Biomechanical characteristics of a novel interspinous distraction fusion device in the treatment of lumbar degenerative diseases: a finite element analysis.

BACKGROUND: A novel interspinous distraction fusion (ISDF) device has been used to treat lumbar degenerative diseases. As a minimally invasive technique, ISDF differs from the traditional interspinous process distraction devices. Currently, biomechanical studies on ISDF are rare. OBJECTIVE: To investigate the biomechanical properties of the ISDF device (BacFuse) which is used to treat lumbar degenerative diseases. METHODS: Three-dimensional L3-L5 models were created. The models were divided into four groups: intact (M1), local decompression alone (M2), internal fixation alone (M3) and local decompression combined with internal fixation (M4), based on different surgical procedures. Local laminectomy was performed to resect the lower part of the L4 lamina and the upper part of the L5 lamina at the right lamina of L4/5 in the M2 and M4 groups. After meshing the models elements, Abaqus were used to perform the finite element (FE) analysis. The intervertebral range of motion (ROM) was measured during flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation under a follower load of 400 N with a 7.5Nm moment. The distributions of disc and facet joint stresses were observed and recorded. Spinal vertebral stress was compared, and internal fixation device stress was observed. RESULTS: The ROM of L4/5 in M2 increased in flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation compared with that in M1. In all motion directions, the ROM at L4/5 decreased, and the ROM at L3/4 increased after implantation of the ISDF device in M3 and M4 groups. The disc stress and facet joint stresses in the instrumented segment decreased after implantation of the ISDF device. The spinous process loaded a certain amount of stress in M3 and M4 groups. The spikes of the internal fixation device were loaded with the maximum stress. CONCLUSION: BacFuse exhibited a reduction in intervertebral ROM, as well as decreased stress on the intervertebral disc and facet joint, while also demonstrating a discernible impact on the upper adjacent segment.

Double Vertebrae Kümmell Disease: Five Cases Report and Literature Review.

Kümmell disease (KD) is a complication of osteoporotic vertebral compression fractures. There is a lot of literature on KD, but the reported cases are all single vertebrae. This study reports five double vertebrae KD cases (10 levels) and discusses the possible underlying mechanisms with a literature review. One hundred and thirty vertebrae KD were diagnosed from 2074 osteoporotic vertebral compression fractures patients treated in our hospital between 2015 and 2019. These vertebrae KD were divided into two groups, one-level vertebrae KD (n = 125) and double-level KD (n = 5). The diagnosis of KD is mainly based on the signs of intravertebral vacuum cleft on X-ray or CT scan. Double vertebrae KD cases were classified by using the KD staging system. The analysis was performed on KD to compare age, gender, femoral neck bone mineral density of femoral neck (BMD), vertebrae distribution, Cobb angle, and visual analog scale (VAS) between one-level KD and double-level by t-tests, Welch's t-test, or hypothesis testing. The mean age of the participants in the one-level KD group was 78.69 years, while the mean age in the double-level KD group was 82.4 years. The difference was statistically significant (t = 3.66, p = 0.0004). There were 89 females and 36 males in the one-level KD group, while the double-level KD group had five females and no males. The femoral neck BMD was significantly different between the two groups, with the one-level KD group having a mean BMD of -2.75 and the double-level KD group having a mean BMD of -4.2 (t = 2.99, p= 0.0061). The vertebrae distribution was different between the groups, with the one-level KD group having vertebrae from T7 to L4 and the double-level KD group having vertebrae from T11 to L1. The Cobb angle was also significantly different between the groups, with the one-level KD group having a mean angle of 20.58 and the double-level KD group having a mean angle of 31.54 (t = 6.22, p = 0.0001). Finally, the VAS scores were similar between the two groups, with the one-level KD group having a mean score of 8.63 and the double-level KD group having a mean score of 8.8 (t = 1.35, p = 0.1790). It is concluded that double vertebrae Kümmell disease has special clinical significance due to its potential to cause greater spinal instability and deformity, increased risk of neurological symptoms, more complex surgical management, and greater risk of complications.

Psoas Hematoma After Posterior Lumbar Interbody fusion: A Case Report and Literature Review.

