A potential strategy for counteracting age-related sarcopenia: preliminary evidence of combined exercise training and leucine supplementation

Previous research has demonstrated the positive effects of concurrent/combined aerobic and resistance exercise or leucine supplementation on skeletal muscle protein synthesis (MPS) and hypertrophy in aging organisms. However, the effects of a multimodal intervention which combines both aerobic and resistance exercise and leucine supplementation has not been fully elucidated. Eighteen month old and 2 month old C57BL/6 mice were assigned to aging control (AC, n = 8), aging and multimodal intervention (AMI, n = 8) and young control (YC, n = 8). Mice in the YC and AC groups were fed an alanine-rich diet (3.4%), and mice in the AMI group received an isonitrogenous leucine-supplemented (5%) diet in combination with combined aerobic (30 minutes swimming) and resistance exercise training (incremental jumping submersed in water with overload corresponding to 40%-50% body weight) for a total of 4 weeks. The gastrocnemius muscles were dissected for western blotting detection (signaling proteins involved in MPS) and the ex vivo determination of protein synthesis and protein content. The muscle strength of the hind limbs was measured pre-experiment and repeated once per week on Sunday for 4 weeks. Mice in the AC and AMI groups showed lower ex vivo protein synthesis, protein content, expression of signaling proteins involved in MPS, maximal grip strength but higher plasma cortisol compared with the YC group post intervention. When compared to AC mice, the multimodal treatment led to lower activity of Sestrin2, higher expression of PI3K III and the phosphorylation of mTOR, p70S6K and 4E-BP1, as well as higher plasma leucine, wet gastrocnemius muscle weight and muscle weight to body weight ratio. Furthermore, the multimodal intervention induced more pronounced anabolic response such as higher ex vivo protein synthesis rate, total protein content, and myofibrillar fractions in gastrocnemius muscle, and greater maximum grip strength. The present research shows that a multimodal intervention including combined both aerobic and resistance exercise training and 5% leucine supplementation has the potential to maintain skeletal muscle protein synthesis and attenuate losses in muscular strength during the aging process.

Genetic Polymorphism of LBX1 Is Associated With Adolescent Idiopathic Scoliosis in Northern Chinese Han Population

STUDY DESIGN

A case-control association study was performed to investigate the relationship between ladybird homeobox (LBX1) and adolescent idiopathic scoliosis (AIS) in northern Chinese Han population.

OBJECTIVE

To explore the prevalence and functional importance of LBX1 polymorphisms in patients with AIS within the northern Chinese Han population.

SUMMARY OF BACKGROUND DATA

AIS is the most common subtype of idiopathic scoliosis. Genetic factors such as LBX1 polymorphisms have been recently proved to be associated with AIS in some populations. In this study we explored the prevalence and functional importance of the polymorphisms around LBX1 in patients with AIS within the northern Chinese Han population.

METHODS

Five tag single nucleotide polymorphisms (SNPs) around or in LBX1 were genotyped in 180 patients with AIS and 182 controls. And the luciferase assay was performed to explore the functional importance of the most significant SNPs.

RESULTS

We replicated that rs11190870, previously reported as the most significantly associated SNP, was enriched in our AIS cohort. In addition, we found that the T allele of rs1322331 was associated with a novel risk allele (odds ratio = 3.349, 95% confidence interval 1.742-6.436). In the following luciferase assay, the TT-type promoter showed significantly reduced transcription activity in vitro.

CONCLUSION

Two SNPs around LBX1, rs11190870 and rs1322331 are associated with AIS in northern Chinese Han population. The T allele of rs1322331 is a novel risk allele. We hypothesize that rs1322331 might increase patients' susceptibility to AIS by reducing LBX1-AS1 transcription and thus upregulating the function of LBX1.

LEVEL OF EVIDENCE

3.

Total hip/knee arthroplasty in the treatment of tumor-induced osteomalacia patients: More than 1 year follow-up

Background

Tumor-induced osteomalacia (TIO) may result in a better prognosis after complete resection of the causative neoplasm. However, tumors located proximal to the articular surface of the metaphysis remain largely uninvestigated.

Methods

A retrospective study of sixteen patients was undertaken to evaluate treatment of tumors with joint arthroplasty and tumor resection. The bone metabolism index, hip/knee joint function, arthroplasty complications and symptoms were followed up for at least 12 months in each patient.

