Exosomes from tendon stem cells promote injury tendon healing through balancing synthesis and degradation of the tendon extracellular matrix

Tendon injuries are common musculoskeletal system disorders in clinical, but the regeneration ability of tendon is limited. Tendon stem cells (TSCs) have shown promising effect on tissue engineering and been used for the treatment of tendon injury. Exosomes that serve as genetic information carriers have been implicated in many diseases and physiological processes, but effect of exosomes from TSCs on tendon injury repair is unclear. The aim of this study is to make clear that the effect of exosomes from TSCs on tendon injury healing. Exosomes were harvested from conditioned culture media of TSCs by a sequential centrifugation process. Rat Achilles tendon tendinopathy model was established by collagenase‐I injection. This was followed by intra‐Achilles‐tendon injection with TSCs or exosomes. Tendon healing and matrix degradation were evaluated by histology analysis and biomechanical test at the post‐injury 5 weeks. In vitro, TSCs treated with interleukin 1 beta were added by conditioned medium including exosomes or not, or by exosomes or not. Tendon matrix related markers and tenogenesis related markers were measured by immunostaining and western blot. We found that TSCs injection and exosomes injection significantly decreased matrix metalloproteinases (MMP)‐3 expression, increased expression of tissue inhibitor of metalloproteinase‐3 (TIMP‐3) and Col‐1a1, and increased biomechanical properties of the ultimate stress and maximum loading. In vitro, conditioned medium with exosomes and exosomes also significantly decreased MMP‐3, and increased expression of tenomodulin, Col‐1a1 and TIMP‐3. Exosomes from TSCs could be an ideal therapeutic strategy in tendon injury healing for its balancing tendon extracellular matrix and promoting the tenogenesis of TSCs.

DCZ0814 induces apoptosis and G0/G1 phase cell cycle arrest in myeloma by dual inhibition of mTORC1/2

Purpose: The present study investigates the effect of DCZ0814 in multiple myeloma (MM) cells, and determines the molecular mechanism of its antitumor activity against MM.

Methods: The effects of DCZ0814 were evaluated in vitro using human MM cell lines (ARP1 and OCI-MY5) and in vivo in a murine xenograft MM model. Cell viability was measured with the CCK-8 assay and mitochondrial membrane potential (MMP) was assessed with the JC-1 dye. Apoptosis and cell cycle distribution were examined by flow cytometry. Inhibition of mTORC1 and mTORC2 was assessed by western blot analysis, and the synergistic effect of DCZ0814 and known MM drugs was assessed by calculating the combination index value, using the CalcuSyn software.

Results: DCZ0814 effectively inhibited proliferation in MM cells, an effect that was associated with the induction of apoptosis, G0/G1 cell cycle arrest, MMP reduction and reactive oxygen species (ROS) generation. Meanwhile, DCZ0814 repressed the mTOR signaling via dual mTORC1/C2 inhibition and overcame the protective effect of the bone marrow (BM) microenvironment in myeloma cells. In addition, co-treatment with DCZ0814 and other anti-MM agents induced synergistic effects. Finally, the efficacy of the DCZ0814 treatment was confirmed in an MM xenograft mouse model.

Conclusion: DCZ0814 exhibits potent anti-MM activity and abrogates the activation of the mTOR/Akt signaling pathway mediated by the BM stroma-derived cytokines. Our results provide a theoretical basis for the development of novel therapeutic strategies in MM using DCZ0814 as a natural product combination compound.

