An Overview of Recent Advances in the Neuroprotective Potentials of Fisetin against Diverse Insults in Neurological Diseases and the Underlying Signaling Pathways.

The nervous system plays a leading role in the regulation of physiological functions and activities in the body. However, a variety of diseases related to the nervous system have a serious impact on human health. It is increasingly clear that neurological diseases are multifactorial pathological processes involving multiple cellular systems, and the onset of these diseases usually involves a diverse array of molecular mechanisms. Unfortunately, no effective therapy exists to slow down the progression or prevent the development of diseases only through the regulation of a single factor. To this end, it is pivotal to seek an ideal therapeutic approach for challenging the complicated pathological process to achieve effective treatment. In recent years, fisetin, a kind of flavonoid widely existing in fruits, vegetables and other plants, has shown numerous interesting biological activities with clinical potentials including anti-inflammatory, antioxidant and neurotrophic effects. In addition, fisetin has been reported to have diverse pharmacological properties and neuroprotective potentials against various neurological diseases. The neuroprotective effects were ascribed to its unique biological properties and multiple clinical pharmacological activities associated with the treatment of different neurological disorders. In this review, we summarize recent research progress regarding the neuroprotective potential of fisetin and the underlying signaling pathways of the treatment of several neurological diseases.

RAD51 paralogs synergize with RAD51 to protect reversed forks from cellular nucleases.

Fork reversal is a conserved mechanism to prevent stalled replication forks from collapsing. Formation and protection of reversed forks are two crucial steps in ensuring fork integrity and stability. Five RAD51 paralogs, namely, RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3, which share sequence and structural similarity to the recombinase RAD51, play poorly defined mechanistic roles in these processes. Here, using purified BCDX2 (RAD51BCD-XRCC2) and CX3 (RAD51C-XRCC3) complexes and in vitro reconstituted biochemical systems, we mechanistically dissect their functions in forming and protecting reversed forks. We show that both RAD51 paralog complexes lack fork reversal activities. Whereas CX3 exhibits modest fork protection activity, BCDX2 significantly synergizes with RAD51 to protect DNA against attack by the nucleases MRE11 and EXO1. DNA protection is contingent upon the ability of RAD51 to form a functional nucleoprotein filament on DNA. Collectively, our results provide evidence for a hitherto unknown function of RAD51 paralogs in synergizing with RAD51 nucleoprotein filament to prevent degradation of stressed replication forks.

The Neuroprotective Role of Fisetin in Different Neurological Diseases: a Systematic Review.

Neurological diseases place a substantial burden on public health and have a serious impact on the quality of life of patients. Despite the multifaceted pathological process involved in the occurrence and development of these neurological diseases, each disease has its own unique pathological characteristics and underlying molecular mechanisms which trigger their onset. Thus, it is unlikely to achieve effective treatment of neurological diseases by means of a single approach. To this end, we reason that it is pivotal to seek an efficient strategy that implements multitherapeutic targeting and addresses the multifaceted pathological process to overcome the complex issues related to neural dysfunction. In recent years, natural medicinal plant-derived monomers have received extensive attention as new neuroprotective agents for treatment of neurological disorders. Fisetin, a flavonoid, has emerged as a novel potential molecule that enhances neural protection and reverses cognitive abnormalities. The neuroprotective effects of fisetin are attributed to its multifaceted biological activity and multiple therapeutic mechanisms associated with different neurological disorders. In this review article, we summarize recent research progression regarding the pharmacological effects of fisetin in treating several neurological diseases and the potential mechanisms.

The aOECs Facilitate the Neuronal Differentiation of Neural Stem Cells in the Inflammatory Microenvironment Through Up-Regulation of Bioactive Factors and Activation of Wnt3/ß-Catenin Pathway.

