UBR2 targets myosin heavy chain IIb and IIx for degradation: Molecular mechanism essential for cancer-induced muscle wasting

Cancer cachexia is a lethal metabolic syndrome featuring muscle wasting with preferential loss of fast-twitching muscle mass through an undefined mechanism. Here, we show that cancer induces muscle wasting by selectively degrading myosin heavy chain (MHC) subtypes IIb and IIx through E3 ligase UBR2-mediated ubiquitylation. Induction of MHC loss and atrophy in C2C12 myotubes and mouse tibialis anterior (TA) by murine cancer cells required UBR2 up-regulation by cancer. Genetic gain or loss of UBR2 function inversely altered MHC level and muscle mass in TA of tumor-free mice. UBR2 selectively interacted with and ubiquitylated MHC-IIb and MHC-IIx through its substrate recognition and catalytic domain, respectively, in C2C12 myotubes. Elevation of UBR2 in muscle of tumor-bearing or free mice caused loss of MHC-IIb and MHC-IIx but not MHC-I and MHC-IIa or other myofibrillar proteins, including α-actin, troponin, tropomyosin, and tropomodulin. Muscle-specific knockout of UBR2 spared KPC tumor-bearing mice from losing MHC-IIb and MHC-IIx, fast-twitching muscle mass, cross-sectional area, and contractile force. The rectus abdominis (RA) muscle of patients with cachexia-prone cancers displayed a selective reduction of MHC-IIx in correlation with higher UBR2 levels. These data suggest that UBR2 is a regulator of MHC-IIb/IIx essential for cancer-induced muscle wasting, and that therapeutic interventions can be designed by blocking UBR2 up-regulation by cancer.

Cancer-Induced Muscle Wasting Requires p38β MAPK Activation of p300

Cancer-associated cachexia, characterized by muscle wasting, is a lethal metabolic syndrome without defined etiology or established treatment. We previously found that p300 mediates cancer-induced muscle wasting by activating C/EBPβ, which then upregulates key catabolic genes. However, the signaling mechanism that activates p300 in response to cancer is unknown. Here, we show that upon cancer-induced activation of Toll-like receptor 4 in skeletal muscle, p38β MAPK phosphorylates Ser-12 on p300 to stimulate C/EBPβ acetylation, which is necessary and sufficient to cause muscle wasting. Thus, p38β MAPK is a central mediator and therapeutic target of cancer-induced muscle wasting. In addition, nilotinib, an FDA-approved kinase inhibitor that preferentially binds p38β MAPK, inhibited p300 activation 20-fold more potently than the p38α/β MAPK inhibitor, SB202190, and abrogated cancer cell-induced muscle protein loss in C2C12 myotubes without suppressing p38α MAPK-dependent myogenesis. Systemic administration of nilotinib at a low dose (0.5 mg/kg/day, i.p.) in tumor-bearing mice not only alleviated muscle wasting, but also prolonged survival. Therefore, nilotinib appears to be a promising treatment for human cancer cachexia due to its selective inhibition of p38β MAPK. SIGNIFICANCE: These findings demonstrate that prevention of p38β MAPK-mediated activation of p300 by the FDA-approved kinase inhibitor, nilotinib, ameliorates cancer cachexia, representing a potential therapeutic strategy against this syndrome.

Associations of maternal upper respiratory tract infection/influenza during early pregnancy with congenital heart disease in offspring: evidence from a case-control study and meta-analysis

Background

Evidences regarding the associations between maternal upper respiratory tract infection/influenza during pregnancy and the risk of congenital heart disease (CHD) is still controversial. This study was specifically designed to examine the associations by a case-control study and a meta-analysis of the published evidences and our finding.

Methods

A hospital-based case-control study involving 262 children with simple CHD and 262 children with complex CHD, along with 262 control children, was conducted through June, 2016 to December, 2017. All children were aged 0–2 years old. Furthermore, a meta-analysis based on both previously published studies and our case-control study was performed.

Results

In the case-control study, after adjusting for possible confounders, maternal upper respiratory tract infection/influenza during early pregnancy was found to be related to an increased risk of CHD (OR = 3.40 and 95% CI: 2.05–5.62 for simple CHD; OR = 2.39 and 95% CI: 1.47–3.88 for complex CHD). After a meta-analysis, the adverse impact was still kept significant (OR = 1.47 and 95% CI: 1.28–1.67 for simple CHD; OR = 1.44 and 95% CI: 1.14–1.75 for complex CHD). The very similar associations were also observed among single type of CHD, herein, ventricular septal defects (VSD) and tetralogy of fallot (TOF) in the case-control study. In the subsequent meta-analysis, however, the significant association only existed in VSD.