DCZ0801, a novel compound, induces cell apoptosis and cell cycle arrest via MAPK pathway in multiple myeloma

Multiple myeloma (MM) is a refractory malignant hematological malignancy, and many therapeutic strategies have been developed to cure patients with MM. DCZ0801 is a compound that consists of oxophenamide and pterostilbene. The role of these compounds in hematological cancers such as MM has yet to be studied. In this study, we explored the potential mechanism of DCZ0801 action, its anti-tumor activity both in vitro and in vivo on MM. This study was carried out via cell cycle proliferation assay, apoptotic analysis, western blot analysis, and examination of xenotransplantation model of tumors. The in vitro studies revealed that DCZ0801 could inhibit cell proliferation and induce apoptosis by regulating both caspase-dependent and mitogen-activated protein kinase signaling pathways, inducing S-phase arrest of the cell cycle related to downregulation of CDK2, cyclin-A2, and CDC25A protein expression. The in vivo studies showed that DCZ0801 could significantly reduce the size of the tumors in nude mice. Our results demonstrated that DCZ0801 may emerge as the new therapeutic option for the patient with MM.

STAT6 phosphorylation upregulates microRNA-155 expression and subsequently enhances the pathogenesis of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL), a clonal expansion of CD5⁺ B cells, is the most common form of adult leukemia; however, the molecular mechanisms underlying its pathogenesis remain undetermined. It has been previously suggested that numerous biological factors, including cytokines, may be involved in the proliferation of malignant cells. For example, interleukin (IL)-4, IL-2, interferon-γ and tumor necrosis factor serve roles as inhibitors of cellular apoptosis; whereas IL-5 and IL-10 are inducers of cellular apoptosis. In the present study, the results demonstrated that the phosphorylation and activation of signal transducer and activator of transcription 6 (STAT6) was induced by IL-4 in a time-dependent manner. Notably, the expression level of microRNA (miR)-155 was increased in MEC-1 cells following treatment with IL-4; however, this effect was attenuated following STAT6 knockdown via RNA interference. In addition, STAT6 knockdown promoted cell apoptosis, which was partly attenuated by treatment with IL-4. Inhibition of miR-155 expression significantly increased cell apoptosis despite the presence of IL-4. The results of the present study suggested that treatment with IL-4 enhanced the expression of miR-155, which regulated CLL cell survival via the enhanced phosphorylation of STAT6.

Size Dependence of Grain Boundary Migration in Metals under Mechanical Loading

The greatly increased grain boundary (GB) mobility in nanograined metals under mechanical loading is distinguished from that in their coarse-grained counterparts. The feature leads to softening of nanograined materials and deviation of strength from the classical Hall-Petch relationship. In this Letter, grain size dependences of GB migration in nanograined Ag, Cu, and Ni under tension were investigated quantitatively in a wide size range. As grain size decreases from submicron, GB migration intensifies and then diminishes below a critical grain size. The GB migration peaks at about 80, 75, and 38 nm in Ag, Cu, and Ni, respectively. The suppression of GB migration below a critical size can be attributed to GB relaxation during sample processing or by postthermal annealing. With relaxed GBs the governing deformation mechanism of nanograins shifts from GB migration to formation of through-grain twins or stacking faults. GB relaxation, analogous to GB segregation, offers a novel approach to stabilizing nanograined materials under mechanical loading.

Simvastatin and Simvastatin-Ezetimibe Improve the Neurological Function and Attenuate the Endothelial Inflammatory Response after Spinal Cord Injury in Rat

During a spinal cord injury (SCI), mechanical trauma rapidly leads to a blood-spinal cord barrier (BSB) disruption, neural cell damage, axonal damage, and demyelination, followed by a cascade of secondary inflammatory reactions. These inflammatory responses spread the damage to the neural cells and impair the recovery of neurological functions. In the present study, we evaluated the efficacy of simvastatin and a simvastatin-ezetimibe combination therapy in managing the endothelial inflammatory response in an SCI rat model. Adult male Sprague-Dawley rats were group-housed and SCI was induced by using the modified weight-drop method. The animals were divided into 4 groups: (1) sham group, laminectomy only (n=6); (2) no-treatment group, SCI without therapy (n=8); (3) simvastatin group (n=8), and (4) ezetimibe and simvastatin combination therapy group (n=8). A high dose (15 mg/kg) of simvastatin was given to the simvastatin group, and 10 mg/kg simvastatin and 10 mg/kg ezetimibe were given to the combination group. Neurological function was assessed using the Basso, Beattie, and Bresnahan locomotor scale score. Intercellular adhesion molecule-1 (ICAM-1) level was used as an SCI biomarker. ICAM-1 level was the highest at 72 hours after SCI in the no-treament group. The treatment groups showed significant reduction in ICAM-1 levels at 72 hours. The treatment groups, especially the combination treatment group, showed better neurological function scores. Simvastatin and simvastatin- ezetimibe all could improve the neurological function and attenuate the endothelial inflammatory response after spinal cord injury in rat.

Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys

Alloy design based on single–principal-element systems has approached its limit for performance enhancements. A substantial increase in strength up to gigapascal levels typically causes the premature failure of materials with reduced ductility. Here, we report a strategy to break this trade-off by controllably introducing high-density ductile multicomponent intermetallic nanoparticles (MCINPs) in complex alloy systems. Distinct from the intermetallic-induced embrittlement under conventional wisdom, such MCINP-strengthened alloys exhibit superior strengths of 1.5 gigapascals and ductility as high as 50% in tension at ambient temperature. The plastic instability, a major concern for high-strength materials, can be completely eliminated by generating a distinctive multistage work-hardening behavior, resulting from pronounced dislocation activities and deformation-induced microbands. This MCINP strategy offers a paradigm to develop next-generation materials for structural applications.

Methylation status of ORMDL3 regulates cytokine production and p-ERK/MMP9 pathway expression

Orosomucoid like-3 (ORMDL3) has been identified to be associated with the development of asthma according to previous studies. However, the definite role of ORMDL3 in the pathogenesis of asthma remains unclear. In this study, we found ORMDL3 was highly expressed in PBMC specimens from childhood asthma patients. Cytokines production and p-ERK/MMP-9 pathway expression was also increased in childhood asthma patients compared with controls. In addition, ORMDL3 overexpression induced IL-6 and IL-8 release and activated p-ERK/MMP-9 pathway in vitro. Increased ORMDL3 expression was observed after treated with 5-Aza-CdR. 5-Aza-CdR decreased the percentage of the CpG island in the ORMDL3 promoter region and increased its promoter activity. In addition, 5-Aza-CdR significantly increased IL-6 and IL-8 levels in NHBE cells while there was no obvious alteration after knocking down ORMDL3. Knockdown of ORMDL3 also significantly decreased the expression of p-ERK/MMP-9 pathway in the presence or absence of 5-Aza-CdR. In conclusion, our study provided novel evidence for the association between ORMDL3 and asthma-associated cytokines. Moreover, DNA methylation plays an important role in ORMDL3-mediated increased IL-6 and IL-8 levels and p-ERK/MMP-9 pathway expression.

Downregulation of thioredoxin-1 in the ventral tegmental area delays extinction of methamphetamine-induced conditioned place preference

BACKGROUND

Drug addiction is characterized by compulsive drug use and relapse. Thioredoxin-1 is emerging as an important modulator involved in the cellular protective response against a variety of toxic stressors. Previous study has reported that thioredoxin-1 overexpression prevents the acquisition of methamphetamine-conditioned place preference. Here, we aimed to investigate the effect of thioredoxin-1 on methamphetamine-conditioned place preference extinction and the possible mechanism.

METHODS

(a) An extinction procedure in mice was employed to investigate the effect of thioredoxin-1 on the extinction of methamphetamine-conditioned place preference. After the acquisition of methamphetamine-conditioned place preference, mice underwent the following procedures: the injection of thioredoxin-1 small interfering RNA in the ventral tegmental area followed by the post-conditioned place preference test, four days of extinction training followed by four days of recovery after surgery. (b) The levels of thioredoxin-1, dopamine D1 receptor, tyrosine hydroxylase, phosphorylated extracellular regulated kinase, and phosphorylated cyclic adenosine monophosphate response element binding protein were examined by using Western blot analysis.

