Caspase-3 promotes genetic instability and carcinogenesis.

Apoptosis is typically considered an anti-oncogenic process since caspase activation can promote the elimination of genetically unstable or damaged cells. We report that a central effector of apoptosis, caspase-3, facilitates rather than suppresses chemical- and radiation-induced genetic instability and carcinogenesis. We found that a significant fraction of mammalian cells treated with ionizing radiation can survive despite caspase-3 activation. Moreover, this sublethal activation of caspase-3 promoted persistent DNA damage and oncogenic transformation. In addition, chemically induced skin carcinogenesis was significantly reduced in mice genetically deficient in caspase-3. Furthermore, attenuation of EndoG activity significantly reduced radiation-induced DNA damage and oncogenic transformation, identifying EndoG as a downstream effector of caspase-3 in this pathway. Our findings suggest that rather than acting as a broad inhibitor of carcinogenesis, caspase-3 activation may contribute to genome instability and play a pivotal role in tumor formation following damage.

Circular RNA hsa_circ_0103552 Promotes Proliferation, Migration, and Invasion of Breast Cancer Cells through Upregulating Cysteine-Rich Angiogenic Inducer 61 (CYR61) Expression via Sponging MicroRNA-515-5p.

Circular RNAs (circRNAs) exert a significant regulatory function on tumor progression. This work intends to probe into the biological function and regulatory mechanism of circRNA_0103552 (circ_0103552) in breast cancer carcinogenesis. In this study, circ_0103552, microRNA-515-5p (miR-515-5p), and cysteine-rich angiogenic inducer 61 (CYR61) mRNA expressions in breast cancer cells and tissues were determined by quantitative real-time polymerase chain reaction, followed by cell counting kit 8 and Transwell experiments to examine the multiplication, migration, and invasion of breast cancer cells. Circular RNA Interactome database and StarBase database were searched, and dual-luciferase reporter gene experiments were applied to verify the targeting relationship between circ_0103552 and miR-515-5p, and between miR-515-5p and CYR61, and Western blot was adopted to the regulatory function of circ_0103552 and miR-515-5p on CYR61 protein expression. Circ_0103552 expression was found to be remarkably up-modulated in breast cancer tissues and cells, and circ_0103552 overexpression facilitated the multiplication, migration, and invasion of breast cancer cells, while knocking down circ_0103552 induced the opposite effects. Mechanistically, circ_0103552 could sponge miR-515-5p and restrained its expression in breast cancer cells. MiR-515-5p could counteract the functions of circ_0103552 in breast cancer cells. Additionally, CYR61 was revealed to be a downstream target of miR-515-5p in breast cancer cells. In summary, this study shows that circ_0103552 up-modulates CYR61 expression by targeting miR-515-5p and thus facilitates the multiplication, migration, and invasion of breast cancer cells.

A Suzuki-Miyaura method for labelling proliferating cells containing incorporated BrdU.

The 5-bromo-2'-deoxyuridine (BrdU) incorporation cell proliferation assay is the most commonly used method for assessing DNA replication. The current detection of BrdU in cells relies on antibody immunostaining, but has various limitations including low antibody specificity and poor tissue penetration. In this study, we utilised a Suzuki-Miyaura reaction to develop a chemical method to label cellular BrdU with fluorescent boronic acid probes. The coupling conditions were optimised for complex cellular environments, and the key observation was the need to use oxygen scavengers and zerovalent palladium to prevent side reactions and increase the rate of coupling. The reliability and specificity of the BrdU Suzuki-Miyaura labelling method were verified under various biological conditions. The applicability of the BrdU Suzuki-Miyaura labelling methodology was also investigated, and we show that labelling cellular BrdU is highly sensitive and reliable, which is comparable to the ideal performance of BrdU immunostaining. Moreover, the Suzuki-Miyaura reaction protocol provides high BrdU recognition specificity. Taken together, the BrdU Suzuki-Miyaura labelling protocol provides an attractive alternative to the more traditional cell proliferation assay.