Conclusions

Although there is still conflicting in TOF, the results are overall consistent, which provide new enforced evidence that maternal upper respiratory tract infection/influenza during early pregnancy, in general, play an important role in the occurrence of CHD.

p300 Mediates Muscle Wasting in Lewis Lung Carcinoma

C/EBPβ is a key mediator of cancer-induced skeletal muscle wasting. However, the signaling mechanisms that activate C/EBPβ in the cancer milieu are poorly defined. Here, we report cancer-induced muscle wasting requires the transcriptional cofactor p300, which is critical for the activation of C/EBPβ. Conditioned media from diverse types of tumor cells as well as recombinant HSP70 and HSP90 provoked rapid acetylation of C/EBPβ in myotubes, particularly at its Lys39 residue. Overexpression of C/EBPβ with mutated Lys39 impaired Lewis lung carcinoma (LLC)-induced activation of the C/EBPβ-dependent catabolic response, which included upregulation of E3 ligases UBR2 and atrogin1/MAFbx, increased LC3-II, and loss of muscle proteins both in myotubes and mouse muscle. Silencing p300 in myotubes or overexpressing a dominant negative p300 mutant lacking acetyltransferase activity in mouse muscle attenuated LLC tumor-induced muscle catabolism. Administration of pharmacologic p300 inhibitor C646, but not PCAF/GCN5 inhibitor CPTH6, spared LLC tumor-bearing mice from muscle wasting. Furthermore, mice with muscle-specific p300 knockout were resistant to LLC tumor-induced muscle wasting. These data suggest that p300 is a key mediator of LLC tumor-induced muscle wasting whose acetyltransferase activity may be targeted for therapeutic benefit in this disease. SIGNIFICANCE: These findings demonstrate that tumor-induced muscle wasting in mice is abrogated by knockout, mutation of Lys39 or Asp1399, and pharmacologic inhibition of p300.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/7/1331/F1.large.jpg.

Using an abnormal increase in postexercise systolic blood pressure to diagnose coronary artery disease in gerontal patients

Data from 66 patients ≥ 60 years old with suspected coronary artery disease (CAD) were studied to determine the diagnostic value of an abnormal increase in postexercise systolic blood pressure (SBP) for detecting CAD in gerontal patients. Treadmill exercise testing (TET) and selective coronary angiography (CAG) were carried out and SBP was measured pre-TET and at each minute during a 6-min post-TET recovery phase. Abnormal increase in postexercise SBP was defined as a higher SBP compared with that measured earlier during the 6-min post-TET period. An abnormal increase of ≥ 7 mmHg in postexercise SBP had a statistically significantly better specificity, and also showed higher sensitivity and accuracy, than ST-segment depression ≥ 1 mV in identifying gerontal patients with CAD. The combination of ST-segment depression and abnormal SBP resulted in further improvement of the specificity for detecting CAD. It is concluded that measurement of abnormal increase in postexercise SBP may be a sensitive indicator of gerontal CAD.

Nanocrystalline silicon-based oligonucleotide chips

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).

Primary study of vascular endothelial growth factor immunohistochemical staining in the diagnosis of early acute myocardial ischemia

The expression of vascular endothelial growth factor (VEGF) in the model of rat early acute myocardial ischemia was studied by Strept-Avidin-Biotin-Peroxidase Complex (SABC) immunohistochemical staining. After ligating the anterior descending branch of the left coronary artery, an initial rapid (30min) positive expression of VEGF in myocardial ischemic areas was observed, the intensity of positive expression of VEGF increased with the continuation of myocardial ischemia. After 5h infarction, the strongly positive myocytes of SABC-VEGF staining were predominantly limited to perimyocardial infarction areas. No positive expression of VEGF was found in the control group. These findings suggested that SABC-VEGF method could give a sensitive, specific, simple and objective morphologic evidence to the diagnosis of sudden cardiac death caused by acute early myocardial ischemia.