Introduction: This article introduced the management of a case with severe left lower extremity pain and forced hip flexion after posterior lumbar interbody fusion and a final diagnosis of left psoas hematoma. Materials and methods: Here we reported a case of a 65-year-old female received posterior lumbar interbody fusion (PLIF) for L4-L5 spondylolisthesis and L4 instability. On the postoperative day one, the hemoglobin level decreased from 108 g/L to 78 g/L. Meanwhile, the patient presented low back pain and inner thigh radiating pain (VAS pain scale = 8). The pain was so severe that it could be barely relieved by keeping left hip in flexion position. On the postoperative day 6, the pain was still severe even after taking mecobalamin, ankylosaurus, dehydrant agents and central pain relievers(VAS pain scale = 9). Computed Tomography indicated a left intramuscular hematoma image extending down to the left iliac fossa. Active hemorrhage of lumbar segmental arterial was detected by B-ultrasound. The patient then received vascular embolization under angiography on the postoperative day 7. Results: The pain in the low back and inner thigh were significantly relieved after the procedure (VAS3-4). On the postoperative day nineteen, the left hip can be fully extended, but the patient was still not able to stand on left leg without a walking stick. On the postoperative day 27, she was able to walk independently. Discussion: The main reason for the complication was the second conical dilation channel slipped and entered the lateral side of the vertebral body along the transverse process. After timely embolization, pain was significantly relieved and muscle strength was improved. Conclusions: Angiographic embolization is an effective treatment for psoas hematoma after posterior lumbar interbody fusion.

Significance of laparoscopic cytoreductive surgery for appendiceal pseudomyxoma peritonei with limited disease and low tumor burden.

OBJECTIVE: To investigate the clinical value of laparoscopic cytoreductive surgery (CRS) in treating of appendiceal pseudomyxoma peritonei with limited disease and low tumor burden. METHODS: The clinical data of patients with appendiceal pseudomyxoma peritonei treated by surgery with CRS at the Aerospace Center Hospital from January 2018 to December 2021 were retrospectively analyzed. The patients were divided into laparoscopic or open CRS groups according to the operation method. A propensity score-matched (PSM) analysis (1:1) was performed, the related clinical variables were compared between the two groups, and the effect on progression-free survival (PFS) was also analyzed. RESULTS: One hundred and eight patients were included in this study. After PSM, 33 patients were selected from each group and the age and peritoneal cancer index were matched between the two groups. There were significant differences in operation time (P < 0.001), intraoperative bleeding (P < 0.001), intraoperative blood transfusion (P = 0.007), hospital stay (P < 0.001). The analysis of PFS showed that there was no significant difference between the two operation methods. After multivariate analysis, the pathologic subtype (P = 0.012) was identified as an independent prognostic factor for PFS. CONCLUSION: The curative effect of laparoscopic CRS is like that of open operation, which can significantly shorten the operation time and hospital stay and reduce intraoperative bleeding and blood transfusion event. The laparoscopic CRS is safe and feasible in strictly selected patients. The pathologic subtype is an independent factor affecting the prognosis for PFS.

HABP1 promotes proliferation and invasion of lung adenocarcinoma cells through NFκB pathway.

The aim of this research was to investigate the role of hyaluronan-binding protein 1 (HABP1) in lung adenocarcinoma. It was demonstrated by bioinformatics analysis that HABP1 was one of the differentially expressed genes in lung adenocarcinoma. Then, it was confirmed by qPCR, western blot, and immunohistochemistry analysis that HABP1 was upregulated in human tissue specimens we collected. Survival analysis showed that HABP1 was promised to serve as a new biomarker to predict the progress and prognosis of lung adenocarcinoma patients. In addition, we further studied the effects of regulating the expression of HABP1 on lung adenocarcinoma cells, indicating that altered expression of HABP1 could adjust cell proliferation and invasion through the NFκB signaling pathway.

Mechanical insight into the formation of H2S from thiophene pyrolysis: The influence of H2O.

