Cisplatin triggers oxidative stress, apoptosis and pro-inflammatory responses by inhibiting the SIRT1-mediated Nrf2 pathway in chondrocytes

Although the height of the proliferating layer that was suppressed in the growth plate has been recognized as an adverse effect of cisplatin in pediatric cancer survivors, the detailed pathological mechanism has not been elucidated. Sirtuin-1 (SIRT1) has been reported as an essential modulator of cartilage homeostasis, but its role in cisplatin-induced damage of chondrocytes remains unclear. In this study, we examined how cisplatin affected the expression of SIRT1 and cell viability. Next, we showed downregulation of SIRT1 after cisplatin treatment resulted in suppression of Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α), leading to inhibition of Nrf2 nuclear translocation and subsequently decreased Heme oxygenase-1(HO-1) and NAD(P)H Quinone Dehydrogenase 1(NQO-1) expression. Blockage of the SIRT1/ PGC-1α axis not only increased oxidative stress with lower antioxidant SOD and GSH, but also contributed to mitochondrial dysfunction evidenced by the collapse of membrane potential and repression of mitochondrial DNA copy number and ATP. We also found that Cisplatin up-regulated the p38 phosphorylation, pro-inflammatory events and matrix metalloproteinases (MMPs) in chondrocytes through the SIRT1-modulated antioxidant manner. Collectively, our findings suggest that preservation of SIRT1 in chondrocytes may be a potential target to ameliorate growth plate dysfunction for cisplatin-receiving pediatric cancer survivors.

Swimming exercise attenuates mechanical hypersensitivity and mitigates peripheral nerve degeneration in rats with painful diabetic neuropathy (PDN)

BACKGROUND

This study aimed to assess the effectiveness of swimming exercise in alleviating mechanical hypersensitivity and peripheral nerve degeneration associated with a pre-clinical model of painful diabetic neuropathy (PDN).

METHODS

This study is a pre-clinical study conducted using the streptozocin (STZ)-induced PDN rat model. Rats were randomly allocated to three groups: a vehicle group of non-diabetic rats (Vehicle, n = 9), a group of rats with PDN (PDN, n = 8), and a group of rats with PDN that performed a swimming exercise program (PDN-SW, n = 10). The swimming exercise program included daily 30-minute swimming exercise, 5 days per week for 4 weeks. Von Frey testing was used to monitor hindpaw mechanical sensitivity over 4 weeks. Assessment of cutaneous peripheral nerve fiber integrity was performed after the 4-week study period via immunohistochemistry for protein gene product 9.5-positive (PGP9.5+) intra-epidermal nerve fiber density (IENFD) in hind-paw skin biopsies by a blinded investigator.

RESULTS

The results showed that swimming exercise mitigated but did not fully reverse mechanical hypersensitivity in rats with PDN. Immunohistochemical testing revealed that the rats in the PDN-SW group retained higher PGP9.5+ IENFD compared to the PDN group but did not reach normal levels of the Vehicle group.

CONCLUSIONS

The results of this study indicate that swimming exercise can mitigate mechanical hypersensitivity and degeneration of peripheral nerve fibers in rats with experimental PDN.

Mangiferin Protects Against Angiotensin-II-Enhanced Hypertrophic Markers and Apoptosis in H9c2 Cardiomyocytes

Hypertrophic cardiomyopathy accompanies numerous cardiovascular diseases, and the intervention of cardiac hypertrophy is an important issue to prevent detrimental consequences. Mangiferin (MGN) is a glucosylxanthone found in Mangifera indica, which exhibits anti-oxidant and anti-inflammatory properties. Various studies have demonstrated the cardioprotective potential of MGN, but the mechanisms behind its beneficial effects have not been fully revealed. Here, angiotensin-II (Ang-II) was used to induce cardiac hypertrophy, and we examined cell size, expression of hypertrophy markers (e.g., ANP, BNP, and [Formula: see text]-MHC), and oxidative stress (e.g., the ratio of NADPH/NADP[Formula: see text], the expression of p22phox and p67phox, and ROS and SOD production) of cardiomyocytes. Moreover, we assessed the activation of mitogen-activated protein kinase (MAPK) signaling (e.g., p38 and ERK) and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, an annexin V/PI assay was employed to evaluate whether MGN administration can attenuate Ang-II-elicited apoptosis. Lastly, the expression of Ang-II type 1 receptor (AT1) was measured to confirm its involvement in MGN-mediated protection. Our results showed that treatment with MGN attenuated the Ang-II-induced cell size, expression of hypertrophy markers, and oxidative stress in cardiomyocytes. MGN also abrogated the activation of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis. Additionally, MGN prevented apoptosis and downregulated the elevation of AT1 in cardiomyocytes that had been exposed to Ang-II. Altogether, these results demonstrated the potential of using MGN to ameliorate the Ang-II-associated cardiac hypertrophy, which may be due to its anti-oxidant and anti-inflammatory effects through suppression of MAPK signaling and the NF-[Formula: see text]Bp65/iNOS axis.

