with NAFLD can be classified into spleen deficiency and Qi stagnation with internal retention of Gaozhuo， spleen Qi deficiency with turbidity and stasis stagnation， and spleen Qi deficiency with toxic stasis and consolidation. Clinically， the treatment principle is to strengthen the spleen and promote Qi， resolve turbidity， and eliminate blood stasis. Both TCM compounds and monomers can effectively inhibit the HSC activation. TCM compounds can be classified into categories for regulating spleen and harmonizing liver， resolving turbidity and removing stasis， and detoxifying and removing stasis. They mainly work by improving lipid metabolism， reducing lipid accumulation in the liver， alleviating inflammatory and oxidative stress responses， inhibiting the activation and proliferation of HSC， and reducing ECM deposition， thereby delaying the progression of liver fibrosis.

Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.

Cancer remains a leading cause of global mortality, necessitating the development of advanced therapeutic strategies with enhanced efficacy and reduced systemic toxicity. Among promising bioactive agents, lactoferrin (LF)—a multifunctional iron-binding glycoprotein abundantly found in mammalian milk and exocrine secretions—has garnered significant interest for its potent and multifaceted anti-cancer properties. This review provides a comprehensive analysis of the current understanding of LF’s role in oncology, encompassing its structural biology, diverse mechanisms of action, and groundbreaking advancements in its application through nano-engineering. LF exerts anti-tumor effects through multiple pathways, including extracellular action, intracellular action, and immune regulation. It demonstrates a remarkable affinity for cancer cell membranes, binding to overexpressed anionic components such as glycosaminoglycans and sialic acids, as well as to specific receptors including the low-density lipoprotein receptor-related protein-1 (LRP-1). This selective binding facilitates targeted uptake. Upon internalization, LF orchestrates a direct assault by inducing cell-cycle arrest in phases such as G0/G1 or S phase through the modulation of key regulators including cyclins, CDKs, and p53. Furthermore, it promotes programmed cell death via apoptotic pathways, involving caspase activation and downregulation of anti-apoptotic proteins such as survivin. A more recently elucidated mechanism is the induction of ferroptosis, an iron-dependent form of cell death characterized by overwhelming lipid peroxidation. Beyond direct cytotoxicity, LF acts as a potent immunomodulator. It enhances natural killer (NK) cell activity, modulates T-lymphocyte populations, and crucially reprograms tumor-associated macrophages (TAMs) from a pro-tumor M2 state to an anti-tumor M1 state, thereby reversing the immunosuppressive tumor microenvironment (TME). The translation of LF’s potential has been significantly accelerated by nanotechnology. The inherent biocompatibility and natural tumor-targeting capabilities of LF make it an ideal platform for sophisticated drug-delivery systems. This review details various fabrication strategies for LF-based nanoparticles (NPs), including self-assembly, sol-in-oil emulsion, and electrostatic nanocomplexes, among others. Research demonstrates that nano-formulations not only protect LF from degradation but also enhance its bioactivity and anti-cancer potency. More importantly, LF NPs serve as versatile carriers for a wide array of therapeutic agents, including conventional chemotherapeutics, natural compounds, and imaging agents. These engineered systems enable synergistic therapy and facilitate site-specific delivery. Notably, the ability of LF to bind to receptors on the blood-brain barrier (BBB) has been leveraged to develop nano-systems for glioblastoma treatment. Other innovative designs utilize LF to modulate the TME—for instance, by alleviating tumor hypoxia to sensitize cells to radiotherapy and chemotherapy. Despite compelling pre-clinical evidence, the clinical translation of LF and its nano-formulations remains nascent. While early-phase trials have established a favorable safety profile for recombinant human LF, larger Phase III studies have yielded mixed results, underscoring the complexity of its action in humans. Key challenges include enhancing drug targeting, optimizing loading efficiency, ensuring batch-to-batch reproducibility, and achieving deep tumor penetration. Future research must focus on the rational design of next-generation LF-NPs. This entails developing standardized manufacturing protocols, engineering “smart” stimuli-responsive systems for targeted drug release in the TME, and constructing multi-targeting platforms. A concerted interdisciplinary effort is paramount to bridge the gap between bench and bedside. In conclusion, LF, particularly in its nano-engineered forms, represents a highly promising and versatile agent in the oncological arsenal, holding immense potential for precise and effective cancer therapy.

