Altered expression of mitofusin 2 in penile tissues of diabetic rats

Diabetic erectile dysfunction (ED) is a common complication in diabetes mellitus, and the efficacy of first-line therapies is not satisfactory. Recent studies revealed that corporal apoptosis was responsible for the nonresponsiveness of severe ED to phosphodiesterase type 5 inhibitors. Mitofusin 2 (Mfn2) is a versatile protein, regulating mitochondrial morphology and playing an important role in apoptosis. Several studies showed that expression of Mfn2 was decreased in STZ-induced diabetic rats' kidney, myocardium and retina, which was associated with diabetic nephropathy, cardiomyopathy and retinopathy respectively. In this study, our aim was to explore the expression of Mfn2 and apoptosis in diabetic rats' penes. We found that erectile function (ICP/MAP) elicited by electrical stimulation of cavernous nerve was markedly impaired in diabetic rats compared with the normal rats. The mRNA and protein levels of Mfn2 were found to be significantly reduced in diabetic rats' penile tissues. Compared with normal rats, the content of smooth muscle and B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio were dramatically decreased, and penile apoptotic index and expression of activated-caspase-3 were dramatically increased in diabetic rats. This data indicated that repression of Mfn2 in diabetic rats' penes might be associated with excessive apoptosis in diabetes-induced severe ED.

Developmental kinetics of pig embryos by parthenogenetic activation or by handmade cloning

The developmental kinetics of pig embryos produced by parthenogenetic activation without (PAZF) or with (PAZI) zona pellucida or by handmade cloning (HMC) was compared by time-lapse videography. After cumulus cell removal, the matured oocytes were either left zona intact (PAZI) or were made zona free by pronase digestion (PAZF) before they were activated (PA). Other matured oocytes were used for HMC based on foetal fibroblast cells. On Day 0 (day of PA or reconstruction), the embryos were cultured for 7 days in vitro in our time-lapse system. Pictures were taken every 30 min, and afterwards, each cell cycle was identified for each embryo to be analysed. Results showed that the PA embryos (both PAZF and PAZI) had shorter first cell cycle compared with HMC (17.4. 17.8 vs 23.6 h), but had a longer time length from four cell to morula stages (57.9, 53.8 vs 44.9 h). However, at the second cell cycle, PAZF embryos needed shorter time, while PAZI embryos had similar time length as HMC embryos, and both were longer than PAZF (23.4, 24.8 vs 14.6 h). Both PAZF and PAZI embryos used similar time to reach the blastocyst stage, and this was later than HMC embryos. In addition, when all of these embryos were grouped into viable (developed to blastocysts) and non-viable (not developed to blastocysts), the only difference in the time length was observed on the first cell cycle (18.6 vs 24.5 h), but not on the later cell cycles. In conclusion, our results not only give detailed information regarding the time schedule of in vitro-handled pig embryos, but also indicate that the first cell cycle could be used as a selecting marker for embryo viability. However, to evaluate the effect of the produced techniques, the whole time schedule of the pre-implantation developmental kinetics should be observed.

Pharmacokinetic and bioequivalence studies of ibuprofen suspension after a single-dose administration in healthy Chinese volunteers

OBJECTIVE

The aim of this study was to assessed the pharmacokinetic and bioequivalence of 2 formulations of ibuprofen suspension.

METHOD

20 healthy volunteers were enrolled into this random, single-dose, 2-way crossover, open-label, single-centre, pharmacokinetic study. After overnight fasting, 2 formulations (test and reference) of ibuprofen (400 mg ibuprofen/20 mL suspension) were administered as a single dose on 2 treatment days separated by a 7-day washout period. After dosing, blood samples were drawn for a period of 12 h. The plasma samples were analyzed for the presence of ibuprofen by HPLC with ultraviolet detection. Pharmacokinetic parameters were determined from plasma concentrations for both formulations.

RESULTS

The main pharmacokinetics parameters of test and reference were as follows: t1/2 was (1.94±0.38) h and (1.95±0.28) h; Cmax was (33.41±7.83) μg · mL- 1 and (31.08±9.30) μg · mL- 1; AUC0-12 was (91.44±19.26) μg · mL-1 · h and (84.75±24.45) μg · mL-1 · h; AUC0-∞ was (92.82±19.94) μg · mL-1 · h and (85.97±24.99) μg · mL-1 · h; median Tmax was 0.5 h (range, 0.25, 2) and 0.5 h (range, 0.25, 1.5). The 90% confidence intervals of the test/reference treatment ratios for Cmax, AUC0-12 and AUC0-∞ were observed to be within the predetermined acceptable interval of 80-125%.