Schisanhenol Attenuates OxLDL-Induced Endothelial Dysfunction via an AMPK-Dependent Mechanism

Atherosclerotic cardiovascular diseases, commonly known as the formation of fibrofatty lesions in the artery wall, are the leading causes of death globally. Oxidized low-density lipoprotein (oxLDL) is one of the major components of atherosclerotic plaques. It is evident that dietary supplementation containing sources of antioxidants can prevent atherogenic diseases. Schisanhenol (SAL), a dibenzocyclooctene lignin, has been shown to attenuate oxLDL-induced apoptosis and the generation of reactive oxygen species (ROS) in endothelial cells. However, the underlying molecular mechanisms are still largely unknown. In this study, human umbilical vein endothelial cells (HUVECs) were pre-treated with SAL and oxLDL. Our results showed that adenosine monophosphate-activated protein kinase (AMPK) phosphorylation was enhanced in cells pre-treated with SAL in time-dependent and dose-dependent manners. Subsequently, oxLDL-induced AMPK dephosphorylation and protein kinase C (PKC) phosphorylation were significantly reversed in the presence of SAL. In addition, SAL treatment led to an inhibiting effect on the oxLDL-induced membrane assembly of NADPH oxidase subunits, and a similar effect was observed in ROS generation. This effect was further confirmed using knockdown AMPK with small interfering RNA (siRNA) and pharmaceutical reagents, such as the AMPK activator (AICAR), PKC inhibitor (Gö 6983), and ROS inhibitor (DPI). Furthermore, the oxLDL-induced intracellular calcium rise and the potential collapse of the mitochondrial membrane reduced the Bcl-2/Bax ratio, and released cytochrome c from the mitochondria, leading to the subsequent activation of caspase-3 in HUVECs, which were also markedly suppressed by SAL pretreatment. The results mentioned above may provide additional insights into the possible molecular mechanisms underlying the cardiovascular protective effects of SAL.

Schisanhenol ameliorates oxLDL-caused endothelial dysfunction by inhibiting LOX-1 signaling

Atherosclerotic lesions play a critical role in leading cardiovascular diseases. Oxidized low-density lipoprotein (OxLDL) is a vital risk factor for atherosclerosis since it acts a crucial role in endothelial dysfunction and foam cell formation. Schisanhenol, a composition extracted from the fruit of Schisandra rubriflora, has been reported to have antioxidative effects on human LDL oxidation. This study investigates whether Schisanhenol protects against oxLDL-mediated endothelial damage by modulating the lectin-like oxLDL receptor-1 (LOX-1)-mediated inflammatory processes. Human umbilical vein endothelial cells (HUVECs) were pre-treated with 10 or 20 μM Schisanhenol for 2 h and then exposed to 150 μg/mL oxLDL. We revealed that Schisanhenol reduced oxLDL-enhanced LOX-1 expression. We also found that oxLDL down-regulated endothelial nitric oxide synthase (eNOS) as well as activated inducible NOS (iNOS), thereby enhancing the generation of nitric oxide (NO). Moreover, oxLDL elevated the expression levels of phosphorylated-p38MAPK, subsequently promoting NF-κB-modulated inflammatory responses. Pretreatment with Schisanhenol exerted significant cytoprotective function in all the above-mentioned detrimental events. Results from this present study reveal that Schisanhenol has a potential therapeutic effect on preventing oxLDL-induced endothelial injuries.

Using an Internal Joint Stabilizer Through a Single Posterior Approach for Elderly Patients With Terrible Triad Injury

Introduction

Treating a terrible triad injury of the elbow remains a challenge for orthopedic surgeons, especially in elderly patients due to the poor quality of the surrounding soft tissue and bony structures. In the present study, we propose a treatment protocol using an internal joint stabilizer through a single posterior approach and analyze the clinical results.

Materials and Methods

We retrospectively reviewed 15 elderly patients with terrible triad injuries of the elbow who underwent our treatment protocol from January 2015 to December 2020. The surgery involved a posterior approach, identification of the ulnar nerve, bone and ligament reconstruction, and the application of the internal joint stabilizer. A rehabilitation program was initiated immediately after the operation. Surgery-related complications, elbow range of motion (ROM), and functional outcomes were evaluated.

Results

The mean follow-up period was 21.7 months (range, 16-36 months). ROM at the final follow-up was 130° in extension to flexion and 164° in pronation to supination. The mean Mayo Elbow Performance Score was 94 at the final follow-up. Major complications included breaking of the internal joint stabilizer in 2 patients, transient numbness over the ulnar nerve territory in one, and local infection due to irritation of the internal joint stabilizer in one.

