Outcomes and Failure Patterns after Chemoradiotherapy for Locally Advanced Rectal Cancer with Positive Lateral Pelvic Lymph Nodes: A Propensity Score-Matched Analysis

PURPOSE/OBJECTIVE(S)

Locally advanced rectal cancer (LARC) combined with positive lateral pelvic lymph nodes (LPLN) tends to present worse prognosis. However, for those patients it remains unclear whether other combination high-risk factors affect the prognosis. This study aimed to use propensity score matching (PSM) to examine long-term outcomes and failure patterns in patients with positive vs. negative LPLN.

MATERIALS/METHODS

Patients with LARC were retrospectively divided into LPLN-positive and LPLN-negative groups. LPLN-positivity was defined as lymph node short diameter greater than or equal to 7 mm with specific morphological features. Clinical characteristics were compared between the groups using the chi-square test. PSM was applied to balance these differences. Progression-free survival (PFS) and overall survival (OS), and local-regional recurrence (LRR) and distant metastasis (DM) rates were compared between the groups using the Kaplan-Meier method and log-rank tests.

RESULTS

Prior to PSM, a total of 651 LARC patients were included. The LPLN-positive group had higher rates of lower location (53.1% vs. 43.0%, P = 0.025), mesorectal fascia (MRF)-positive (53.9% vs. 35.4%, P<0.001) and extramural venous invasion (EMVI)-positive (51.2% vs. 27.2%, P<0.001) disease than the LPLN-negative group. After PSM, there were 114 patients for each group along with the balanced clinical factors, and both groups had comparable surgery, pathologic complete response (pCR), and ypN stage rates. The median follow-up time was 45.9 months, 3-year OS (88.3% vs. 92.1%, P = 0.276) and LRR (5.7% vs. 2.8%, P = 0.172) rates were comparable between LPLN-positive and LPLN-negative groups. Meanwhile, despite no statistical difference, 3-year PFS (78.8% vs. 85.9%, P = 0.065) and DM (20.4% vs. 13.3%, P = 0.061) rates slightly differed between the groups. Among 10 patients with LRR, seven (70.0%) had lateral pelvic recurrence, among them, five patients were LPLN-positive, and four (80.0%) of these patients did not receive simultaneous integrated boost intensity-modulated radiotherapy (SIB- IMRT).45 patients were diagnosed with DM, 11 (40.7%) LPLN-positive and 3 (17.6%) LPLN-negative patients were diagnosed with oligometastases (P = 0.109).

CONCLUSION

Our study shows there is a tendency of worse PFS and DM in LPLN-positive than LPLN-negative patients, for LPLN-positive patients, oligometastases account for a large proportion of all distant metastases.

Heterogeneity analysis of astrocytes following spinal cord injury at single-cell resolution

Astrocytes play many important functions in response to spinal cord injury (SCI) in an activated manner, including clearance of necrotic tissue, formation of protective barrier, maintenance of microenvironment balance, interaction with immune cells, and formation of the glial scar. More and more studies have shown that the astrocytes are heterogeneous, such as inflammatory astrocyte 1 (A1) and neuroprotective astrocyte 2 (A2) types. However, the subtypes of astrocyte resulting from SCI have not been clearly defined. In this study, using single-cell RNA sequencing, we constructed the transcriptomic profile of astrocytes from uninjured spinal cord tissue and injured tissue nearby the lesion epicenter at 0.5, 1, 3, 7, 14, 60, and 90 days after mouse hemisection spinal cord surgery. Our analysis uncovered six transcriptionally distinct astrocyte states, including Atp1b2⁺ , S100a4⁺ , Gpr84⁺ , C3⁺ /G0s2⁺ , GFAP⁺ /Tm4sf1⁺ , and Gss⁺ /Cryab⁺ astrocytes. We used these new signatures combined with canonical astrocyte markers to determine the distribution of morphologically and physiologically distinct astrocyte population at injured sites by immunofluorescence staining. Then we identified the dynamic evolution process of each astrocyte subtype following SCI. Finally, we also revealed the evolution of highly expressed genes in these astrocyte subtypes at different phases of SCI. Together, we provided six astrocyte subtypes at single-cell resolution following SCI. These data not only contribute to understand the heterogeneity of astrocytes during SCI but also help to find new astrocyte subtypes as a target for SCI repair.

[Pyroptosis of lens epithelial cells in diabetic cataract]

Objective: To investigate the possible role of pyroptosis of lens epithelial cells (LECs) in the occurrence of diabetic cataract. Methods: Experimental research. A total of 70 cataract lens anterior capsule and aqueous humor samples were obtained from 70 eyes (70 patients) with cataracts in the operation room of Tianjin Medical University Eye Hospital between March 2020 and November 2020. Patients were divided into the non-diabetic and diabetic groups, with 35 patients (35 eyes) in each group. The expressions of Nod like receptor protein 3 (NLRP3), cysteine-aspartic proteases 1 (caspase-1) and Gasdermin D protein (GSDMD) in the lens anterior capsule were detected by Western blotting, real-time quantitative PCR and immunohistochemical staining. Interleukin (IL)-1β and IL-18 inaqueous humor were detected by enzyme-linked immunosorbent assay (ELISA). The independent sample t-test was used for statistical analysis. Results: The age was (70±9) years in the diabetic group and (71±8) years in the non-diabetic group. There was no significant difference in age and gender distribution between the two groups (both P>0.05). Western blotting analysis showed that the expression levels of NLRP3, caspase-1 and GSDMD protein in the LECs of anterior capsule were 1.11±0.06, 0.95±0.04 and 0.39±0.03 in the diabetic group, significantly higher than those of the non-diabetic group (0.81±0.04, 0.33±0.11 and 0.16±0.04; t=4.38, 5.36, 4.63; all P<0.05). Real-time quantitative PCR showed that the levels of NLRP3, caspase-1 and GSDMD mRNA in the LECs of anterior capsule were 1.98±0.07, 54.36±4.88 and 6.98±1.18 in the diabetic group, significantly higher than those of the non-diabetic group (1.38±0.16, 15.31±1.51 and 2.41±0.95; t=3.49, 7.64, 3.00, all P<0.05). Immunohistochemical staining showed that the average gray values of NLRP3, caspase-1 and GSDMD in the diabetic group were higher than those of the non-diabetic group (all P˂0.01). ELISA showed that the levels of IL-1β and IL-18 in the aqueous humor were (4.178±0.028) fg/L and (20.983±0.018) fg/L in the diabetic group, significantly higher than those of the non-diabetic group [(4.063±0.017) fg/L and (20.509±0.073) fg/L; t=20.63, 37.21; both P˂0.01]. Conclusion: Caspase-1-mediated pyroptosis of LECs and the release of inflammatory mediators induced by pyroptosis may be involved in the occurrence and development of diabetic cataract.

Effects of Mechanical Compression on Chondrogenesis of Human Synovium-Derived Mesenchymal Stem Cells in Agarose Hydrogel

Mechanical compression is a double-edged sword for cartilage remodeling, and the effect of mechanical compression on chondrogenic differentiation still remains elusive to date. Herein, we investigate the effect of mechanical dynamic compression on the chondrogenic differentiation of human synovium-derived mesenchymal stem cells (SMSCs). To this aim, SMSCs encapsulated in agarose hydrogels were cultured in chondrogenic-induced medium with or without dynamic compression. Dynamic compression was applied at either early time-point (day 1) or late time-point (day 21) during chondrogenic induction period. We found that dynamic compression initiated at early time-point downregulated the expression level of chondrocyte-specific markers as well as hypertrophy-specific markers compared with unloaded control. On the contrary, dynamic compression applied at late time-point not only enhanced the levels of cartilage matrix gene expression, but also suppressed the hypertrophic development of SMSCs compared with unloaded controls. Taken together, our findings suggest that dynamic mechanical compression loading not only promotes chondrogenic differentiation of SMSCs, but also plays a vital role in the maintenance of cartilage phenotype, and our findings also provide an experimental guide for stem cell-based cartilage repair and regeneration.

