[Transitional urology-current status and prospects of pediatric over-age practice].

With the continuous advancement of medicine, more children with congenital or pediatric-onset chronic urologic conditions are surviving well into adulthood, which imposes an ever-rising need for adequate transition of these patients from pediatric to adult care. Transitional Urology focuses on the health care needs of adolescents and young adults with congenital urological disorders as they transfer from pediatric to adult care, maximizing the best interests of the children. Since Shanghai Children's Medical Center has been approved for over-age continuous medical care, this paper aims to analyze the currently perceived barriers in care transition within the urological context, explore the ways of previously implemented transition models, and propose the suggestions for improvement.

[Quantitative HER2 mRNA assay in breast cancer with HER2 immunohistochemistry 0].

Objective: To investigate HER2 mRNA expression in breast cancer with HER2 immunohistochemistry (IHC) 0 and to analyze the feasibility of distinguishing between the tumor with HER2 µltra-low expression and the one without expression of HER2 (no staining by IHC) by HER2 mRNA level preliminarily. Methods: HER2 mRNA was analyzed by reverse transcription digital PCR in 41 cases of formalin-fixed paraffin-embedded surgical tissue samples of invasive breast cancer obtained between January 2020 and March 2023 at Peking Union Medical College Hospital. The cohort included 21 HER2 IHC 1+ and 20 IHC 0 (12 ultra-low and 8 non-expression of HER2). HER2 mRNA expression level was quantitatively evaluated by the FAM (HER2)/VIC (reference gene) ratio. Results: The expression of HER2 mRNA for the cases with 1+, ultra-low, and non-expression of HER2 by IHC was 0.30 to 1.78 (average 0.90, median 0.82), 0.55 to 1.51 (average 0.93, median 0.90) and 0.22 to 0.78 (average 0.41, median 0.36), respectively. For the mean and median HER2 mRNA levels, there was no significant difference between HER2 IHC 1+ and HER2 ultra-low expression diseases (P=0.757). A remarkable difference in HER2 gene expression was found between the tumors with 1+ and non-expression of HER2 by IHC (P=0.002). And, HER2 ultra-low cases contained statistically higher levels of HER2 mRNA compared with non-expression of HER2 subgroup by IHC (P=0.001). Conclusions: Based on HER2 mRNA, HER2 non-expression and HER2 weak expression (including HER2 IHC 1+ and ultra-low) belong to two different types of the tumor and the disease with HER2 IHC 1+ and HER2 ultra-low expression may be the same. It is necessary to further test the performance of HER2 mRNA detection for stratifying the HER2 weak expression subgroup and to determine the threshold.

[Clinicopathological features of breast cancer with HER2 low expression: a real-world retrospective study].

Objective: To investigate the clinical and pathological characteristics of breast cancer with HER2 low expression. Methods: The data from 3 422 patients with invasive breast cancer which archived in Peking Union Medical College Hospital between April 2019 and July 2022 were retrospectively reviewed. Among them, 136 patients were treated with neoadjuvant chemotherapy. The tumor size, histological type, tumor differentiation, lymph node metastasis, Ki-67 index, the status of estrogen receptor, progesterone receptor and HER2 as well as pathological complete response (pCR) rate were collected. Results: The HER2 status of 3 286 patients without neoadjuvant therapy, 616 (616/3 286, 18.7%) score 0, 1 047 (1 047/3 286, 31.9%) score 1+, 1 099 (1 099/3 286,33.4%) score 2+ and 524 (524/3 286,15.9%) score 3+ by immunohistochemistry (IHC). Among the 1 070 IHC 2+ cases, 161 were classified as HER2 positive by reflex fluorescence in situ hybridization (FISH) assay. In our cohort, 1 956 cases of HER2-low (IHC 1+ and IHC 2+/FISH-) breast cancer were identified. Compared to the HER2 IHC 0 group, HER2-low tumors more frequently occurred in patients with hormone receptor (HR) positive (P<0.001), Ki-67 index below 35% (P<0.001), well or moderate differentiation (P<0.001) and over the age of 50 (P=0.008). However, there were no significant differences in histological type, tumor size, and lymph node metastasis between HER2-low and HER2 IHC 0 group. For patients who had neoadjuvant therapy, the pCR rate in the patients with HER2-low was lower than those with HER2 IHC 0 (13.3%, 23.9%), but there was no significant difference. Although HER2-low breast cancers showed a slightly lower pCR rate than HER2 IHC 0 tumors, no remarkable difference was observed between tumors with HER2-low and HER2 IHC 0 regardless of hormone receptor status. Conclusions: The clinicopathological features of HER2-low breast cancers are different from those with HER2 IHC 0. It is necessary to accurately distinguish HER2-low breast cancer from HER2 IHC 0 and to reveal whether HER2-low tumor is a distinct biological entity.