Conclusions

Although the current study involved only a small number of patients and the protocol comprised two stages of operation, we believe that such a technique may be a valuable alternative for the treatment of these difficult cases.

Level of Clinical Evidence

4.

Using External Joint Stabilizer - Elbow (EJS-E) for treating elbow instability-biomechanical assessment and clinical outcomes

BACKGROUND

This study aimed to evaluate the outcome of using an External Joint Stabilizer - Elbow (EJS-E) for persistent elbow instability based on biomechanical experiments and analysis of clinical results.

METHODS

An EJS-E was used in 17 elbow instability patients. The median follow-up was 26 months (range, 12-42 months). We evaluated the flexion-extension and pronation-supination movement arcs, visual analog scale (VAS) score, Mayo Elbow Performance Score (MEPS), Broberg and Morrey classification system, and occurrence of complications in these patients. Moreover, construct stiffness and maximum strength tests were performed to evaluate the strength of the fixation techniques.

RESULTS

The final median range of the extension-to-flexion and pronation-to-supination arc of the elbow was 135° (range, 110°-150°) and 165° (range, 125°-180°), respectively. The VAS pain scores were > 3 in two patients. The median MEPS was 90 (range, 80-100 points). Five patients showed signs of grade I post-traumatic osteoarthritis according to the Broberg and Morrey radiographic classification system, while grade II changes were observed in three patients. Complications included axis pin loosening with pin-tract infection in two patients, transient ulnar nerve symptoms in two patients, heterotopic ossification in two patients, and suture anchors infection in one patient. Based on the biomechanical testing results, the EJS-E exhibited higher stiffness and resisting force in varus loading. It was 0.5 (N/mm) stiffer and 1.8 (N·m) stronger than the internal joint stabilizer (IJS) by difference of medians (p < 0.05).

CONCLUSIONS

Biomechanical and clinical outcomes show that EJS-E via the posterior approach can restore mobility and stability in all patients, thus serving as a valuable alternative option for the treatment of persistent instability of the elbow.

Effects of percutaneous vertebroplasty on respiratory parameters in patients with osteoporotic vertebral compression fractures

Background: Vertebral compression fractures (VCFs) often occur in patients with osteoporosis. These fractures can also lead to postural changes. Several studies have shown that patients with vertebral compression fractures have a restrictive pattern in their pulmonary function. Percutaneous vertebroplasty (PVP) is the standard treatment for vertebral compression fractures, with the benefits of pain relief and enhancement of vertebral stability for partially collapsed vertebral bodies. However, the effects of PVP on short-term recovery of respiratory performance have not been investigated. Therefore, this study aimed to investigate the changes in pulmonary function, respiratory muscle strength, maximal voluntary ventilation (MVV), and chest mobility in patients with vertebral compression fractures after PVP.Methods: This research was approved by the clinic committee of the E-DA Hospital Institutional Review Board (EMRP07109N) and registered in the Thai Clinical Trials Registry (TCTR20211029005). We recruited 32 VCF patients. Four-time points were measured: before and after PVP and 1 and 3 weeks after PVP. We measured pulmonary function and maximum voluntary ventilation (MVV) by using spirometry. Respiratory muscle strength was assessed by using a respiratory pressure meter. The chest expansion test was used to evaluate chest mobility. A visual analogue scale (VAS) was used to assess resting and aggravated back pain.Results: Chest expansion and back pain improved at each time point after PVP. MVV showed significant progress at both 1 and 3 weeks after discharge. Forced expiratory volume in 1 second (FEV1) and maximal inspiratory muscle strength significantly improved 1 week after discharge.Conclusion: Taking all the data together, PVP not only can resolve severe back pain but can also provide excellent improvements in MVV and chest mobility in patients with vertebral compression fractures.

The fully engaged inspiratory muscle training reduces postoperative pulmonary complications rate and increased respiratory muscle function in patients with upper abdominal surgery: a randomized controlled trial

BACKGROUND

Upper abdominal surgical treatment may reduce respiratory muscle function and mucociliary clearance, which might be a cause of postoperative pulmonary complications (PPCs). Threshold inspiratory muscle training (IMT) may serve as an effective modality to improve respiratory muscle strength and endurance in patients. However, whether this training could help patients with upper abdominal surgery remains to be determined. The aim of the present investigation was to determine the effect of a fully engaged IMT on PPCs and respiratory function in patients undergoing upper abdominal surgery. We hypothesized that the fully engaged IMT could reduce PPCs and improve respiratory muscle function in patients with upper abdominal surgery.