ObjectiveTo explore the mechanism by which modified Guishenwan alleviates inflammation in the rat model of polycystic ovary syndrome （PCOS） by regulating the mitogen-activated protein kinase （MAPK）/nuclear factor kappa B （NF-κB） pathway. MethodsAccording to the random number table method， 60 SPF female SD rats were randomized into a normal group （n=10） and a modeling group （n=50）. The normal group received routine feeding， while the modeling group was administrated with letrozole （1 mg·kg^-1·d^-1） by gavage for 21 days for the modeling of PCOS. The successfully modeled rats were randomized into model， diane-35 （0.2 g·kg^-1·d^-1）， high- （16.04 g·kg^-1·d^-1）， medium- （8.02 g·kg^-1·d^-1）， low- （4.01 g·kg^-1·d^-1） dose modified Guishenwan groups. The drug intervention groups were administrated with modified Guishenwan at corresponding doses by gavage， and the normal group and model group were given equal volumes of normal saline. All the groups were continuously treated for 28 days. After treatment， Gram staining of vaginal smears was employed to observe the estrous cycle in each group. Enzyme-linked immunosorbent assay was employed to determine the levels of follicle-stimulating hormone （FSH）， estradiol （E₂）， luteinizing hormone （LH）， testosterone （T）， and progesterone （PROG） in the plasma， as well as interleukin-1 beta （IL-1β）， tumor necrosis factor-alpha （TNF-α）， and interleukin-10 （IL-10） in the plasma and ovarian tissue. The LH/FSH ratio was calculated. The morphological changes in the ovarian tissue were observed by hematoxylin-eosin （HE） staining. Western blot was employed to determine the protein levels of extracellular-regulated protein kinase （ERK）， c-Jun N-terminal kinase （JNK）， p38 MAPK， NF-κB p65， IκBα， p-JNK， p-ERK， p-p38 MAPK， p-NF-κB p65， and p-IκBα in the ovarian tissue. Real-time quantitative polymerase chain reaction was used to determine the mRNA levels of ERK， JNK， p38 MAPK， NF-κB p65， and IκBα in the ovarian tissue. ResultsCompared with the normal group， the model group was in the estrus phase， with an increase in the number of ovarian vesicles and decreases in granulosa cells and corpus luteum formation （P<0.05）， and lowered levels of FSH and E₂ and elevated levels of LH， T， and LH/FSH in the plasma （P<0.05）. Compared with the model group， high-， medium-， and low-dose modified Guishenwan recovered the estrous cycle， increased the generation of granulosa cells and corpus luteum， reduced the number of vesicles， elevated the levels of FSH and E₂， and lowered the levels LH， T， and LH/FSH （P<0.05， P<0.01） in a dose-dependent manner. High-dose modified Guishenwan demonstrated the best therapeutic effect. Therefore， subsequent experiments for exploring the treatment mechanism were conducted in the normal group， model group， and high-dose modified Guishenwan group. The results showed that compared with the model group， high-dose modified Guishenwan lowered the levels of IL-1β， TNF-α， and IL-10 and elevated the level of IL-10 in the plasma and ovarian tissue （P<0.05， P<0.01）， down-regulated the protein levels of p-ERK， p-JNK， p-p38 MAPK， p-NF-κB p65， and p-IκBα， while up-regulating the protein level of IκBα （P<0.01）. At the same time， the mRNA levels of ERK， JNK， p38 MAPK， and NF-κB p65 in the high-dose modified Guishenwan group were down-regulated （P<0.05， P<0.01）. ConclusionModified Guishenwan can improve the ovarian function in rat model of PCOS induced by letrozole and has anti-inflammatory effects， which may be related to inhibition of the MAPK/NF-κB pathway.