Results

All patients presented with neoplasms situated in the articular surface of the metaphysis, with 13 cases undergoing hip arthroplasty and 3 undergoing knee arthroplasty. Treatment of the tumors with joint arthroplasty and tumor resection significantly and rapidly ameliorate bone metabolism indexes in patients with TIO (p<0.01), with no identified tumor recurrence. The joint function evaluation score was improved in 15 patients (93.75%). Complications in these patients included post-operative pain, joint squeaking and secondary hyperparathyroidism.

Conclusions

Joint arthroplasty that includes tumor-expanding resection appears to be a safe and appropriate method for the treatment of TIO patients with a neoplasm located in the metaphysis proximal to the articular surface.

Level of evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Laparoscopic assisted low anterior resection for advanced rectal cancer in a kidney transplant recipient: A case report

INTRODUCTION

Development of de novo malignancy has become a major cause of late mortality in solid organ transplant recipients. Surgery is currently the most important treatment of choice for transplant patients with resectable CRC. However, conventional open surgery represents a great risk to these high-risk patients. They seem to benefit more from laparoscopic surgery, based on the favorable oncological outcome and remarkable short-term advantages of this approach.

PATIENT CONCERNS

In this study, we have reported a case of a 50-year-old man who had underwent kidney transplantation for 4 years. He presented with recurrent hematochezia and frequent loose stools for 1 year, and consulted a doctor for recent progressive general malaise and weight loss.

DIAGNOSES

Colonoscopy revealed a near-circumferential mass at the middle rectum about 8 cm from anal verge. Further biopsy confirmed a diagnosis of adenocarcinoma. Following computed tomography demonstrated peripheral lymph node metastasis, but no signs of distant metastasis.

INTERVENTIONS

The patient underwent a laparoscopic assisted low anterior resection with total mesorectal excision for rectal cancer. Concomitantly, a loop transverse colostomy was performed to prevent anastomotic leakage. The surgery was completed within 120 min with a blood loss of 100 mL, and immunosuppressive therapy was not stopped perioperatively. Considering the tumor stage of pT3N1M0, the patient also received adjuvant chemotherapy with a regimen of FOLFOX for 8 cycles.

OUTCOMES

Anastomotic bleeding occurred in this patient about 4 h after surgery, and a control of hemorrhage per anus was performed timely. The following postoperative course was uneventful without any complications, and graft function stayed well. After 4 months of follow-up period, the patient was in a good condition. No evidences of local recurrence and distant metastasis were found.

CONCLUSION

We have presented a case of successful laparoscopic resection for advanced rectal cancer in a kidney transplant recipient. We believe laparoscopic surgery for CRC in transplant recipients is technically feasible and oncologically safe, which could be a preferred option of surgical procedure in the near future.

Mechanical environment change in root, periodontal ligament, and alveolar bone in response to two canine retraction treatment strategies

OBJECTIVE

To investigate the initial mechanical environment (ME) changes in root surface, periodontal ligament (PDL), and alveolar bone due to two treatment strategies, low or high moment-to-force ratio (M/F).

SETTING AND SAMPLE POPULATION

Indiana University-Purdue University Indianapolis. Eighteen patients who underwent maxillary bilateral canine retraction.

MATERIAL AND METHOD

Finite element models of the maxillary canines from the patients were built based on their cone beam computed tomography scans. For each patient, the canine on one side had a specially designed T-loop spring with the M/F higher than the other side. Four stress invariants (1st principal/dilatational/3rd principal/von Mises stress) in the tissues were calculated. The stresses were compared with the bone mineral density (BMD) changes reported previously for linking the ME change to bone modeling/remodeling activities. The correlation was tested by the mixed-model anova.

RESULTS

The alveolar bone in the direction of tooth movement is primarily in tension, while the PDL is in compression; the stresses in the opposite direction have a reversed pattern. The M/F primarily affects the stress in root. Three stress invariants (1st principal/3rd principal/dilatational stress) in the tooth movement direction have moderate correlations with BMD loss.

CONCLUSIONS

The stress invariants may be used to characterize what the osteocytes sense when ME changes. Their distributions in the tissues are significantly different, meaning the cells experience different stimuli. The higher bone activities along the direction of tooth movement may be related to the initial volumetric increase and decrease in the alveolar bone.