METHODS

This is a randomized controlled trial (RCT) with 28 patients who underwent upper abdominal surgery. Patients were randomly assigned to the control (CLT) group or the IMT group. The CTL group received regular health care. The IMT group received 3 weeks of IMT with 50% of MIP as the initial intensity before the operation. The intensity of MIP increased by 5-10% per week. The IMT was continued for 4 weeks after the operation. The study investigated the outcomes including PPCs, respiratory muscle strength, diaphragmatic function, cardiopulmonary function, and quality of life (QoL).

RESULTS

We found that IMT improved respiratory muscle strength and diaphragmatic excursion. IMT also had a beneficial effect on the incidence of postoperative pulmonary complications (PPCs) compared to CLT care.

CONCLUSION

The results from this study revealed that IMT provided positive effects on parameters associated with the respiratory muscle function and reduced the incidence of PPCs. We propose that fully engaged IMT should be a part of clinical management in patients with upper abdominal surgery.KEY MESSAGESThe fully engaged inspiratory muscle training reduces postoperative pulmonary complications rate in patients with upper abdominal surgery.The fully engaged inspiratory muscle training increases maximal inspiratory pressure in patients with upper abdominal surgery.The fully engaged inspiratory muscle training increases diaphragm function in patients with upper abdominal surgery.The fully engaged inspiratory muscle training increases the quality of life in patients with upper abdominal surgery.

External Locking Plate Fixation for Femoral Subtrochanteric Fractures

Introduction

Internal fixation is the treatment of choice for subtrochanteric fractures in most conditions. However, it may be an unsuitable procedure for patients with poor health status, osteomyelitis, and surrounding soft tissue compromise. This study aimed to ascertain the viability and reliability of using external locking plate fixation for these difficult cases.

Methods

Eleven patients with femoral subtrochanteric fractures who received external locking plate fixation in our institute from January 2014 to December 2019 were enrolled in our study. The bone union time, wound complication, alignment, and necessity for narcotic agents were evaluated.

Results

The average length of follow-up was 17.5 months (range, 14-26 months). The mean time for bone union was 17.7 weeks (range, 15-21 weeks). The indications included poor health condition, soft tissue compromise, and post-operative osteomyelitis. Pin tract infection was noted in two patients who were treated successfully with oral antibiotics administration and removal of the involved screws. Osseous union with varus deformity <10° was achieved in all patients except one. Three patients required an orally administered pain killer at the final visit. The average Harris Hip Score at one year post-operatively was 66.6 (range, 49-80).

Conclusions

Although the current study only involved 11 patients, we believe that our method may serve as a valuable alternative for the treatment of a femoral subtrochanteric fracture in selected cases.

Level of Evidence

Level IV, retrospective case series.

Dapagliflozin Mitigates Doxorubicin-Caused Myocardium Damage by Regulating AKT-Mediated Oxidative Stress, Cardiac Remodeling, and Inflammation

Doxorubicin (Dox) is a commonly used anthracycline chemotherapy with a side effect of cardiotoxicity, which may increase the risk of heart failure for cancer patients. Although various studies have demonstrated the cardioprotective property of dapagliflozin (DAPA), a sodium-glucose cotransporter 2 inhibitor, the detailed mechanism underlying its effect on Dox-induced cardiomyopathy is still limited. In this study, we showed that DAPA induced the activation of AKT/PI3K signaling in cardiac myoblast H9c2 cells following Dox treatment, leading to the upregulation of antioxidant HO-1, NQO1, and SOD, as well as an improved mitochondrial dysfunction via Nrf2. In addition, the reduced oxidative stress resulted in the downregulation of hypertrophy (ANP and BNP) and fibrosis (phospho-Smad3, collagen I, fibronectin, and α-SMA) markers. Furthermore, the inflammatory IL-8 concentration was inhibited after DAPA, possibly through PI3K/AKT/Nrf2/p38/NF-κB signaling. Moreover, our results were validated in vivo, and echocardiography results suggested an improved cardiac function in DAPA-receiving rats. In summary, we demonstrated that the administration of DAPA could mitigate the Dox-elicited cardiotoxicity by reducing oxidative stress, mitochondrial dysfunction, fibrosis, hypertrophy, and inflammation via PI3K/AKT/Nrf2 signaling.

Effects of Neural Mobilization on Sensory Dysfunction and Peripheral Nerve Degeneration in Rats With Painful Diabetic Neuropathy

OBJECTIVE

This study aims to evaluate the effectiveness of neural mobilization (NM) in the management of sensory dysfunction and nerve degeneration related to experimental painful diabetic neuropathy (PDN).