Load-induced regulation of tendon homeostasis by SPARC, a genetic predisposition factor for tendon and ligament injuries

Tendons and tendon interfaces have a very limited regenerative capacity, rendering their injuries clinically challenging to resolve. Tendons sense muscle-mediated load; however, our knowledge on how loading affects tendon structure and functional adaption remains fragmentary. Here, we provide evidence that the matricellular protein secreted protein acidic and rich in cysteine (SPARC) is critically involved in the mechanobiology of tendons and is required for tissue maturation, homeostasis, and enthesis development. We show that tendon loading at the early postnatal stage leads to tissue hypotrophy and impaired maturation of Achilles tendon enthesis in Sparc ^-/- mice. Treadmill training revealed a higher prevalence of spontaneous tendon ruptures and a net catabolic adaptation in Sparc ^-/- mice. Tendon hypoplasia was attenuated in Sparc ^-/- mice in response to muscle unloading with botulinum toxin A. In vitro culture of Sparc ^-/- three-dimensional tendon constructs showed load-dependent impairment of ribosomal S6 kinase activation, resulting in reduced type I collagen synthesis. Further, functional calcium imaging revealed that lower stresses were required to trigger mechanically induced responses in Sparc ^-/- tendon fascicles. To underscore the clinical relevance of the findings, we further demonstrate that a missense mutation (p.Cys130Gln) in the follistatin-like domain of SPARC, which causes impaired protein secretion and type I collagen fibrillogenesis, is associated with tendon and ligament injuries in patients. Together, our results demonstrate that SPARC is a key extracellular matrix protein essential for load-induced tendon tissue maturation and homeostasis.

[Prognosis and related risk factors of acute respiratory distress syndrome in elder patients]

Objective: To study the risk factors associated with the hospital survival rate of elder patients with acute respiratory distress syndrome (ARDS) in Medical/Respiratory Intensive Care Units (MICUs/RICUs) by evaluating the prognosis, and therefore to provide insight into patient treatment strategy. Methods: Twenty MICUs/RICUs of 19 general hospitals in mainland China participated in the multicenter prospective cohort study carried out from Mar 1^st, 2016 to Feb 28^th, 2018. Patients who met the criteria of Berlin ARDS and older than 65 years were recruited. Baseline data, risk factors of ARDS, ventilator setup and prognosis data were collected from all patients. Univariant and multivariant regression analysis were conducted to analyze the factors associated with the prognosis. Results: 170 elder ARDS patients (age≥65 years) met the Berlin ARDS criteria, among whom 8.8% (15/170), 42.9% (73/170) and 48.2% (82/170) patients had mild, moderate and severe ARDS, respectively. The most common predisposing factor for elder ARDS was pneumonia, which was present in 134 patients (78.8%). 37.6% (64/170) patients were treated with noninvasive mechanical ventilation (NIV), but 43.8% (28/64) cases experienced treatment failure. 76.5% (130/170) patients were treated with invasive mechanical ventilation. All patients 80 years or older were given invasive mechanical ventilation. 51.8% (88/170) cases had complications of non-pulmonary organ failure. 61.8% (105/170) patients deceased during hospital stay. Multivariant logistic analysis showed that the independent risk factors for hospital survival rate in elder patients with ARDS were SOFA score (P=0.030, RR=0.725, 95% CI 0.543-0.969), oxygen index after 24 hours of ARDS diagnosis (P=0.030, RR=0.196, 95% CI 0.045-0.853), accumulated fluid balance within 7 days after diagnosis of ARDS (P=0.026, RR=1.000, 95% CI 1.000-1.000) and shock (P=0.034, RR=0.140, 95% CI 0.023-0.863). Conclusion: Among 20 ICUs, the high mortality rate of elder patients with ARDS was correlated with higher 24 hour SOFA score, lower 24 hour oxygen index after ARDS diagnosis, more positive fluid balance within 7 days and concomitant shock. The conservative fluid strategy within 7 days of ARDS diagnosis may benefit the elder ARDS patients.

Identification of differential gene expression related to epirubicin-induced cardiomyopathy in breast cancer patients

BACKGROUND

Epirubicin is a potent chemotherapeutic agent for the treatment of breast cancer. However, it may lead to cardiotoxicity and cardiomyopathy, and no reliable biomarker was available for the early prediction of epirubicin-induced cardiomyopathy.

METHODS

Global gene expression changes of peripheral blood cells were studied using high-throughput RNA sequencing in three pair-matched breast cancer patients (patients who developed symptomatic cardiomyopathy paired with patients who did not) before and after the full session of epirubicin-based chemotherapy. Functional analysis was conducted using gene ontology and pathway enrichment analysis.

RESULTS

We identified 13 significantly differentially expressed genes between patients who developed symptomatic epirubicin-induced cardiomyopathy and their paired control who did not. Among them, the upregulated Bcl-associated X protein was related to "apoptosis," while the downregulated 5'-aminolevulinate synthase 2 (ALAS2) was related to both "glycine, serine, and threonine metabolism" and "porphyrin and chlorophyll metabolism" in pathway enrichment analysis.

CONCLUSIONS

ALAS2 and the metabolic pathways which were involved may play an important role in the development of epirubicin-induced cardiomyopathy. ALAS2 may be useful as an early biomarker for epirubicin-induced cardiotoxicity detection.

Estrogen prevents articular cartilage destruction in a mouse model of AMPK deficiency via ERK-mTOR pathway

Background

To investigate the mechanism underlying the chondroprotective effect of estrogen in AMP-activated protein kinase (AMPK) deficiency mice.

Methods

Female cartilage-specific AMPKα double knockout (AMPKα cDKO) mice were generated and subjected to ovariectomy (OVX). The model of osteoarthritis (OA) was induced by destabilization of medial meniscus (DMM). Histopathological changes were evaluated by using OARSI scoring systems. Autophagy changes were analyzed by immunofluorescence staining. Human chondrocytes were subjected to mechanical stress to mimic OA development. and incubated in presence of or absence of 17β-estradiol or/and compound C (AMPK inhibitor) or/and U0126 (ERK inhibitor). The expression levels of ERK1/2 phosphorylation, p70S6K phosphorylation and light chain 3 (LC3) were detected by Western blot.

Results

Compared with in OVX-sham AMPKα cDKO and OVX-sham WT mice, DMM-induced OA is more severe, and significantly low level of LC3 was observed in articular cartilage in OVX AMPK cDKO mice. Both mechanical stress and compound C were shown to induce an increase in phosphorylation of p70S6K, respectively. 17β-estradiol stimulation led to a reduction in the basal level of p70S6K phosphorylation as well as in the compound C or mechanical stress-induced level of p70S6K phosphorylation. 17β-estradiol stimulation not only led to an increase in LC3 conversion but also overrode the inhibitory effect of compound C on LC3 conversion. The effects of 17β-estradiol were abrogated by blocking ERK signaling pathway.

Conclusions

Our findings suggest that estrogen can protect articular cartilage from damage during OA development by promoting chondrocyte autophagy via ERK-mammalian target of rapamycin (mTOR) signaling, and give new insight into the mechanism of the chondroprotective effect of estrogen.

[Effects of SMP-30 overexpression on apoptosis of human lens epithelial cells induced by ultraviolet B irradiation]

Objective: This study was to observe the effect of SMP-30 on ultraviolet B (UVB)-induced apoptosis of human lens epithelial cells(HLE-B3) in vitro. Methods: Experimental study. The SMP-30 cDNA was amplified by PCR and inserted into the pRFP-N1 expressing vector which had been double digested by XhoI/HindIII. HLE-B3 cells were cultured and divided into three groups: normal group, pRFP-N1 vector plasmid group and pRFP-N1-SMP-30 plasmid group (SMP-30). Then cells were exposed to UVB and the survival rate of cells was detected by MTT assay. The effects of SMP-30 on UVB-induced HLE-B3 apoptosis were measured by the Cell Death Detection ELISA kit. Meanwhile, the influence of SMP-30 on UVB-induced apoptosis-relative protein expression in HLE-B3 cells was tested by Western blots. Moreover, 2', 7'-Dichlorofluorescin diacetate staining was performed to monitor the protective effects of SMP-30 on UVB-induced HLE-B3 reactive oxygen species(ROS). One-way analysis of variance combined with Dunnett's statistical method were performed to analyze the data. Results: The full length of PSF cDNA fragment was correctly inserted into the pRFP-N1 vector, which was confirmed by DNA sequencing. The SMP-30 fragment was inserted to the plasmid pRFP-N1 correctly, which was also confirmed by DNA sequencing. The PRFP-N1-SMP-30 plasmid was transfected into HLE-B3 successfully. SMP-30 expression was up-regulated in the transfection group, compared with the control group. Data showed that the survival rate of HLE-B3 after the pRFP-N1-SMP-30 plasmid transfection was 0.90±0.14, while the apoptosis rate was 0.43±0.06 and the ROS production was 0.52±0.02, showing significant difference in comparison with the vector plasmid group and the normal group(t=5.830, 9.934, 12.19, P<0.05). In the meantime, SMP-30 overexpression down-regulated the levels of Bax and cleav-caspase-3, but up-regulated the Bcl-2 and Pro-caspase-3 expression levels under UVB irradiation. Conclusion: SMP-30 overexpression plays a protective role in UVB-induced apoptosis via regulating the expression of apoptosis-related proteins and inhibiting the production of ROS in HLE-B3 cells. (Chin J Ophthalmol, 2017, 53: 835-841).