CONCLUSION

This single-dose study in healthy Chinese fasted volunteers was shown that the ibuprofen test and reference met the requirement of the State Food and Drug Administration, and the test and reference were bioequivalent.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The organizing principle of the platelet glycoprotein Ib-IX-V complex

The glycoprotein (GP)Ib-IX-V complex is the platelet receptor for von Willebrand factor and many other molecules that are critically involved in hemostasis and thrombosis. The lack of functional GPIb-IX-V complexes on the platelet surface is the cause of Bernard-Soulier syndrome, a rare hereditary bleeding disorder that is also associated with macrothrombocytopenia. GPIb-IX-V contains GPIbα, GPIbβ, GPIX and GPV subunits, all of which are type I transmembrane proteins containing leucine-rich repeat domains. Although all of the subunits were identified decades ago, not until recently did the mechanism of complex assembly begin to emerge from a systematic characterization of inter-subunit interactions. This review summarizes the forces driving the assembly of GPIb-IX-V, discusses their implications for the pathogenesis of Bernard-Soulier syndrome, and identifies questions that remain about the structure and organization of GPIb-IX-V.

[Chronic periapical periodontitis of left maxillary first premolar with localized mineralized structure at periapical region: a case report]

Chronic periapical periodontitis is characterized by destruction of periapical tissue and demonstrates translucent feature under X-ray examination. In this article, a localized mineralized structure, which showed high density under X-ray examination, was reported in a patient with chronic periapical periodontitis of left maxillary first premolar. Possible causes of the structure were analyzed and relevant literatures were reviewed.

miR-21 is a key therapeutic target for renal injury in a mouse model of type 2 diabetes

AIMS/HYPOTHESIS

As microRNA-21 (miR-21) plays a pathological role in fibrosis, we hypothesised that it may be a therapeutic target for diabetic nephropathy.

METHODS

Abundance of miR-21 was examined in diabetic kidneys from db/db mice. The therapeutic potential of miR-21 in diabetic kidney injury was examined in db/db mice by an ultrasound-microbubble-mediated miR-21 small hairpin RNA transfer. In addition, the role and mechanisms of miR-21 in diabetic renal injury were examined in vitro under diabetic conditions in rat mesangial and tubular epithelial cell lines by overexpressing or downregulating miR-21.

RESULTS

In db/db mice, a mouse model of type 2 diabetes, renal miR-21 at age 20 weeks was increased twofold compared with db/m (+) mice at the same age, and this increase was associated with the development of microalbuminuria and renal fibrosis and inflammation. More importantly, gene transfer of miR-21 knockdown plasmids into the diabetic kidneys of db/db mice at age 10 weeks significantly ameliorated microalbuminuria and renal fibrosis and inflammation at age 20 weeks, revealing a therapeutic potential for diabetic nephropathy by targeting miR-21. Overexpression of miR-21 in kidney cells enhanced, but knockdown of miR-21 suppressed, high-glucose-induced production of fibrotic and inflammatory markers. Targeting Smad7 may be a mechanism by which miR-21 regulates renal injury because knockdown of renal miR-21 restored Smad7 levels and suppressed activation of the TGF-β and NF-κB signalling pathways.

CONCLUSIONS/INTERPRETATION

Inhibition of miR-21 might be an effective therapy for diabetic nephropathy.

Paradoxical role of autophagy in the dysplastic and tumor-forming stages of hepatocarcinoma development in rats

Many reports have shown that autophagy has a role as both a promoter and inhibitor in tumor development. However, the mechanism of this paradox is unknown. Tumor development is a multistep process. Therefore, we investigated whether the role of autophagy in hepatocarcinoma formation depended on the stage of tumor development. Based on our results, autophagy inhibition by chloroquine had a tumor-promotive effect in the rat model with N-diethylnitrosamine-induced hepatocarcinogenesis in its dysplastic stage (Ds) and a tumor-suppressive effect in its tumor-forming stage (Ts). In the Ds, autophagy inhibition enhanced cell proliferation, DNA damage and inflammatory cytokines expression in liver. These changes were dependent on the upregulation of reactive oxygen species (ROS) that was resulted from autophagy inhibition, and ultimately accelerated the process of hepatocarcinogenesis. However, in the Ts, autophagy inhibition restrained tumor formation by decreasing tumor cell survival and proliferation. In this stage, autophagy inhibition led to excessive ROS accumulation in the tumor, which promoted cell apoptosis, and prominently suppressed tumor cell metabolism. Taken together, our data suggested that autophagy suppressed hepatocarcinogenesis in the Ds by protecting normal cell stability and promoted hepatocarcinogenesis in the Ts by supporting tumor cells growth. Autophagy always had a role as a protector throughout the process of hepatocarcinoma development.