Exploration of the Fluorescent Properties and the Modulated Activities against Sirtuin Fluorogenic Assays of Chromenone-Derived Natural Products.

Chromenone-derived natural products include chromones (flavone, isoflavone) and coumarins. Chromenone compounds not only exhibit impressive biological activities, but also are an important resource of experimentally used fluorophores, such as, 7-amino-4-methylcoumarin (AMC). Various chromenone compounds have reported to have weak fluorescence, and this has the potential to interfere with the measurements during AMC fluorogenic assays and result in non-robust assay readouts. Several flavones and isoflavones were found as SIRT1 activators, while fluorogenic sirtuin assays utilized AMC labelled peptides as the substrates. In this study we investigated whether the fluorescent properties of chromenone-derived natural products interrupt the measurement of SIRT1/2 modulated activities. We found that the reported SIRT1 activators: flavones were detected with the SIRT1 activation activity, but isoflavones were not detected with SIRT1 activation activity, and instead that they were found to be fluorogenic compounds. Another chromenone compound, osthole, exhibited a moderate SIRT2 inhibitory activity with an IC50 of 10 µM. In conclusion, the fluorescent properties of these chromenone compounds do affect the measurement of the sirtuin activities of both inhibitors and activators. However, if the possible fluorescence properties are mitigated in the assay readout, these fluorogenic assays enable the screening of activity modulators.

Expression, purification, and characterization of a novel acidic Lipoxygenase from Myxococcus xanthus.

The gene encoding a novel acidic lipoxygenase from Myxococcus xanthus DK1622 (accession: WP_011551853.1) was cloned into vector pET-28a and expressed in Escherichia coli BL21(DE3). The recombinant enzyme (rMxLOX), with a molecular weight of approximately 80 kDa, was purified to homogeneity using one-step nickel-affinity chromatography and showed an activity of 5.6 × 104 U/mg. The optimum pH and temperature for rMxLOX activity were found to be 3.0 and 30 °C, respectively. Purified rMxLOX exhibited activity towards linoleic acid and arachidonic acid as substrates, with linoleic acid being the better substrate (Km and kcat values of 0.048 mM and 13.3/s, respectively). The synthetic dye aniline blue was decolorized 69.7 ± 3.5%, following incubation with rMxLOX for 35 min. These results reveal the potential for the use of rMxLOX in the pulp, textile, and wastewater treatment industries.

Mammalian target of rapamycin complex 1 (mTORC1) enhances bortezomib-induced death in tuberous sclerosis complex (TSC)-null cells by a c-MYC-dependent induction of the unfolded protein response.

Many factors, including duration and intensity of the unfolded protein response (UPR), dictate whether cells will adapt to endoplasmic reticulum stress or undergo apoptosis. In tuberous sclerosis (TSC), elevation of mammalian target of rapamycin complex 1 (mTORC1) activity has been proposed to compound the induction of UPR transcription factors ATF4 and CHOP, suggesting that the UPR could be targeted to eradicate TSC1/2-null cells during patient therapy. Here we report that control of c-MYC translation by mTORC1 plays a key role in determining whether TSC2-null Elt3 rat leiomyoma cells apoptose in response to UPR induction by the proteasome inhibitor bortezomib. Although bortezomib induces eukaryotic initiating factor 2α phosphorylation, mTORC1 activity was also required for downstream induction of the UPR transcription factors ATF4 and CHOP by a mechanism involving increased expression of c-MYC. Although bortezomib-induced c-MYC transcription was resistant to rapamycin treatment, mTORC1 activity was required for efficient c-MYC translation. c-MYC subsequently bound to the ATF4 promoter, suggesting direct involvement of an mTORC1/c-MYC-driven signaling pathway in the activation of the UPR. Consistent with this notion, exogenously expressed c-MYC reversed the ability of rapamycin to prevent bortezomib-induced CHOP and ATF4 expression as well as apoptosis. These findings indicate that the induction of ATF4/CHOP expression occurs via mTORC1 regulation of c-MYC and that this signaling pathway is a major determinant in the ability of bortezomib to induce apoptosis.