Inactivation of Lkb1 in postnatal chondrocytes leads to epiphyseal growth-plate abnormalities and promotes enchondroma-like formation

Liver serine-threonine kinase B1 (LKB1) is a tumor suppressor that has been linked to many types of tumors. However, the role of LKB1 in cartilaginous tumorigenesis is still poorly understood. In this study, we find that cartilage-specific, tamoxifen-inducible Lkb1 knockout results in multiple enchondroma-like lesions adjacent to the disorganized growth plates. We showed that chondrocytes retain an immature status caused by loss of Lkb1, which may lead to the dramatic expansion of growth-plate cartilage and the formation of enchondroma-like lesions. Additionally, increased mammalian target of rapamycin complex 1 (mTORC1) activity is observed in the Lkb1 conditional knockout (cKO) chondrocytes, and rapamycin (mTORC1 inhibitor) treatment significantly alleviates the expansion of growth-plate cartilage and eliminates the enchondroma-like lesions in Lkb1 cKO mice. Thus, our findings indicate that loss of Lkb1 leads to the expansion of chondrocytes and the formation of enchondroma-like lesions during postnatal cartilage development, and that the up-regulated mTORC1-signaling pathway is implicated in this process. Our findings suggest that modulation of LKB1 and related signaling is a potential therapy in cartilaginous tumorigenesis.-Zhou, S., Li, Y., Qiao, L., Ge, Y., Huang, X., Gao, X., Ju, H., Wang, W., Zhang, J., Yan, J., Teng, H., Jiang, Q. Inactivation of Lkb1 in postnatal chondrocytes leads to epiphyseal growth-plate abnormalities and promotes enchondroma-like formation.

Inhibition of pyroptosis attenuates Staphylococcus aureus-induced bone injury in traumatic osteomyelitis

Background

Osteomyelitis is a severe bone infection and typically leads to progressive bone resorption, destruction and dysfunction. Pyroptosis is a form of programmed cell death involved in various infectious diseases. However, the identification of pyroptosis and the role it plays in osteomyelitis remains to be clarified. In this study, we investigated the expression of pyroptosis-associated proteins in osteomyelitis and the effects of inhibiting pyroptosis on S. aureus-induced osteomyelitis both in vitro and in vivo.

Methods

The expression of pyroptosis-associated protein-NLRP3 (NLR Family Pyrin Domain Containing 3), Caspase1 and GSDMD (GasderminD) were examined in murine and human infectious bone fragments by western blot. Bone destruction was evaluated by microcomputed tomography (µCT). The concentration of inflammatory factors was tested by Enzyme linked Immunosorbent Assay (ELISA). The expression of pyroptosis-associated gene was detected by real-time quantitative polymerase chain reaction (RT-qPCR).

Results

The expression of pyroptosis-associated proteins in infectious bone fragments from patients with osteomyelitis was significantly higher than uninfected bone. Additionally, in S. aureus-induced murine osteomyelitis model, higher expression of pyroptosis-associated proteins was noticed. Furthermore, the inhibitors of pyroptosis-associated proteins alleviated S. aureus-induced pyroptosis both in vivo and in vitro. More importantly, the inhibition of pyroptosis restored the bone formative property, attenuated the aberrant activation of osteoclast in vitro and reversed bone injury in vivo.

Conclusions

Our study identified pyroptosis as a key pathway in osteomyelitis and elaborated that the inhibition of pyroptosis could attenuate S. aureus-induced bone destruction in osteomyelitis, providing a potential treatment target to osteomyelitis.

Nonlinear optical properties of MoS2-WS2 heterostructure in fiber lasers

As a saturable absorption material, the heterostructure with the van der Waals structure has been paid much attention in material science. In general, the heterogeneous combination is able to neutralize, or even exceed, the individual material's advantages in some aspects. In this paper, which describes the magnetron sputtering deposition method, the tapered fiber is coated by the MoS₂-WS₂ heterostructure, and the MoS₂-WS₂ heterostructure saturable absorber (SA) is fabricated. The modulation depth of the prepared MoS₂-WS₂ heterostructure SA is measured to be 19.12%. Besides, the theoretical calculations for the band gap and carrier mobility of the MoS₂-WS₂ heterostructure are provided. By employing the prepared SA, a stable and passively erbium-doped fiber laser is implemented. The generated pulse duration of 154 fs is certified to be the shortest among all fiber lasers based on transition mental dichalcogenides. Results in this paper provide the new direction for the fabrication of ultrafast photon modulation devices.

Recruitment of Brd3 and Brd4 to acetylated chromatin is essential for proinflammatory cytokine-induced matrix-degrading enzyme expression

BACKGROUND

Proinflammatory cytokines, which can upregulate the expression of matrix-degrading enzymes in chondrocytes, play important roles in the development of osteoarthritis. BET family proteins, acting as the "readers" of acetylated modifications on histones, have been linked to transcriptional regulation. And a BET protein inhibitor, I-BET151, has been shown to inhibit the induction of matrix-degrading enzymes by proinflammatory cytokines in chondrocytes. Our objective is to clarify the role and mechanism of BET proteins on matrix-degrading enzyme gene expression by using a human chondrosarcoma cell line (SW1353).

METHODS

We pretreated SW1353 cells with I-BET151 prior to treatment with IL-1β or TNF-α and then checked the expression of four matrix-degrading enzyme genes (MMP1, MMP3, MMP13, and ADAMTS4). We performed knockdown of BET protein family members (BRD2, BRD3, and BRD4) with corresponding siRNAs in SW1353 cells prior to treatment with IL-1β or TNF-α and checked the expression of the matrix-degrading enzyme genes. We evaluated Brd-mediated transcriptional regulation on the matrix-degrading enzyme genes by ChIP assay.

RESULTS

We confirmed that I-BET151 could suppress the IL-1β- or TNF-α-induced expression of MMP1, MMP3, MMP13, and ADAMTS4 in SW1353 cells. Brd3 and Brd4 were required for the IL-1β- or TNF-α-induced expression of matrix-degrading enzyme genes in SW1353 cells. We revealed that inducible acetylation of H4k5/8/12 and the recruitment of Brd3, Brd4, and p-TEFb to chromatin were involved in IL-1β- or TNF-α-induced transcription.

CONCLUSIONS

Our findings suggested that Brd3 and Brd4 were essential for the IL-1β- or TNF-α-induced transcription of matrix-degrading enzyme genes, and recruitment of Brd3 and Brd4 to chromatin of these genes played the main role in this process.

A genome-wide association study identifies new genes associated with developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is one of the most common congenital malformations and covers a spectrum of hip disorders from mild dysplasia to irreducible dislocation. The pathological mechanisms of DDH are poorly understood, which hampers the development of diagnostic tools and treatments. To gain insight into its disease mechanism, we explored the potential biological processes that underlie DDH by integrating pathway analysis tools and performing a genome-wide association study (GWAS). A total of 406 DDH-associated genes (P < 0.001) were identified by our GWAS using a Chinese Han cohort consisting of 386 DDH cases and 500 healthy controls (Set A). We verified the significant loci (P < 10^-5 ) in another Chinese Han cohort consisting of 574 DDH patients and 569 healthy controls (Set B). An intronic Single Nucleotide Polymorphism (SNP) (rs61930502) showed significant association in Set A and Set B (P = 2.65 × 10^-7 and 2.0 × 10^-4 , respectively). The minor allele, rs61930502-A, which tended to prevent DDH showed a dominant effect. Heat shock 70 kDa protein 8 (HSPA8) showed the most direct interactions with other proteins which were coded by DDH-associated genes in the protein-protein interaction analysis. Interestingly, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested a relation between DDH and the genes involved in type II diabetes mellitus pathway (P = 0.0067). Our genetic and protein interaction evidence could open avenues for future studies of DDH.

