Regenerative approaches for cartilage repair in the treatment of osteoarthritis

Osteoarthritis (OA) as a debilitating affliction of joints currently affects millions of people and remains an unsolved problem. The disease involves multiple cellular and molecular pathways that converge on the progressive destruction of cartilage. Activation of cartilage regenerative potential and specific targeting pathogenic mediators have been the major focus of research efforts aimed at slowing the progression of cartilage degeneration and preserve joint function. This review will summarize recent key discoveries toward better understanding of the complex mechanisms behind OA development and highlight the latest advances in basic and clinical research in the approach for cartilage regeneration. Prospectively, more potent therapeutic strategies against progressive cartilage deterioration may use a combination of cytotherapy, pharmacotherapy, and bioscaffoldings for improved chondrogenic differentiation and stem/progenitor cell homing as well as the concomitant reduced enzymatic matrix degradation and inflammation. Further, treatments need to be provided with increased preciseness of targeted therapy. One might expect that the regenerative therapies could potentially control or even possibly cure OA if performed at early stages of the disease.

The Hemagglutinin A Stem Antibody MEDI8852 Prevents and Controls Disease and Limits Transmission of Pandemic Influenza Viruses

Background

MEDI8852 is a novel monoclonal antibody (mAb) that neutralizes both group I and group II influenza A viruses (IAVs) in vitro. We evaluated whether MEDI8852 was effective for prophylaxis and therapy against representative group I (H5N1) and group II (H7N9) pandemic IAVs in mice and ferrets and could be used to block transmission of influenza H1N1pdm09 in ferrets, compared to an irrelevant control mAb R347 and oseltamivir.

Methods

MEDI8852 was administered to mice and ferrets by intraperitoneal injection at varying doses, 24 hours prior to intranasal infection with H5N1 and H7N9 viruses for prophylaxis, and 24, 48, and 72 hours post-infection for treatment. A comparison with oseltamivir alone and combination of MEDI8852 and oseltamivir was included in some studies. Survival, weight loss, and viral titers were assessed over a 14-day study period. For the transmission study, naive respiratory contact ferrets received MEDI8852 or R347 prior to exposure to ferrets infected with an H1N1pdm09 virus.

Results

MEDI8852 was effective for prophylaxis and treatment of H7N9 and H5N1 infection in mice, with a clear dose-dependent response and treatment with MEDI8852 24, 48, or 72 hours postinfection was superior to oseltamivir for H5N1. MEDI8852 alone was effective treatment for lethal H5N1 infection in ferrets compared to oseltamivir and R347, and MEDI8852 plus oseltamivir was better than oseltamivir alone. MEDI8852 or oseltamivir alone early in infection was equally effective for H7N9 infection in ferrets while the combination yielded similar protection when treatment was delayed. MEDI8852 was able to protect naive ferrets from airborne transmission of H1N1pdm09.

Conclusions

MEDI8852, alone or with oseltamivir, shows promise for prophylaxis or therapy of group I and II IAVs with pandemic potential. Additionally, MEDI8852 blocked influenza transmission in ferrets, a unique finding among influenza-specific mAbs.

Sodium butyrate suppresses angiotensin II-induced hypertension by inhibition of renal (pro)renin receptor and intrarenal renin-angiotensin system

OBJECTIVES

Butyrate, a short-chain fatty acid, is the end product of the fermentation of complex carbohydrates by the gut microbiota. Recently, sodium butyrate (NaBu) has been found to play a protective role in a number of chronic diseases. However, it is still unclear whether NaBu has a therapeutic potential in hypertension. The present study was aimed to investigate the role of NaBu in angiotensin II (Ang II)-induced hypertension and to further explore the underlying mechanism.

METHODS

Ang II was infused into uninephrectomized Sprague-Dawley rats with or without intramedullary infusion of NaBu for 14 days. Mean arterial blood pressure was recorded by the telemetry system. Renal tissues, serum samples, and 24-h urine samples were collected to examine renal injury and the regulation of the (pro)renin receptor (PRR) and renin.

RESULTS

Intramedullary infusion of NaBu in Sprague-Dawley rats lowered the Ang II-induced mean arterial pressure from 129 ± 6 mmHg to 108 ± 4 mmHg (P < 0.01). This corresponded with an improvement in Ang II-induced renal injury, including urinary albumin, glomerulosclerosis, and renal fibrosis, as well as the expression of inflammatory mediators tumor necrosis factor α, interleukin 6. The renal expression of PRR, angiotensinogen, angiotensin I-converting enzyme and the urinary excretion of soluble PRR, renin, and angiotensinogen were all increased by Ang II infusion but decreased by NaBu treatment. In cultured innermedullary collecting duct cells, NaBu treatment attenuated Ang II-induced expression of PRR and renin.

