Understanding the Impact of Communicating Uncertainty About COVID-19 in the News: Randomized Between-Subjects Factorial Experiment.

BACKGROUND: Whether and how the uncertainty about a public health crisis should be communicated to the general public have been important and yet unanswered questions arising over the past few years. As the most threatening contemporary public health crisis, the COVID-19 pandemic has renewed interest in these unresolved issues by both academic scholars and public health practitioners. OBJECTIVE: The aim of this study was to investigate the impact of communicating uncertainty about COVID-19-related threats and solutions on individuals' risk perceptions and misinformation vulnerability, as well as the sequential impact of these effects on health information processing and preventative behavioral intentions. METHODS: A 2×2 (threat uncertainty [presence vs absence]×solution uncertainty [presence vs absence]) full-fractional between-subjects online experiment was conducted with 371 Chinese adults. Focusing on the discussion of whether the asymptomatic cases detected during the COVID-19 pandemic would further lead to an uncontrolled pandemic, news articles were manipulated in terms of whether the infectiousness of asymptomatic cases and the means to control the transmission are presented in terms of their certainty or uncertainty. Participants were randomly assigned to one of the four experimental conditions, being instructed to read one news article. After reading the news article assigned, participants were asked to respond to a series of questions to assess their cognitive and behavioral responses. RESULTS: Individuals were more susceptible to believing false COVID-19-related information when a certain threat and uncertain solution were framed in the news article. Moreover, individuals' perceptions of crisis severity increased when exposed to news information containing uncertain solutions. Both misinformation vulnerability and perceived severity were positively associated with information processing. Information seeking was positively associated with protective behavioral intention, whereas information avoidance was negatively associated with protective behavioral intention. CONCLUSIONS: Our findings imply that uncertainty, depending on its aspect, can be effectively communicated to the public during an emerging public health crisis. These results have theoretical and practical implications for health communicators and journalists. Given its limited influence on individuals' cognitive and behavioral responses, uncertainty related to a health threat should be disseminated to meet the public's expectation of information transparency. However, caution is advised when communicating uncertainty related to potential solutions, as this factor exhibited a mixed impact on individual responses during a crisis.

Analysis of influencing factors of viral load in patients with high-risk human papillomavirus.

BACKGROUND: High-risk human papillomavirus (HR-HPV) load is thought to be influenced by many factors, and the relationship between viral load and the degree of cervical lesion is controversial. This study explored the possible influencing factors of HR-HPV viral load in the uterine cervix. METHODS: A total of 605 women who needed colposcopic evaluation for abnormal cervical screening at the Affiliated Hospital of Weifang Medical University, China, between November 2017 and September 2018 were enrolled. Cervical specimens were collected from the endo- and ectocervix separately using two different cervical brushes. The hybrid capture II test was used to measure HR-HPV load. Age, histological severity, number of viral types, and area and location of cervical lesions were recorded. The correlations between viral load and influencing factors were analysed using univariate and multivariate analyses. RESULTS: HR-HPV load was positively correlated with age, histological severity, multiple HPV types and area of cervical lesions (P < 0.05). Viral load with the combination of endo- and ectocervical sampling was significantly higher than simple endocervical sampling (P < 0.001). Multivariate analysis showed that age, multiple HPV types and area of cervical lesions were independent factors for HR-HPV load with a combination of endo- and ectocervical sampling (P < 0.05). However, only age and area of cervical lesions were independent factors for viral load with simple endocervical sampling (P < 0.05). No significant association was found between viral load and lesion severity in multivariate analysis (P > 0.05). CONCLUSION: HR-HPV load is influenced by age, histological severity, multiple viral types, area of cervical lesion and sampling methods. Age and area of cervical lesions are independent factors for viral load.

Exosomes derived from high-glucose-stimulated Schwann cells promote development of diabetic peripheral neuropathy.