RESULTS

Thioredoxin-1 downregulation in the ventral tegmental area delayed methamphetamine-conditioned place preference extinction. The expression of thioredoxin-1 was decreased in the ventral tegmental area of mice in control and negative groups after methamphetamine-conditioned place preference extinction, but not in the thioredoxin-1 siRNA group. The levels of dopamine D1 receptor, tyrosine hydroxylase, phosphorylated extracellular regulated kinase, and phosphorylated cyclic adenosine monophosphate response element binding protein were decreased in the ventral tegmental area, nucleus accumbens, and prefrontal cortex of mice in the control and negative groups after methamphetamine-conditioned place preference extinction, but were inversely increased in thioredoxin-1 siRNA group.

CONCLUSIONS

The results suggest that downregulation of thioredoxin-1 in the ventral tegmental area may delay methamphetamine-conditioned place preference extinction by regulating the mesocorticolimbic dopaminergic signaling pathway.

Fluoroscopically-Guided Superior Hypogastric Plexus Neurolysis Using a Single Needle: A Modified Technique for a Posterolateral Transdiscal Approach

BACKGROUND

A superior hypogastric plexus block is difficult to perform and hampered by bony structures of the iliac crest and transverse process of L5.

OBJECTIVE

We report on a fluoroscopically guided posterolateral transdiscal technique for superior hypogastric plexus neurolysis using a single needle.

STUDY DESIGN

A technical note describing interventional procedures.

SETTING

The neurosurgery department of a cancer hospital.

METHODS

The patient was placed in the prone position with a pillow beneath the iliac crest to facilitate opening of the intervertebral disc. The entry point for the needle was 7-8 cm to the left of the midline of the L45 level. The spinal needle was slightly advanced caudally toward the L5-S1 disc and at a 40° angle from the vertical plane. Using lateral fluoroscopic control, the needle was advanced beneath the inferior aspect of the facet joint. After entering the disc, the needle was then advanced until it passed the anterior annulus fibrosus of the L5S1 disc. After verifying adequate position using contrast, 3 mL of 75% ethanol was injected for neurolysis.

RESULTS

During the follow-up, the patient reported reduction of pain in the lower abdomen and quality of life was significantly improved.

LIMITATIONS

Sample size; no placebo control.

CONCLUSION

Although different approaches exist, we prefer the posterolateral transdiscal approach for superior hypogastric plexus block and neurolysis using a single needle. This technique is a valuable alternative.

KEY WORDS

Superior hypogastric plexus neurolysis, transdiscal approach, cancer pain.

Comparative Cost Analysis for the Surgical and Endovascular Treatment of Ruptured Intracranial Aneurysms in Taiwan: A Nationwide Population-Based Cohort Study

OBJECTIVE

Using a database that enabled longitudinal follow-up, we assessed the cost, outcome, complications, and readmission rate of ruptured cerebral aneurysms repaired by surgical clipping and endovascular coiling.

METHODS

This study was a retrospective review of data from a series of patients who underwent surgical clipping or endovascular coiling of ruptured cerebral aneurysms between 1996 and 2013. The medical records and hospital cost data were all examined.

RESULTS

A total of 7690 and 1380 cases were treated with clipping and coiling, respectively. Patients treated with clipping had more comorbidities and were older. The average total cost for endovascular coiling was $13,974.3, whereas the average total cost for surgical clipping was $16,581.7. Perioperative (30-day) mortality was 10.7% in patients with coiled aneurysms, compared with 12.6% in those with clipped aneurysms (P = 0.045). After 1 year of follow-up, clipping was associated with a significantly longer length of hospital stay (P < 0.001) and significantly higher total hospital costs (P < 0.001).

CONCLUSIONS

In Taiwan, the total hospital costs for the surgical clipping of cerebral aneurysms were higher than for endovascular coiling, and the surgical results were associated with significant complications. We suggest that the indications for coiling might need to be expanded from the current standards dictated by the guidelines in Taiwan.