CONCLUSION

These results demonstrate that NaBu exerts an antihypertensive action, likely by suppressing the PRR-mediated intrarenal renin-angiotensin system.

A rapid method to extract Seebeck coefficient under a large temperature difference

The Seebeck coefficient is one of the three important properties in thermoelectric materials. Since thermoelectric materials usually work under large temperature difference in real applications, we propose a quasi-steady state method to accurately measure the Seebeck coefficient under large temperature gradient. Compared to other methods, this method is not only highly accurate but also less time consuming. It can measure the Seebeck coefficient in both the temperature heating up and cooling down processes. In this work, a Zintl material (Mg_3.15Nb_0.05Sb_1.5Bi_0.49Te_0.01) was tested to extract the Seebeck coefficient from room temperature to 573 K. Compared with a commercialized Seebeck coefficient measurement device (ZEM-3), there is ±5% difference between those from ZEM-3 and this method.

Associations between serum ghrelin and knee symptoms, joint structures and cartilage or bone biomarkers in patients with knee osteoarthritis

OBJECTIVE

The roles of ghrelin in knee osteoarthritis (OA) are unclear. This study aimed to examine cross-sectional associations of ghrelin with knee symptoms, joint structures and cartilage or bone biomarkers in patients with knee OA.

METHODS

This study included 146 patients with symptomatic knee OA. Serum levels of ghrelin and cartilage or bone biomarkers including cartilage oligomeric matrix protein (COMP), cross linked C-telopeptide of type I collagen (CTXI), cross linked N-telopeptide of type I collagen (NTXI), N-terminal procollagen III propeptide (PIIINP), and matrix metalloproteinase (MMP)-3, 10, 13 were measured using Enzyme-linked immunosorbent assay (ELISA). Knee symptoms were assessed using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Infrapatellar fat pad (IPFP) volume, IPFP signal intensity alternation, cartilage defects, bone marrow lesions (BMLs) and effusion-synovitis were assessed using the (MRI). Osteophytes and joint space narrowing (JSN) were assessed using the Osteoarthritis Research Society International atlas.

RESULTS

After adjustment for potential confounders, ghrelin quartiles were positively associated with knee symptoms including pain, stiffness, dysfunction and total score (quartile 4 vs 1: β 24.19, 95% CI 8.13-40.25). Ghrelin quartiles were also significantly associated with increased IPFP signal intensity alteration (quartile 4 vs 1: OR 3.57, 95% CI 1.55-8.25) and NTXI, PIIINP, MMP3 and MMP13. Ghrelin was not significantly associated with other joint structures and biomarkers.

CONCLUSIONS

Serum levels of ghrelin were significantly associated with increased knee symptoms, IPFP signal intensity alteration and serum levels of MMP3, MMP13, NTXI and PIIINP, suggesting that ghrelin may have a role to play in knee OA.

Proximity hybridization-mediated isothermal exponential amplification for ultrasensitive electrochemical protein detection

In this study, we fabricated a novel electrochemical biosensing platform on the basis of target-triggered proximity hybridization-mediated isothermal exponential amplification reaction (EXPAR) for ultrasensitive protein analysis. Through rational design, the aptamers for protein recognition were integrated within two DNA probes. Via proximity hybridization principle, the affinity protein-binding event was converted into DNA assembly process. The recognition of protein by aptamers can trigger the strand displacement through the increase of the local concentrations of the involved probes. As a consequence, the output DNA was displaced, which can hybridize with the duplex probes immobilized on the electrode surface subsequently, leading to the initiation of the EXPAR as well as the cleavage of duplex probes. Each cleavage will release the gold nanoparticles (AuNPs) binding sequence. With the modification of G-quadruplex sequence, electrochemical signals were yielded by the AuNPs through oxidizing 3,3',5,5'-tetramethylbenzidine in the presence of H₂O₂. The study we proposed exhibited high sensitivity toward platelet-derived growth factor BB (PDGF-BB) with the detection limit of 52 fM. And, this method also showed great selectivity among the PDGF isoforms and performed well in spiked human serum samples.

NaCl-assisted one-step growth of MoS2-WS2 in-plane heterostructures

Transition metal dichalcogenides (TMDs) have attracted considerable interest for exploration of next-generation electronics and optoelectronics in recent years. Fabrication of in-plane lateral heterostructures between TMDs has opened up excellent opportunities for engineering two-dimensional materials. The creation of high quality heterostructures with a facile method is highly desirable but it still remains challenging. In this work, we demonstrate a one-step growth method for the construction of high-quality MoS₂-WS₂ in-plane heterostructures. The synthesis was carried out using ambient pressure chemical vapor deposition (APCVD) with the assistance of sodium chloride (NaCl). It was found that the addition of NaCl played a key role in lowering the growth temperatures, in which the Na-containing precursors could be formed and condensed on the substrates to reduce the energy of the reaction. As a result, the growth regimes of MoS₂ and WS₂ are better matched, leading to the formation of in-plane heterostructures in a single step. The heterostructures were proved to be of high quality with a sharp and clear interface. This newly developed strategy with the assistance of NaCl is promising for synthesizing other TMDs and their heterostructures.