Schwann cells actively interact with axons of dorsal root ganglia (DRG) neurons. Exosomes mediate intercellular communication by transferring their biomaterials, including microRNAs (miRs) into recipient cells. We hypothesized that exosomes derived from Schwann cells stimulated by high glucose (HG) exosomes accelerate development of diabetic peripheral neuropathy and that exosomal cargo miRs contribute to this process. We found that HG exosomes contained high levels of miR-28, -31a, and -130a compared to exosomes derived from non-HG-stimulated Schwann cells. In vitro, treatment of distal axons with HG exosomes resulted in reduction of axonal growth, which was associated with elevation of miR-28, -31a, and -130a and reduction of their target proteins of DNA methyltransferase-3α, NUMB (an endocytic adaptor protein), synaptosome associated protein 25, and growth-associated protein-43 in axons. In vivo, administration of HG exosomes to sciatic nerves of diabetic db/db mice at 7 wk of age promoted occurrence of peripheral neuropathy characterized by impairment of nerve conduction velocity and induction of mechanic and thermal hypoesthesia, which was associated with substantial decreases in intraepidermal nerve fibers. Our findings demonstrate a functional role of exosomes derived from HG-stimulated Schwann cells in mediating development of diabetic peripheral neuropathy.-Jia, L., Chopp, M., Wang, L., Lu, X., Szalad, A., Zhang, Z. G. Exosomes derived from high-glucose-stimulated Schwann cells promote development of diabetic peripheral neuropathy.

Comparative proteomic analysis of exosomes derived from endothelial cells and Schwann cells.

Exosomes derived from endothelial cells and Schwann cells have been employed as novel treatments of neurological diseases, including peripheral neuropathy. Exosomal cargo plays a critical role in mediating recipient cell function. In this study, we thus performed a comprehensive proteomic analysis of exosomes derived from healthy mouse dermal microvascular endothelial cells (EC-Exo) and healthy mouse Schwann cells (SC-Exo). We detected 1,817and 1,579 proteins in EC-Exo and SC-Exo, respectively. Among them, 1506 proteins were present in both EC-Exo and SC-Exo, while 311 and 73 proteins were detected only in EC-Exo and SC-Exo, respectively. Bioinformatic analysis revealed that EC-Exo enriched proteins were involved in neurovascular function, while SC-Exo enriched proteins were related to lipid metabolism. Western blot analysis of 14 enriched proteins revealed that EC-Exo contained proteins involved in mediating endothelial function such as delta-like 4 (DLL4) and endothelial NOS (NOS3), whereas SC-Exo had proteins involved in mediating glial function such as apolipoprotein A-I (APOA1) and phospholipid transfer protein (PLTP). Collectively, the present study identifies differences in the cargo protein profiles of EC-Exo and SC-Exo, thus providing new molecular insights into their biological functions for the treatment of peripheral neuropathy.

Evaluation of antibacterial activities of silver nanoparticles on culturability and cell viability of Escherichia coli.

Nanoparticles released into the environment are attracting increasing concern because of their potential toxic effects. Conventional methods for assessing the toxicity of nanoparticles are usually confined to cultivable cells, but not applicable to viable but non-culturable (VBNC) cells. However, it remains unknown whether silver nanoparticles (AgNPs), a typical antimicrobial agent, could induce bacteria into a VBNC state in natural environments. In this work, the viability of E. coli, an indicator bacterium widely used for assessing the antibacterial activity of AgNPs, was examined through coupling plate counting, fluorescence staining and adenosine triphosphate (ATP) production. AgNPs were found to have a considerable antibacterial ability, which resulted in less than 0.0004% of culturable cells on plates. However, more than 80% of the cells still maintained their cell membrane integrity under the stress of 80 mg/L AgNPs. Meanwhile, the residue of ATP production (0.6%) was 1500 times higher than that of the culturable cells (< 0.0004%). These results clearly demonstrate that when exposed to AgNPs, most of cells fell into a VBNC state, instead of dying. Environmental factors, e.g., Cl- and illumination, which could change the dissolution, hydrophilicity and zeta potential of AgNPs, eventually influenced the culturability of E. coli. Inhibition of dissolved Ag+ and reactive oxygen species was found to facilitate the mitigation of the strain into a VBNC state. Our findings suggest the necessity of re-evaluating the environmental effects and antibacterial activities of AgNPs.

Accuracy of HPV E6/E7 mRNA examination using in situ hybridization in diagnosing cervical intraepithelial lesions.