Association between ADAMTS-4 gene polymorphism and lumbar disc degeneration in Chinese Han population

Low back pain (LBP) is a common health problem and many LBP are caused by lumbar disc degeneration (LDD). ADAMTS-4 (a disintegrin and metalloprotease with thrombospondin motifs-4), also known as aggrecanse-1, plays a core role in degeneration of extracellular matrix in LDD. To investigate the association between ADAMTS-4 genetic polymorphism and LDD, we genotyped SNPs in and around ADAMTS-4. We recruited 482 sporadic cases of LDD and 496 healthy controls from Chinese Han population. Five SNPs were selected and phenotyped by the Sequenom MassARRAY system. Allelic, genotypic, and haplotypic association was performed. Rs4233367 (c.1877 C>T), which located in exon of ADAMTS-4 showed significant association with LDD. The T allele conferred a lower risk of LDD with an OR of 0.69 and TT genotype is at nearly one-fifth of the risk compared to CC genotype. Other tested SNPs didn't show significant difference between the case and control groups. The SNP rs4233367 in the exon of ADAMTS-4 gene may be associated with lumbar disc degeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:860-864, 2016.

Altered function in cartilage derived mesenchymal stem cell leads to OA-related cartilage erosion

A portion of osteoarthritis (OA) patients with total knee arthroplasty (TKA) had monocondylar destruction in medial femoral condyle, but healthy-appearant cartilage in lateral side. However, there is limited information concerning functional differences of cartilage derived mesenchymal stem cell (CMSC) between these two locations in the same donor and its possible role in the pathogenesis of OA. Cells isolated from the degraded cartilage in medial condyle and normal cartilage in lateral side from OA patients were identified with co-expressed markers CD105 and CD166 and confirmed as CMSCs by immunophenotype. The relative percentage, proliferation activity, multi-lineage differentiation potential and miRNA expression profile of CMSCs in two groups were compared by flow cytometry, CCK-8 assay, cytochemical staining, immunohistochemistry, real-time PCR and miRNA microarray analysis. Our study suggested that the percentage (10.61±6.97% vs. 18.44±9.97%, P<0.05) and proliferation rate (P<0.01) of CD105+/CD166+ CMSCs from the degraded cartilage were significantly reduced compared with those from the normal cartilage. CMSCs from the degraded cartilage also showed stronger osteogenic (P<0.05), weaker adipogenic (P<0.01), and comparable chondrogenic potential (P>0.05) during differentiation. MiR-31-5p and miR-424-5p were down regulated in CMSCs from the degraded cartilage. In conclusion, altered function such as reduced percentage and proliferation ability, as well as changes in differentiation profile of CMSC contributed to homeostasis imbalance, leading to OA-related cartilage erosion. Furthermore, regulatory networks of multiple miRNAs may be partially responsible for the dysfunction of CMSCs.

Harpagoside ameliorates the amyloid-β-induced cognitive impairment in rats via up-regulating BDNF expression and MAPK/PI3K pathways

So far, no effective disease-modifying therapies for Alzheimer's disease (AD) aiming at protecting or reversing neurodegeneration of the disease have been established yet. The present work aims to elucidate the effect of Harpagoside (abbreviated HAR), an iridoid glycosides purified from the Chinese medicinal herb Scrophularia ningpoensis, on neurodegeneration induced by β-amyloid peptide (Aβ) and the underlying molecular mechanism. Here we show that HAR exerts neuroprotective effects against Aβ neurotoxicity. Rats injected aggregated Aβ₁₋₄₀ into the bilateral hippocampus displayed impaired spatial learning and memory ability in a Y-maze test and novel object recognition test, while HAR treatment ameliorated Aβ₁₋₄₀-induced behavioral deficits. Moreover, administration of HAR increased the expression levels of brain-derived neurotrophic factor (BDNF) and activated the extracellular-regulated protein kinase (ERK) and the phosphatidylinositol 3-kinase (PI3-kinase) pathways both in the cerebral cortex and hippocampus of the Aβ₁₋₄₀-insulted rat model. Furthermore, in cultured primary cortical neurons, Aβ₁₋₄₂ induced significant decrease of choline acetyltransferase (ChAT)-positive neuron number and neurite outgrowth length, both of which were dose dependently increased by HAR. In addition, HAR pretreatment also significantly attenuated the decrease of cell viability in Aβ₁₋₄₂-injured primary cortical neurons. Finally, when K252a, an inhibitor of Trk tyrosine kinases, and a BDNF neutralizing antibody were added to the culture medium 2 h prior to HAR addition, the protective effect of HAR on Aβ₁₋₄₂-induced neurodegeneration in the primary cortical neuron was almost inhibited. Taken together, HAR exerting neuroprotection effect and ameliorating learning and memory deficit appears to be associated, at least in part, with up-regulation of BDNF content as well as activating its downstream signaling pathways, e.g., MAPK/PI3K pathways. It raises the possibility that HAR has potential to be a therapeutic agent against AD.