[PIK3CA gene mutations in Chinese women with HR+/HER2- breast cancer].

Objective: To investigate the spectrum of PIK3CA gene mutations in Chinese women with hormone receptor positive and HER2 negative (HR+/HER2-) breast cancer, to provide the genetic evidence for identifying potential beneficiaries from specific PI3K isoform inhibitors in Chinese women with breast cancer and to develop detection strategies. Methods: A total of 365 breast cancer specimens archived at the Peking Union Medical College Hospital, Beijing, China from January 2017 to October 2017 were screened. Among these patients, 186 HR+/HER2- women with invasive breast cancer were collected. PIK3CA gene mutations were detected using next generation sequencing technology. The gene variant features were then analyzed and compared with reported data. Results: Among the 186 HR+/HER2- breast cancer cases, 40 (21.5%,40/186) cases harbored PIK3CA gene mutations. Exons 9 and 20 of PIK3CA mutations occurred in 92.5%(37/40)of the tumors, which included E545K, E545G, Q546K, E542K, Q546R, P539R, E547D, H1047R, H1047L, H1047Q and N1044Y. Only one case harbored the exon 7 C420R mutation. Additionally, exons 1 (F83C) and 5 (G364R) uncommon mutations were discovered respectively in 2 cases. Based on the finding, 85.0% (34/40) of cases with known mutations could be detected using companion diagnostic methods. Moreover, 25.0% (10/40) of patients had two or three variants, which were composed of E726K/N345K, H1047Q/N345K, H1047R/G364R, H1047R/E453K, E545G/E726K, E542K/E726K, E542K/H1047R, E545K/H1047R/H1047L and E545K/E547D. The lymph node positive rate in these patients with PIK3CA mutation was remarkably higher than those without (i.e., wild type, P<0.05). Conclusions: In this group of HR+/HER2- breast cancer patients, common PIK3CA gene mutations account for the vast majority of the mutations. New rare variants in PIK3CA are also identified while their clinical significance needs to be further studied in a large cohort and/or multi-center study.

[Application of diffusion-weighted magnetic resonance imaging in evaluating the efficacy of radiotherapy and chemotherapy for esophageal cancer].

This study was a prospective single arm trial conducted in Zhejiang Jinhua Guangfu hospital from February 2018 to June 2020. A total of 39 patients (32 males and 7 females) with esophageal cancer, aged from 44 to 82 (69±9) years were enrolled. Diffusion weighted magnetic resonance imaging(MR-DWI) was implemented to evaluate the changes of apparent diffusion coefficient(ADC) value before and after chemoradiotherapy. The results showed that the ADC value after chemoradiotherapy was higher than that before treatment[(2.03±0.42)×10⁻³ mm 2/s vs (1.60±0.28)×10⁻³ mm2/s], and there was a positive correlation between the increase of ADC value and the prognosis of patients.

Research Progress on the Molecular Mechanisms of Toxicology of Ethanol-Aconitine Induced Arrhythmia.