The therapeutic application of neural stem cells (NSCs) in the central nerve system (CNS) injury is a promising strategy for combating irreversible neuronal loss. However, a variety of obvious inflammatory responses following nerve injury rapidly create an unfavorable microenvironment for survival and neuronal differentiation of NSCs in lesion area, limiting the efficacy of NSC-based therapy for CNS injury. It remained unknown how to effectively increase the neuronal differentiation efficiency of NSCs through transplantation. Here, we demonstrated that curcumin (CCM)-activated olfactory ensheathing cells (aOECs) effectively promoted neuronal differentiation of NSCs in the activated microglial inflammatory condition, and co-transplantation of aOECs and NSCs improved neurological recovery of rats after spinal cord injury (SCI), as evidenced by higher expression levels of neuronal markers and lower expression levels of glial markers in the differentiated cells, greater number of Tuj-1-positive cells as well as higher Basso, Beattie, and Bresnahan (BBB) locomotor scale, compared to the corresponding controls. Pathologically, hematoxylin and eosin (HE) staining and immunostaining also showed that aOECs remarkably enhanced the in vivo neuronal differentiation of NSCs and migration, and nerve repair. Further analysis revealed that the underlying mechanisms of aOECs potentiating the neuronal conversion of NSCs under inflammatory environment were tightly associated with up-regulation of anti-inflammatory cytokines and neurotrophic factors in OECs, and importantly, the activation of Wnt3/ß-catenin pathway was likely involved in the mechanisms underlying the observed cellular events. Therefore, this study provides a promising strategy for SCI repair by co-transplantation of aOECs and NSCs.

The different prognostic factors between metastatic and nonmetastatic disease of esophageal neuroendocrine carcinoma.

PURPOSE: The specific risk factors of metastatic and nonmetastatic esophageal neuroendocrine carcinoma (NEC) are still uncertain. Whether primary site surgery is necessary for all patients with esophageal NEC is unknown. METHODS: Patients with esophageal NEC in the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2014 were selected. STATA 12 was used to analyze the clinical and pathological features of esophageal NEC. RESULTS: In total, 241 patients with esophageal NEC were included. Metastatic patients had shorter overall survival than nonmetastatic patients (6.03 versus 11.90 months, respectively). Prognostic factors varied between metastatic and nonmetastatic esophageal NEC. The location of the primary tumor is a key point for the prognosis of esophageal NEC. For nonmetastatic esophageal NEC, patients with tumors in the upper third of the esophagus had the worst survival, and patients with metastatic esophageal NEC with a primary tumor in the lower part of the esophagus tended to have an increased risk of death. Moreover, age ≥68 years (hazard ratio [HR] = 2.05; 95% confidence interval [CI]: 1.28-3.31; P < 0.01) and large cell carcinoma (HR = 2.79; 95% CI: 1.30-6.00; P < 0.01) were independent risk factors in patients with metastatic esophageal NEC. Primary site resection benefited patients with nonmetastatic esophageal NEC (HR = 0.20; 95% CI: 0.07-0.56; P < 0.01) rather than patients with metastatic esophageal NEC (HR = 0.91; 95% CI: 0.29-2.83; P > 0.05). CONCLUSIONS: Our study presented that primary tumor location is an important risk factor for nonmetastatic esophageal NEC patients. Age and pathological type are important risk factors for patients with metastatic esophageal NEC. Nonmetastatic esophageal NEC will benefit from primary tumor resection. Systematic treatment is recommended for metastatic esophageal NEC.

PARP1 recruits DNA translocases to restrain DNA replication and facilitate DNA repair.

Replication fork reversal which restrains DNA replication progression is an important protective mechanism in response to replication stress. PARP1 is recruited to stalled forks to restrain DNA replication. However, PARP1 has no helicase activity, and the mechanism through which PARP1 participates in DNA replication restraint remains unclear. Here, we found novel protein-protein interactions between PARP1 and DNA translocases, including HLTF, SHPRH, ZRANB3, and SMARCAL1, with HLTF showing the strongest interaction among these DNA translocases. Although HLTF and SHPRH share structural and functional similarity, it remains unclear whether SHPRH contains DNA translocase activity. We further identified the ability of SHPRH to restrain DNA replication upon replication stress, indicating that SHPRH itself could be a DNA translocase or a helper to facilitate DNA translocation. Although hydroxyurea (HU) and MMS induce different types of replication stress, they both induce common DNA replication restraint mechanisms independent of intra-S phase activation. Our results suggest that the PARP1 facilitates DNA translocase recruitment to damaged forks, preventing fork collapse and facilitating DNA repair.

The Anti-inflammation Property of Olfactory Ensheathing Cells in Neural Regeneration After Spinal Cord Injury.