CD146 as a new marker for an increased chondroprogenitor cell sub-population in the later stages of osteoarthritis

Cartilage-derived mesenchymal stem cells (MSCs) have been isolated with different methods. In this study lateral and medial femoral condyles were respectively collected from patients with late-stage osteoarthritis during the total knee arthroplasty. After digestion of the cartilage tissues with type II collagenase and analysis by fluorescence-activated cell sorting (FACS) with CD146, a chondroprogenitor cell sub-population were isolated and purified. The expression of other MSC-associated markers in the CD146+ chondroprogenitors was analyzed by flow cytometry. Multi-lineage differentiation capacity of CD146+ chondroprogenitors was compared with that of unsorted chondrocytes and adipose-derived MSCs (ADMSCs). Higher percentage of CD146+ chondroprogenitors isolated from the medial femoral condyles was observed than that from the lateral. CD146+ chondroprogenitors expressed high levels of MSC-specific surface antigens, and showed higher chondrogenesis capacity than ADMSCs and unsorted chondrocytes in a 3D cell pellet culture model. Thus CD146 might be a new cell surface marker for cartilage progenitor cell population in the late-stage osteoarthritis.

Personal inhalation exposure to polycyclic aromatic hydrocarbons in urban and rural residents in a typical northern city in China

Personal inhalation exposure samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) for 126 selected volunteers during heating and non-heating seasons in a typical northern Chinese city, Taiyuan. Measured personal PAH exposure levels for the urban residents in the heating and non-heating seasons were 690 (540-1051) and 404 (266-544) ng/m(3) , respectively, while, for the rural residents, they were 770 (504-1071) and 312 (201-412) ng/m(3) , respectively. Thus, rural residents are exposed to lower PAH contamination in comparison with the urban residents in the non-heating seasons. In the heating season, personal PAH inhalation exposure levels were comparable between the urban and rural residents, in part owing to the large rate of residential solid fuel consumption in the rural area for household cooking and heating. The estimated incremental lifetime cancer risks (ILCR) due to PAH exposure in Taiyuan were 3.36 × 10(-5) and 2.39 × 10(-5) for the rural and urban residents, respectively, significantly higher than the literature-reported national average level, suggesting an urgent need of PAH pollution control to protect human health.

A Biomimetic Collagen-Apatite Scaffold with a Multi-Level Lamellar Structure for Bone Tissue Engineering

Collagen-apatite (Col-Ap) scaffolds have been widely employed for bone tissue engineering. We fabricated a Col-Ap scaffold with a unique multi-level lamellar structure consisting of co-aligned micro and macro pores. The basic building blocks of this scaffold are bone-like mineralized collagen fibers developed via a biomimetic self-assembly process in a collagen-containing modified simulated body fluid (m-SBF). This biomimetic method preserves the structural integrity and great tensile strength of collagen by reinforcing the collagen hydrogel with apatite nano-particles. Unidirectional aligned macro pores with a size of 63.8 to 344 μm are created by controlling the freezing rate and direction. The thickness of Col-Ap lamellae can be adjusted in the range 3.6 to 23 μm depending on the self-compression time. Furthermore, the multi-level lamellar structure has led to a twelve-fold increase in Young's modulus and a two-fold increase in the compression modulus along the aligned direction compared to a scaffold of the same composition with an isotropic equiaxed pore structure. Moreover, this novel lamellar scaffold supports the attachment and spreading of MC3T3-E1osteoblasts. Therefore, owing to the biomimetic composition, tunable structure, improved mechanical strength, and good biocompatibility of this novel scaffold, it has great potential to be used in bone tissue engineering applications.

Effects of the probiotic Arthrobacter sp. CW9 on the survival and immune status of white shrimp (Penaeus vannamei)

The probiotic Arthrobacter sp. CW9 isolated from guts of white shrimp (Penaeus vannamei) was used to improve the survival rate, growth rate and immune status of white shrimp (P. vannamei). Arthrobacter sp. CW9 was added to the saline rearing water at 0, 10(5), 10(6) and 10(7) CFU ml(-1) once every 5 days during the 24-day breeding experiment. The probiotic group had significantly higher survival rates, mean shrimp weights, phenoloxidase activity, phagocytic activity and clearance efficiency compared with the control group (P < 0.05). Therefore, Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates that Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties. Such new strain therefore represents an alternative to the use of white shrimp (Penaeus vannamei) culture. New bacterial having both probiotic and immunostimulatory properties are the major novelty of this study. The results are of industrial relevance.