The effectiveness of allogeneic mesenchymal stem cells therapy for knee osteoarthritis in pigs

Background

Intraarticular injection of the mesenchymal stem cells (MSCs) has shown to be successful for treating osteoarthritis (OA). Nevertheless, many studies have been focusing on autologous MSCs. The following study investigates the safety and effectiveness of intraarticular injection of allogenic MSCs in a pig OA model.

Methods

Superparamagnetic iron oxide (SPIO) nanoparticles were labelled with bone marrow-derived mesenchymal stem cells (BM-MSCs) to allow cells tracking using magnetic resonance imaging (MRI). A pig OA model was established by bilateral medial meniscectomy. Next, SPIO-BM-MSCs were injected into the right knee, while the left knee was left untreated. MRI and radiography were used to assess the degree of OA and to evaluate the effectiveness of allogenic MSCs. Hematoxylin and eosin (H&E), safranin-o fast green staining, toluidine blue, and immunohistochemical staining were used to evaluate the therapeutic effect of the injections.

Results

At concentration of ≤20 µg/mL, SPIO caused no toxicity to BM-MSCs. Four weeks after surgery, OA changes were observed on MRI scan. The SPIO labeled BM-MSCs were found moving towards the impaired part of the cartilage 8 to 24 h after injections. In addition, no significant differences between the right side (therapeutic side) and the left side (untreated side) were observed following histological and immunohistochemistry analysis.

Conclusions

The suitable concentration of SPIO for labelling BMSCs was 20 µg/mL, while the allogenic MSCs could move towards and accumulate around the impaired cartilage. No significant difference was found between treatment and control group.

3D printing individualized heel cup for improving the self-reported pain of plantar fasciitis

BACKGROUND

To explore the therapeutic effect and the biomechanical mechanism of 3D printing individualized heel cup in treating of plantar heel pain.

METHODS

The clinical effect was evaluated by plantar pressure analysis and pain assessment in participants. Its biomechanical mechanism of protecting the plantar heel was explored using finite element simulation.

RESULTS

The individualized heel cup could support and protect the osseous structure and soft tissue of plantar heel while walking and jogging, as well as significantly reduce the self-reported pain after being worn for 4 weeks. The nylon heel cup could alter the load concentration of the heel as well as decrease the load affected on plantar fascia and calcaneus bone. It also provided an obvious support for heel pad.

CONCLUSION

To summarize, the 3D printed individualized heel cup can be used as an effective method for the treatment of plantar heel pain.

Bi-directional regulation of cartilage metabolism by inhibiting BET proteins-analysis of the effect of I-BET151 on human chondrocytes and murine joints

Background

Proinflammatory cytokines, which can upregulate the expression of matrix-degrading enzymes in chondrocytes, play important roles in the development of osteoarthritis. And a BET protein inhibitor, I-BET151, has been shown to exert an anti-inflammatory effect by repressing the BET protein-mediated expression of inflammatory genes. Our objective is to investigate the effect of I-BET151 on a surgical mouse model of osteoarthritis (OA) and human chondrocytes.

Methods

We first treated a surgical mouse model of OA with I-BET151 once per day and evaluated the knee joints at 6 and 8 weeks after treatment. We then pretreated the human chondrocytes with I-BET151 prior to treatment with IL-1β or TNF-α and checked the expression and activity of the matrix-degrading enzyme genes. We also checked the expression of ACAN, COL2A1, and SOX9.

Results

We demonstrated that I-BET151 could prevent articular cartilage damage in the surgical mouse model of OA at an earlier time after treatment, but not at a later time after treatment. I-BET151 could robustly suppress the IL-1β- and TNF-α-induced expression and activity of several matrix-degrading enzymes in human chondrocytes. I-BET151 could also suppress the expression of ACAN, COL2A1, and SOX9.

Conclusions

Our findings suggested that inhibiting BET proteins could exert a repression effect on both of chondrocyte anabolism and catabolism, and the effect of BET protein inhibitor on surgical mouse model of OA needs further evaluation.

High preoperative serum leptin level is an independent risk factor for deep vein thrombosis after total knee arthroplasty in osteoarthritis patients: A prospective and cross-sectional study

It suggests that a high leptin level may increase the risk of venous thromboembolism (VTE) in animal studies. However, clinical studies in this field are still largely unexplored. Our objective was to evaluate the relationship between the preoperative serum leptin levels and postoperative VTE incidence in osteoarthritis (OA) patients who underwent total knee arthroplasty (TKA) at our institute.We conducted a prospective and cross-sectional study in these OA patients from March 2014 to March 2016. Preoperative leptin levels were analyzed by Luminex assays. VTE was assessed preoperatively and on postoperative day 5 and 7. The potential risk factors for VTE were also documented.We enrolled 203 OA patients. No PE was detected and DVT was diagnosed in 34 patients postoperatively. There were significant differences between the median leptin levels in DVT group and non-DVT group [25.13 ng/mL (interquartile range, 14.51-44.31) vs 18.71 ng/mL (8.26-28.99), P = .007]. The relative risk of DVT significantly increased with natural logarithm (ln) leptin (per SD increase) (OR 2.37, 95% confidence interval (95% CI), 1.29-4.33, P = .005). Multivariate analyses adjusted for potential confounders showed ln leptin (per SD increase) was significantly associated with the relative risk of DVT (OR 2.17, 95% CI, 1.01-4.64, P = .046). When patients were subdivided into tertiles according to their leptin values, the OR for DVT increased with increasing tertiles of serum leptin (OR 1.03, 95% CI, 1.01-1.06, P for trend = .023).In the present study, our results indicate that a high preoperative leptin level may be an independent risk factor for postoperative DVT.

FTO variant is not associated with osteoarthritis in the Chinese Han population: replication study for a genome-wide association study identified risk loci

BACKGROUND

Osteoarthritis is the most prevalent form of arthritis worldwide and is the major cause of pain and loss of function in elderly people. A signal of the fat mass and obesity-associated (FTO) gene had been reported in a genome-wide association study of osteoarthritis. The FTO polymorphism (rs8044769) might exert its effect on osteoarthritis through obesity, because it was reported as a body mass index-associated single-nucleotide polymorphism. And replication studies showed inconsistent results for this association. Our present study is to check the association of rs8044769 with osteoarthritis and body mass index in Chinese Han population.

METHODS

A case-control association study was conducted by using 890 osteoarthritis cases and 844 controls in Chinese Han population. rs8044769 was genotyped in all subjects. Allelic and genotypic frequencies were compared between osteoarthritis cases and control subjects. Associations between rs8044769 and body mass index, and body mass index and osteoarthritis were also assessed.

RESULTS

No significant difference was detected in genotype or allele distribution between osteoarthritis cases and controls (P > 0.05). Stratification by gender and body mass index revealed negative association between rs8044769 and osteoarthritis. We did not find any solid association between rs8044769 and higher body mass index. Meanwhile, we demonstrated that higher body mass index (body mass index ≥ 25) was associated with osteoarthritis.

CONCLUSION

Our present study suggested that rs8044769 was not associated with osteoarthritis susceptibility or higher body mass index, and higher body mass index was a risk factor for osteoarthritis in the Chinese Han population. We also proposed that stratification by clinical parameters was crucial to reduce false-positive result in OA association studies.