ObjectiveBased on the adenosine 5'-monophosphate （AMP）-activated protein kinase/protein kinase B/nuclear factor erythroid 2-related factor 2 （AMPK/Akt/Nrf2） pathway， this study aims to explore the mechanism by which modified Guishenwan improves glucose and lipid metabolism and oxidative stress in polycystic ovary syndrome （PCOS） rats. MethodsA PCOS rat model was established by continuous oral administration of letrozole （1 mg·kg^-1·d^-1） for 21 days. Successfully modeled rats were randomly divided into a model group， a metformin group （0.25 g·kg^-1）， and low-， medium-， and high-dose modified Guishenwan groups （4.01， 8.02， and 16.04 g·kg^-1·d^-1）， with 8 rats in each group. Ten normal rats were assigned to the normal group. The drug groups were given their respective doses， while the normal and model groups were given an equal volume of normal saline. Intervention lasted for 4 weeks. Testosterone （T）， estradiol （E₂）， follicle-stimulating hormone （FSH）， and luteinizing hormone （LH） were measured by enzyme-linked immunosorbent assay （ELISA）， and the LH/FSH ratio was calculated. Fasting blood glucose （FPG）， fasting insulin （FINS）， triglyceride （TG）， and total cholesterol （TC） levels were measured using an automatic biochemical analyzer， and the insulin resistance index （HOMA-IR） and insulin sensitivity index （HOMA-ISI） were calculated. Oral glucose tolerance test （OGTT） and insulin tolerance test （ITT） were conducted. Malondialdehyde （MDA）， advanced glycation end products （AGEs）， and superoxide dismutase （SOD） levels in serum and ovarian tissue were measured using a chemical fluorescence method. Hematoxylin-eosin （HE） staining was used to assess ovarian tissue pathology. Real-time quantitative fluorescent polymerase chain reaction （Real-time PCR） and Western blot were used to measure the expression of AMPK/Akt/Nrf2 pathway-related genes and proteins in ovarian tissue. ResultsCompared with the normal group， the model group exhibited significantly increased levels of T， LH， LH/FSH， FPG， FINS， TG， TC， and HOMA-IR， while FSH， E₂， and HOMA-ISI were significantly decreased （P<0.05， P<0.01）. MDA and AGEs levels were significantly higher in both serum and ovarian tissue， and SOD levels were significantly reduced （P<0.05）. AMPK， Akt， and Nrf2 mRNA and protein expression in ovarian tissue was also significantly reduced （P<0.05）. The OGTT and ITT results showed significantly higher blood glucose levels at each time point （P<0.05， P<0.01）， with impaired glucose and insulin tolerance. Ovarian follicles showed polycystic changes， reduced corpus luteum， and sparse granulosa cell layers. Compared with the model group， the metformin group and the high-dose modified Guishenwan group showed significant decreases in T， LH， LH/FSH， FPG， FINS， TG， TC， and HOMA-IR， while FSH， E₂， and HOMA-ISI were significantly increased （P<0.05， P<0.01）. In the high-dose modified Guishenwan group， MDA and AGEs levels in serum and ovarian tissue were significantly reduced， and SOD levels were significantly increased （P<0.05）. The mRNA and protein expression of AMPK， Akt， and Nrf2 in ovarian tissue was significantly increased （P<0.05）. OGTT and ITT results showed that blood glucose levels in rats decreased significantly at each time point （P<0.05， P<0.01）. No obvious abnormalities were observed in ovarian tissue. Compared with the low-dose modified Guishenwan group， the high-dose group showed significant decreases in T， LH， LH/FSH， FPG， FINS， TG， TC， and HOMA-IR， while FSH， E₂， and HOMA-ISI were significantly increased （P<0.05）. OGTT and ITT results indicated that the high-dose modified Guishenwan group significantly improved glucose and insulin tolerance in rats. No significant abnormalities were observed in ovarian tissue. ConclusionModified Guishenwan effectively improves glucose and lipid metabolism abnormalities and inhibits oxidative stress in PCOS rats， potentially through regulation of the AMPK/Akt/Nrf2 pathway.