ABSTRACT: Aconitum is one of the most widely used Chinese herbal medicines, and aconitine is the major toxic component in it. Aconitine can induce a variety of arrhythmias, resulting in death. Acute ethanol consumption causes arrhythmia as well. Poisoning cases caused by aconitum medicinal liquor are frequently encountered in the practice of forensic medicine. The molecular mechanisms of myocardial toxicity of these two drugs have much in common, and both of them affect the sodium channel, calcium channel and potassium channel of myocardial cell membrane and so on. This paper analyzes and discusses the possible co-effects of ethanol-aconitine on cardiomyocyte channel proteins, by reviewing researches on the mechanism of cardiotoxicity of ethanol and aconitine in recent years, in order to provide ideas and references for the research on the molecular mechanism of arrhythmia caused by combined poisoning.

[HER2 gene status and mRNA expression in immunohistochemistry 1+ breast cancer].

Objective: To investigate human epidermal growth factor 2 (HER2) gene status and in situ mRNA expression in breast cancers with immunohistochemistry(IHC) 1+ , and to reveal HER2 positive rate in these patients to provide reference data for obtaining precise HER2 results and modifying relevant clinical strategy to breast cancer. Methods: Sixty-five IHC 1+ formalin-fixed and paraffin-embedded samples of invasive breast carcinoma of no special type (IBC-NST) were collected by surgical operation at Peking Union Medical College Hospital during 2011 to 2013. HER2 status and in situ mRNA expression were tested by fluorescence in situ hybridization (FISH) and RNAscope, respectively, by using tissue microarray. Metastatic lymph node was re-tested by FISH if HER2 status was equivocal or negative and with high expression of mRNA in the primary lesion. Results: Four of 65 samples (6.2%) were FISH positive, which included 2 cases of HER2/CEP17>2 and average HER2 copy number>4 and 2 cases of HER2/CEP17<2 and average HER2 copy number>6. In the 4 samples of HER2 positive, 2 patients showed high in situ mRNA expression (3 scores by RNAscope), 2 patients showed moderate in situ mRNA expression (2 scores by RNAscope). In addition, 3 specimens with HER2/CEP17>2 and average HER2 copy number<4 were found in all patients, which included 2 cases of high in situ mRNA expression (3 and 4 scores by RNAscope) and 1 cases of moderate in situ mRNA expression (2 scores by RNAscope). There was no significant association between HER2 status or mRNA expression and clinicopathological characteristics, including tumor size, histopathological differentiation, lymph node metastasis and lymphovascular invasion (P>0.05). Conclusions: A small number of HER2 IHC 1+ patients exist mRNA expression by using FISH method, which suggested that these patients might benefit from anti-HER2 therapy potentially. Since the importance for patients with breast cancers to develop diagnostic and therapeutic strategies from accurate molecular typing, further studies based on a larger cohort are needed to validate our findings.

[Application of Mixed-effect Model in PMI Estimation by Vitreous Humor].

OBJECTIVES: To test the changes of the potassium （K⁺） and magnesium （Mg²âºï¼‰ concentrations in vitreous humor of rabbits along with postmortem interval （PMI） under different temperatures, and explore the feasibility of PMI estimation using mixed-effect model. METHODS: After sacrifice, rabbit carcasses were preserved at 5 ℃, 15 ℃, 25 ℃ and 35 ℃, and 80-100 µL of vitreous humor was collected by the double-eye alternating micro-sampling method at every 12 h. The concentrations of K⁺ and Mg²âº in vitreous humor were measured by a biochemical-immune analyser. The mixed-effect model was used to perform analysis and fitting, and established the equations for PMI estimation. The data detected from the samples that were stoned at 10 ℃, 20 ℃ and 30 ℃ with 20, 40 and 65 h were used to validate the equations of PMI estimation. RESULTS: The concentrations of K⁺ and Mg²âº [f（x,y）] in vitreous humor of rabbits under different temperature increased along with PMI （x）. The relative equations of K⁺ and Mg²âº concentration with PMI and temperature under 5 ℃~35 ℃ were fK⁺（x,y）=3.413 0+0.309 2 x+0.337 6 y+0.010 83 xy-0.002 47 x² （P<0.000 1）, and fMg²âºï¼ˆx,y）=0.745 6+0.006 432 x+0.033 8 y （P<0.000 1）, respectively. It was proved that the time of deviation for PMI estimation by K⁺ and Mg²âº was in 10 h when PMI was between 0 to 40 h, and the time of deviation was in 21 h when PMI was between 40 to 65 h. CONCLUSIONS: the ambient temperature range of 5 ℃-35 ℃, the mixed-effect model based on temperature and vitreous humor substance concentrations can provide a new method for the practical application of vitreous humor chemicals for PMI estimation.