BACKGROUND: The consistency of pathologists in the diagnosis of cervical intraepithelial neoplasia (CINs) is not ideal, especially between low- and high-grade squamous intraepithelial lesions (LSIL and HSIL). This study was aimed to explore efficient strategies for the grading of CINs. METHODS: The medical records of patients with high risk human papillomavirus (HR-HPV) infections who had underwent cervical biopsy or conization from April 2018 to April 2019 in Beijing Chao-Yang Hospital were collected and examined. The HR-HPV E6/E7 mRNA in the tissues of patients with CINs was detected using RNAscope chromogenic in situ hybridization (RISH). Immunohistochemistry (IHC) was performed to evaluate the expression of p16INK4a (P16) and Ki67. RESULTS: HR-HPV E6/E7 mRNA signals were detected in 3/27 (11.1 %) of CIN 1, and in 32/33 (97.0 %) of CIN 2/3. Most of the staining patterns (27/32, 84.4 %) had a full-thickness epithelial layer staining with weak-to-strong nuclear and cytoplasmic dot-like signals in CIN 2/3, and there were also few special staining patterns that were significantly different from the others. A number of indicators were compared between LSIL and HSIL. There were statistically significant differences in E6/E7 mRNA, p16, Ki67 and cytology between the two groups (P < 0.05). According to the logistic regression analysis, merely E6/E7 mRNA positivity was significantly associated with CIN2/3 (OR: 52.53, 95 % CI, P < 0.05). In the detection of CIN 2/3, the sensitivity and specificity of HPV E6/E7 mRNA alone was not significantly inferior to that of its different combinations with Ki67, p16 and cytology (all, P > 0.05). CONCLUSIONS: RISH is efficient in grading of CINs. The HPV E6/E7 mRNA expression might reflect the phase HPV infections, and its positive pattern might predict the development direction of CINs, providing the possibility to realize more accurate treatments for patients.

Small extracellular vesicles ameliorate peripheral neuropathy and enhance chemotherapy of oxaliplatin on ovarian cancer.

There are no effective treatments for chemotherapy induced peripheral neuropathy (CIPN). Small extracellular vesicles (sEVs) facilitate intercellular communication and mediate nerve function and tumour progression. We found that the treatment of mice bearing ovarian tumour with sEVs derived from cerebral endothelial cells (CEC-sEVs) in combination with a chemo-drug, oxaliplatin, robustly reduced oxaliplatin-induced CIPN by decreasing oxaliplatin-damaged myelination and nerve fibres of the sciatic nerve and significantly amplified chemotherapy of oxaliplatin by reducing tumour size. The combination therapy substantially increased a set of sEV cargo-enriched miRNAs, but significantly reduced oxaliplatin-increased proteins in the sciatic nerve and tumour tissues. Bioinformatics analysis revealed the altered miRNAs and proteins formed two distinct networks that regulate neuropathy and tumour growth, respectively. Intravenously administered CEC-sEVs were internalized by axons of the sciatic nerve and cancer cells. Reduction of CEC-sEV cargo miRNAs abolished the effects of CEC-sEVs on oxaliplatin-inhibited axonal growth and on amplification of the anti-cancer effect in ovarian cancer cells, suggesting that alterations in the networks of miRNAs and proteins in recipient cells contribute to the therapeutic effect of CEC-sEVs on CIPN. Together, the present study demonstrates that CEC-sEVs suppressed CIPN and enhanced chemotherapy of oxaliplatin in the mouse bearing ovarian tumour.

Exosomes Derived From Schwann Cells Ameliorate Peripheral Neuropathy in Type 2 Diabetic Mice.

Schwann cell-derived exosomes communicate with dorsal root ganglia (DRG) neurons. The current study investigated the therapeutic effect of exosomes derived from healthy Schwann cells (SC-Exos) on diabetic peripheral neuropathy (DPN). We found that intravenous administration of SC-Exos to type 2 diabetic db/db mice with peripheral neuropathy remarkably ameliorated DPN by improving sciatic nerve conduction velocity and increasing thermal and mechanical sensitivity. These functional improvements were associated with the augmentation of epidermal nerve fibers and remyelination of sciatic nerves. Quantitative RT-PCR and Western blot analysis of sciatic nerve tissues showed that SC-Exo treatment reversed diabetes-reduced mature form of miRNA (miR)-21, -27a, and -146a and diabetes-increased semaphorin 6A (SEMA6A); Ras homolog gene family, member A (RhoA); phosphatase and tensin homolog (PTEN); and nuclear factor-κB (NF-κB). In vitro data showed that SC-Exos promoted neurite outgrowth of diabetic DRG neurons and migration of Schwann cells challenged by high glucose. Collectively, these novel data provide evidence that SC-Exos have a therapeutic effect on DPN in mice and suggest that SC-Exo modulation of miRs contributes to this therapy.