Knockdown of Ggps1 in chondrocyte expedites fracture healing by accelerating the progression of endochondral ossification in mice

Bone fracture healing is achieved through the proliferation and differentiation of stem cells, while bone marrow stem cells (BMSCs) contribute to endochondral ossification. During fracture healing, mesenchymal progenitor cells first form a cartilaginous blastema that becomes vascularized to recruit precursor cells of osteoblasts through the bone morphogenetic protein 2 (Bmp2)/Smad-dependent Runx2 pathway. Statins deplete geranylgeranyl diphosphate (GGPP), which participates in the regulation of BMSCs differentiation, through the inhibition of 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase, leading to impaired protein geranylgeranylation, which strongly impacts the bone synthesis induced by Bmp2. Accordingly, we would like to investigate the role of geranylgeranyl diphosphate synthase 1 (Ggps1) in bone fracture via endochondral ossification in mice. We used a Cre-loxP system, namely the tamoxifen-inducible Collagen 2-CreER^T2 Ggps1 ^fl/fl, to eliminate specifically the Ggps1 activity in chondrocytes of 8-10-week-old mice. We found that the endochondral bone formation, calcification and vasculogenesis of the bony callus were accelerated in fractures in Ggps1^-/-mice. Together, the results of this study confirm that the specific deletion of Ggps1, using the Collagen 2-CreER^T2 mice, will accelerate the fracture healing process by activating the Bmp2/Smad-dependent Runx2 pathway. In addition, we managed to improve the fracture healing process by inhibiting the Ggps1 activity and its related products with statin drugs.

Zhuangguguanjie formulation protects articular cartilage from degeneration in joint instability-induced murine knee osteoarthritis

Zhuangguguanjie formulation (ZG) can provide noticeable relief from joint pain in patients suffering from knee osteoarthritis (OA). However, the underlying mechanism has not been fully described. Male C57BL/6 mice were administered either ZG or normal saline (NS) following surgical destabilization of the medial meniscus (DMM). At weeks 4, 6 and 8 (post-surgery), knee joints were harvested and assessed with Safranin-O staining. Blood serum was collected and tested. In vitro analysis was carried out to evaluate the effects of ZG on the expression of the OA-related genes. DMM mice indicated reduced cartilage destruction and lower blood serum biomarkers of OA (COMP1 and CTX-1) following ZG treatment. Moreover, the femoral condyle and tibial plateau histological scores were significantly reduced following ZG treatment of the DMM mice. ZG could markedly downregulate the expression of OA-related genes namely, ADAMTS5, MMP3 and MMP13, while it simultaneously upregulated collagen II as demonstrated by in vitro assays. Moreover, chondrocyte apoptosis was significantly decreased following ZG treatment. These results may be caused by the up-regulation of p-AKT expression levels, since the anti-apoptotic effects of ZG can be blocked by treatment with an AKT inhibitor. ZG is capable of preventing and/or reducing the progression of OA by inhibiting chondrocyte apoptosis via the p-AKT/Caspase 3 pathway.

Age-dependent variations of cancellous bone in response to ovariectomy in C57BL/6J mice

The ovariectomized (OVX) mouse model has been widely accepted to be suitable for the study of postmenopausal osteoporosis. However, whether C57BL/6J mice, a commonly used genetic background mouse strain, is an appropriate model for postmenopausal osteoporosis remains controversial. The present study investigated the effect of the OVX model on alterations in bone density and microarchitecture in C57BL/6J female mice of different ages. C57BL/6J mice were divided into 8-, 12- and 16-week-old groups (OVX₈, OVX₁₂ and OVX₁₆) from the beginning of OVX. At 8 weeks post-surgery, the mice were anesthetized and micro-computed tomography was used to analyze the bone density and microarchitecture. The results revealed that OVX-induced loss of cancellous bone was greatest in OVX₈, moderate in OVX₁₂, and only a weak bone loss was observed in the OVX₁₆ group when compared with the SHAM₁₆ control group. In addition, the effect of genetic backgrounds in response to the OVX model were examined. Several other strains of mice, including inbred (BALB/c) and outbred (ICR and Kunming), were used in the present study, all of which were subjected to OVX at 8 weeks of age. The present findings revealed that the highest rate of bone loss was detected in C57BL/6J female mice. In addition, treatment with estrogen (17β-estradiol, 30 µg/kg five times per week) led to a significant increase in bone density in C57BL/6J mice compared with the other strains of mice. Therefore, these results may provide novel insights into the age- and strain-associated effect of OVX on regulating turnover of bone in female mice. The present findings also suggest 8-week-old C57BL/6J mice as an animal model for postmenopausal osteoporosis and preclinical testing of potential therapies for this disease.

Accelerated development of instability-induced osteoarthritis in transgenic mice overexpressing SOST

OBJECTIVE

Sclerostin (SOST), acting as a Wnt antagonist, has been shown to play a key role in regulating bone homestasis, and has also been linked to osteoarthritis (OA) development. Here, we investigated whether overexpressing SOST could affect OA development after destabilization of the medial meniscus (DMM) using SOST transgenic (Tg) mice.

METHODS

Bone and cartilage phenotypes of SOST Tg mice at 10 weeks of age were investigated by dual x-ray absorptiometry (DXA) and histology. Subsequently, 10-week-old SOST Tg mice and their wild-type (WT) littermates were subjected to DMM or sham surgery. Knee joints were isolated to evaluate the cartilage damage and the subchondral bone plate thickness at 2 and 8 weeks post-surgery. The changes of chondrocyte anabolic and catabolic responses after IL-1β or TNFα stimulation, β-catenin signaling and apoptosis were also measured.

RESULTS

Ten-week-old SOST Tg mice were identical to their WT littermate males except that they displayed digit abnormalities and osteopenic, whereas more severe OA was observed in SOST Tg mice at 2 and 8 weeks post-DMM. In addition, DMM resulted in significantly greater subchondral bone changes compared with sham surgery in SOST Tg mice at 8 weeks post-surgery. The accelerated OA in SOST Tg mice may be associated with reduced β-catenin signaling and increased chondrocyte apoptosis.

CONCLUSION

Overexpressing SOST led to accelerated development of instability-induced OA. Our data further highlight that cartilage homeostasis requires finely tuned Wnt signaling.

Fenofibrate decreases the bone quality by down regulating Runx2 in high-fat-diet induced Type 2 diabetes mellitus mouse model

Background

This study is to investigate the effect of fenofibrate on the bone quality of Type 2 diabetes mellitus (T2DM) mouse model.

Methods

T2DM mouse model was induced by high-fat-diet, and the mice were treated with fenofibrate (100 mg/kg) (DIO-FENO) or PBS (DIO-PBS) for 4 weeks. The bone microstructure and biomechanical properties of femora were analyzed by micro-CT and 3-Point bending test. The protein expression was detected by immunohistochemical staining and Western blot. The cell apoptosis was evaluated by TUNEL staining. The Bcl2, caspase 3, and osteoblast marker genes were detected by RT-qPCR.

Results

The biomechanical properties of bones from DIO-FENO group were significantly lower than those in the control and DIO-PBS groups. Besides, the trabecular number was lower than those of the other groups, though the cortical porosity was decreased compared with that of DIO-PBS group because of the increase of apoptotic cells. The expression of osteocalcin and collagen I were decreased after treatment with fenofibrate in T2DM mice. Moreover, the cell viability was decreased after treated with different concentrations of fenofibrate, and the expression of Runx2 decreased after treated with high dose of fenofibrate.

Conclusion

Fenofibrate decreases the bone quality of T2DM mice through decreasing the expression of collagen I and osteocalcin, which may be resulted from the down regulation of Runx2 expression.

A novel missense variant in TXNDC3 is associated with developmental dysplasia of the hip in Han Chinese population

Developmental dysplasia of the hip (DDH) is one of the most common inborn disabilities of the hip joint and a common disease with a genetic component for its etiology. However, genetic basis of Developmental dysplasia of the hip (DDH) remains largely unknown. Previous study has identified that TXNDC3 is significant associated with osteoarthritis and the development of chondrocytes and bone. In this study, we carried out a case-control study to investigate for the association between TXNDC3 and DDH, to find whether acetabular cartilage and bone formation in hip developmental progress is regulated by TXNDC3. We totally enrolled 984 radiology confirmed DDH children and 2043 healthy controls to conduct a case-control association study by genotyping SNP rs10250905 on TXNDC3. The rs10250905 variant is further detected in 7 DDH pedigrees which comprise total 15 familial DDH patients. The SNP was significantly associated with DDH, P = 1.53*10^-5 with the odds ratio of 0.786 (0.705-0.877) for allele T; P = 0.0075 with the odds ratio of 0.761 (0.622-0.930) for genotype TT. Furthermore, the significant difference was also detected in samples when stratified by gender. In case-control study, the allele T frequency in cases (0.397) was lower than in controls (0.456). In addition, the allele T frequency in cases of DDH families was 0.300 and in controls was 0.433. In conclusion, our study demonstrates a novel missense variant of TXNDC3, rs10250905, is strongly associated with DDH in Han Chinese population and it shows protective allele T.