Ascorbic Acid Alleviates Damage from Heat Stress in the Photosystem II of Tall Fescue in Both the Photochemical and Thermal Phases

L-Ascorbate (Asc) plays important roles in plant development, hormone signaling, the cell cycle and cellular redox system, etc. The higher content of Asc in plant chloroplasts indicates its important role in the photosystem. The objective of this study was to study the roles of Asc in tall fescue leaves against heat stress. After a heat stress treatment, we observed a lower value of the maximum quantum yield for primary photochemistry (φPo), which reflects the inhibited activity of the photochemical phase of photosystem II (PSII). Moreover, we observed a higher value of efficiency of electron transfer from QB to photosystem I acceptors (δR0), which reflects elevated activity of the thermal phase of the photosystem of the tall fescue. The addition of Asc facilitate the behavior of the photochemical phase of the PSII by lowering the ROS content as well as that of the alternative electron donor to provide electron to the tyrosine residue of the D1 protein. Additionally, exogenous Asc reduces the activity of the thermal phase of the photosystem, which could contribute to the limitation of energy input into the photosystem in tall fescue against heat stress. Synthesis of the Asc increased under heat stress treatment. However, under heat stress this regulation does not occur at the transcription level and requires further study.

[Expression of long non-coding RNA SNHG8 in Epstein-Barr virus-related gastric cancer and clinical outcome]

Objective: To investigate the expression of long non-coding RNA (lncRNA) SNHG8 in EB virus related gastric cancer and their correlation prognosis. Methods: The expression of SNHG8 in 93 gastric cancers and 93 cancer-free controls, matched by age and sex, were determined by real-time PCR. EB virus expression was detected by EBER in situ hybridization. Results: Forty-one gastric cancers were EB virus associated. For all gastric cancers, SNHG8 expression was 14 times higher (P=0.001) than that in non-cancer controls; in the EB virus related gastric cancers, SNHG8 expression was increased 25 times (P<0.05) over EB virus negative gastric cancers. SNHG8 expression level was also significantly associated with TNM staging (P<0.05). Conclusions: SNHG8 may act as a proto-oncogene, participating in gastric carcinogenesis.EB virus infection of gastric mucosa may promote SNHG8 expression.

[Effect of calcium on sporulation of Taiwanofungus camphoratus in submerged fermentation]

Taiwanofungus camphoratus is a valuable and rare medicinal mushroom with various bioactivities, such as liver protection and anti-cancer. T. camphoratus can produce many arthroconidia at the end of submerged fermentation, but molecular mechanism underlying this submerged conidiation remains unknown. In this study, we found that Ca²⁺ concentration in culture medium significantly affected the arthroconidium production of T. camphoratus. Then, we identified two proteins (CaM and HSP90) involved in Ca²⁺/calmodulin signaling pathway and one protein (AbaA) involved in FluG-mediated conidiation pathway by two-dimensional electrophoresis analyses. Furthermore, we proposed a Ca²⁺/calmodulin- and FluG-mediated signaling pathway by bioinformatics analysis. By real-time quantitative PCR analyses of 23 key genes in the Ca²⁺/calmodulin- and FluG-mediated conidiation pathway, we found that expression levels of 7 genes (crz1, hsp90, flbB, brlA, abaA, wetA and fadA) showed significant responses to Ca²⁺ concentration in fermentation medium. Our research is beneficial for elucidating the underlying mechanism of submerged fermentation conidiation for T. camphoratus.

Infusion of Valproic Acid Into the Renal Medulla Activates Stem Cell Population and Attenuates Salt-Sensitive Hypertension in Dahl S Rats

BACKGROUND

Our previous study has detected a stem cell deficiency in the renal medulla in Dahl salt-sensitive (S) rats. This study determined whether infusion of valproic acid (VA), an agent known to stimulate the stem cell function, attenuated salt-sensitive hypertension in Dahl S rats.

METHODS

Uninephrectomized Dahl S rats were infused with vehicle or VA (50mg/kg/d) into the renal medulla and fed with a low (LS) or high salt diet (HS). Stem cell marker and number were analyzed by immunohistochemistry, Real-time RT-PCR and Western blot. Sodium excretion and blood pressure were measured.