Angiopoietin-1/Tie2 signaling pathway contributes to the therapeutic effect of thymosin ß4 on diabetic peripheral neuropathy.

Angiopoietin-1 (Ang1) and its receptor Tie2 regulate vascular function. Our previous study demonstrated that thymosin beta 4 (Tß4) ameliorates neurological function of diabetic peripheral neuropathy. Mechanisms underlying the therapeutic effect of Tß4 on diabetic peripheral neuropathy have not been fully investigated. The present in vivo study investigated whether the Ang1/Tie2 signaling pathway is involved in Tß4-improved neurovascular remodeling in diabetic peripheral neuropathy. Diabetic BKS. Cg-m+/+Leprdb/J (db/db) mice at age 20 weeks were treated with Tß4 and neutralizing antibody against mouse Tie2 for 4 consecutive weeks. Neurological functional and neurovascular remodeling were measured. Administration of the neutralizing antibody against Tie2 attenuated the therapeutic effect of Tß4 on improved diabetic peripheral neuropathy as measured by motor and sensory nerve conduction velocity and thermal hypoesthesia compared to diabetic db/db mice treated with Tß4 only. Histopathological analysis revealed that the neutralizing antibody against Tie2 abolished Tß4-increased microvascular density in sciatic nerve and intraepidermal nerve fiber density, which were associated with suppression of Tß4-upregulated occludin expression and Tß4-reduced protein levels of nuclear factor-κB (NF-κB) and vascular cell adhesion molecule-1 (VCAM1). Our data provide in vivo evidence that the Ang1/Tie2 pathway contributes to the therapeutic effect of Tß4 on diabetic peripheral neuropathy.

miR-146a mediates thymosin ß4 induced neurovascular remodeling of diabetic peripheral neuropathy in type-II diabetic mice.

Diabetes induces neurovascular dysfunction leading to peripheral neuropathy. MicroRNAs (miRNAs) affect many biological processes and the development of diabetic peripheral neuropathy. In the present study, we investigated whether thymosin-ß4 (Tß4) ameliorates diabetic peripheral neuropathy and whether miR-146a mediates the effect of Tß4 on improved neurovascular function. Male Type II diabetic BKS. Cg-m+/+Leprdb/J (db/db) mice at age 20 weeks were treated with Tß4 for 8 consecutive weeks, and db/db mice treated with saline were used as a control group. Compared to non-diabetic mice, diabetic mice exhibited substantially reduced miR-146a expression, and increased IL-1R-associated kinase-1 (IRAK1), tumor necrosis factor (TNFR)-associated factor 6 (TRAF6) levels and nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) activity in sciatic nerve tissues. Treatment of diabetic mice with Tß4 significantly elevated miR-146a levels and overcame the effect of diabetes on these proteins. Tß4 treatment substantially improved motor and sensory conduction velocity of the sciatic nerve, which was associated with improvements in sensory function. Tß4 treatment significantly increased intraepidermal nerve fiber density and augmented local blood flow and the density of fluorescein isothiocyanate (FITC)-dextran perfused vessels in the sciatic nerve tissue. In vitro, treatment of dorsal root ganglion (DRG) neurons and mouse dermal endothelial cells (MDEs) with Tß4 significantly increased axonal outgrowth and capillary-like tube formation, whereas blocking miR-146a attenuated Tß4-induced axonal outgrowth and capillary tube formation, respectively. Our data indicate that miR-146a may mediate Tß4-induced neurovascular remodeling in diabetic mice, by suppressing pro-inflammatory signals.

MiR-34a Regulates Axonal Growth of Dorsal Root Ganglia Neurons by Targeting FOXP2 and VAT1 in Postnatal and Adult Mouse.