[Histochemical observation of changes of neurons and axons in injured brainstem]

Brainstem of rats were stabbed with a needle and pathological changes of neurons and axons in brainstem were observed at different time after injury with Nissl's body staining, silver staining and modified trichrome staining. It was found that, by silver staining, the axons showed irregular swelling and disconnection at 1-3 h, marked swelling of the severe end at 6 h, retraction ball at 15 h and remarkable retraction ball at 24 h. By modified trichrome staining, the space between myelin sheaths and axons was widened at 3-6 h, and tortuous myelin sheaths adhered incompletely on axons, or even peeled off at 15 h to 24 h. Perinuclear lysis of Nissl's bodies at 24 h after injury could be seen by Nissl body staining. The results indicated that, the pathological changes in injured brainstem could be observed with histochemical staining, which might be used for timing brainstem injuries.

[Study on the specificity of complement C5 for the postmortem diagnosis of myocardial infarction]

In order to explore the specificity of complement C5 in the postmortem diagnosis of myocardial infarction, changes of C5 staining in normal, infarcted and other non-infarcted myocardia with direct or indirect myocardial injuries (myocarditis, mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion and organophosphate poisoning) were studied with immunohistochemistry and image analysis. The results showed that positive C5 staining could be observed in groups of myocardial infarction and myocarditis, but not in groups of mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion, and organophosphate poisoning. It is indicated that positive reaction of C5 could only be affected by myocarditis, which means that it was more specific for the diagnosis of myocardial infarction.

[Gas chromatographic and gas chromatography-mass spectrometric analyses of aromatic hydrocarbons in oils and rock extracts simultaneously by using bench-top gas chromatograph-mass spectrometer]

This article reports a successful example that an injected sample is simultaneously introduced into two fused silica capillary columns and detected separately by a flame ionization detector (FID) and an HP 5973 mass selective detector (MSD) both installed on an HP 6890 Gas Chromatograph. This GC and GC/MS analyses of aromatic hydrocarbons in oils and rock extracts were carried out by using this method and good results were achieved. This method is of great value in organic geochemistry research because it is efficient and economical.

[Immunohistochemical study on myocardial acute ischemia reperfusion injury in rats with anti-FOS protein antibody]

To investigate law of FOS protein induced by myocardial ischemia reperfusion (MI/R) in acute period, a model in 20 anaethetized SD rats was established. Rats with normal and ischemia were used as control groups. Specimens were studied immunohistochemically with c-fos antibody. After ischemia 20 minutes, followed by 30 minutes reperfusion, the area of MI/R showed nuclei of myocytes positive staining in cryosection slides. In C2 group, the area showed nuclei of myocytes (37.76% +/- 9.66%) positive staining weakly. In C3 group, nuclei of cardiac myocytes(40.34% +/- 3.32%) was significantly positive. In C4 group it began to attenuate(35.36% +/- 4.81%). The myocardium in normal and ischemic control groups showed negative staining. No changes were seen with HE staining. Our data indicated that immunohistochemical method may reveal acute MI/R injury of ischemia 20 min and reperfusion 30 min with anti-FOS protein staining and there is problely a peak between 60-120 min after reperfusion. It is possible that the method be used to diagnose sudden cardiac death in forensic medicine.

[Evaluation of anti-muscle actin monoclonal antibody HHF35 in the diagnosis of early myocardial infarction]

In order to explore the specificity of anti-muscle actin monoclonal antibody HHF35 in the postmortem diagnosis of early myocardial infarction, the changes of HHF35 staining in the infarcted myocardia and other non-infarcted myocardia with direct or indirect myocardial injury were studied with immunohistochemical S-P method. The results showed that the loss of HHF35 staining of different degrees was found in the infarcted myocardia, but also in the other non-infarcted myocardia with direct or indirect myocardial injury, such as cardiac contusion, myocarditis, hemorrhagic shock, electrocution, mechanical asphyxia. So it should be cautious in diagnosing early myocardial infarction with HHF35 immunohistochemistry.

[Brainstem changes in death from head injury]

The cortex and brainstem changes in death from head injury were observed. There were hemorrhage, edema and neuron necrosis in brain injury group, and also in disputed group of brainstem injury.

[Observation of repair of wounded rat skin by affinity histochemical method of SJA]

Time expression of SJA tissue receptors surrounding wounded skin of 40 rats was studied by affinity histochemical method. The results were compared to that by EGFR immunohistochemical method and c-myc situ hydridization method. It was observed that SJA receptors began to decrease after the skin was injured and reached the lowest quantities in 15 minutes. After that, they began to increase and reached the highest quantities in 2 hours. It needs to be further studied whether there is the correlation between SJA receptors and EGFR has the function of repairing wounded skin.