Association between RECQL5 genetic polymorphisms and susceptibility to breast cancer.

Previous studies indicated that the RECQL5 gene polymorphism was associated with human cancers. However, the association of RECQL5 gene polymorphism with breast cancer remains unclear. In the present study, we investigated the association between polymorphisms of the RECQL gene and breast cancer in a Chinese population. We selected four polymorphisms of the RECQL5 gene (rs820186, rs820196, rs820200, and rs4789223) for the present study. The genotyping was performed using the TaqMan method in 510 patients with breast cancer and 510 age- and sex-matched non-cancer controls. We found that rs820196 and rs828200 polymorphisms of RECQL5 were associated with breast cancer. For rs820196, the CC genotype (16.7 vs 9.4 %, P < 0.001) and C allele (42.5 vs 34.3 %, P < 0.001) were common in the breast cancer patients than in the control subjects, respectively. For rs828200, the GG genotype (23.7 vs 18.0 %, P < 0.001) and G allele (52.7 vs 43.8 %, P < 0.001) were common in the breast cancer patients than in the control subjects, respectively. Haplotype analysis showed that C-G (odds ratio (OR) = 2.247, 95 % confidence interval (CI) 1.854∼2.722; P < 0.001) was associated with increased risk for breast cancer. However, the C-T (OR = 0.175, 95 % CI 0.110∼0.278; P < 0.001) and T-G (OR = 0.544; 95 % CI 0.428∼0.692; P < 0.001) were associated with decreased risk for breast cancer, respectively. The present study indicated that the RECQL5 genetic polymorphism and haplotypes were associated with breast cancer in a Chinese population.

Application of nano-carbon in lymph node dissection for thyroid cancer and protection of parathyroid glands.

BACKGROUND: The aim of this study was to explore a new method to identify and protect parathyroid glands in neck lymph node dissection for patients with thyroid cancer. MATERIAL AND METHODS: One hundred patients with thyroid cancer underwent total thyroidectomy combined with central neck lymph node dissection. During the operation, 50 patients receiving nano-carbon suspension were included in the experiment group, and 50 patients without nano-carbon suspension were included in the control group. We compared changes in parathyroid hormone levels before surgery and at 48 h after surgery between the 2 groups and of serum Ca^2+ level within 48 h after surgery, as well as postoperative parathyroid pathological and lymph node dissection results. RESULTS: Eight and 1 parathyroid glands were detected pathologically in the control and experimental group, respectively. Decrease in parathyroid hormone level at 48 h occurred in 7 patients in the control group and 1 patient in the experimental group. Hypocalcemia was found at 48 h after surgery in 10 patients in the control group and 2 patients in the experimental group. CONCLUSIONS: Nano-carbon suspension can cause development of the thyroid gland and the central lymph node and a negative development of parathyroid glands. Careful identification and removal of black-stained lymphatic tissues in the process of total thyroidectomy with neck lymph node dissection can ensure a complete lymph node dissection and prevent parathyroid damage, thus effectively reducing the incidence of hypoparathyroidism.

Evaluating bandgap distributions of carbon nanotubes via scanning electron microscopy imaging of the Schottky barriers.

We show that the Schottky barrier at the metal-single walled carbon nanotube (SWCNT) contact can be clearly observed in scanning electron microscopy (SEM) images as a bright contrast segment with length up to micrometers due to the space charge distribution in the depletion region. The lengths of the charge depletion increase with the diameters of semiconducting SWCNTs (s-SWCNTs) when connected to one metal electrode, which enables direct and efficient evaluation of the bandgap distributions of s-SWCNTs. Moreover, this approach can also be applied for a wide variety of semiconducting nanomaterials, adding a new function to conventional SEM.

By Carrot or by Stick: The Influence of Encouraging and Discouraging Facial Feedback on Implicit Rule Learning.