Hyperglycemia impairs nerve fibers of dorsal root ganglia (DRG) neurons, leading to diabetic peripheral neuropathy (DPN). However, the molecular mechanisms underlying DPN are not fully understood. Using a mouse model of type II diabetes (db/db mouse), we found that microRNA-34a (miR-34a) was over-expressed in DRG, sciatic nerve, and foot pad tissues of db/db mice. In vitro, high glucose significantly upregulated miR-34a in postnatal and adult DRG neurons, which was associated with inhibition of axonal growth. Overexpression and attenuation of miR-34a in postnatal and adult DRG neurons suppressed and promoted, respectively, axonal growth. Bioinformatic analysis suggested that miR-34a putatively targets forkhead box protein P2 (FOXP2) and vesicle amine transport 1 (VAT1), which were decreased in diabetic tissues and in cultured DRG neurons under high glucose conditions. Dual-luciferase assay showed that miR-34a downregulated FOXP2 and VAT1 expression by targeting their 3' UTR. Gain-of- and loss-of-function analysis showed an inverse relation between augmentation of miR-34a and reduction of FOXP2 and VAT1 proteins in postnatal and adult DRG neurons. Knockdown of FOXP2 and VAT1 reduced axonal growth. Together, these findings suggest that miR-34a and its target genes of FOXP2 and VAT1 are involved in DRG neuron damage under hyperglycemia.

Combined intra- and extracellular reduction involved in the anaerobic biodecolorization of cationic azo dye by Shewanella oneidensis MR-1.

Microbial reduction decolorization is a promising strategy for cationic azo dye pollution remediation, but the reduction mechanism is unclear yet. In this work, the anaerobic reduction decolorization mechanism of cationic red X-GRL (X-GRL) by Shewanella oneidensis MR-1 (MR-1) was investigated from both intracellular and extracellular aspects. The exogenous additional riboflavin treatment test was used to analyze the extracellular reduction mechanism of X-GRL, and the actual role of riboflavin during the reduction of X-GRL was identified by three-dimensional fluorescence analysis for the first time. The proteinase K and the electron competitor treatment tests were used to analyze the intracellular reduction mechanism of X-GRL. Moreover, the effect of external environment on the reduction mechanism of X-GRL was elucidated by the decolorization performance of MR-1 wild type and its mutants, ΔomcA/mtrC, ΔmtrA, ΔmtrB and ΔcymA, under different external pH conditions. The results indicated that X-GRL could be decolorized by MR-1 in both extracellular and intracellular spaces. The extracellular decolorization of X-GRL could be caused by Mtr respiratory pathway or the indirect reduction of riboflavin, while the intracellular decolorization might occur due to the intracellular reduction depending on CymA pathway and a NADH-dependent reduction catalyzed by intracellular azoreductases. Furthermore, the proportion of extracellular decolorization decreased, whereas that of intracellular decolorization increased as the environmental pH rose.

A simple method for assaying anaerobic biodegradation of dyes.

Anaerobic dye degradation is usually assayed using serum vials, which is time-consuming and costly. In this work, a simple method was established for real-time nondestructive assay of dye biodegradation using 96-well microtiter plates with petrolatum oil to avoid the volatilization and high transmittance transparent tape to prevent the permeation of oxygen. With the anaerobic degradation of methyl red and amaranth by Shewanella oneidensis MR-1, this assay method was verified. Further experiments revealed that blocking Mtr pathway had no substantial effect on the degradation of methyl red and dose of riboflavin also failed to promote the degradation of methyl red. On the contrary, the anaerobic degradation of amaranth depended mainly on the electron transmembrane transfer through Mtr pathway. Our work clearly indicates that Mtr pathway had different effects on intra- and extra-cellular degradation of azo dyes by S. oneidensis MR-1. Such a developed method is helpful for investigating anaerobic dye decolorization.

Anaerobic decolorization and detoxification of cationic red X-GRL by Shewanella oneidensis MR-1.

The ability of an electrochemically active bacterium, Shewanella oneidensis MR-1, to decolorize azo dye cationic red X-GRL (X-GRL) was investigated. S. oneidensis MR-1 showed a high decolorization capability for X-GRL under anaerobic conditions. The Mtr respiratory pathway was proved to be involved in the extracellular decolorization of X-GRL. The decolorization efficiency of S. oneidensis MR-1 was significantly inhibited when the initial X-GRL concentration was over 200 mg L-1. Increasing the inoculum volume of S. oneidensis MR-1 could obviously promote the X-GRL decolorization. The 100 mg L-1 X-GRL and 6% (v/v) inoculum volume were chosen as the optimal parameter. Under such a condition, almost all of X-GRL (100 mg L-1) could be completely reduced after 12-h incubation at the pH range of 5.5-8.0 and temperature range of 30-40°C. Salinity in the medium also affected X-GRL decolorization. Lactate and citric acid were found to be the suitable electron donors for X-GRL decolorization. Although the genotoxicity increased slightly, the phytotoxicity of X-GRL in the decolorization process was significantly reduced by S. oneidensis MR-1.