Neural regeneration has troubled investigators worldwide in the past decades. Currently, cell transplantation emerged as a breakthrough targeted therapy for spinal cord injury (SCI) in the neurotrauma field, which provides a promising strategy in neural regeneration. Olfactory ensheathing cells (OECs), a specialized type of glial cells, is considered as the excellent candidate due to its unique variable and intrinsic regeneration-supportive properties. In fact, OECs could support olfactory receptor neuron turnover and axonal extension, which is essential to maintain the function of olfactory nervous system. Hitherto, an increasing number of literatures demonstrate that transplantation of OECs exerts vital roles in neural regeneration and functional recovery after neural injury, including central and peripheral nervous system. It is common knowledge that the deteriorating microenvironment (ischemia, hypoxia, scar, acute and chronic inflammation, etc.) resulting from injured nervous system is adverse for neural regeneration. Interestingly, recent studies indicated that OECs could promote neural repair through improvement of the disastrous microenvironments, especially to the overwhelmed inflammatory responses. Although OECs possess unusual advantages over other cells for neural repair, particularly in SCI, the mechanisms of OEC-mediated neural repair are still controversial with regard to anti-inflammation. Therefore, it is significant to summarize the anti-inflammation property of OECs, which is helpful to understand the biological characteristics of OECs and drive future studies. Here, we mainly focus on the anti-inflammatory role of OECs to make systematic review and discuss OEC-based therapy for CNS injury.

[Retracted] MicroRNA­874 is downregulated in cervical cancer and inhibits cancer progression by directly targeting ETS1.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the Transwell migration assay data shown in Fig. 3A were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article were already under consideration for publication prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a satisfactory reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 40: 2389­2398, 2018; DOI: 10.3892/or.2018.6624].

The Immunological Roles of Olfactory Ensheathing Cells in the Treatment of Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating type of neurological disorder of the central nervous system (CNS) with high mortality and disability. The pathological processes of SCI can usually be described as two stages, namely, primary and acute secondary injuries. Secondary injury produces more significant exacerbations of the initial injury. Among all the mechanisms of secondary damage, infection and inflammatory responses, as the principle culprits in initiating the second phase of SCI, can greatly contribute to the severity of SCI and numerous sequelae after SCI. Therefore, effectively antagonizing pro-inflammatory responses may be a promising treatment strategy to facilitate functional recovery after SCI. Olfactory ensheathing cells (OECs), a unique type of glial cells, have increasingly become potential candidates for cell-based therapy in the injured CNS. Strikingly, there is growing evidence that the mechanisms underlying the anti-inflammatory role of OECs are associated with the immune properties and secretory functions of these cells responsible for anti-neuroinflammation and immunoregulatory effects, leading to maintenance of the internal microenvironment. Accordingly, a more profound understanding of the mechanism of OEC immunological functions in the treatment of SCI would be beneficial to improve the therapeutic clinical applications of OECs for SCI. In this review, we mainly summarize recent research on the cellular and molecular immune attributes of OECs. The unique biological functions of these cells in promoting neural regeneration are discussed in relation of the development of novel therapies for CNS injury.

Hsa_circ_0010957 knockdown attenuates lipopolysaccharide-induced HK2 cell injury by regulating the miR-1224-5p/IRAK1 axis.

Circular RNAs (circRNAs) are involved in the progression of various diseases, including lupus nephritis. Hsa_circ_0010957 is reported to be dysregulated in lupus nephritis, but the exact function of this circRNA is unknown. This research aims to study the function and mechanism of circRNA hsa_circ_0010957 in a lipopolysaccharide (LPS)-induced cellular model of lupus nephritis. Human renal proximal tubular cell line HK2 cells were challenged by LPS. Hsa_circ_0010957, microRNA-1224-5p (miR-1224-5p), and interleukin-1 receptor-associated kinase 1 (IRAK1) abundances were examined by quantitative reverse transcription polymerase chain reaction or western blot. LPS-induced damage was evaluated via cell viability, apoptosis, inflammatory response and oxidative injury. The target interaction was analyzed by dual-luciferase reporter analysis and RNA immunoprecipitation. Hsa_circ_0010957 abundance was enhanced in LPS-challenged HK2 cells. Hsa_circ_0010957 knockdown alleviated LPS-induced apoptosis, the inflammatory response and oxidative injury in HK2 cells. MiR-1224-5p was targeted by hsa_circ_0010957, and miR-1224-5p knockdown reversed the influence of hsa_circ_0010957 silence on LPS-induced injury. IRAK1 was targeted via miR-1224-5p, and hsa_circ_0010957 could regulate IRAK1 by miR-1224-5p. MiR-1224-5p overexpression could mitigate LPS-induced apoptosis, the inflammatory response and oxidative injury, and this effect was abolished by IRAK1. Hsa_circ_0010957 silence weakened LPS-induced HK2 cell apoptosis, the inflammatory response and oxidative injury via regulating the miR-1224-5p/IRAK1 axis.