The thermal utilization of waste rubber is accompanied by the release of sulfur, and the release of H2S to the gas phase is one of the crucial issues. In this work, density functional theory (DFT) calculations and wave function analysis were employed to explore the possible formation pathways of H2S and its precursor (·SH radical) during the pyrolysis of thiophene in the presence of H2O. It indicates that H2O affects the decomposition of thiophene and the formation of H2S in two patterns. First, H2O can participate in the hydrogen transfer process by acting as a catalyst or generating weak hydrogen bonds with thiophene. In this way, the hydrogen transfer reactions are promoted with lower energy barriers, and thus the formation of H2S is facilitated by H2O without changing the pyrolysis pathways. Secondly, H2O can saturate the thiophene ring by addition reactions and alter the generation pathways of H2S significantly. The energy barriers can be decreased with one or two CC bonds of thiophene being saturated. The completely saturated thiophene results in a greater decline of the overall energy barriers for H2S formation. H2O provides the H atom for H2S in the second pattern. Due to the combination of the two influence patterns, the release of H2S can be promoted greatly in the presence of H2O. The present study aims to lay a foundation for the clean thermal utilization of thiophene/rubber and to inspire the advance of desulfurization techniques.

Comprehensive Interventions Including Vitamin D Effectively Reduce the Risk of Falls in Elderly Osteoporotic Patients.

OBJECTIVE: To evaluate the effects of different intervention measures to prevent falls in elderly osteoporotic patients. METHODS: A randomized controlled trial was conducted in our outpatient ward from August 2014 to September 2015. A total of 420 patients over 60 years of age were assigned to four groups. NA VitD group took 800 mg calcium and 800 IU non-active vitamin D. P-NA VitD group took 800 mg calcium, 800 IU non-active vitamin D, and received physical exercise. A VitD group took 800 mg calcium and 0.5 µg active vitamin D. P-A VitD took 800 mg calcium, 0.5 µg active vitamin D, and received physical exercise. Physical exercise includes guidance in improving muscle strength and balance ability. Short physical performance battery (SPPB), grip strength, modified falls efficacy scale (MFES), blood calcium, and 25-hydroxyl vitamin D were measured before interventions and at 3, 6, and 12 months after interventions. Bone mineral density (BMD) was detected before interventions and at 12 months after interventions. The incidence of falls and fractures, adverse events, and drug reactions were recorded for 12 months. RESULTS: A total of 420 patients were allocated in the four groups: 98 cases into the NA VitD group (11 males, 87 females), 97 cases into the P-NA VitD group (13 males, 84 females), 99 cases in the A VitD group (15 males, 84 females), and 98 cases into the P-A VitD group (11 males, 87 females). At 6 months after interventions, the SPPB of A VitD group significantly increased from 6.9 ± 1.9 to 8.0 ± 2.4 (P < 0.05), and the SPPB of A VitD group significantly increased from 7.2 ± 2.1 to 8.6 ± 1.7 (P < 0.05). At 6 months after interventions, MFES of P-NA VitD group 7.0 ± 1.6 to 7.6 ± 1.6 (P < 0.05), and MFES of P-A VitD group significantly increased from 6.7 ± 1.6 to 7.5 ± 1.6 (P < 0.05). At 12 months after interventions, SPPB of all groups, grip strength, and MFES of P-NA VitD group, A VitD group, P-A VitD group were significantly improved (P < 0.05). The BMD of lumbar vertebrae of A VitD group significantly increased from 0.742 ± 0.042 to 0.776 ± 0.039, and P-A VitD group significantly increased from 0.743 ± 0.048 to 0.783 ± 0.042 (P < 0.05). No serious adverse events occurred during the 12 months of follow-up. CONCLUSION: Active vitamin D is better than non-active vitamin D to improve physical ability and the BMD of lumbar vertebrae and reduce the risk of falls.

A new interspinous process distraction device BacFuse in the treatment of lumbar spinal stenosis with 5 years follow-up study.