Implicit learning refers to the process of unconsciously learning complex knowledge through feedback. Previous studies investigated the influences of different types of feedback (e.g., social and non-social feedback) on implicit learning. This study focused on the social information presented in the learning situation and tried to explore the effects of different social feedback on implicit rule learning. We assigned participants randomly into an encouraging facial feedback group (happy expression for correct answer, neutral but not negative expression for incorrect answer) and a discouraging facial feedback group (neutral but not happy expression for correct answer, negative expression for incorrect answer). The implicit learning task included four difficulty levels, and social feedback was presented in the learning phase but not the testing phase in two experiments. The only difference between the two experiments was that the sad face used as negative feedback in Experiment 1 was replaced with an angry face in Experiment 2 to enhance the ecological validity of the discouraging facial feedback group. These two experiments yielded consistent results: the performances in the encouraging facial feedback group were more accurate in both the learning and the testing phases at all difficulty levels. These findings indicated that the influence of encouraging social feedback for a better implicit learning achievement was stable and established a new groundwork for future research on incentive-based education, making it critical to investigate the impact of various forms of encouraging-based education on learning.

A Data Mining Study for Analysis of Acupoint Selection and Combinations in Acupuncture Treatment of Carpal Tunnel Syndrome.

Background: Carpal tunnel syndrome (CTS) is the most prevalent upper limb compressive neuropathy. A considerable number of clinical trials and meta-analyses have provided evidence supporting the effectiveness of acupuncture in treating CTS. Nevertheless, the ideal choice of acupoints remains ambiguous. Objective: A data mining analysis was conducted with the objective of determining the most effective acupoint combinations and selection for CTS. Methods: A search was conducted across seven Chinese and English electronic bibliographic databases spanning from their inception to March 2023. Selected were clinical trials that evaluated the efficacy of acupuncture therapy for CTS, with or without randomised controlled methods. Data extraction mainly included acupoint prescriptions. Information such as first author, study design and study setting were also extracted. The principal outcomes comprised the clinical manifestations linked to CTS. Statistical descriptions were generated using Excel 2019. The analysis of association rules was conducted using SPSS Modeler 18.0. Using SPSS Statistics 26.0, exploratory factor analysis and cluster analysis were conducted. Results: 142 trials (including 86 RCTs and 56 non RCTs) were identified, and 193 groups of effective prescriptions involving 68 acupoints were extracted. The most frequently used acupoints were Da-ling (PC7), Nei-guan (PC6), He-gu (LI4), Wai-guan (TE5), and Yang-xi (LI5). The most frequently used meridians were the pericardial meridian and the large intestine meridian. The majority of special acupoints used were Five-shu points and Yuan-source points, with acupoints on the upper limbs being the most frequently used. The core acupoint groups were analyzed and 11 groups of association rules, 8 factors, and 5 effective cluster groups were obtained. Conclusion: The evidence-based acupoint selection and combinations of acupuncture therapy for carpal tunnel syndrome were provided by the findings of this study.

A Shape-Consistent Deep-Learning Segmentation Architecture for Low-Quality and High-Interference Myocardial Contrast Echocardiography.

OBJECTIVE: Myocardial contrast echocardiography (MCE) plays a crucial role in diagnosing ischemia, infarction, masses and other cardiac conditions. In the realm of MCE image analysis, accurate and consistent myocardial segmentation results are essential for enabling automated analysis of various heart diseases. However, current manual diagnostic methods in MCE suffer from poor repeatability and limited clinical applicability. MCE images often exhibit low quality and high noise due to the instability of ultrasound signals, while interference structures can further disrupt segmentation consistency. METHODS: To overcome these challenges, we proposed a deep-learning network for the segmentation of MCE. This architecture leverages dilated convolutions to capture high-scale information without sacrificing positional accuracy and modifies multi-head self-attention to enhance global context and ensure consistency, effectively overcoming issues related to low image quality and interference. Furthermore, we also adapted the cascade application of transformers with convolutional neural networks for improved segmentation in MCE. RESULTS: In our experiments, our architecture achieved the best Dice score of 84.35% for standard MCE views compared with that of several state-of-the-art segmentation models. For non-standard views and frames with interfering structures (mass), our models also attained the best Dice scores of 83.33% and 83.97%, respectively. CONCLUSION: These studies proved that our architecture is of excellent shape consistency and robustness, which allows it to deal with segmentation of various types of MCE. Our relatively precise and consistent myocardial segmentation results provide fundamental conditions for the automated analysis of various heart diseases, with the potential to discover underlying pathological features and reduce healthcare costs.