METHODS

This is a pre-clinical animal study performed in the streptozocin-induced diabetic rat model. Three groups were included: a treatment group of rats with PDN receiving NM under anesthesia (PDN-NM, n = 10), a sham treatment group of rats with PDN that received only anesthesia (PDN-Sham, n = 9), and a vehicle control group with nondiabetic animals (Vehicle, n = 10). Rats in the PDN-NM and PDN-Sham groups received 1 treatment session on days 10, 12, and 14 after streptozocin injection, with a 48-hour rest period between sessions. Behavioral tests were performed using von Frey and Plantar tests. Evaluation for peripheral nerve degeneration was performed through measuring protein gene product 9.5-positive intra-epidermal nerve fiber density in hind-paw skin biopsies. All measurements were performed by a blinded investigator.

RESULTS

The behavioral tests showed that a single NM session could reduce hyperalgesia, which was maintained for 48 hours. The second treatment session further improved this treatment effect, and the third session maintained it. These results suggest that it requires multiple treatment sessions to produce and maintain hypoalgesic effects. Skin biopsy analysis showed that the protein gene product 9.5-positive intra-epidermal nerve fiber density was higher on the experimental side of the PDN-NM group compared with the PDN-Sham group, suggesting NM may mitigate the degeneration of peripheral nerves.

CONCLUSION

This study demonstrated that NM may be an effective method to manage experimentally induced PDN, potentially through mitigation of nerve degeneration. Further studies are needed to develop standardized protocols for clinical use.

IMPACT

These findings provide neurophysiological evidence for the use of NM in PDN and can form the basis for the development of physical therapy-based programs in clinics.

Quercetin Mitigates Cisplatin-Induced Oxidative Damage and Apoptosis in Cardiomyocytes through Nrf2/HO-1 Signaling Pathway

Cisplatin is massively used to treat solid tumors. However, several severe adverse effects, such as cardiotoxicity, are obstacles to its clinical application. Cardiotoxicity may lead to congestive heart failure and even sudden cardiac death in patients receiving cisplatin. Therefore, finding a novel therapeutic strategy for the prevention of cisplatin-induced cardiotoxicity is urgent. Quercetin is a flavonol compound that can be found in dietary fruits and vegetables. The antioxidant function and anti-inflammatory capacity of quercetin have been reported. However, whether quercetin could protect against cisplatin-caused apoptosis and cellular damage in cardiomyocytes is still unclear. H9c2 cardiomyocytes were treated with cisplatin (40 μM) for 24 h to induce cellular damage with or without quercetin pretreatment. We found that quercetin activates Nrf2 and HO-1 expression, thereby mitigating cisplatin-caused cytotoxicity in H9c2 cells. Quercetin also increases SOD levels, maintains mitochondrial function, and reduces oxidative stress under cisplatin stimulation. Quercetin attenuates cisplatin-induced apoptosis and inflammation in H9c2 cardiomyocytes; however, these cytoprotective effects were diminished by silencing Nrf2 and HO-1. In conclusion, this study reports that quercetin has the potential to antagonize cisplatin-caused cardiotoxicity by reducing ROS-mediated mitochondrial damage and inflammation via the Nrf2/HO-1 and p38MAPK/NF-[Formula: see text]Bp65/IL-8 signaling pathway. This study provided the theoretical basis and experimental proof for the clinical application of quercetin as a new effective strategy to relieve chemotherapy-induced cardiotoxicity.

Galectin-3 facilitates inflammation and apoptosis in chondrocytes through upregulation of the TLR-4-mediated oxidative stress pathway in TC28a2 human chondrocyte cells

Osteoarthritis (OA) is a common degenerative joint disease. The pathological changes of chondrocytes involve oxidative stress, the pro-inflammatory response, and pro-apoptotic events. Galectin-3 (Gal-3) is a 35 kDa protein with a special chimeric structure. Gal-3 participates in the progression of many diseases, such as cancer metastasis and heart failure. A previous study demonstrated that Gal-3 expression in human cartilage with OA is increased. However, the role of Gal-3 in chondrocyte dysfunction in joints is still unclear. In this study, we applied Gal-3 (5-20 μg/ml) to TC28a2 human chondrocyte cells for 24 h to induce chondrocyte dysfunction. We found that Gal-3 upregulated TLR-4 and MyD88 expression and NADPH oxidase, thereby increasing intracellular ROS in the chondrocytes. Gal-3 increased phosphorylated MEK1/2 and ERK levels, and promoted NF-κB activity. This activation of NF-κB was reduced by silencing TLR-4 and NOX-2. In addition, Gal-3 caused apoptosis of chondrocytes through the mitochondrial-dependent pathway via the TLR-4/NADPH oxidase/MAPK axis. Our study proves the pathogenic role of Gal-3 in Gal-3-induced chondrocyte dysfunction and injuries.