To explore a suitable indication of interspinous process distraction device for lumbar spinal stenosis with BacFuse.Patients of lumbar spinal stenosis (LSS) who experienced interspinous process distraction device surgery with BacFuse from June 2014 to January 2015 in our institute were included. We classified LSS into central and lateral types, and then divided these into severe and moderate according to the degree of stenosis. Each type was divided into 2 groups. Patients in group A underwent distraction without bone decompression (stand-alone), while patients in group B underwent bone decompression combined with distraction. Follow-up was performed at 1 month, 3 months, 6 months, 2 years, and 5 years after surgery. Zurich Claudication Questionnaire (ZCQ) was recorded to assess the patient's postoperative condition at each follow-up.A total of 142 patients were available for follow up at each time interval. There was a significant difference between the preoperative and final follow-up ZCQ scores for every LSS type. In addition, there was no difference between group A and group B in the postoperative ZCQ scores with the exception of the lateral severe type. In the study, 22 of the 23 patients (95.65%) in the lateral moderate type were considered to have a satisfactory result in group B, with a similar result of 93.33% (14/15) in group A (P = .75). In the lateral severe type, the patient satisfaction rate was 65.22% (15/23) and 90.63% (29/32) in group A and group B (P = .02), respectively. In the central moderate type, the patient satisfaction rate was 81.82% (15/23) and 76.92% (10/13) in group A and group B (P = .77), respectively. Satisfaction rate for the follow-up results in the central severe type reached 57.14% (4/7) in group A, and 54.55% (6/11) in group B (P = .91). Moreover, no relationship was found between satisfaction and neurogenic intermittent claudication.The most suitable indication for BacFuse treatment was the lateral moderate type. For lateral severe patients, distraction combined with decompression is suggested for a higher satisfaction rate. Severe central spinal stenosis was shown to be a relative contraindication for BacFuse.

Ex situ catalytic fast pyrolysis of soy sauce residue with HZSM-5 for co-production of aromatic hydrocarbons and supercapacitor materials.

A promising approach is proposed for the efficient conversion of soy sauce residue (SSR) into aromatic hydrocarbons and a supercapacitor electrode material by ex situ catalytic fast pyrolysis (CFP) technology with HZSM-5. The thermal decomposition behaviors of SSR were first investigated via thermogravimetry (TG) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses. The ex situ CFP of SSR was conducted to elucidate the aromatic hydrocarbons production under different pyrolysis temperatures and HZSM-5-to-SSR (HZ-to-SSR) ratios using both Py-GC/MS and lab-scale instruments. The results indicated that the aromatic hydrocarbons reached the maximal yields of 22.20 wt% from Py-GC/MS with an HZ-to-SSR ratio of 11 at 650 °C, and 17.61 wt% from the lab-scale device with an HZ-to-SSR ratio of 2, respectively. The as-obtained yield of aromatic hydrocarbons was far higher than those obtained from typical lignocellulosic biomass materials, confirming that SSR is a promising material for aromatics production. The pyrolytic solid product collected with this method was further activated by KOH to synthesize N-doped activated carbon (NAC) for supercapacitors. The physicochemical analysis showed that NAC possessed N-incorporated hierarchical pores, and exhibited a promising capacitance of 274.5 F g-1 at 1 A g-1.

A case of multilevel percutaneous vertebroplasty for vertebral metastases resulting in temporary paraparesis.

Percutaneous vertebroplasty (PVP) is a minimally invasive treatment that has been widely used for the treatment of osteoporotic vertebral compression fractures and vertebral tumors. However, the maximum number of vertebral segments treated in a single PVP remains controversial. Furthermore, PVP may cause complications, including cement leakage, pulmonary embolism, bone cement toxicity, and spinal nerve-puncture injury. We report the rare case of a patient who underwent multilevel PVP for vertebral metastases, with no bone cement leakage or spinal cord injury, but who developed temporary paraparesis.

The emissions from co-firing of biomass and torrefied biomass with coal in a chain-grate steam boiler.

