Pain, especially when chronic, is a common reason patients seek medical care and it affects the quality of life and well-being of the patients. Unfortunately, currently available therapies for chronic pain are often inadequate because the neurobiological basis of such pain is still not fully understood. Although dopamine has been known as a neurotransmitter to mediate reward and motivation, accumulating evidence has shown that dopamine systems in the brain are also involved in the central regulation of chronic pain. Most importantly, descending dopaminergic pathways play an important role in pain modulation. In this review, we discuss dopamine receptors, dopaminergic systems in the brain, and the role of descending dopaminergic pathways in the modulation of different types of pain.

Background: In the present study, we aim to investigate the potential role of propofol in the tumor progression of colon cancer.Methods: Human colon cancer cell lines were cultured and exposed with 8 μg/mL propofol. RNA interference was performed to silence the expression of HOTAIR or STAT3 to explore their biological functions in colon cancer. Cell apoptosis and invasion were assessed using flow cytometry and transwell assays, respectively. Quantitative real‐time PCR, western blot, and immunohistochemistry were subjected to measure the expression patterns of HOTAIR, STAT3, Wnt signaling factors, and epithelial‐mesenchymal transition‐related markers, respectively. Besides, nude mice were transplanted with colon cancer cells for further exploration. Tumor formation, volume, and weight were evaluated to validate the in vitro findings.Results: Propofol treatment promoted cell apoptosis and inhibited cell invasion in colon cancer cells, while the effects were reversed by HOTAIR overexpression. Additionally, STAT3 positively regulated HOTAIR expression, which was also negatively modulated by propofol. Moreover, STAT3 and HOTAIR were shown to independently regulate colon cancer cell apoptosis and invasion. Furthermore, HOTAIR could stimulate Wnt signaling pathway via inhibiting WIF‐1 expression and upregulating β‐catenin expression, which was also demonstrated by in vivo study.Conclusion: Taken together, the current study demonstrated that propofol exerts the inhibition on cell invasion and promotion on cell apoptosis through regulating STAT3/HOTAIR by activating WIF‐1 and suppressing Wnt pathway, indicating that propofol might serve as a therapeutic role for colon cancer patients in the future.

Available evidence indicates that neuregulin-1 (NRG-1) can provide a protection against myocardial ischemia/reperfusion (I/R) injury and is involved in various cardioprotective interventions by potential regulation of mitophagy. However, the molecular mechanisms linking NRG-1 and mitophagy remain to be clarified. In this study, both an in vivo myocardial I/R injury model of rats and an in vitro hypoxia/reoxygenation (H/R) model of H9C2 cardiomyocytes were applied to determine whether NRG-1 postconditioning attenuated myocardial I/R injury through the regulation of mitophagy and to explore the underlying mechanisms. In the in vivo experiment, cardioprotective effects of NRG-1 were determined by infarct size, cardiac enzyme and histopathologic examinations. The potential downstream signaling pathways and molecular targets of NRG-1 were screened by the RNA sequencing and the Protein-Protein Interaction Networks. The expression levels of mitochondrial uncoupling protein 2 (UCP2) and mitophagy-related proteins in both the I/R myocardium and H/R cardiomyocytes were measured by immunofluorescence staining and Western blots. The activation of mitophagy was observed with transmission electron microscopy and JC-1 staining. The KEGG and GSEA analyses showed that the mitophagy-related signaling pathways were enriched in the I/R myocardium treated with NRG-1, and UCP2 exhibited a significant correlation between mitophagy and interaction with PINK1. Meanwhile, the treatment with mitophagy inhibitor Mdivi-1 significant eliminated the cardioprotective effects of NRG-1 postconditioning in vivo, and the challenge with UCP2 inhibitor genipin could also attenuate the activating effect of NRG-1 postconditioning on mitophagy. Consistently, the in vitro experiment using H9C2 cardiomyocytes showd that NRG-1 treatment significantly up-regulated the expression levels of UCP2 and mitophagy-related proteins, and activated the mitophagy, whereas the challenge with small interfering RNA-mediated UCP2 knockdown abolished the effects of NRG-1. Thus, it is conclused that NRG-1 postconditioning can produce a protection against the myocardial I/R injury by activating mitophagy through the UCP2/PINK1/LC3B signaling pathway.