The pathogenesis of central precocious puberty(CPP)is due to the early initiation of the function of the hypothalamic-pituitary-gonadal axis,which is driven by the gonadotrophin-releasing hor-mone(GnRH)from the hypothalamus.The increase of GnRH secretion will promote the secretion of gon-adotropin by the pituitary gland,which leads to the development of reproductive organs and the secretion of sex hormones.The timing of puberty onset is influenced by the interaction between nutritional,envi-ronmental,and socioeconomic factors.In the study of pathogenic genes,loss-of-function mutations of MKRN3,LIN28 and DLK1 genes can lead to early onset of puberty,among which loss-of-function muta-tions of MKRN3 are one of the most common single-gene causes of familial CPP.Since 2013,when the MKRN3 mutation was first identified in five CPP families,the role of MKRN3 in adolescence has gradu-ally been discovered.MKRN3 is a member of the E3 ubiquitin ligase family and is expressed in the cen-tral nervous system of many eukaryotes.MKRN3 may act as an E3 ubiquitin ligase to inhibit GnRH activ-ity.Recently,more and more studies have explored the molecular mechanism of MKRN3 in CPP,revea-ling a variety of genes and proteins that interact with MKRN3.For example,MKRN3 can inhibit KISS1 and TAC3 activities,thereby affecting the expression of kisspeptin and neurokinin B to regulate GnRH se-cretion.MKRN3 also inhibited GNRH1 mRNA translation through PABPC1 ubiquitination.In addition,there are other targets such as MBD3,IGF2BP1 and NPTX1,all of which are involved in GnRH regula-tion downstream of MKRN3.Upstream of MKRN3,miR-30 can bind to three sites in the 3'-untranslated region of the MKRN3 gene to block MKRN3 transcription.Here we review the role of MKRN3 in the path-ogenesis of CPP and the research progress of its molecular mechanism,which will help to better under-stand the pathogenesis of CPP,provide new ideas and treatment methods for CPP-related fields in the fu-ture,and lay a theoretical foundation for further exploration of the molecular mechanism of MKRN3.

AIM:Fine particulate matter(PM2.5)is closely associated with airway hyper-responsiveness(AHR).However,the underlying mechanism by which PM2.5 leads to AHR is still unclear.This study aimed to investi-gate the respiratory effects of ambient PM2.5 exposure.METHODS:Forty mice were randomly divided into five groups:control group(intranasal saline),lipopolysaccharide(LPS)group(100 mg/L),PM2.5 low-dose group(0.003 5 mg/d),PM2.5 medium-dose group(0.007 mg/d),and PM2.5 high-dose group(0.014 mg/d).They were treated with intranasal in-stillation for 30 d.Lung function and tracheal contractile responses were evaluated using whole-body plethysmography and sensitive wire myograph.Inflammatory mediators in serum and oxidative stress parameters were detected using enzyme-linked immunosorbent assay(ELISA).Lung tissues were subjected to HE and Masson staining.RT-qPCR and Western blot were used to determine the expression of contractile receptors and the phosphorylation of the mitogen-activated protein kinase(MAPK)signal pathway.RESULTS:Intranasal instillation of PM2.5 significantly increased airway resistance in mice and enhanced tracheal contractility in response to carbachol.PM2.5 elevated levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,and IL-6 in serum.PM2.5 instillation also led to a decrease in glutathione peroxidase(GSH-Px)levels and an increase in malondialdehyde(MDA)levels.Lung tissue exhibited notable pathological changes,including inflammatory cell infiltration,hyperplasia of alveolar epithelial cells,and collagen deposition.Mechanistically,exposure to PM2.5 increased the expression of muscarinic M3 receptor mRNA and protein,as well as the phosphorylation of p-ERK1/2 and p-p38 proteins following PM2.5 instillation.CONCLUSION:Intranasal instillation of PM2.5 induced inflammation and oxidative stress,along with the activation of the extracellular signal-regulated kinase 1/2(ERK1/2)and p38 MAPK pathways,resulting in the upregulation of M3 receptor-induced AHR.