In this study, biomass of rice straw (RS) and wood (WD) and their torrefied biomass (RST and WDT) were used as solid biofuel (SBF) for co-firing individually with coal in a commercial continuous chain-grate steam boiler system, which was conducted at fixed input rate of heating value of mixture of SBF and coal and at fixed airflow rate. The effects of key system parameters on the gaseous and particulate pollutions and ash were examined. These include SBF type and blending ratio (RBL) of biomass (i.e., SBF) in the mixture of coal and biomass based on heating values for co-firing.The results indicated that wood, which possesses high heating value while less amount of ash, is more suitable for co-firing with coal than rice straw. Torrefaction can increase the heating value of biomass and homogenize its property, being beneficial to co-firing. Also, torrefaction can decompose the hydroxyl group of biomass, which makes biomass tending to possess hydrophobicity. This, in turn, helps the storage and transportation of biomass. Generally, adding the RS (with RBL = 5-10%), WD (2-15%), RST (2-10%) and WDT (2-20%), respectively, with coal decreases the emissions of NOx and SO2, but increases that of CO (except RST). The emission of HCl is little. The addition of biomass also increases the emission of fine particulate matters (PM) especially PM2.5 in the flue gases, raising PM2.5/PM100 from 34.87 to 78.35 wt.% (Case 50%WDT). These emissions for the Cases tested satisfy with Taiwanese emission standards of stationary sources which set limitations of NOx, SO2, CO and HCl < 350, 300, 2000 and 80 ppmv, while PM < 50 mg/m3, respectively. The results support the use of RS, WD, RST and WDT for co-firing with coal.Implications: This study examined the suitability of using solid bio-fuels to co-fire with coal in an industrial chain-grate steam boiler system with a capacity of 100 kW, in order to achieve carbon-free emissions. Both biomass and torrefied biomass of solid bio-fuel were tested. The findings would be useful for proper design and rational operation of solid bio-fuel/coal co-firing combustion matching the appeal of sustainable material management and circular economy of biomass, and of adaptation of global warming induced by greenhouse gases. It also provides information for policy-makers to promote the co-firing application of biomass and related bio-waste materials.

LncRNA-LINC00472 contributes to the pathogenesis of atrial fibrillation (Af) by reducing expression of JP2 and RyR2 via miR-24.

BACKGROUND: Dysregulated methylation of the promoter of lncRNA LINC00472 reduces the expression of LINC00472 and subsequently up-regulates the expression of its competing endogenous RNA miR-24. In addition, JP2 can stabilize the expression of RyR2, whereas the deregulation of RyR2 expression may contribute to the pathogenesis of atrial fibrillation (AF). In this study, we aimed to study the role of LINC00472 in the pathogenesis of AF. METHODS: 125 AF patients and 168 healthy controls were enrolled to compare their expression of miR-24, LINC00472, JP2 and RyR2. A dual-luciferase reporter gene assay accompanied by real-time PCR, Western blot and IHC assay was subsequently conducted to evaluate the regulatory relationship among miR-24, LINC00472, JP2 and RyR2 in HCM and H9C2 cells. RESULTS: AF patients were associated with an increased level of miR-24 expression and reduced level of LINC00472 expression. Also, the level of DNA methylation in LINC00472 was increased in AF patients. MiR-24 could negatively regulate the expression of LINC00472 and JP2 by directly binding to them. CONCLUSIONS: LINC00472 could regulate the progression of AF via modulating the LINC00472/miR-24/JP2/RyR2 signaling pathway.

An analysis of the causes of transient paraplegia during percutaneous vertebral augmentation under local anesthesia: A case series of 12 patients.

BACKGROUND: Percutaneous vertebral augmentation (PVA) under local anesthesia has been widely used to treat osteoporotic vertebral compression fractures and vertebral body tumors. However, the occurrence of spinal cord or nerve root dysfunction may result in poor prognosis for patients. The aim of this study was to analyze the causes of transient paraplegia in 12 patients undergoing PVA. METHODS: The medical records of 12 patients with transient paraplegia during PVA in our hospital were analyzed. Data, including operation, vertebral, anesthetic dose, operation time, recovery time, and follow-up, were extracted. RESULTS: Among the 12 patients, ranging in age from 62 years to 83 years, with a mean age of 74 years, 8 were females and 4 were males. The average anesthetic dose injected per vertebral body was 6.38 ml. Patients required an average of 218.75 min to recover sensation and movement completely. However, the amount of anesthetic injected into each vertebral body was not related to the time required for complete recovery. Follow-up showed that all patients had regained normal bilateral sensation and motor function. Postoperative visual analog scale and Oswestry Disability Index values of the 12 patients were significantly improved compared with preoperative values. CONCLUSION: The complication of transient paraplegia was caused by local anesthetic drugs infiltrating into the spinal canal and inhibiting nerve conduction in the spinal cord.

Multilevel percutaneous kyphoplasty in painful osteolytic vertebral metastases: a study of the efficacy and safety.