RESULTS

VA significantly increased the mRNA and protein levels of FGF2, a stem cell niche factor, and CD133, a stem cell marker. The number of CD133+ cells was significantly increased in the renal medulla in VA-treated rats. Meanwhile, high salt-induced increases in the mRNA level of proinflammatory factors interleukin-1β and interleukin-6 were blocked in VA-treated rats. Functionally, sodium excretion in response to the blood pressure increase and acute sodium loading was significantly enhanced, sodium retention attenuated, high salt-induced increase of blood pressure reduced in VA-treated rats.

CONCLUSION

Activation of stem cell function by VA inhibits the activation of proinflammatory factors and attenuates salt-sensitive hypertension in Dahl S rats.

DMAb inoculation of synthetic cross reactive antibodies protects against lethal influenza A and B infections

Influenza virus remains a significant public health threat despite innovative vaccines and antiviral drugs. A major limitation to current vaccinations and therapies against influenza virus is pathogenic diversity generated by shift and drift. A simple, cost-effective passive immunization strategy via in vivo production of cross-protective antibody molecules may augment existing vaccines and antiviral drugs in seasonal and pandemic outbreaks. We engineered synthetic plasmid DNA to encode two novel and broadly cross-protective monoclonal antibodies targeting influenza A and B. We utilized enhanced in vivo delivery of these plasmid DNA-encoded monoclonal antibody (DMAb) constructs and show that this strategy induces robust levels of functional antibodies directed against influenza A and B viruses in mouse sera. Mice receiving a single inoculation with anti-influenza A DMAb survive lethal Group 1 H1 and Group 2 H3 influenza A challenges, while inoculation with anti-influenza B DMAb yields protection against lethal Victoria and Yamagata lineage influenza B morbidity and mortality. Furthermore, these two DMAbs can be delivered coordinately resulting in exceptionally broad protection against both influenza A and B. We demonstrate this protection is similar to that achieved by conventional protein antibody delivery. DMAbs warrant further investigation as a novel immune therapy platform with distinct advantages for sustained immunoprophylaxis against influenza.

A novel innoculation technique involving the injection of antibody-producing plasmid DNA has shown to be effective against influenza in mice. The flu is responsible for up to half a million deaths each year and up to five million cases of severe disease, while also posing a substantial pandemic threat, even with our current repertoire of vaccines. A team of researchers led by Sarah Elliott and David Weiner of The Wistar Institute of Anatomy and Biology, Philadelphia, developed potent plasmid-based constructs that, once injected, entered hosts’ cells and utilized cellular machinery to encode antibodies protective against a range of influenza A and B subtypes. DNA inoculation conferred acute protection from disease, with treated individuals also being immune to subsequent exposure. This approach warrants further investigation as an alternative technology for practical delivery of monoclonal antibody therapeutics.

Tanshinone IIA ameliorates chronic arthritis in mice by modulating neutrophil activities

Rheumatoid arthritis (RA) is a chronic immune inflammatory disease mediated by the influx of immune cells into the synovial joint space. As Tanshinone IIA (TIIA) has potent anti-oxidant and anti-inflammatory activities, we used the adjuvant-induced arthritis (AA) murine model of RA to investigate the impact of TIIA on RA and immune cell activation. The anti-arthritic activity of TIIA was investigated in an adjuvant-induced arthritis model of RA in mice. Myeloperoxidase and neutrophil elastase expression levels were assessed in ankle joints by immunohistochemistry analysis. Immune cell infiltration was evaluated in air pouch experiments. Proinflammatory cytokines expression levels were determined by quantitative real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays. Neutrophil extracellular traps (NETs) were assessed by immunostaining and confocal microscopy. Treatment with TIIA alleviated cartilage erosion and neutrophil infiltration in the ankle joints of AA mice and reduced proinflammatory cytokine expression levels in sera. TIIA suppressed interleukin-6 and tumour necrosis factor-α expression and release in neutrophils and promoted neutrophil apoptosis. TIIA also inhibited the NET formation of neutrophils. Our findings demonstrated that TIIA can ameliorate RA effectively by targeting neutrophils, indicating that TIIA may act as a potential therapeutic for RA.

Iron modulates the activity of monoamine oxidase B in SH-SY5Y cells

Both monoamine oxidase B (MAO-B) and iron accumulation are associated with neurologic diseases including Parkinson's disease. However, the association of iron with MAO-B activity was poorly understood. Here we took advantage of highly sensitive and specific fluorescence probes to examine the change in MAO-B activity in human dopaminergic neuroblastoma (SH-SY5Y) cells upon iron exposure. Both ferric and ferrous ions could significantly enhance the activity of MAO-B, instead of MAO-A, in SH-SY5Y cells. In addition, iron-induced increase in MAO-B probe fluorescence could be prevented by pargyline and other newly developed MAO-B inhibitors, suggesting that it was MAO-B activity-dependent. These findings may suggest MAO-B is an important sensor in iron-stressed neuronal cells.