Acrobeads test as a predictor of fertilization in vitro

PROBLEM

To determine whether the results of the Acrobeads test, which measures the expression of the complement regulator molecule CD46 on the inner acrosomal membrane following the acrosome reaction, accurately identifies semen specimens that will exhibit reduced or failed fertilization following conventional IVF insemination.

METHOD

The Acrobeads test was performed on semen specimens from 97 consecutive patients preparing to undergo an IVF cycle utilizing a standardized insemination protocol. Motile sperm populations were examined at 6 h and 24 h post-isolation for sperm-bead agglutination. Results of the Acrobeads test were compared to that of TRITC-PSA staining in matched specimens to directly measure the spontaneous loss of acrosome content. The percentages of TRITC-PSA-negative sperm were determined in freshly isolated motile populations and in duplicate aliquots incubated 18 to 20 h under sperm capacitating conditions. The relationship between the results of both analyses estimating spontaneous acrosome reactions and the rate of fertilization of metaphase II oocytes was examined.

RESULTS

The Acrobeads score did not correlate significantly with the rate of fertilization by insemination at 6 h or at 24 h. The negative predictive value of this test was 21.4%. There was no correlation between the Acrobeads score and the percentage of sperm undergoing a spontaneous acrosome reaction as detected by TRITC-PSA labeling. In contrast, the increment increase in the percentage of spontaneous acrosome reactions as quantified by TRITC-PSA staining was correlated with the fertilization rate.

CONCLUSIONS

Contrary to previous reports, our prospective, double-blinded study failed to demonstrate that the Acrobeads test can accurately predict fertilization outcome in IVF. Therefore, the routine use of this test to screen patients prior to an IVF cycle in order to select appropriate treatment (i.e., ICSI) cannot be recommended.

Immunohistochemical study of fibronectin for postmortem diagnosis of early myocardial infarction

The postmortem diagnosis of early myocardial infarction has been a puzzling problem in forensic practice. In the present study, an immunohistochemical study of fibronectin (FN) was performed for the first time on 34 autopsy hearts to determine early myocardial infarction with streptavidin/biotin/peroxidase technique. Five cases of definite myocardial infarction showed positive FN staining of cardiomyocytes; of 18 cases where early myocardial infarction was suspected, positive FN staining of cardiomyocytes was found in 15 cases, but no such staining was seen in 11 non-cardiac death controls. The results led to the conclusion that positive FN staining in cardiomyocytes is a reliable marker of acute myocardial infarction and could be used as a new, sensitive method for the postmortem diagnosis of early myocardial infarction. It is worth noting that all cases in this study were autopsied between 8 h and 4 days after death and 5 cases had been fixed in 10% formalin for over 10 years. FN immunohistochemistry still gave satisfactory results in those cases. It seemed that FN was not affected by postmortem autolysis and formalin-fixation and could be used in routine forensic practice, especially for retrospective analysis of cases.

Diagnostic value of ions as markers for differentiating antemortem from postmortem wounds

In the present study, the diagnostic value of ions as markers for differentiating antemortem from postmortem wounds was investigated. To accomplish this, skin and muscle samples were taken from antemortem and postmortem wounded cadavers and the contents of ions (Fe, Zn, Mg, Cu, K and Na) were determined with atomic absorption spectrophotometry. Our results show that the concentrations of Fe in antemortem wounded skin and muscle were significantly higher as compared with the control skin and muscle and the K/Na ratio in antemortem wounded muscle was reduced significantly compared to control muscle. However, the concentrations of Zn, Mg, Cu in antemortem wounded skin and muscle, and the K/Na ratio in antemortem wounded skin, were not significantly different from their controls. The concentrations of all these ions in postmortem wounded skin and muscles were not significantly different from their controls. It is indicated that the concentrations of Fc in skin and muscle and K/Na ratio in muscle are useful markers for differentiating antemortem from postmortem wounds. However, their routine use in forensic practice needs further investigation, since there are some overlaps of the ionic concentrations between normal and wounded skin and muscle.