Collision carcinoma of endometrial adenocarcinoma and primary serous fallopian tube carcinoma: a case report.

Collision carcinoma is a rare malignancy that generally occurs in cervical, esophageal, pulmonary, and squamous cell cancers. Few studies have been reported involving endometrial adenocarcinoma and fallopian tube carcinoma. We reported the case of a 58-year-old woman who presented because of irregular vaginal bleeding for more than 1 month. Cervical biopsy suggested moderately differentiated cervical adenocarcinoma, and the patient underwent radical hysterectomy under general anesthesia. However, postoperative pathology and immunohistochemical results indicated a collision tumor comprising endometrial adenocarcinoma (grade I) and primary serous fallopian tube carcinoma. According to the treatment principle of multiple primary tumors, a regimen of paclitaxel combined with carboplatin was administered. The patient also underwent local pelvic radiotherapy to treat lymph node metastasis. One month later, the patient developed brain metastases and died.

Nutrition and metabolism status alteration in advanced hepatocellular carcinoma patients treated with anti-PD-1 immunotherapy.

PURPOSE: The aim of this study was to evaluate the nutrition and metabolism status alteration during immunotherapy in advanced hepatocellular carcinoma (HCC) patients. METHODS: Patients with advanced HCC who participated in the clinical trials of single-agent anti-PD-1 immunotherapy or sorafenib were retrospectively included. We analyzed self-comparison of the nutritional and metabolic indices of patients in the anti-PD-1 and sorafenib treatment group. We conducted mutual-comparison of the mentioned indices between the disease progression group and disease control group among anti-PD-1 treatment patients. We further analyzed those indices with statistical differences by partial correlation and survival analysis. RESULTS: Both self-comparison before and after treatment in the anti-PD-1 group and mutual-comparison of disease progression and the control group showed significant differences in multiple indices, but we did not observe significant differences in the sorafenib group. Strikingly, albumin (ALB)/prognostic nutritional index (PNI, calculated by serum albumin and lymphocyte count) decreased distinctly in the immunotherapy disease progression group patients. However, changes in ALB/PNI were not significant in disease progression patients from the sorafenib group or in the disease control patients with immunotherapy. Partial correlation analysis suggested that ALB and PNI were positively correlated with the efficacy of immunotherapy. Furthermore, survival analysis showed that the median progression-free survival and median overall survival of patients in the ALB/PNI decreased group were significantly shorter than those of patients from the ALB/PNI increased group. CONCLUSION: Anti-PD-1 immunotherapy might alter the nutritional and metabolic status in advanced HCC patients. We also should pay attention to the nutritional and metabolic status of patients when drug resistance is detected.

PIM3 Functions as Oncogenic Factor and Promotes the Tumor Growth and Metastasis in Colorectal Cancer.

Colorectal cancer (CRC) is one of the common human malignancies. Discovery and identification of novel therapeutic target is imperative to improve the prognosis of CRC patients. As a member of the PIM family, PIM3 has been found to be overexpressed in a variety of cancerous tumors. In this study, we evaluated the expression of PIM3 in CRC tissues and analyzed the role of PIM3 in CRC. Our results showed that PIM3 expression was significantly higher in CRC tissues compared with adjacent noncancerous tissues. The PIM3 expression level was found to be correlated with advanced disease stage and lymph node metastasis. Moreover, PIM3 was found to be able to predict poor prognosis in CRC patients as an independent factor. In vitro studies also showed that knockdown of PIM3 exhibited inhibitory effect on cell growth, promoted cell apoptosis and dampened invasive capability of HCT116 and SW620 cells. Moreover, PIM3 knockdown was able to delay tumor growth and suppress lung metastasis in xenograft model. Our results indicated that PIM3 is a potential therapeutic target for CRC. Anat Rec, 302:1552-1560, 2019. © 2018 American Association for Anatomy.

MicroRNA­874 is downregulated in cervical cancer and inhibits cancer progression by directly targeting ETS1.