In situ repair of bone and cartilage defects using 3D scanning and 3D printing

Three-dimensional (3D) printing is a rapidly emerging technology that promises to transform tissue engineering into a commercially successful biomedical industry. However, the use of robotic bioprinters alone is not sufficient for disease treatment. This study aimed to report the combined application of 3D scanning and 3D printing for treating bone and cartilage defects. Three different kinds of defect models were created to mimic three orthopedic diseases: large segmental defects of long bones, free-form fracture of femoral condyle, and International Cartilage Repair Society grade IV chondral lesion. Feasibility of in situ 3D bioprinting for these diseases was explored. The 3D digital models of samples with defects and corresponding healthy parts were obtained using high-resolution 3D scanning. The Boolean operation was used to achieve the shape of the defects, and then the target geometries were imported in a 3D bioprinter. Two kinds of photopolymerized hydrogels were synthesized as bioinks. Finally, the defects of bone and cartilage were restored perfectly in situ using 3D bioprinting. The results of this study suggested that 3D scanning and 3D bioprinting could provide another strategy for tissue engineering and regenerative medicine.

Serum levels of the bone turnover markers dickkopf-1, osteoprotegerin, and TNF-α in knee osteoarthritis patients

Knee osteoarthritis (KOA) is a common degenerative joint disease causing pain, stiffness, reduced motion, swelling, crepitus, and disability. Several inflammatory markers and cartilage degradation products can be used as biomarkers in OA. The key factors of bone metabolism in normal joint bone, dickkopf-1 (DKK1) and osteoprotegerin (OPG), interact with Wnt signaling pathway, balancing between bone absorption and bone reconstruction. TNF-α is a key inducer of DKK-1, which belongs to the family of proteins involved in joint remodeling. The present study compared the serum levels of DKK1, TNF-α, and OPG in patients with KOA and healthy controls to analyze the interrelationship and the severity of joint destruction. One hundred forty-eight patients with KOA and 101 healthy controls were enrolled in this study. Anteroposterior knee radiographs determined the severity of the disease in the affected knee. The radiographic grading of KOA was performed by the Kellgren-Lawrence criteria. Serum levels of DKK-1, TNF-α, and OPG were estimated using the multiplex particle-based flow cytometry. Higher serum levels of OPG and TNF-α were observed in KOA than the controls; KOA patients showed a lower serum level of DKK-1, whereas the serum levels of DKK1 correlated with the progression of KOA. The serum levels of TNF-α, OPG, and DKK-1 correlated with incident KOA. In the ROC curve analysis, DKK1 levels showed 78.6% sensitivity and 40% specificity, TNF-α levels showed 74.1% sensitivity and 76.0% specificity, and OPG showed 88.1% sensitivity and 81% specificity in predicting severe KOA. In the univariate and multivariate analyses, TNF-α and OPG emerged as independent predictors of severe KOA. This study, for the first time, combined TNF-α, DKK1, and OPG as valuable biological markers in predicting the severity of KOA radiographically in the clinic. This study also supported the inflammation-induced DKK1 and OPG in OA pathogenesis.

In vivo repair of full-thickness cartilage defect with human iPSC-derived mesenchymal progenitor cells in a rabbit model

Cell-based tissue engineering has the potential to restore cartilage defects. Induced pluripotent stem cells (iPSCs) are regarded as an alternative cell source in regenerative medicine. The purpose of the present study was to evaluate the use of mesenchymal stem cells (MSCs) derived from human iPSCs (hiPSCs) for the regeneration of cartilage defects in a rabbit model. Cartilage defects were made in the patellar grooves of New Zealand white rabbits. The rabbits were then divided into three groups according to implantation: Control group, scaffold implantation group and scaffold/hiPSCs-MSCs (experimental) group. MSCs were generated from hiPSCs via a step of embryoid body formation. Following flow cytological analysis, the hiPSCs-MSCs were plated onto poly(lactic-co-glycolide) and then transplanted into the cartilage defects in the experimental group. Six rabbits from each group were sacrificed at each time point. The outcome was assessed macroscopically and histologically at 3 and 6 weeks post-surgery. At 3 and 6 weeks, the experimental group showed more cartilage defect filling compared with the control and scaffold implantation groups. At 3 weeks, the experimental group showed much more repair tissue in the cartilage defect, although no cartilage-like tissue was observed. At 6 weeks, cartilage-like tissue was observed in the experimental group but not in the control or scaffold implantation groups. No teratoma formation was observed in any of the groups. The results indicate that iPSCs have the potential to repair cartilage defects in vivo. Therefore, iPSCs could be a new cell source for cartilage defect repair.

Essential Role for Polycomb Group Protein Pcgf6 in Embryonic Stem Cell Maintenance and a Noncanonical Polycomb Repressive Complex 1 (PRC1) Integrity

The Polycomb group (PcG) proteins have an important role in controlling the expression of key genes implicated in embryonic development, differentiation, and decision of cell fates. Emerging evidence suggests that Polycomb repressive complexes 1 (PRC1) is defined by the six Polycomb group RING finger protein (Pcgf) paralogs, and Pcgf proteins can assemble into noncanonical PRC1 complexes. However, little is known about the precise mechanisms of differently composed noncanonical PRC1 in the maintenance of the pluripotent cell state. Here we disrupt the Pcgf genes in mouse embryonic stem cells by CRISPR-Cas9 and find Pcgf6 null embryonic stem cells display severe defects in self-renewal and differentiation. Furthermore, Pcgf6 regulates genes mostly involved in differentiation and spermatogenesis by assembling a noncanonical PRC1 complex PRC1.6. Notably, Pcgf6 deletion causes a dramatic decrease in PRC1.6 binding to target genes and no loss of H2AK119ub1. Thus, Pcgf6 is essential for recruitment of PRC1.6 to chromatin. Our results reveal a previously uncharacterized, H2AK119ub1-independent chromatin assembly associated with PRC1.6 complex.

Microarray analysis of microRNA deregulation and angiogenesis-related proteins in endometriosis

We examined the aberrant microRNA (miRNA) expression profile responsible for the changes in angiogenesis observed in endometriotic lesions. This study revealed characteristic miRNA expression profiles associated with endometriosis in endometrial tissue and endometriotic lesions from the same patient, and their correlation with the most important angiogenic and fibrinolytic factors. miRNA expression was quantified using a microRNA array and reverse-transcription microRNA polymerase chain reaction. Levels of vascular endothelial growth factor A (VEGFA), epidermal growth factor receptor 2 (EGFR2), phosphatase and tensin homolog (PTEN), and C-X-C chemokine receptor type 4 (CXCR4) were quantified using enzyme-linked immunosorbent assay. The endometrial tissue showed significantly lower levels of miR-200b, miR-15a-5p, miR-19b-1-5p, miR-146a-5p, and miR-200c, and higher levels of miR-16-5p, miR-106b-5p, and miR-145-5p. VEGFA was significantly upregulated, whereas EGFR2, PTEN, and CXCR4 were markedly downregulated, in the endometriotic tissues compared to that in the normal endometrial tissues. In conclusion, differences in the miRNA levels could modulate the expression of VEGFA, EGFR2, PTEN, and CXCR4, and may play an important role in the pathogenesis of endometriosis. The higher angiogenic and proteolytic activities observed in the eutopic endometrium might facilitate the implantation of endometrial cells at ectopic sites.

[The study of cyclosporin A modified intraocular lens preventing posterior capsular opacification in rabbit eyes]

OBJECTIVE

To investigate the safety and efficacy of cyclosporine A sustained release from modified intraocular lens for preventing posterior capsular opacification (PCO) in rabbit eyes.

METHODS

Forty-five New Zealand albino rabbits undergoing phacoemulsification in their right eyes were randomly and equally divided into three groups. Group A had implanted original IOL, group B had implanted PLGA-IOL(IOL coated with polylactide-glycoli acid), and group C had implanted CsA-PLGA-IOL (CsA loaded PLGA-IOL). All the 45 eyes were examined by a slit-lamp microscope. The intraocular pressures were recorded. Anterior chamber flare and aqueous humor cells were graded at different time point after surgery. The concentrations of CsA in the aqueous humor and blood were determined by high performance liquid chromatography. Anterior segment tissue was histologically examined. Wet posterior capsules were weighed. PCO was graded 6 months later.