Reversal of dopamine neurons and locomotor ability degeneration in aged rats with smilagenin

The purpose of this paper is to study the effect of smilagenin (SMI) (PYM50028), a sapogenin compound originally identified from Chinese medicinal herb, on dopamine neurons and locomotor ability in aged rats. Experiments were carried out on young and aged Sprague-Dawley rats, which were daily administered with either SMI (18mg/kg/day) or vehicle (0.5% sodium carboxymethycellulose [CMCNa]). Open-field and rotarod performance tests revealed that behavioral ability was impaired in aged rats and was improved by oral administration of smilagenin. Immunohistochemical data showed that tyrosine hydroxylase (TH)-positive neuron numbers in the substantia nigra pars compacta (unbiased stereological counting) were altered with aging and were increased by smilagenin treatment. Likewise, the dopamine receptor density and the striatal dopamine transporter (DAT) density ((125)I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane [(125)I-FP-CIT] autoradiography) were significantly lowered in aged rats as compared to young rats, and treatment with smilagenin significantly elevated the dopamine receptor and DAT density in aged rats. Furthermore, smilagenin enhances glial cell-derived neurotrophic factor (GDNF) release both in the striatum and midbrain. These results indicate a possible role of smilagenin in the treatment of age-related extrapyramidal disorders.

Recombinant PTD-Cu/Zn SOD attenuates hypoxia-reoxygenation injury in cardiomyocytes

BACKGROUND

Oxidative stress plays a pivotal role in myocardial ischemia-reperfusion injury. Increasing the protein expression of intracellular Cu/Zn SOD, which is the major endogenous antioxidant enzyme, may attenuate or prevent hypoxia-reoxygenation injury (HRI) in cultured cardiomyocytes. However, ectogenic Cu/Zn-SOD can hardly be transferred into cells to exert biological effects. In this study, we constructed PTD-Cu/Zn SOD plasmid with a kind of translocation structure-Protein transduction domain (PTD) and detected its transmembrane ability and antioxidant effects in H9c2 rat cardiomyocytes subjected to hypoxia/reoxygenation injury (HRI).

METHODS

We constructed the pET-PTD-Cu/Zn SOD (CDs) prokaryotic expression vectors in plasmid that were inserted into E. coli BL21 to induce the protein expression of PTD-Cu/Zn SOD. H9c2 cardiomyocyte HRI was achieved by exposing cardiomyocytes to 12 h hypoxia followed by 2 h reoxygenation. Protein expression of PTD-Cu/Zn SOD in cardiomyocytes was assayed by Western blot and their enzyme activities were investigated by immunohistochemistry and flow cytometry.

RESULTS

In cultured cardiomyocytes hypoxia-reoxygenation injury model, exogenous PTD-Cu/Zn SOD could penetrate cell membrane to clear superoxide anion and decrease hydrogen peroxide level in H9c2 cardiomyocytes subjected to HRI. The level of mitochondrial membrane potential was restored to normal, and the cell apoptosis was reduced in cardiomyocytes with PTD-Cu/Zn SOD treatment during HRI.

CONCLUSION

Recombinant PTD-Cu/Zn SOD could scavenge intracellular-free superoxide anion, protect mitochondria from damages, and attenuate the hypoxia-reoxygenation injury in cultured cardiomyocytes.

p53 protein accumulation and genetic alterations in human giant cell tumors of bone (osteoclastomas)

Inactivation of tumor suppressor genes represents a critical determinant in the development of a large proportion of human cancers. The tumor suppressor gene p53 is the most frequently altered gene in human cancers. In the present study, p53 protein accumulation, gene mutation and the association between p53 alteration and clinicopathological parameters was analyzed in 29 giant cell tumors of bone. p53 overexpression was detected by immunohistochemistry in 23 of 29 (79%) primary tumors but not in adjacent bone tissue. p53 gene mutations in exons 5-8 were detected in 15 of 29 (52%) of the tumors by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. In 15 (52%) of 29 patient specimens, p53 immunostaining and mutations in exons 5-8 were concordant. Eleven (38%) of 29 tumors overexpressed p53 in the absence of mutations in exons 5-8. No significant association between p53 alterations and clinicopathological parameters was found. The present study represents the first report to assess p53 protein content and gene mutation in a substantial number of giant cell tumors of bone and suggests that p53 alterations play an important role in the development of this neoplasm.