[Comparison of HER2 gene status between primary breast cancer and synchronous axillary lymph node metastasis].

OBJECTIVE: To investigate the discordant rate of HER2 gene status between primary breast cancer and synchronous axillary lymph node metastasis. METHODS: One hundred and fifty cases of primary breast cancer with corresponding synchronous lymph node metastases were collected, including 50 cases of HER2 FISH positive, 50 cases of HER2 FISH negative and 50 cases of HER2 FISH equivocal primary tumors, at Peking Union Medical College Hospital between May 2012 and June 2015. The HER2 gene status in lymph node metastatic tumors was analyzed by FISH, and the discordance of HER2 gene status was identified between primary and metastatic tumors. RESULTS: The incidence of discordant HER2 gene status between primary breast cancer and synchronous lymph node metastasis was 20.67%(31/150). Forty-four FISH positive, 3 FISH equivocal and 3 FISH negative cases were found in the first group of 50 patients with HER2 positive results in primary tumor. Forty seven FISH negative, 3 FISH equivocal cases were discovered in the second group of 50 patients with HER2 negative results in primary tumor. Four FISH positive, 18 FISH negative and 28 equivocal cases were observed in the third group of 50 patients with HER2 equivocal results in primary tumor. The discordance of HER2 gene status between primary tumor and lymph node metastasis in the third group of patients was significantly higher than the other two groups (P<0.05). CONCLUSIONS: Significant discordance of HER2 gene status between the primary and lymph node metastatic tumors exists. Patients with lymph node metastasis, simultaneous testing of HER2 status may be performed in both primary breast tumor and its lymph node metastasis. HER2 status of nodal metastatic lesion may be more relevant for guiding anti-HER2 target therapy.

Superfamily of genes encoding G protein-coupled receptors in the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae).

G protein-coupled receptors (GPCRs) are the largest and most versatile superfamily of cell membrane proteins, which mediate various physiological processes including reproduction, development and behaviour. The diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), is one of the most notorious insect pests, preferentially feeding on cruciferous plants. P. xylostella is not only one of the world's most widespread lepidopteran insects, but has also developed resistance to nearly all classes of insecticides. Although the mechanisms of insecticide resistance have been studied extensively in many insect species, few investigations have been carried out on GPCRs in P. xylostella. In the present study, we identified 95 putative GPCRs in the P. xylostella genome. The identified GPCRs were compared with their homologues in Bombyx mori and Drosophila melanogaster. Our results suggest that GPCRs in different insect species may have evolved by a birth-and-death process. One of the differences among compared insects is the duplication of short neuropeptide F receptor and adipokinetic hormone receptors in P. xylostella and B. mori. Another divergence is the decrease in quantity and diversity of the stress-tolerance gene, Mth, in P. xylostella. The evolution by the birth-and-death process is probably involved in adaptation to the feeding behaviour, reproduction and stress responses of P. xylostella. Some of the genes identified in the present study could be potential targets for the development of novel pesticides.

Tempo and mode of recurrent polyploidization in the Carassius auratus species complex (Cypriniformes, Cyprinidae).