Purpose: The spine is the most common skeletal site for metastatic tumors. In the treatment of vertebral metastases, the absolutely safe number of levels that can be treated via percutaneous kyphoplasty (PKP) during one procedure remains controversial. Thus, the present study aimed to evaluate the safety and efficacy of multilevel (>3) PKP for painful osteolytic vertebral metastases. Patients and methods: We retrospectively analyzed the data from 176 patients who received PKP for painful osteolytic spinal metastases. Group A (n=104) received PKP at a maximum of three vertebral levels per procedure, while group B (n=72) received PKP at more than three levels during one operation. Surgical efficacy was assessed via a comparison of the VAS, Oswestry Disability Index (ODI), and general health (GH) and mental health (MH) scores of the Short Form-36 Health Survey before and after PKP. The complications were observed to evaluate the safety. Results: Both groups had significantly improved VAS, ODI, GH and MH scores after PKP (P<0.05). One week after surgery, group A had significantly less pain (VAS 3.41±0.1) than group B (VAS 3.74±0.13) (P<0.05). At 3 and 6 months postoperatively, the GH score was more significantly improved in group A than group B (P<0.05). There were no significant differences between the two groups in the ODI, MH score, and complications (P>0.05). Conclusion: Multilevel PKP is safe and results in effective pain relief, and improvement of spinal mobility and GH in patients with osteolytic vertebral metastases. However, patients who undergo PKP at more than three levels have slightly worse short-term pain relief (less than 1 week postoperatively) and improvement of GH in the long-term (more than 3 months postoperatively) compared with patients who undergo PKP at less than three levels.

Percutaneous osteoplasty for the management of a humeral head metastasis: Two case reports.

RATIONALE: Percutaneous osteoplasty (POP) has been proved effective to relieve pain in metastases of vertebral, pelvis, and femur. Nevertheless, there are few reports about the effectiveness of POP in the humeral head metastases. In this study, we described 2 patients with humeral head metastases treated with POP in our hospital. PATIENT CONCERNS: Case 1 was a 79-year-old man with vertebral and right humeral head metastasis after radical surgery or and periods of chemotherapy for bladder cancer. He suffered constant severe back and right shoulder joint pain even if taking much non-steroidal anti-inflammatory drugs. Case 2 was a 59-year-old woman with vertebral and right humeral head metastasis from lung cancer. She received regular radiotherapy and took much painkillers to relieve pain. However, the pain could not be relieved any more after 1 month and severely affects sleeping and daily activities. DIAGNOSIS: Both 2 patients were diagnosed as vertebral metastases and right proximal humeral head metastases. INTERVENTIONS: POP was performed to treat the right humeral head metastases. Percutaneous vertebroplasty (PVP) was performed to treat vertebral metastases. OUTCOMES: After surgery, the patients experienced significant decrease in pain and better motor function. Both patients did not suffer from pulmonary embolism, infection, nerve injury, and bone cement syndrome. LESSONS: For the pain that cannot be relieved by radiotherapy and analgesic drugs, POP is a safe and beneficial minimally invasive procedure that provides immediate and substantial relief from pain for humerus head metastases.

Percutaneous osteoplasty for the management of a pubic bone metastasis.

Percutaneous osteoplasty (POP) has been proven to relieve pain due to osteolytic metastases by injecting bone cement to stabilize the pathological fracture. Nevertheless, there have been few reports about POP of metastases in the pubis. This article presents a case involving the use of POP to manage a metastasis in the pubis. After POP the patient experienced significant pain relief and improvement in the quality of life.

Necroptosis occurs in osteoblasts during tumor necrosis factor-α stimulation and caspase-8 inhibition

Necroptosis is a regulated cell death mechanism. However, it is unknown whether necroptosis is involved in the death of tumor necrosis factor-α (TNF-α)-treated osteoblasts. Therefore, we conducted the study with TNF-α, Nec-1 (a specific inhibitor of necroptosis), and Z-IETD-FMK (a specific inhibitor of apoptosis) to determine whether necroptosis plays a role in the death of TNF-α-treated osteoblast cell line MC3T3-E1. Cell viability, cell death, and lactate dehydrogenase (LDH) release were assayed to evaluate cytotoxicity. Specific marker proteins receptor interacting protein kinase (RIPK3) and phosphorylated mixed lineage kinase domain-like protein (p-MLKL) for necroptosis, and cleaved caspase 3 for apoptosis were detected by western blot, and mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). We found that TNF-α inhibited cell proliferation in a dose- and time-dependent manner. Nec-1 plus Z-IETD-FMK restored cell viability and significantly decreased LDH release. In addition, TNF-α alone increased the cell population of AV+PI−, while Z-IETD-FMK caused a shift in the cell population from AV+PI− to AV+PI+. Furthermore, TNF-α significantly increased protein cleaved caspase 3. TNF-α plus Z-IETD-FMK significantly increased the proteins RIPK3 and MLKL phosphorylation in MC3T3-E1 cells, while the changes in mRNA levels of RIPK3, MLKL, and caspase 3 were not consistent with the changes in the corresponding protein expression levels. In conclusion, TNF-α induced preferentially apoptosis in osteoblast cell line and necroptosis played a decisive role when TNF-α-induced death was inhibited by the inhibitor of apoptosis. Combined treatment with Nec-1 and Z-IETD-FMK protected mouse osteoblasts from death induced by TNF-α.