RESULTS

The mean concentrations of CsA in group C at 2 h,1 d,3 d,7 d,14 d,30 d,60 d after operation were (11.47±2.42) mg/L, (10.30±2.15) mg/L, (6.71±1.45) mg/L, (4.81±1.16) mg/L, (6.11±0.84) mg/L, (2.53±0.77) mg/L, (0.86±0.28) mg/L. The concentrations of CsA in blood were undetectable. During the early days after operation, the reactions of the anterior chamber in group A and B were more severe than group C. The initial appearance of PCO in group C was much later than in the other two groups, and the grade of PCO in group C was much lower than the other two groups. The mean weights of wet posterior capsules in group A(312.86±52.91) mg and B(310.64±62.42) mg were much heavier than that of group C(56.93 ± 24.24) mg. Histological observation showed that there was remarkably less accumulation of lens materials on the posterior capsules in group C than in the other two groups. No toxic actions were found in intraocular tissues in group C.

CONCLUSION

Our study suggested that Cyclosporin A modified intraocular lens could effectively and safely prevent the formation and development of posterior capsular opacification in rabbit eyes for a relatively long term.

Localized lower extremity ischemic preconditioning prevents against local thrombus formation

BACKGROUND

Ischemic preconditioning (IPC) has many beneficial effects on the cardiovascular system. However, whether localized lower extremity IPC could be protective against the thrombogenic activity generated by lower extremity ischemia is unclear.

MATERIAL AND METHODS

41 male Sprague-Dawley rats were randomly assigned to either a IPC group or a sham group. The lower extremity blood inflow was previously treated with 4 cycles of 5 min ischemia followed by 5 min of reperfusion by clamping the abdominal aortic just before ligature of the left iliac vein(LIV) in the IPC group. Rats in the sham group had a 40-minute blank before left iliac vein ligation. The rats were euthanized at day 2 after ligation and the thrombosed LIV was carefully dissected out, while thrombi harvested from the LIV were measured with weight (g), length (mm) and weight/length (mg/mm). Influence of IPC on coagulation function was also tested.

RESULTS

21 and 20 rats were randomly assigned to einter the IPC group or the control group. Left iliac vein thrombosis was successfully generated in all 41 rats. IPC significantly protects the rats from experimental lower extremity thrombosis. Compared to control group, generated thrombus in rats in the IPC group showed significantly lower weight (2.73 ± 0.16 mg vs 1.82 ± 0.13 mg, P < 0.001), length (2.99 ± 0.17 mm vs 2.44 ± 0.08 mm, P < 0.009) and density (0.95 ± 0.05 mg/mm vs 0.75 ± 0.05 mg/mm, P = 0.01). Influence on coagulation function by IPC itself was not significant (P > 0.05).

CONCLUSIONS

Our study demonstrated that localized lower extremity IPC could reduce DVT formation in rats in an in vivo experimental thrombosis model.

Higher Levels of Serum Triglycerides were Associated with Postoperative Deep Vein Thrombosis After Total Hip Arthroplasty in Patients with Nontraumatic Osteonecrosis of the Femoral Head

This retrospective study aimed to evaluate the association of serum lipids and deep vein thrombosis (DVT) risk following total hip arthroplasty (THA) in patients with nontraumatic osteonecrosis of the femoral head (ONFH). A total of 224 nontraumatic ONFH patients were enrolled. Serum levels of triglycerides (TG), total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were detected preoperatively. All the patients underwent unilateral lower extremity venography on postoperative days 3 to 5 for DVT screening. In females, patients who were venogram positive for DVT had a higher serum TG level than those who were venogram negative for DVT (P = .029) and a higher TG level was associated with an increased DVT risk (P = .042). Serum TG levels considerably affect DVT risk after THA in female nontraumatic ONFH patients.

A common variant of ubiquinol-cytochrome c reductase complex is associated with DDH

Purpose

Genetic basis of Developmental dysplasia of the hip (DDH) remains largely unknown. To find new susceptibility genes for DDH, we carried out a genome-wide association study (GWAS) for DDH.

Methods

We enrolled 386 radiology confirmed DDH patients and 558 healthy controls (Set A) to conduct a genome-wide association study (GWAS). Quality-control was conducted at both the sample and single nucleotide polymorphism (SNP) levels. We then conducted a subsequent case-control study to replicate the association between a promising loci, rs6060373 in UQCC gene and DDH in an independent set of 755 cases and 944 controls (set B).

Results

In the DDH GWAS discovering stage, 51 SNPs showed significance of less than 10^-4, and another 577 SNPs showed significance of less than 10-3. In UQCC, all the 12 genotyped SNPs showed as promising risk loci. Genotyping of rs6060373 in set A showed the minor allele A as a promising risk allele (p = 4.82*10^-7). In set A, the odds ratio of allele A was 1.77. Genotyping of rs6060373 in Set B produced another significant result (p = 0.0338) with an odds ratio of 1.18 for risk allele A. Combining set A and set B, we identified a total p value of 3.63*10^-6 with the odds ratio of 1.35 (1.19–1.53) for allele A.

Conclusion

Our study demonstrates common variants of UQCC, specifically rs6060373, are associated with DDH in Han Chinese population.

Influence of intra-articular administration of trichostatin a on autologous osteochondral transplantation in a rabbit model

Autologous osteochondral transplantation (AOT) is a method for articular cartilage repair. However, several disadvantages of this method have been reported, such as transplanted cartilage degeneration and the lack of a connection between the grafted and adjacent cartilage tissues. To evaluate the effect of intra-articular administration of trichostatin A (TSA) on AOT, we conducted a case control study in a rabbit model. International Cartilage Repair Society (ICRS) macroscopic scores, the modified O'Driscoll histology scores, and real-time PCR were utilized to evaluate the results. At 4 weeks, both macroscopic and histological assessments showed that there was no significant difference between the TSA and control groups. However, the mean macroscopic and histological scores for the TSA-treated group were significantly higher than the scores for the control group at 12 weeks. TSA was shown to directly reduce collagen type II (COL2), aggrecan, matrix metalloproteinase (MMP), and a disintegrin and metalloproteinase domain with thrombospondin motifs 5 (ADAMTS-5) expression and to simultaneously repress the upregulation of MMP-3, MMP-9, and MMP-13 levels induced by interleukin 1β (IL-1β) in chondrocytes. In conclusion, TSA protects AOT grafts from degeneration, which may provide a benefit in the repair of articular cartilage injury.

Full-thickness cartilage defects are repaired via a microfracture technique and intraarticular injection of the small-molecule compound kartogenin

INTRODUCTION

Microfracture does not properly repair full-thickness cartilage defects. The purpose of this study was to evaluate the effect of intraarticular injection of the small-molecule compound kartogenin (KGN) on the restoration of a full-thickness cartilage defect treated with microfracture in a rabbit model.

METHODS

Full-thickness cartilage defects (3.5 mm in diameter and 3 mm in depth) were created in the patellar groove of the right femurs of 24 female New Zealand White rabbits. The rabbits were divided into two groups (12 in each group) based on postsurgery treatment differences, as follows: microfracture plus weekly intraarticular injection of KGN (group 1) and microfracture plus dimethyl sulfoxide (group 2). Six rabbits from each group were illed at 4 and 12 weeks after surgery, and their knees were harvested. The outcome was assessed both macroscopically, by using the International Cartilage Repair Society (ICRS) macroscopic evaluation system, and histologically, by using the modified O'Driscoll histologic scoring system. Immunohistochemistry for type II and I collagen was also conducted.

RESULTS

At 4 weeks, group 1 showed better defect filling and a greater number of chondrocyte-like cells compared with group 2. At 12 weeks, group 1 showed statistically significantly higher ICRS scores and modified O'Driscoll scores compared with group 2. More hyaline cartilage-like tissue was found in the defects of group 1 at 12 weeks.

CONCLUSIONS

Intraarticular injection of KGN enhances the quality of full-thickness cartilage defects repair after microfracture, with better defect filling and increased hyaline-like cartilage formation.

Histone deacetylase 4 alters cartilage homeostasis in human osteoarthritis

BACKGROUND

Osteoarthritis (OA) is the most common degenerative joint disorder, and a major cause of pain and disability among the elderly. Histone deacetylase 4 (HDAC4) has been shown to be a key regulator of chondrocyte hypertrophy during skeletogenesis. The aims of present study were to investigate the expression of HDAC4 in normal and OA cartilage and its potential roles during OA pathogenesis.