Regulation of Oxidative Stress by Long Non-Coding RNAs in Vascular Complications of Diabetes

Diabetes mellitus is a well-known metabolic disorder with numerous complications, such as macrovascular diseases (e.g., coronary heart disease, diabetic cardiomyopathy, stroke, and peripheral vascular disease), microvascular diseases (e.g., diabetic nephropathy, retinopathy, and diabetic cataract), and neuropathy. Multiple contributing factors are implicated in these complications, and the accumulation of oxidative stress is one of the critical ones. Several lines of evidence have suggested that oxidative stress may induce epigenetic modifications that eventually contribute to diabetic vascular complications. As one kind of epigenetic regulator involved in various disorders, non-coding RNAs have received great attention over the past few years. Non-coding RNAs can be roughly divided into short (such as microRNAs; ~21–25 nucleotides) or long non-coding RNAs (lncRNAs; >200 nucleotides). In this review, we briefly discussed the research regarding the roles of various lncRNAs, such as MALAT1, MEG3, GAS5, SNHG16, CASC2, HOTAIR, in the development of diabetic vascular complications in response to the stimulation of oxidative stress.

Low-level laser prevents doxorubicin-induced skeletal muscle atrophy by modulating AMPK/SIRT1/PCG-1α-mediated mitochondrial function, apoptosis and up-regulation of pro-inflammatory responses

Background

Doxorubicin (Dox) is a widely used anthracycline drug to treat cancer, yet numerous adverse effects influencing different organs may offset the treatment outcome, which in turn affects the patient’s quality of life. Low-level lasers (LLLs) have resulted in several novel indications in addition to traditional orthopedic conditions, such as increased fatigue resistance and muscle strength. However, the mechanisms by which LLL irradiation exerts beneficial effects on muscle atrophy are still largely unknown.

Results

The present study aimed to test our hypothesis that LLL irradiation protects skeletal muscles against Dox-induced muscle wasting by using both animal and C2C12 myoblast cell models. We established SD rats treated with 4 consecutive Dox injections (12 mg/kg cumulative dose) and C2C12 myoblast cells incubated with 2 μM Dox to explore the protective effects of LLL irradiation. We found that LLL irradiation markedly alleviated Dox-induced muscle wasting in rats. Additionally, LLL irradiation inhibited Dox-induced mitochondrial dysfunction, apoptosis, and oxidative stress via the activation of AMPK and upregulation of SIRT1 with its downstream signaling PGC-1α. These aforementioned beneficial effects of LLL irradiation were reversed by knockdown AMPK, SIRT1, and PGC-1α in C2C12 cells transfected with siRNA and were negated by cotreatment with mitochondrial antioxidant and P38MAPK inhibitor. Therefore, AMPK/SIRT1/PGC-1α pathway activation may represent a new mechanism by which LLL irradiation exerts protection against Dox myotoxicity through preservation of mitochondrial homeostasis and alleviation of oxidative stress and apoptosis.

Conclusion

Our findings may provide a novel adjuvant intervention that can potentially benefit cancer patients from Dox-induced muscle wasting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00719-w.

Ipsilateral vascularised fibula with external locking plate for treatment of massive tibial bone defects

INTRODUCTION

Management of massive tibial bone defects remains challenging for orthopaedic doctors. This study aimed to ascertain the viability and reliability of utilising an ipsilateral vascularised fibula with an external locking plate for the difficult situation.

MATERIALS AND METHODS

Between January 2012 and December 2017, eight patients (7 men) with a mean age of 32.3 (19-54) years who presented with massive tibial bone defects were treated using the described technique. The mean length of the bone defect was 12.4 (8-20) cm. The patients were assessed for clinical and radiographic results, hypertrophy of the fibular graft with DeBoer and Wood's method, and SF-36 functional score.

RESULTS

The mean follow-up period was 40.3 (26-60) months. The average time for union was 5.6 (3-8) months. At the final follow-up, all patients had fully united grafts and walked without restriction. The mean graft hypertrophy index was 98.2 %. The SF-36 score was > 75 % in five patients, and 50-75 % in three. Three patients had a leg length discrepancy of > 1.5 cm. Two patients with equinus foot were treated using tibiotalocalcaneal fusion. Three patients had pin-tract infections. Four screws were broken in two cases.

CONCLUSION

Ipsilateral vascularised fibular transfer combined with an external locking plate as a definitive external fixator provides a simple and comfortable treatment, and appropriate mechanical loading and vascularisation of the graft site to achieve hypertrophy of the fibular graft. Hence, our technique can serve as a valuable alternative for the treatment of massive tibial bone defects.

Dapagliflozin attenuates hypoxia/reoxygenation-caused cardiac dysfunction and oxidative damage through modulation of AMPK

Background

Emerging evidence demonstrated dapagliflozin (DAPA), a sodium-glucose cotransporter 2 inhibitor, prevented various cardiovascular events. However, the detailed mechanisms underlying its cardioprotective properties remained largely unknown.