[Dynamic investigation of antithrombin III in the plasma of patients with acute myocardial infarction]

Antithrombin III level in the plasma of patients with AMI was determined dynamically by using the methods of chromogenic substrate and rocket electrophoresis. Meanwhile, plasma specimens of 40 normal subjects were examined with the same method. The results showed that the AT III level in AMI patients was much lower than that in normal controls at the first and third day after infarction. The level was also significantly lower than that at the 7th, 14th and 21st day after the onset of the disease. It revealed that there was a hypercoagulative state in patients within the first three days of infarction. The AT III level in patients who died within ten days was much lower than that in the survivor group, P less than 0.01. The authors concluded that a patient may be in a severe condition when their plasma AT III levels decrease apparently and persistently.

Preliminary report on a new method of human age estimation from single adult teeth

A total of 317 upper and lower third molars were randomly divided into working and control samples and used to estimate chronological age employing a method which combined multiple regression analysis of data from Gustafson's and Maples's scoring system, direct morphological measurements obtained with a Kontron image analysis system and logarithmic data transformation. The standard errors of estimate were 2.4-6.8 years in the working sample and 1.9-7.5 years when the derived formulae were tested on the control sample, respectively. Compared to previous studies, this method provides a smaller standard error of estimate from a single molar tooth. The method is presently being tested on other tooth categories, like premolars, canines and other types of molars.

Study on the microstructures of skull fracture

The authors observed the edges of skull fractures under the scanning electron microscope. Many microfractures can be found along the main fracture lines. The width of the microfractures varies from 5 to 100 microns. They may be located either in the external compact bone or between the outer compact bone and diplöe, or in the diplöe. Those within the diplöe form transverse, longitudinal or spiral fractures of bony trabeculae. Collagenous fibre bunches in the bony matrix may be divided or broken and the different layers of collagenous fibre may be separated. The blood vessels inside the skull may be crosscut or longitudinally torn by the fracture lines. Sometimes the torn blood vessels may be drawn out of the Haversian canals. In antemortem fractures, the fibrin networks and red blood cells can be easily found in the depths of those cracks. The possible mechanism of formation of the microfractures and the possibility of differentiation between ante- and post-mortem fractures are discussed.

The significance of detecting serum fluorine level in the diagnosis of drowning

In view of the high content of fluorine in the water of a vast area of Guangdong Province, we detected the serum fluorine level in rabbits that died of drowning and compared them with those obtained from rabbits immersed in water after death from hanging. The fluorine content in water is about 15-fold higher than in the normal serum content. In drowned rabbits, the serum fluorine values are significantly higher than normal while in control cases the serum fluorine values are slightly lower than normal. The fluorine content in human serum is similar with that of rabbits. It suggests that detection of serum fluorine content might be a valuable method for the diagnosis of drowning in those areas where there are high water fluorine content.

[Analysis of 128 cases of multiple myeloma and 31 cases of monoclonal gammapathies of undetermined significance]

Monoclonal immunoglobulin from 138 patients with multiple myeloma (MM) showed that 68 patients were of IgG type, 23 of IgA type,33 of BJ type, 6 of IgD type, one of IgM type, 5 of nonsecreting type and the remaining 2 of IgA and IgG double monoclonal type. Urinary Bence Jones protein was tested with concentrated urine specimen with a positive rate of 75%. Classification of light chain revealed the ratio of oK/L being 1.09:1. The difference of distribution of K or L among IgG, IgA BJ types was no significant. 31 cases with monoclonal gammapathies of undetermined significance (MGUS) were also analyzed in this study. There were some difficulties in the differential diagnosis of MGUS and MM,but a significant difference was present in the plasma cell percentage of bone marrow smear of the two groups. Dynamic investigation in this series showed that patients with percentage of plasma cell less than 10% persisting for a long duration are likely to have MGUS only.

[Significance of serum beta 2-microglobulin in the differential diagnosis of benign and malignant M-globulinemia]

Serum beta 2-microglobulin (S beta 2-M) and marrow plasma cell count were surveyed in 30 cases of M-globulinemia. The average value of S beta 2-M and number of patients with increased value were much higher in 20 malignant than 10 benign patients including cases of undetermined causes of M-globulinemia (P less than 0.005) with the same results as traditional examination of plasma cell. This method is useful in the differential diagnosis of benign and malignant cases. However, for those patients with undetermined causes of M-globulinemia and different lengths of disease course, the values may vary to a greater extent. In 11 cases multiple myeloma the value of S beta 2-M was high before treatment and decreased after chemotherapy. When the disease was exacerbated (as in 2 cases before dying), the value remained high persistently. Therefore, serum beta 2-M level can be used to predict the therapeutic effect as well as the prognosis.