METHODS

The knee cartilage specimen (a total of 18, 12 female and 6 male) were obtained from primary OA patients undergoing total knee arthroplasty (TKA) and normal donors. By using immunohistochemistry staining, we detected the expression patterns of HDAC4 in OA cartilage and normal cartilage respectively. To assess the potential roles of HDAC4, HDAC4 expression in human chondrosarcoma cells (SW1353) was down-regulated by transfecting small interference RNA (siRNA), thereafter, cells were treated with IL-1β or TNF-α, and the expressions of several matrix-degrading enzymes and anabolic factors were examined by using quantitative PCR.

RESULTS

The expression of HDAC4 was observed in the OA cartilage, whereas it was barely detected in the normal cartilage. The extent of HDAC4 expression had a statistically negative correlation with OA severity. We further explored that the reduction of HDAC4 level led to a significant repression of proinflammation cytokines induced up-regulated expressions of matrix-degrading enzymes (MMP1 (Matrix metalloproteinase 1), MMP3 (Matrix metalloproteinase 3) , MMP13 (Matrix metalloproteinase 13), ADAMTS4 (aggrecanase 1) and ADAMTS5 (aggrecanase 2)) in SW1353 in vitro. Moreover, knockdown of HDAC4 inhibited the expression of some anabolic genes (such as aggrecan).

CONCLUSIONS

In this study, our findings suggest that the abnormal expression of HDAC4 in osteoarthritic cartilage might be implicated in promoting catabolic activity of chondrocyte, which is associated with OA pathogenesis. Thus, our findings give a new insight into the mechanism of articular cartilage damage, and indicate that HDAC4 might be a potential target for the therapeutic interventions of OA.

Meta-analysis demonstrates no association between XRCC1 Arg399Gln polymorphism and bladder cancer risk

We examined whether the X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism is a risk factor for bladder cancer by conducting a meta-analysis. We searched the Pubmed and Embase databases for study retrieval. This meta-analysis examined 16 case-control studies, including 892 prostate cancer cases and 1020 healthy controls. Meta-analysis results based on these studies showed no significant association between the XRCC1 Arg399Gln polymorphism and bladder cancer risk in comparisons of the glutamine (Gln) allele vs arginine (Arg) allele, Arg/Arg vs (Gln/Gln + Gln/Arg), Gln/Gln vs (Gln/Arg + Arg/Arg), Gln/Gln vs Arg/Arg, and Gln/Arg vs Arg/Arg [odds ratio (OR) = 0.96, 95% confidence interval (CI) = 0.80-1.16, P = 0.70; OR = 1.13, 95%CI = 0.70-1.82, P = 0.62; OR = 0.92, 95%CI = 0.79-1.07, P = 0.29; OR = 0.90, 95%CI = 0.69-1.16, P = 0.42; OR = 0.89, 95%CI = 0.75-1.05, P = 0.17, respectively]. In subgroup analysis by ethnicity, no association was observed between the XRCC1 Arg399Gln polymorphism and bladder cancer risk in Caucasian, Mongoloid, or black populations. We identified no association between the XRCC1 Arg399Gln polymorphism and bladder cancer risk.

The anti-proliferative function of the TGF-β1 signaling pathway involves the repression of the oncogenic TBX2 by its homologue TBX3

A growing body of work has shown that the highly homologous T-box transcription factors TBX2 and TBX3 play critical but distinct roles in embryonic development and cancer progression. For example, TBX2 and TBX3 are up-regulated in several cancers and recent evidence suggests that whereas TBX2 functions as a pro-proliferative factor, TBX3 inhibits cell proliferation but promotes cancer cell migration and invasion. While the molecular mechanisms regulating these functions of TBX2 and TBX3 are poorly understood we recently reported that the TGF-β1 signaling pathway up-regulates TBX3 expression to mediate, in part, its well described anti-proliferative and pro-migratory roles. The TBX3 targets responsible for these functions were however not identified. Here we reveal for the first time that the TGF-β1 signaling pathway represses TBX2 transcriptionally and we provide a detailed mechanism to show that this is mediated by TBX3. Furthermore, we implicate the down-regulation of TBX2 in the anti-proliferative function of the TGF-β1-TBX3 axis. These findings have important implications for our understanding of the regulation of TBX2 and TBX3 and shed light on the mechanisms involved in the anti-proliferative and pro-migratory roles of TGF-β1.

Evidence of b-jet quenching in PbPb collisions at √(s(NN))=2.76 TeV

The production of jets associated to bottom quarks is measured for the first time in PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair. Jet spectra are reported in the transverse momentum (p(T)) range of 80-250  GeV/c, and within pseudorapidity |η|<2. The nuclear modification factor (R(AA)) calculated from these spectra shows a strong suppression in the b-jet yield in PbPb collisions relative to the yield observed in pp collisions at the same energy. The suppression persists to the largest values of p(T) studied, and is centrality dependent. The R(AA) is about 0.4 in the most central events, similar to previous observations for inclusive jets. This implies that jet quenching does not have a strong dependence on parton mass and flavor in the jet p(T) range studied.

Study of the production of charged pions, kaons, and protons in pPb collisions at [Formula: see text]5.02[Formula: see text]

Spectra of identified charged hadrons are measured in pPb collisions with the CMS detector at the LHC at [Formula: see text]. Charged pions, kaons, and protons in the transverse-momentum range [Formula: see text]-1.7[Formula: see text] and laboratory rapidity [Formula: see text] are identified via their energy loss in the silicon tracker. The average [Formula: see text] increases with particle mass and the charged multiplicity of the event. The increase of the average [Formula: see text] with charged multiplicity is greater for heavier hadrons. Comparisons to Monte Carlo event generators reveal that Epos Lhc, which incorporates additional hydrodynamic evolution of the created system, is able to reproduce most of the data features, unlike Hijing and Ampt. The [Formula: see text] spectra and integrated yields are also compared to those measured in pp and PbPb collisions at various energies. The average transverse momentum and particle ratio measurements indicate that particle production at LHC energies is strongly correlated with event particle multiplicity.

Association of a single nucleotide polymorphism in HOXB9 with developmental dysplasia of the hip: a case-control study

Developmental dysplasia of the hip (DDH) is one of the most common skeletal disorders. It comprises a spectrum of abnormalities, including shallow acetabulum and decreased coverage of the femoral head. Genetic component plays a considerable role in the aetiology of DDH. HOXB9 may be involved in the aetiology and pathogenesis of DDH, as it plays an important role in the development of the limbs. Our objective was to evaluate whether single nucleotide polymorphisms (SNPs) of HOXB9 (rs2303486 and rs8844) were associated with DDH in Chinese population. The HOXB9 tag SNPs were genotyped in 460 DDH cases and 562 control subjects by Taqman assay, and their association was examined. rs8844 was not associated with DDH. rs2303486 was associated with DDH in the dominant genetic model (p = 0.037; odds ratio (OR) = 1.32; 95% confidence interval (CI) = 1.02–1.71). After stratification by sex, significant association of the dominant genetic model still existed in the female subjects (p = 0.015; OR = 1.46; 95% CI = 1.08–1.98),but not in the male subjects. After stratification by severity, we discovered an association with hip dislocation in the dominant model(p=0.042; OR = 1.35; 95% CI = 1.01–1.80), but not with subluxation or instability. HOXB9 is associated with DDH in Chinese.

Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at [Formula: see text]

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb-1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.

Deep Vein Thrombosis After Total Hip Arthroplasty and Total Knee Arthroplasty in Patients With Previous Ischemic Stroke

The present study evaluated the prevalence and therapy of deep vein thrombosis (DVT) after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in 57 patients with previous ischemic stroke. Postoperative anticoagulants were used for DVT prophylaxis, and batroxobin and prolonged anticoagulants were used for thrombolysis in DVT subjects. The incidence of DVT after THA and TKA in patients with previous ischemic stroke was 16.2% and 20%, respectively. No bleeding complications were observed and no new ischemic stroke occurred during the following 3 months. The prevalence DVT after THA and TKA in patients with previous ischemic stroke was not specific, and the treatment of DVT with batroxobin and anticoagulants was effective and safe.