Polyploidization is an evolutionarily rare but important mechanism in both plants and animals because it increases genetic diversity. Goldfish of the Carassius auratus species complex can be tetraploids, hexaploids and octaploids. Polyploidization events have occurred repeatedly in goldfish, yet the extent of this phenomenon and its phyletic history are poorly understood. We explore the origin, tempo and frequency of polyploidization in Chinese and Japanese goldfish using both mitochondrial (mtDNA) and nuclear DNA sequences from up to 1202 individuals including the outgroup taxon, Cyprinus carpio. Analyses of de novo nuclear gene data resolve two clusters of alleles and the pattern supports the prior hypothesis of an ancient allotetraploidization for Carassius. Alleles shared by tetraploid and hexaploid individuals indicate recent autoploidizations within the C. auratus complex. Sympatric tetraploids and hexaploids share mtDNA haplotypes and these frequently occur independently within six well-supported lineages and sublineages on a small spatial scale. Gene flow estimates (Fst values) indicate that hexaploids differ only slightly from sympatric tetraploids, if at all. In contrast, allopatric populations of tetraploids and hexaploids differ from one another to a far greater extent. Gene flow between sampled localities appears to be limited. Coalescence-based time estimations for hexaploids reveal that the oldest lineage within any sampled locality is around one million years old, which is very young. Sympatric, recurrent autoploidization occurs in all sampled populations of the C. auratus complex. Goldfish experience polyploidization events more frequently than any other vertebrate.

HLA-B*15:02 is associated with anemia in patients with chronic hepatitis C treated with pegylated interferon-α and ribavirin.

To investigate the relationship between human leukocyte antigen (HLA) class I and II alleles and treatment-induced anemia in chronic hepatitis C (CHC) patients receiving combination therapy with pegylated interferon-α (PEG-IFN-α) and ribavirin (RBV). One hundred six naïve CHC patients (59 females and 47 males; mean age, 53.08 years) who underwent combination treatment were enrolled. The patients were considered positive for hemoglobin (Hb)-related side effects if the Hb concentrations dropped below 10 g/dl during PEG-IFN-α plus RBV treatment. The HLA-A, -B, -C, -DR, and -DQ loci were investigated by sequence-based genotyping. The effects of the clinical characteristics, virologic variables, and the HLA alleles on treatment-induced anemia were evaluated by a logistic regression analysis. Forty patients (37.7%) had Hb levels below 10 g/dl during the treatment course. Low baseline Hb levels and an advanced liver fibrosis stage were associated with decreases in Hb levels to below 10 g/dl. The occurrence of treatment-related anemia (Hb < 10 g/dl) was significantly associated with HLA-B*15:02 as shown by multivariate analysis (adjusted odds ratio, 8.13; 95% confidence interval: 1.19-55.70; P-value after Holm's procedure, 0.03). HLA-B*15:02 is associated with treatment-induced anemia in Taiwanese CHC patients receiving combination therapy with PEG-IFN-α plus RBV.

Anti-hepatitis C virus activity of 3-hydroxy caruilignan C from Swietenia macrophylla stems.

Chronic hepatitis C virus (HCV) infection ultimately leads to chronic hepatitis, hepatic cirrhosis and hepatocellular carcinoma (HCC). As the standard treatment is not completely efficacious, a safer and more effective agent against HCV infection needs to be developed. In this report, we demonstrated that 3-hydroxy caruilignan C (3-HCL-C) isolated from Swietenia macrophylla stems exhibited high anti-HCV activity at both protein and RNA levels at nontoxic concentrations, with an EC(50) value of 10.5 ± 1.2 µm. Combinations of 3-HCL-C and interferon-α (IFN-α), an HCV NS5B polymerase inhibitor (2'-C-methylcytidine; NM-107) or an HCV NS3/4A protease inhibitor (Telaprevir; VX-950) increased the suppression of HCV RNA replication. The results suggested that 3-HCL-C may be a potential anti-viral agent. We then demonstrated that 3-HCL-C interfered with HCV replication by inducing IFN-stimulated response element transcription and IFN-dependent anti-viral gene expression.

Altered expression of survivin, Fas and FasL contributed to cervical cancer development and metastasis.