Background: Perioperative anemia and transfusion are intertwined with each other, and both have adverse impacts on the survival of colorectal cancer (CRC) patients. But the treatment of anemia still relies on transfusion in several countries, which leads us to question the effects of anemia tolerance and transfusion on the long-term outcomes of CRC patients. We investigated the combined effect of preoperative anemia and postoperative anemia and of preoperative anemia and blood transfusion, which imposes a greater risk to survival, to compare the effects of anemia tolerance and transfusion on overall survival (OS) and disease-free survival (DFS) in patients undergoing CRC surgery.Methods: A retrospective propensity-score-matched analysis included patients with CRC undergoing elective surgery between January 1, 2008, and December 31, 2014. After propensity-score matching, Kaplan–Meier survival analysis and univariable and multivariable Cox proportional hazards models were used to study the prognostic factors for survivals. In univariate and multivariate Cox regression analysis, two novel models were built.Results: Of the 8,121 patients with CRC, 1,975 (24.3%) and 6,146 (75.7%) patients presented with and without preoperative anemia, respectively. After matching, 1,690 patients remained in each group. In the preoperative anemia and postoperative anemia model, preoperative anemia and postoperative anemia was independent risk factor for OS (HR, 1.202; 95% CI, 1.043–1.385; P=0.011) and DFS (HR, 1.210; 95% CI, 1.050–1.395; P=0.008). In the preoperative anemia and transfusion model, preoperative anemia and transfused was the most dangerous independent prognostic factor for OS (HR, 1.791; 95% CI, 1.339–2.397; P<0.001) and DFS (HR, 1.857; 95% CI, 1.389–2.483; P<0.001). In patients with preoperative anemia, the OS and DFS of patients with transfusion were worse than those of patients without transfusion (P=0.026 in OS; P=0.037 in DFS).Conclusions: Preoperative anemia and blood transfusion imposed a greater risk to OS and DFS in patients undergoing CRC surgery, indicating that the harm associated with blood transfusion was greater than that associated with postoperative anemia. These findings should encourage clinicians to be vigilant for the timely prevention and treatment of anemia, by appropriately promoting toleration of anemia and restricting the use of blood transfusion in patients with CRC.

BACKGROUND Postoperative pain management and cognitive function preservation are crucial for patients undergoing thoracoscopic surgery for lung cancer (LC). This is achieved using either a thoracic paravertebral block (TPVB) or sufentanil (SUF)-based multimodal analgesia. However, the efficacy and impact of their combined use on postoperative pain and postoperative cognitive dysfunction (POCD) remain unclear. AIM To explore the analgesic effect and the influence on POCD of TPVB combined with SUF-based multimodal analgesia in patients undergoing thoracoscopic radical resection for LC to help optimize postoperative pain management and improve patient outcomes. METHODS This retrospective analysis included 107 patients undergoing thoracoscopic radical resection for LC at The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital between May 2021 and January 2023. Patients receiving SUF-based multimodal analgesia (n = 50) and patients receiving TPVB + SUF-based multimodal analgesia (n = 57) were assigned to the control group and TPVB group, respectively. We compared the Ramsay Sedation Scale and visual analog scale (VAS) scores at rest and with cough between the two groups at 2, 12, and 24 h after surgery. Serum levels of epinephrine (E), angio-tensin II (Ang II), norepinephrine (NE), superoxide dismutase (SOD), vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and S-100 calcium-binding protein β (S-100β) were measured before and 24 h after surgery. The Mini-Mental State Examination (MMSE) was administered 1 day before surgery and at 3 and 5 days after surgery, and the occurrence of POCD was monitored for 5 days after surgery. Adverse reactions were also recorded. RESULTS There were no significant time point, between-group, and interaction effects in Ramsay sedation scores between the two groups (P > 0.05). Significantly, there were notable time point effects, between-group differences, and interaction effects observed in VAS scores both at rest and with cough (P < 0.05). The VAS scores at rest and with cough at 12 and 24 h after surgery were lower than those at 2 h after surgery and gradually decreased as postoperative time increased (P < 0.05). The TPVB group had lower VAS scores than the control group at 2, 12, and 24 h after surgery (P < 0.05). The MMSE scores at postoperative days 1 and 3 were markedly higher in the TPVB group than in the control group (P < 0.05). The incidence of POCD was significantly lower in the TPVB group than in the control group within 5 days after surgery (P < 0.05). Both groups had elevated serum E, Ang II, and NE and decreased serum SOD levels at 24 h after surgery compared with the preoperative levels, with better indices in the TPVB group (P < 0.05). Marked elevations in serum levels of VEGF, TGF-β1, TNF-α, and S-100β were observed in both groups at 24 h after surgery, with lower levels in the TPVB group than in the control group (P < 0.05). CONCLUSION TPVB combined with SUF-based multimodal analgesia further relieves pain in patients undergoing thoracoscopic radical surgery for LC, enhances analgesic effects, reduces postoperative stress response, and inhibits postoperative increases in serum VEGF, TGF-β1, TNF-α, and S-100β levels. This scheme also reduced POCD and had a high safety profile.