Identification of novel ROCK inhibitors with anti-migratory and anti-invasive activities

ROCK1 and ROCK2 mediate important processes such as cell migration, invasion and metastasis; making them good targets for the development of antitumor agents. Recently, using a fragment-based approach and X-ray crystallography, we reported on the design and synthesis of novel Rho-kinase inhibitors (RKIs). Here, we selected a pair of RKIs, the closely-related structural analogues RKI-18 (potent; IC₅₀ values of 397 nM (ROCK1) and 349 nM (ROCK2)) and RKI-11 (weak/inactive; IC₅₀ values of 38 µM (ROCK1) and 45 µM (ROCK2), as chemical probes and determined their effects on cytoskeleton organization, signaling, apoptosis, anchorage-dependent and –independent growth, migration and invasion. RKI-18 but not RKI-11 suppresses potently the phosphorylation of the ROCK substrate MLC2 in intact human breast, lung, colon and prostate cancer cells. Furthermore, RKI-18 is highly selective at decreasing the levels of P-MLC2 over those of P-Akt, P-S6 and P-Erk ½. RKI-18 suppresses ROCK-mediated actin fiber formation following stimulation with LPA as well as PAK-mediated lamelipodia and filopodia formation following bradykinin or PDGF stimulation. Furthermore, RKI-18 but not RKI-11 inhibits migration, invasion and anchorage-independent growth of human breast cancer cells. The fact that the active ROCK inhibitor RKI-18 but not the inactive closely related structural analogue RKI-11 is effective at suppressing malignant transformation suggests that inhibition of ROCK with RKI-18 results in preventing migration, invasion and anchorage-independent growth. The potential of this class of RKIs as anti tumor agents warrants further advanced preclinical studies.

Radiological and clinical features of adult non-puerperal mastitis

OBJECTIVE

To describe the radiological and clinical features of adult non-puerperal mastitis and to determine the most accurate method of preventing unnecessary surgical procedures.

METHODS

Clinical and imaging findings were retrospectively reviewed in 51 females with non-puerperal mastitis, which was confirmed by biopsy/surgical pathology. All 51 patients had pre-operative MRI; 45 patients also had sonograms and 25 also had mammograms, pre-operatively.

RESULTS

Of the 51 cases with non-puerperal mastitis, 94.1% (48/51) were confirmed as having acute or chronic inflammation, and the other 3 had plasma cell mastitis; areola papillaris inflammation was found in 39.2% (20/51) of the cases. Overall, 6 of the 25 cases that were examined with mammography and 2 of the 45 cases that were examined with sonography appeared normal, but all 51 lesions were positively identified on MRI. Asymmetrical density (12/25) on mammograms and solitary or separated/contiguous, clustered, hypoechoic mass-like lesions (31/45) on ultrasound were the most common signs of non-puerperal mastitis. On enhanced MRI, 90.2% (46/51) of patients showed non-mass-like enhanced lesions. Multiple regional enhancements in the pattern of distribution (32/46) and separated or contiguous, clustered, rim-like enhancements in the pattern of internal enhancement (29/46) were the most common manifestations in non-mass-like enhanced lesions. Of the 51 patients, mastitis Type 1 and Type 2 in the time-signal intensity curve were detected in 47.1% and 51.0% of the patients, respectively. The breast imaging reporting and data system categories with the highest number of patients were Category 0 (9/25) on mammography, Category 4a on sonography (18/45) and Category 4a on MRI (29/51).

CONCLUSION

The findings from mammography and ultrasound are non-specific; therefore, using MR can be helpful in the diagnosis, especially in the presence of non-mass-like enhancements that are multiple, regional, separated, or contiguous, clustered and rim-like.

ADVANCES IN KNOWLEDGE

Mastitis is often neglected because of the lack of typical clinical signs and symptoms. This study has assessed and described the clinical features and imaging findings of adult non-puerperal mastitis on mammograms, sonograms and MRI and found that MRI is more specific in the diagnosis of disease.

[Analysis of hydrodynamics parameters of runoff erosion and sediment-yielding on unpaved road]

By the method of field runoff washout experiment, a simulation study was conducted on the relationships between the soil detachment rate and the hydrodynamic parameters on unpaved road, and the related quantitative formulas were established. Under the conditions of different flow discharges and road gradients, the averaged soil detachment rate increased with increasing flow discharge and road gradient, and the relationships between them could be described by a power function. As compared with road gradient, flow discharge had greater effects on the soil detachment rate. The soil detachment rate had a power relation with water flow velocity and runoff kinetic energy, and the runoff kinetic energy was of importance to the soil detachment rate. The soil detachment rate was linearly correlated with the unit runoff kinetic energy. The averaged soil erodibility was 0.120 g m-1.J-F-1, and the averaged critical unit runoff kinetic energy was 2.875 g.m-1.J-1. Flow discharge, road gradient, and unit runoff kinetic energy could be used to accurately describe the soil erosion process and calculate the soil erosion rate on unpaved road.