Necroptosis occurs in osteoblasts during tumor necrosis factor-α stimulation and caspase-8 inhibition.

Necroptosis is a regulated cell death mechanism. However, it is unknown whether necroptosis is involved in the death of tumor necrosis factor-α (TNF-α)-treated osteoblasts. Therefore, we conducted the study with TNF-α, Nec-1 (a specific inhibitor of necroptosis), and Z-IETD-FMK (a specific inhibitor of apoptosis) to determine whether necroptosis plays a role in the death of TNF-α-treated osteoblast cell line MC3T3-E1. Cell viability, cell death, and lactate dehydrogenase (LDH) release were assayed to evaluate cytotoxicity. Specific marker proteins receptor interacting protein kinase (RIPK3) and phosphorylated mixed lineage kinase domain-like protein (p-MLKL) for necroptosis, and cleaved caspase 3 for apoptosis were detected by western blot, and mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). We found that TNF-α inhibited cell proliferation in a dose- and time-dependent manner. Nec-1 plus Z-IETD-FMK restored cell viability and significantly decreased LDH release. In addition, TNF-α alone increased the cell population of AV+PI-, while Z-IETD-FMK caused a shift in the cell population from AV+PI- to AV+PI+. Furthermore, TNF-α significantly increased protein cleaved caspase 3. TNF-α plus Z-IETD-FMK significantly increased the proteins RIPK3 and MLKL phosphorylation in MC3T3-E1 cells, while the changes in mRNA levels of RIPK3, MLKL, and caspase 3 were not consistent with the changes in the corresponding protein expression levels. In conclusion, TNF-α induced preferentially apoptosis in osteoblast cell line and necroptosis played a decisive role when TNF-α-induced death was inhibited by the inhibitor of apoptosis. Combined treatment with Nec-1 and Z-IETD-FMK protected mouse osteoblasts from death induced by TNF-α.

Optimization of the protocols for induction and differentiation of bone marrow mesenchymal stem cells into chondrocytes: a synergistic action between transforming growth factor beta1 and insulin-like growth factor 1 / 中国组织工程研究

BACKGROUND: Inducing factors are currently used as a main method for the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocytes. OBJECTIVE: To investigate the collaborative stimulation of transforming growth factor beta1 (TGF-β1) and insulin-like growth factor 1 (IGF-1) to induce the directed differentiation of BMSCs to chondrocytes, and to explore the best inductive effect. METHODS: Rat BMSCs were isolated, cultured and purified using adherent culture. Then, different inducing factors were added in the induction medium: TGF-β1+IGF-1 group, TGF-β1 group, IGF-1 group, and control group without growth factors. Immunofluorescence was carried out at 21 days of induction. The expression of collagen type Ⅱ was evaluated by immuncytochemical staining at 7, 14 and 21 days of induction. RESULTS AND CONCLUSION: (1) Immunofluorescence detection of the TGF-β1+IGF-1 and TGF-β1 groups showed highly expressed collagen type Ⅱ (brown red-stained cytoplasm), while negatively expressed collagen type Ⅱ in the other two groups. (2) Findings from the immuncytochemical staining showed that the expression of collagen type Ⅱ was stronger in the TGF-β1+IGF-1 group than the TGF-β1 group (P < 0.01), and the expression was gradually enhanced with time. Meanwhile, there was also no expression of collagen type Ⅱ in the IGF-1 and control groups. To conclude, the combination of TGF-β1 and IGF-1 can achieve the better inductive effect on the chondrogenic differentiation of BMSCs in vitro.