An increasing number of studies have reported that microRNAs (miRNAs) are dysregulated in cervical cancer and serve critical roles in cervical oncogenesis and progression. Therefore, identifying the aberrantly expressed miRNAs implicated in the formation and progression of cervical cancer may provide key clues for the development of effective therapeutic targets in treating patients with this type of malignancy. In the present study, miRNA­874 (miR­874) was downregulated in cervical cancer tissues and cell lines, and this downregulation was associated with International Federation of Gynaecology and Obstetrics stage and lymph node metastasis. The restored expression of miR­874 prohibited the proliferation, migration and invasion, but promoted the apoptosis of cervical cancer cells. In addition, E26 transformation specific­1 (ETS1) was identified as the direct target of miR­874 in cervical cancer. Inhibition of ETS1 served tumour­suppressive roles similar to miR­874 overexpression in cervical cancer cells. A series of rescue experiments revealed that restoring ETS1 expression abolished the tumour­suppressing effects of miR­874 in cervical cancer cells. Taken together, the results of the present study indicated that miR­874 may serve as a tumour suppressor in cervical cancer by directly targeting ETS1. This function suggested that miR­874 holds potential therapeutic applications in treating patients with this type of malignancy.

SPECT imaging of neuropilin receptor type-1 expression with 131I-labeled monoclonal antibody.

As a novel co-receptor for vascular endothelial growth factor (VEGF), neuropilin receptor type-1 (NRP-1) is overexpressed in several cancers and metastases, and serves as an attractive target for cancer molecular imaging and therapy. Previous single photon emission computerized tomography (SPECT) studies demonstrated that the small NRP-1-targeting peptides 99mTc-MA-ATWLPPR and 99mTc-CK3 showed poor tumor imaging quality, because of their rapid blood clearance and very low tumor uptake. Compared with small peptides, monoclonal antibodies (mAbs) can improve imaging of NRP-1-expression, due to their high affinity, specificity and slow extraction. A6-11-26 is a novel monoclonal antibody against NRP-1 b1b2 domain that exhibits inhibition of tumor growth in NPR-1-expressing preclinical models. The aim of the present study was to develop the 131I-labeled anti-NRP-1 monoclonal antibody A6-11-26 as a SPECT probe for imaging of NRP-1-positive tumor. An anti-NRP-1 monoclonal antibody (A6-11-26) was produced by hybridomas and was labeled with iodine-131 by the iodogen method. In vitro, the radiolabeling efficiency, radiochemical purity, immunoreactive fraction and stability were assessed. Binding affinity and specificity of 131I­A6-11-26 to NRP-1 were evaluated using human glioblastoma U87MG cells. In vivo, biodistribution and SPECT/CT studies were conducted on mice bearing U87MG xenografts after the injection of 131I-A6-11-26 with or without co-injection of unlabeled A6-11-26 antibody. A6-11-26 was generated successfully by hybridoma with high purity (>95%) and was labeled with iodine-131 within 60 min with high labelling efficiency (95.46±3.34%), radiochemical purity (98.23±1.41%). 131I-A6-11-26 retained its immunoreactivity and also displayed excellent stability in mouse serum and PBS solution during 1 to 96 h. Cell uptake assays showed high NRP-1-specific uptake (15.80±1.30% applied activity at 6 h) in U87MG cells. 131I-A6-11-26 bound to NRP-1 with low nanomolar affinity (KD=1.67±0.14 nM) in U87MG cells. In vivo, biodistribution study demonstrated targeting of U87MG glioma xenografts was NRP-1 specific. The tumor uptake was 6.00±1.24%ID/g at 24 h, and the tumor to muscle ratio was 3.20±0.30 at 24 h, and reached the highest level of 6.13±0.24 at 120 h after injection. SPECT imaging studies revealed that 131I-A6-11-26 could clearly identify U87MG tumors with good contrast, especially at 72-120 h after injection. The present study demonstrates that 131I-A6-11-26 is capable of detecting lesions in an NRP-1-expressing tumor with high target selectivity, and may offer a promising SPECT agent for NRP-1 expression positive tumor and encourage further investigation.

High Expression of Neuropilin-1 Associates with Unfavorable Clinicopathological Features in Hepatocellular Carcinoma.