Acupoint selection rules of acupuncture and moxibustion in treating neurogenic bladder based on data mining. / 基于数据挖掘技术分析针灸治疗神经源性膀胱的选穴规律.

OBJECTIVES: To explore the rules of acupoint selection in the treatment of neurogenic bladder (NB) with acupuncture and moxibustion by using data mining. METHODS: The clinical research literatures on acupuncture treatment of NB were collected from PubMed, Embase, Cochrane Library, CNKI, Wanfang Database, VIP Database and China Biology Medicine from retrieved to January 1, 2023. The acupoint prescription database was established using Excel 2019. SPSS Modeler 18.0 and SPSS Statistics 26.0 softwares were used to conduct the frequency, meri-dians, locations, specific acupoints analysis and association rules analysis, factor analysis, cluster analysis, etc., to explore the characteristics and rules of acupoint selection in acupuncture and moxibustion treatment of NB. RESULTS: Totally 313 papers were included, including 110 acupoints with a total frequency of 1 995. The high-frequency acupoints are Zhongji (CV3), Guanyuan (CV4), Sanyinjiao (SP6), etc. The commonly used meridians are the Bladder Meridian of Foot Taiyang and Conception Vessel. The involved acupoints are mostly located in the lumbosacral region and abdomen, and intersection acupoints, mu-front acupoints and back-shu acupoints are the majority in the specific acupoints. The core acupoints group was analyzed, and 17 groups of association rules, 7 factors and 6 effective cluster groups were obtained. CONCLUSIONS: Acupuncture and moxibustion treatment of NB follows the therapeutic principles of toni-fying the kidney, invigorating the spleen, and soothing the liver. The core acupoints group is CV3-CV4-SP6.

Analysis on acupoint selection rules in the treatment of metabolism-associated fatty liver disease based on data mining. / åŸºäºŽæ•°æ®æŒ–æŽ˜æŠ€æœ¯åˆ†æžé’ˆç¸æ²»ç–—ä»£è°¢ç›¸å ³è„‚è‚ªæ€§è‚ç— çš„é€‰ç©´è§„å¾‹.

OBJECTIVES: To explore the rules of acupoint selection in the treatment of metabolic-associated fatty liver disease (MAFLD) with acupuncture and moxibustion by using data mining technology. METHODS: The clinical research literature on acupuncture treatment of MAFLD was collected from PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, VIP Database and China Biology Medicine from their inception to November 20, 2022. According to our inclusion and exclusion criteria, the literature was independently screened and re-screened by two research members, and the screened results were checked, followed by establishing an acupoint prescription database using Excel 2019. Descriptive statistics of acupoints applied frequency, involved meridians, locations and specific acupoints were perpormed. Then, SPSS Modeler18.0 software was used to conduct analysis about association rules, and the SPSS Statistics 26.0 software was used to perform cluster analysis on high-frequency acupoints, exploring the characteristics and rules of acupoint selection and combination in the treatment of MAFLD. RESULTS: Totally, 178 papers were collected, containing 130 acupoints, with a total application frequency of 1 305. The top five acupoints are Zusanli (ST36), Fenglong (ST40), Ganshu (BL18), Taichong (LR3) and Sanyinjiao (SP6). The commonly involved meridians are the Stomach Meridian of Foot Yangming, Bladder Meridian of Foot Taiyang, and Spleen Meridian of Foot Taiyin. The employed acupoints are mostly located in the lower limbs and abdomen, and the five Shu acupoints and crossing acupoints are in the majority. The association rule analysis of high frequency acupoints indicated that of the 16 qualified acupoint groups, the top 5 with close correlation degrees are ST36 and ST40, ST36 and LR3, ST36 and SP6, ST40 and LR3 and ST36, ST36 and SP6 and ST40. Further, 3 effective clusters were obtained by cluster analysis. CONCLUSIONS: Acupuncture and moxibustion treatment of MAFLD follows the therapeutic principles of soothing the liver, invigorating the spleen, tonifying the kidney, and resolving phlegm and removing dampness. The core acupoint group is ST36, ST40 and LR3, and the combination of acupoints is based on syndrome differentiation. These results may provide a useful reference for clinical practice.