OBJECTIVE: To evaluate the expression of apoptosis-related genes and their correlation with prognosis in cervical cancer patients. MATERIALS AND METHODS: The expressions of Survivin, Fas and FasL in tissues of cervical cancer, cervical intraepithelial neoplasia (CIN), chronic cervicitis and normal cervix wer detected by immunohistochemical staining, and the relationship between the expression of Survivin, Fas and FasL and clinical pathologic characteristics of cervical cancer was correlation analysis. RESULTS: The positive expression rates of Survivin and FasL in cervical cancer tissues were significantly higher than those in tissues of normal cervix, chronic cervicitis and CIN (p < 0.05), but lower positive expression rate of Fas was observed in cervical cancer tissues when compared with that in normal cervix, chronic cervicitis and CIN tissues (p < 0.05). The expression of Survivin was significantly correlated with clinical staging and lymph node metastases of cervical cancer (p < 0.05). The expression of FasL was correlated with lymph node metastases, clinical staging and pathological grading of cervical cancer (p < 0.05). The expression of Survivin was negatively correlated with that of Fas (r = -0.517, p < 0.01), but positively correlated with that of FasL (r = 0.381, p < 0.01) in tissues of cervical cancer. CONCLUSIONS: The up-regulated expression of Survivin and FasL and down-regulated expression of Fas may be involved in the carcinogenesis and development of cervical cancer. The expression of FasL may be one of the prediction indexes for disease progression and prognosis in cervical cancer.

San-Huang-Xie-Xin-Tang extract suppresses hepatitis C virus replication and virus-induced cyclooxygenase-2 expression.

Chronic hepatitis C virus (HCV) infection is associated with chronic inflammation of liver, which leads to the development of cirrhosis and hepatocellular carcinoma (HCC). Because of severe side effects and only a 50-70% cure rate in genotype 1 HCV-infected patients upon current standard treatment with pegylated interferon-α plus ribavirin, new therapeutic regimens are still needed. San-Huang-Xie-Xin-Tang (SHXT) is a transitional Chinese herbal formula, composed of Rhei rhizoma, Scutellaria radix and Coptidis rhizome, and possesses anti-inflammatory effect. Here, we describe a (+)-catechin-containing fraction extracted from SHXT, referred as SHXT-frC, exhibited effective inhibition of HCV replication, with selectivity index value (SI; CC50 /EC50) of 84, and displayed synergistic anti-HCV effects when combined with interferon-α, HCV protease inhibitor telaprevir or polymerase inhibitor 2'-C-methylcytidine. The activation of factor-κB (NF-κB) and cyclooxygenase-2 (COX-2) signalling pathway has particular relevance to HCV-associated HCC. SHXT-frC treatment also caused a concentration-dependent decrease in the induction of COX-2 and NF-κB expression caused by either HCV replication or HCV NS5A protein. Collectively, SHXT-frC could be an adjuvant treatment for patients with HCV-induced liver diseases.

Current evidence of acupuncture on polycystic ovarian syndrome.

OBJECTIVE: This paper aims to provide a literature review on evaluating the efficacy of acupuncture therapy in the treatment of polycystic ovarian syndrome (PCOS) by reviewing clinical trials; randomised and non-randomised and observational studies on PCOS. The paper will also determine the possible mechanism of acupuncture treatment in PCOS, limitations of recruited studies and suggest further improvements in future studies. DESIGN: A comprehensive literature search was conducted through the databases Medline, PubMed, EMBASE, Cochrane, AMED (Allied and Complementary Medicine), NCCAM (The National Centre for Complementary and Alternative Medicine) to identify relevant monographs. RESULTS: Four studies were recruited. Several studies showed that acupuncture significantly increases beta-endorphin levels for periods up to 24 h and may have regulatory effect on FSH, LH and androgen. beta-endorphin increased levels secondary to acupuncture affects the hyperthalamic-pituitary-adrenal (HPA) axis through promoting the release of ACTH through stimulation of its precursor pro-opiomelanocortin synthesis. INCLUSION CRITERIA: All available acupuncture studies on human subjects with PCOS from June 1970 to June 2009. EXCLUSION CRITERIA: Studies not meeting the inclusion criteria, published in languages other than English or animal studies. CONCLUSION: Acupuncture is a safe and effective treatment to PCOS as the adverse effects of pharmacologic interventions are not expected by women with PCOS. Acupuncture therapy may have a role in PCOS by: increasing of blood flow to the ovaries, reducing of ovarian volume and the number of ovarian cysts, controlling hyperglycaemia through increasing insulin sensitivity and decreasing blood glucose and insulin levels, reducing cortisol levels and assisting in weight loss and anorexia. However, well-designed, randomised controlled trials are needed to elucidate the true effect of acupuncture on PCOS.

