Copper is an essential trace element in the human body, extensively involved in key physiological and biochemical processes such as antioxidant defense, energy metabolism, neural signaling, and immune regulation. In recent years, increasing research has focused on the potential role of copper dyshomeostasis in the development of chronic diseases. Studies indicate that abnormal copper levels, particularly elevated free copper, may increase the risk of cardiovascular disease, neurodegenerative disorders, diabetes, and cancer by inducing oxidative stress, impairing mitochondrial function, and disrupting immune regulation. Concurrently, copper homeostasis abnormalities have been demonstrated to be closely associated with increased all-cause mortality and accelerated aging. This systematic review comprehensively examined physiological functions, metabolic pathways, and environmental exposure characteristics of copper. It emphasized the epidemiological and mechanistic links between copper metabolism disorders and multiple chronic diseases, while exploring the potential applications of copper ion transporters and chelating agents in disease intervention. This work provides scientific evidence for the prevention, control, and precision treatment of copper-related chronic diseases.

ObjectiveTo explore the mechanism through which Gantou Fumu decoction （GDFMT）-containing serum inhibits the activation of hepatic stellate cells. MethodsSerum pharmacology techniques were employed to prepare GDFMT-containing serum samples. Rat hepatic stellate cells （HSCT6） were randomly allocated into three groups： Control， penicillamine （90 mg·kg^-1）， and GDFMT （6.8 g·kg^-1）. Cell viability was assessed by the cell counting kti-8 （CCK-8） assay， intracellular ROS levels were determined by flow cytometry using the DCFH‑DA fluorescent probe and while extracellular collagen Ⅰ （ColⅠ） levels were quantified via enzyme linked immunosorbent assay （ELISA）. Intracellular α-smooth muscle actin （α-SMA） expression was visualized through immunofluorescence staining. Real-time polymerase chain reaction（Real-time PCR） and Western blot were performed to evaluate alterations in the expression of nuclear factor-erythroid 2-related factor 2 （Nrf2）， glutamate cysteine ligase， catalytic （GCLC）， glutamate-cysteine ligase， modifier subunit （GCLM）， Kelch-like ECH-associated protein 1 （Keap1）， NAD（P）H：Quinone oxidoreductase 1 （NQO1）， and heme oxygenase-1 （HO-1）. Genetic knockdown of Nrf2 was achieved through small interfering （siRNA） transfection to validate pathway specificity. ResultsCCK-8 data indicated that under the selected experimental conditions， culturing HSCT6 cells with 10% （volume fraction） GDFMT-containing serum for 48 h demonstrated equivalent effect in inhibiting HSCT6 cell proliferation compared with culturing HSCT6 cells with 10% （volume fraction） penicillamine-containing serum for 36 h， with no statistically significant difference between the two groups. After treatment of HSCT6 cells with siRNA-mediated Nrf2 gene transfection technique， the inhibitory effect of GDFMT on the activation process of HSCT6 cells was significantly weakened. After HSCT6 cells were cultured with GDFMT-containing serum for 48 h， the flow cytometry with a fluorescence probe showed that the content of reactive oxygen species （ROS） in the cells was significantly reduced. After the expression level of the Nrf2 gene in HSCT6 cells was knocked down by siRNA transfection， the content of ROS increased （P<0.01）， indicating that GDFMT significantly reduced the ROS level in activated HSCT6 cells， and this effect strictly depended on the integrity of the Nrf2 pathway. Quantitative analysis by ELISA showed that the synthesis of ColⅠ in the HSCT6 cell culture system treated with GDFMT-containing serum for 48 h was lower than that in the control group （P<0.01）. After the Nrf2 gene level of HSCT6 cells was knocked down by siRNA transfection， the ColⅠ concentration in the culture supernatant increased （P<0.01）. The results of α-SMA detection by IF method showed that compared with the normal group， GDFMT-containing serum reduced the expression of α-SMA （P<0.01） and the protein level of α-SMA in HSCT6 cells was increased （P<0.01） after siRNA-mediated Nrf2 silencing， suggesting that Nrf2 signaling pathway may be involved in regulating the phenotypic transformation process of the cells. Real-time PCR and Western blot results showed that GDFMT-containing serum reduced the protein level of α-SMA （P<0.01） and enhanced the gene and protein levels of Nrf2 in the nucleus and GCLC， HO-1， Keap1， GCLM， and NQO1 in the cytoplasm of HSCT6 cells （P<0.05， P<0.01）. After the Nrf2 gene level of HSCT6 cells was knocked down by siRNA transfection， the protein level of α-SMA was increased （P<0.01）， and the levels of GCLC， GCLM， Keap1， NQO1， and HO-1 were decreased （P<0.05， P<0.01）. These results indicated that GDFMT-containing serum successfully triggered the Nrf2 signaling pathway of HSCT6 cells. ConclusionThe anti-hepatic fibrosis effect of 10%GDFMT was equivalent to that of penicillamine. In addition， GDFMT can inhibit HSC activation and reduce oxidative stress damage by activating the Nrf2/antioxidant response element （ARE） pathway， as manifested by the up-regulated expression of Nrf2 and downstream antioxidant genes （GCLC， GCLM， HO-1， Keap1， and NQO1） and reduced secretion of ROS， α-SMA， and ColⅠ.

Orthodontic tooth movement elicits alveolar bone remodeling and orofacial pain that is manifested by tooth mechanical hyperalgesia. Nerve growth factor (NGF) is upregulated in periodontium and may modulate tooth mechanical hyperalgesia. The objectives were to examine the role of NGF in tooth mechanical hyperalgesia and to elucidate the underlying mechanisms. Tooth mechanical hyperalgesia was induced by ligating closed coil springs between incisors and molars in Sprague-Dawley rats. Retrograde labeling was performed by periodontal administration of fluor-conjugated NGF and the detection of fluorescence in trigeminal ganglia (TG). Lentivirus vectors carrying NGF shRNA were employed to knockdown the expression of NGF in TG. The administration of agonists, antagonists, and virus vectors into TG and periodontium was conducted. Tooth mechanical hyperalgesia was examined through the threshold of biting withdrawal. Our results revealed that tooth movement elicited tooth mechanical hyperalgesia that could be alleviated by NGF neutralizing antibody and that NGF was upregulated in periodontium (mainly in periodontal fibroblasts) and TG. Retrograde labeling revealed that periodontal NGF was retrogradely transported to TG after day 1. Acid-sensing ion channel 3 (ASIC3) and NGF were co-expressed in trigeminal neurons and the percentage of co-expression was significantly higher following tooth movement. The administration of NGF and NGF neutralizing antibody into TG could upregulate and downregulate the expression of ASIC3 in TG, respectively. NGF aggravated tooth mechanical hyperalgesia that could be alleviated by ASIC3 antagonist (APETx2). Moreover, NGF neutralizing antibody mitigated tooth mechanical hyperalgesia that could be recapitulated by ASIC3 agonist (GMQ). NGF-based gene therapy abolished tooth mechanical hyperalgesia and downregulated ASIC3 expression. Taken together, in response to force stimuli, periodontal fibroblasts upregulated the expressions of NGF that was retrogradely transported to TG, where NGF elicited tooth mechanical hyperalgesia through upregulating ASIC3. NGF-based gene therapy is a viable method in alleviating tooth-movement-induced mechanical hyperalgesia.