Design, synthesis and biological evaluation of indeno[1,2-d]thiazole derivatives as potent histone deacetylase inhibitors.

Novel indeno[1,2-d]thiazole hydroxamic acids were designed, synthesized, and evaluated for histone deacetylases (HDACs) inhibition and antiproliferative activities on tumor cell lines. Most of the tested compounds exhibited HDAC inhibition and antiproliferative activity against both MCF7 and HCT116 cells with GI50 values in the sub-micromolar range. Among them, compound 6o showed good inhibitory activity against pan-HDAC with IC50 value of 0.14 µM and significant growth inhibition on MCF7 and HCT116 cells with GI50 values of 0.869 and 0.535 µM, respectively.

Design, synthesis and biological evaluation of di-substituted cinnamic hydroxamic acids bearing urea/thiourea unit as potent histone deacetylase inhibitors.

A novel class of di-substituted cinnamic hydroxamic acid derivatives containing urea or thiourea unit was designed, synthesized and evaluated as HDAC inhibitors. All tested compounds demonstrated significant HDAC inhibitory activities and anti-proliferative effects against diverse human tumor cell lines. Among them, 7l exhibited most potent pan-HDAC inhibitory activity, with an IC50 value of 130 nM. It also showed strong cellular inhibition against diverse cell lines including HCT-116, MCF-7, MDB-MB-435 and NCI-460, with GI50 values of 0.35, 0.22, 0.51 and 0.48 µM, respectively.

Direct identification of metallic and semiconducting single-walled carbon nanotubes in scanning electron microscopy.

Because of their excellent electrical and optical properties, carbon nanotubes have been regarded as extremely promising candidates for high-performance electronic and optoelectronic applications. However, effective and efficient distinction and separation of metallic and semiconducting single-walled carbon nanotubes are always challenges for their practical applications. Here we show that metallic and semiconducting single-walled carbon nanotubes on SiO(2) can have obviously different contrast in scanning electron microscopy due to their conductivity difference and thus can be effectively and efficiently identified. The correlation between conductivity and contrast difference has been confirmed by using voltage-contrast scanning electron microcopy, peak force tunneling atom force microscopy, and field effect transistor testing. This phenomenon can be understood via a proposed mechanism involving the e-beam-induced surface potential of insulators and the conductivity difference between metallic and semiconducting SWCNTs. This method demonstrates great promise to achieve rapid and large-scale distinguishing between metallic and semiconducting single-walled carbon nanotubes, adding a new function to conventional SEM.

[Research progresses of the PARP inhibitors for the treatment of cancer].

The poly(ADP-ribose) polymerases (PARPs) is an important group of enzymes in DNA repair pathways, especially the base excision repair (BER) for DNA single-strand breaks (SSBs) repair. Inhibition of PARP in DNA repair-defective tumors (like those with BRAC1/2 mutations) can lead to cell death and genomic instability, what is so called "synthetic lethality". Currently, PARP inhibitors combined with cytotoxic chemotherapeutic agents in the treatment of BRCA-1/2 deficient cancers are in the clinical development. In this review, we will be focused on the development of combination application of PARP inhibitors with other anticancer agents in clinical trials.

Research Trends of Acupuncture Therapy for Chronic Pain-Related Depression or Anxiety from 2003 to 2023: A Bibliometric Analysis.