As a co-receptor for vascular endothelial growth factor (VEGF), Neuropilin-1 (NRP-1) plays an important role in angiogenesis and malignant progression of many human cancers. However, the role of NRP-1 in hepatocellular carcinoma (HCC) is not well understood. The study aimed to detected the expression of Neuropilin-1 in HCC and investigate the association between its expression and the clinicopathological characteristics and prognosis of HCC. Quantitative real-time PCR (qRT-PCR), Western blot, Immunofluorescence and immunohistochemistry (IHC) analyses were performed to characterize the expression of NRP-1 in HCC cell lines and tissues. The association of NRP-1 expression with the clinicopathological characteristics and the prognosis was subsequently assessed. qRT-PCR and Western blot assays revealed that the expression of NRP-1 in HCC was significantly increased relative to that of normal live cells and tissues (P < 0.05,and <0.001, respectively). In addition, high expression of NRP-1 was significantly associated with intrahepatic metastasis (P = 0.036), Edmondson grade (P = 0.007), TNM classification (P = 0.0031), and portal vein invasion (P = 0.004). Furthermore, the HCC patients with high NRP-1 expression had shorter overall survival (OS), and recurrence-free survival (RFS), whereas, patients with low NRP-1 expression had better OS and RFS (P = 0.0035, and 0.0048, respectively). These data indicate that NRP-1 expression may play an important role in the progression of HCC, and that high NRP-1 expression suggests unfavorable clinicopathological characteristics and survival in HCC patients.

[In vitro culture of primary islet cells of suckling rats].

OBJECTIVE: To find a new method for obtaining abundant, well-purified and functionally active rat islet cells cultured in vitro. METHOD: The pancreatic tissues of suckling rats underwent repeated digestion for short durations with collagenase, and the cell growth was observed under inverted microscope 18 h after cell inoculation. The cultured cells were then transferred to a new culture plate and the supernate was harvested regularly to determine the concentration of insulin, amylase and glucose-stimulated insulin release. RESULTS: The fibroblast cells in the primary cultured suckling rat cells were obviously reduced, and the ratio of dithizone-stained cells were 85%-90% with the viability exceeding 90% as assessed by trypan blue staining. The secretion function of the cultured cells remained normal after a 7- to 11-day culture. CONCLUSION: Repeated digestion of the pancreatic tissues for short durations with collagenase and timely cell transfer to new plate may help achieve highly purified viable monolayer islet cells that are well applicable for experimental studies.

[Effect of triglycerides on rat islet cell function in vitro].

OBJECTIVE: To study the effect of triglycerides (TGs) on the function of in vitro cultured rat islet cells. METHODS: SD rat islet cells were isolated for monolayer cell culture and treated with TGs at different concentrations (0, 0.5, 2.5, 5.0, 10.0 mmol/L) for 72 h. Insulin level in the cell culture media was measured after glucose loading test, and the deposition of fat droplets in the islet cells observed by oil red O-staining. RESULTS: No obvious effect was observed after a 72-h incubation of the islet cells with TGs at low glucose level (2.8 mmol/L), while with the stimulation of high-level glucose (27.8 mmol/L), the insulin secretion was significantly inhibited by TGs of higher concentrations (5.0, 10.0 mmol/L). The deposition of fat droplets was found in the islet cells after incubation with TGs, with TGs of higher concentrations. CONCLUSION: TGs induces deposition of fat droplets in islet cells in vitro, and may inhibit the insulin-secreting function of the cells.

[Apoptosis-inducing effect of palmitic acids on rat pancreatic islet cells in primary culture: a preliminary study].

OBJECTIVE: To investigate the in vitro apoptosis-inducing effect of palmitic acid on pancreatic islet cells in primary culture, thereby to understand the role of palmitic acid in the pathogenesis of type 2 diabetes mellitus. METHOD: SD rat pancreatic islet cells were isolated and cultured in monolayer in vitro followed by incubation with stepwise diluted palmitic acid (0, 0.125, 0.25 mmol/L and 0.5 mmol/L respectively), and the insulin concentrations in the culture medium were determined by radio immunological methods. Morphological observation with a fluorescence microscope was conducted after double staining of the cells with PI/Hoechst 33342. RESULTS: The glucose-stimulated insulin secretion was inhibited by palmitic acid at the concentration of 0.25 and 0.5 mmol/L, which also induced obvious cell apoptosis. CONCLUSION: Palmitic acid is capable of inducing islet cell apoptosis in a dose-dependent manner.