Results

In the present study, we sought to investigate the effects of DAPA on the cardiac ischemia/reperfusion (I/R) injury. Results from in vitro experiments showed that DAPA induced the phosphorylation of AMPK, resulting in the downregulation of PKC in the cardiac myoblast H9c2 cells following hypoxia/reoxygenation (H/R) condition. We demonstrated that DAPA treatment diminished the H/R-elicited oxidative stress via the AMPK/ PKC/ NADPH oxidase pathway. In addition, DAPA prevented the H/R-induced abnormality of PGC-1α expression, mitochondrial membrane potential, and mitochondrial DNA copy number through AMPK/ PKC/ NADPH oxidase signaling. Besides, DAPA reversed the H/R-induced apoptosis. Furthermore, we demonstrated that DAPA improved the I/R-induced cardiac dysfunction by echocardiography and abrogated the I/R-elicited apoptosis in the myocardium of rats. Also, the administration of DAPA mitigated the production of myocardial infarction markers.

Conclusions

In conclusion, our data suggested that DAPA treatment holds the potential to ameliorate the I/R-elicited oxidative stress and the following cardiac apoptosis via modulation of AMPK, which attenuates the cardiac dysfunction caused by I/R injury.

Anti-IL-20 Antibody Protects against Ischemia/Reperfusion-Impaired Myocardial Function through Modulation of Oxidative Injuries, Inflammation and Cardiac Remodeling

Acute myocardial infarction (AMI) is the most critical event in the disease spectrum of coronary artery disease. To rescue cardiomyocytes in AMI, it is important to restore blood supply as soon as possible to reduce ischemia-induced injury. However, worse damage can occur during the reperfusion phase, called the reperfusion injury. Under ischemia/reperfusion (I/R) injury, elevated oxidative stress plays a critical role in regulation of apoptosis, inflammation and remodeling of myocardium. Our previous study has demonstrated that interleukin (IL)-20 is increased during hypoxia/reoxygenation stimulation and promotes apoptosis in cardiomyocytes. This study was, therefore, designed to investigate whether IL-20 antibody could reduce I/R-induced myocardial dysfunction. Results from this study revealed that IL-20 antibody treatment significantly suppressed I/R-induced nicotinamide adenine dinucleotide phosphate oxidase, oxidative stress, apoptosis, proinflammatory responses, cardiac fibrosis, and expression of cardiac remodeling markers in Sprague-Dawley rats. Plasma B-type natriuretic peptide level was also reduced by IL-20 antibody injection. IL-20 antibody treatment appeared to restore cardiac function under the I/R injury in terms of greater values of ejection fraction and fractional shortening compared to the control group. Two commonly used indicators of cardiac injury, lactate dehydrogenase and creatine kinase-MB, were also lower in the IL-20 antibody injection group. Taken together, our results suggested that IL-20 antibody holds the potential to reduce the I/R-elicited cardiac dysfunction by preventing cardiac remodeling.

Effect of ultrasound-detected synovitis on therapeutic efficacy of hyaluronic acid injection for symptomatic knee osteoarthritis

Objective

To determine whether ultrasound (US)-detected synovitis affects the therapeutic efficacy of hyaluronic acid (HA) injection for treating knee OA.

Methods

Patients with symptomatic knee OA were recruited. All the patients received HA injection two times at 2-week intervals. Clinical assessments were performed using a visual analogue scale (VAS) and the Western Ontario and McMaster Universities OA Index (WOMAC) at baseline and 1 and 6 months after treatment. Imaging evaluation was based on complete knee US examination and the Kellgren–Lawrence grading. Suprapatellar synovial fluid (SF) depth, synovial hypertrophy (SH) and vascularity were measured through US.

Results

In total, 137 patients who fulfilled the inclusion criteria were included in the analysis. All patients demonstrated improvement in VAS and WOMAC scores at 1 and 6 months after treatment (P < 0.001). Moreover, regression model-based analysis revealed significant associations of SF depth with the VAS and WOMAC scores in all patients. Each centimetre increase in the effusion diameter was associated with a decrease in the 1-month post-treatment VAS improvement percentage (15.26; 95% CI: 0.05, 29.5; P = 0.042) and 6-month post-treatment WOMAC improvement (37.43; 95% CI: 37.68, 50.69; P < 0.01). However, SH and vascularity were not significantly associated with VAS or WOMAC scores.