Background: Chronic pain (CP) as a long-lasting stressor can often cause mood disorders, such as depression or anxiety. The comorbidity of CP and mood disorders poses challenges for treatment and increases healthcare costs. Acupuncture has emerged as a widely utilized approach to alleviate both CP and mood disorders. However, there is a lack of well-established bibliometric analyses in this area of research. Therefore, this study aimed to identify the current hotspots and research trends regarding the use of acupuncture for treating CP-related depression or anxiety. Methods: We searched the Web of Science Core Collection spanning from 2003 to 2023 to identify relevant literature about the use of acupuncture for treating CP-related depression or anxiety. Bibliometric and visualization analyses were performed using CiteSpace 5.7.R5 and Vosviewer 1.6.19 software. Results: A total of 254 articles published between 2003 and 2023 were included, revealing an upward trajectory with some fluctuations in publication numbers over the past two decades. China and the Beijing University of Chinese Medicine were the most productive country and institution in this field. Fang JQ and Vickers AJ ascended as the most prolific and influential authors, respectively. Trials was the journal with the highest number of publications, while Pain and BMJ-British Medical Journal exhibited the highest citation and centrality, respectively. "Acupuncture", "depression", and "chronic pain" were the top three keywords. The hotspots in this domain encompass types of chronic pain that predispose to negative mood, including fibromyalgia, irritable bowel syndrome (IBS), and neuropathic pain. Randomized controlled trials (RCTs), mechanisms, and evidence-based evaluations are the main research directions. Conclusion: This study uses bibliometric techniques to analyze the research hotspots and forefronts of acupuncture as a therapeutic approach for CP-related depression or anxiety. Our objective is to provide researchers with valuable references and identify research focal points for future investigations.

Electroacupuncture promotes synaptic plasticity in rats with chronic inflammatory pain-related depression by upregulating BDNF/TrkB/CREB signaling pathway.

BACKGROUND: Chronic inflammatory pain (CIP) frequently coincides with depression among patients. The onset and development of pain and depression are associated with altered neural synaptic plasticity. Electroacupuncture (EA) can effectively relieve CIP and depression. However, the underlying mechanisms have not been fully illustrated. OBJECTIVE: To explore whether EA can relieve CIP and depression by regulating hippocampal synaptic plasticity, and the present study offers foundational evidence for the efficacy of EA in treating CIP-related depression (CIPD). METHODS: Rats were divided into four groups: 0.9% normal saline group, complete Freund's adjuvant (CFA) group, CFA + duloxetine group, and CFA + EA group. Pain hypersensitivity was detected by mechanical withdrawal threshold and thermal paw withdrawal latency, and the depression level was gauged using the open field test, the sucrose preference test, and the forced swimming test. The morphology of the hippocampal neurons was observed using Nissl staining. The protein expression levels of synuclein (Syn), postsynaptic density protein-95 (PSD-95), brain-derived neurotrophic factors (BDNFs), tyrosine-protein kinase B (TrKB), p-TrkB, cAMP response element binding protein (CREB), and p-CREB were measured by western blotting and immunofluorescence staining. BDNF and TrkB mRNA expression were detected using quantitative real-time polymerase chain reaction (PCR) (qRT-PCR). The content of 5-hydroxytryptamine (5-HT) and γ-aminobutyric acid (GABA) was detected using enzyme-linked immunosorbent assay, and the glutamic acid (Glu) content was determined using the ultraviolet colorimetry method. The hippocampal neuron ultrastructure was observed using transmission electron microscopy. RESULTS: EA could alleviate CIP and related depressive behaviors as well as protect the hippocampal neuronal structure from damage and regulate 5-HT/GABA/Glu levels in the hippocampus. Additionally, EA could significantly increase the expression of synapse-associated proteins such as PSD-95 and Syn by activating the BDNF/TrKB/CREB signaling pathway. CONCLUSION: EA improves pain and depressive behaviors in CIPD rats, and the mechanism may be related to synaptic plasticity mediated by the BDNF/TrKB/CREB signaling pathway.