[Advances in the research of pain assessment and non-drug intervention in burn children].

Children are a high-risk group of burn, and burn pain is a special type of pain. Because children of different ages have different cognitive ability and behavioral response to pain, thus it is particularly difficult to effectively evaluate the pain. It is very important for medical staff to understand the pain of children, to define the adverse reactions of pain, to evaluate and take appropriate pain intervention measures in time and effectively. In this paper, different evaluation methods of burn pain in children and non-drug intervention related measures were reviewed in order to provide references for clinical practice.

[Advances in the research of virtual reality technology for pain intervention after burns].

Pain is one of the most common complications of burn patients. Burn from onset to rehabilitation is a long and complex process, during which dressing change, debridement, operation, and rehabilitation may cause different degrees of pain to the patients. As one of the means of non-pharmaceutical pain management, the interventional effect of virtual reality technology has gradually been recognized by more and more researchers. This paper reviewed the definition, the interventional mechanisms, and the interventional effect on burn pain of virtual reality technology, to provide a reference for clinical application of virtual reality technology in pain management of burn patients.

Wharton's Jelly-derived mesenchymal stem cells suppress apoptosis of nucleus pulposus cells in intervertebral disc degeneration via Wnt pathway.

OBJECTIVE: Aberrant apoptosis of nucleus pulposus cells (NPCs) is one of the most remarkable pathological changes in intervertebral disc degeneration (IDD) development. Albeit the advances in the application of stem cell-based therapy in IDD treatment, the molecular mechanisms underlying the anti-apoptotic actions of mesenchymal stem cell (MSC) remain poorly elucidated. PATIENTS AND METHODS: The expression patterns of apoptosis-related proteins and Wnt/ß-catenin-related genes in NP samples isolated from patients with mild or severe IDD were compared by performing immunoblot assay and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. NPCs were in vitro treated with compression to induce apoptosis and then co-cultured with Wharton's Jelly-derived MSCs without direct interaction. After that, flow cytometry was carried out to detect the apoptosis rate of NPCs and the activity of Wnt/ß-catenin pathway was determined. DKK-1 was used to inhibit Wnt signaling, in prior to evaluation of the effects of WJ-MSCs on apoptosis within the co-cultured NPCs. RESULTS: Compared to the mild IDD group, there was a significant increase in the expression of Caspase-3 and Bax in the NP tissues from severe IDD patients, whereas Bcl-2 displayed an opposite result. In addition, the expression of Wnt 3a, Wnt 5a, Wnt 10a, GSK-3ß, cyclinD1 and ß-catenin was notably augmented in parallel with IDD progression. After compression treatment, the proportion of apoptotic NPCs was increased, which was then dramatically reversed by WJ-MSCs co-culture. Likewise, WJ-MSCs suppressed compression-induced Wnt-related gene expression and blocking Wnt/ß-catenin pathway using DKK-1 enhanced the anti-apoptotic impacts of WJ-MSCs. In the presence of DKK-1, there was no significant difference between NPCs co-cultured with WJ-MSCs and those cells cultured alone. CONCLUSIONS: WJ-MSCs attenuate the compression-induced apoptosis in NPCs and inhibit the activation of Wnt/ß-catenin signaling. Blocking Wnt/ß-catenin pathway further facilitates the actions of WJ-MSCs in anti-apoptosis, indicating that Wnt/ß-catenin signaling plays a crucial role in this process and may function as a potential therapeutic target for IDD treatment.