Conclusion

Ultrasound detected suprapatellar effusion predicts reduced efficacy of HA injection in knee OA

Real-time exercise reduces impaired cardiac function in breast cancer patients undergoing chemotherapy: a randomized controlled trial

BACKGROUND

Previous studies have reported that chemotherapy results in substantial long-term risk of heart failure. Exercise ameliorates exercise responses and exercise tolerance in patients receiving chemotherapy. The cardioprotective effect of real-time exercise in breast cancer is still unclear.

OBJECTIVES

The aim of the present study was to determine the effect of real-time moderate-to-high-intensity exercise training in women with breast cancer undergoing chemotherapy and to follow up on parameters of cardiac function and exercise capacity at different times. We hypothesized that early moderate-to-high-intensity exercise training has beneficial effects on cardiac function in women with breast cancer undergoing chemotherapy.

METHODS

This was a randomized controlled study that included 32 women randomly allocated into the control or exercise group. Exercise began with the first cycle of chemotherapy, and the training program was maintained during chemotherapy with 2 to 3 sessions per week for 3 months. Patients were instructed to perform moderate-to-high-intensity training with aerobic and resistance training. Outcome measurements were echocardiography and cardiopulmonary exercise test. The primary outcome was the change in left ventricle ejection fraction (LVEF). The secondary outcome was peak oxygen consumption (peak VO₂).

RESULTS

The control group showed lower cardiac systolic function than the exercise group [mean (SD) LVEF 62% (2) and 70% (5), p < 0.05], reduced cardiac diastolic function, and cardiac hypertrophy at 3, 6 and 12 months after chemotherapy. At 6 months after chemotherapy, the exercise group exhibited relatively higher exercise capacity than controls [mean (SD) VO₂ 12.1 (2.2) and 13.6 (2.2) mL/kg/min, p < 0.05]. The main effect size of the study based on echocardiography outcomes was 0.25 (95% confidence interval 0.23 to 0.27), a medium effect size.

CONCLUSIONS

Moderate-to-high-intensity exercise training in breast cancer patients undergoing chemotherapy may prevent impaired cardiac function.

Epigallocatechin Gallate Reduces Homocysteine-Caused Oxidative Damages through Modulation SIRT1/AMPK Pathway in Endothelial Cells

Elevated plasma concentration of total homocysteine is a pathological condition that causes vascular endothelial injury and subsequently leads to the progression of endothelial apoptosis in atherosclerosis. Epigallocatechin gallate (EGCG), a well-known anti-oxidant in green tea, has been reported with benefits on metabolic and cardiovascular diseases. This study aimed to explore that EGCG ameliorates homocysteine-induced endothelial cell apoptosis through enhancing the sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) survival signaling pathway. Human umbilical endothelial cells were treated with homocysteine in the presence or absence of EGCG. We found that EGCG significantly increased the activities of SIRT1 and AMPK. EGCG diminished homocysteine-mediated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation by inhibiting protein kinase C activation as well as reactive oxygen species (ROS) generation and recovered the activity of the endogenous antioxidant enzyme, superoxidase dismutase (SOD). Besides, EGCG also restores homocysteine-mediated dephosphorylation of Akt and decreases endothelial NO synthase (eNOS) expression. Furthermore, EGCG ameliorates homocysteine-activated pro-apoptotic events. The present study shows that EGCG prevents homocysteine-induced endothelial cell apoptosis via enhancing SIRT1/AMPK as well as Akt/eNOS signaling pathways. Results from this study indicated that EGCG might have some benefits for hyperhomocysteinemia.

Oxidative stress mediates age-related hypertrophy of ligamentum flavum by inducing inflammation, fibrosis, and apoptosis through activating Akt and MAPK pathways

The role of oxidative stress in ligamentum flavum (LF) hypertrophy has not been elucidated. We hypothesize that oxidative stress induces inflammatory responses and the subsequent fibrotic processes in LF, via activation of the Akt and MAPK pathways. Specimens of LFs were collected during surgeries for lumbar disc herniation (LDH) or lumbar spinal stenosis (LSS). Part of the LF specimens underwent analyses for ROS, fibrotic markers, and inflammatory mediators, with the remainder minced for cell cultures. The cell cultures were treated with H₂O₂, after which the cells were lysed and analyzed via western blotting. The specimens of the LSS patients showed increased infiltration of inflammatory cells and were stained positively for MMP-3, MMP-9, vimentin, and fibronectin. The LF of the LSS patients had increased oxidative stress and inflammation compared to that of the LDH patients. In vitro analyses demonstrated that oxidative stress rapidly activated the Akt and MAPK pathways. Inflammatory mediators, iNOS and NF-κB, and fibrotic markers, including TGF-β, β-catenin, α-SMA and vimentin, were significantly upregulated after induction of oxidative stress. Oxidative stress activated the intrinsic apoptotic pathway. These findings revealed that oxidative stress is one of the etiological factors of LF hypertrophy, which might provide new insights into treatment approaches.