Tadalafil Promotes the Recovery of Peripheral Neuropathy in Type II Diabetic Mice.

We previously demonstrated that treatment of diabetic peripheral neuropathy with the short (4 hours) half-life phosphodiesterase 5 (PDE5) inhibitor, sildenafil, improved functional outcome in diabetic db/db mice. To further examine the effect of PDE5 inhibition on diabetic peripheral neuropathy, we investigated the effect of another potent PDE5 inhibitor, tadalafil, on diabetic peripheral neuropathy. Tadalafil is pharmacokinetically distinct from sildenafil and has a longer half-life (17+hours) than sildenafil. Diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 20 weeks were treated with tadalafil every 48 hours for 8 consecutive weeks. Compared with diabetic mice treated with saline, tadalafil treatment significantly improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal sensitivity. Tadalafil treatment also markedly increased local blood flow and the density of FITC-dextran perfused vessels in the sciatic nerve concomitantly with increased intraepidermal nerve fiber density. Moreover, tadalafil reversed the diabetes-induced reductions of axon diameter and myelin thickness and reversed the diabetes-induced increased g-ratio in the sciatic nerve. Furthermore, tadalafil enhanced diabetes-reduced nerve growth factor (NGF) and platelet-derived growth factor-C (PDGF-C) protein levels in diabetic sciatic nerve tissue. The present study demonstrates that tadalafil increases regional blood flow in the sciatic nerve tissue, which may contribute to the improvement of peripheral nerve function and the amelioration of diabetic peripheral neuropathy.

Therapeutic Benefit of Extended Thymosin ß4 Treatment Is Independent of Blood Glucose Level in Mice with Diabetic Peripheral Neuropathy.

Peripheral neuropathy is a chronic complication of diabetes mellitus. To investigated the efficacy and safety of the extended treatment of diabetic peripheral neuropathy with thymosin ß4 (Tß4), male diabetic mice (db/db) at the age of 24 weeks were treated with Tß4 or saline for 16 consecutive weeks. Treatment of diabetic mice with Tß4 significantly improved motor (MCV) and sensory (SCV) conduction velocity in the sciatic nerve and the thermal and mechanical latency. However, Tß4 treatment did not significantly alter blood glucose levels. Treatment with Tß4 significantly increased intraepidermal nerve fiber density. Furthermore, Tß4 counteracted the diabetes-induced axon diameter and myelin thickness reductions and the g-ratio increase in sciatic nerve. In vitro, compared with dorsal root ganglia (DRG) neurons derived from nondiabetic mice, DRG neurons derived from diabetic mice exhibited significantly decreased neurite outgrowth, whereas Tß4 promoted neurite growth in these diabetic DRG neurons. Blockage of the Ang1/Tie2 signaling pathway with a neutralized antibody against Tie2 abolished Tß4-increased neurite outgrowth. Our data demonstrate that extended Tß4 treatment ameliorates diabetic-induced axonal degeneration and demyelination, which likely contribute to therapeutic effect of Tß4 on diabetic neuropathy. The Ang1/Tie2 pathway may mediate Tß4-induced axonal remodeling.

Sildenafil ameliorates long term peripheral neuropathy in type II diabetic mice.

Diabetic peripheral neuropathy is a common complication of long-standing diabetes mellitus. To mimic clinical trials in which patients with diabetes enrolled have advanced peripheral neuropathy, we investigated the effect of sildenafil, a specific inhibitor of phosphodiesterase type 5 enzyme, on long term peripheral neuropathy in middle aged male mice with type II diabetes. Treatment of diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 36 weeks with sildenafil significantly increased functional blood vessels and regional blood flow in the sciatic nerve, concurrently with augmentation of intra-epidermal nerve fiber density in the skin and myelinated axons in the sciatic nerve. Functional analysis showed that the sildenafil treatment considerably improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal stimulus sensitivity compared with the saline treatment. In vitro studies showed that mouse dermal endothelial cells (MDE) cultured under high glucose levels exhibited significant down regulation of angiopoietin 1 (Ang1) expression and reduction of capillary-like tube formation, which were completely reversed by sildenafil. In addition, incubation of dorsal root ganglia (DRG) neurons with conditioned medium harvested from MDE under high glucose levels suppressed neurite outgrowth, where as conditional medium harvested from MDE treated with sildenafil under high glucose levels did not inhibit neurite outgrowth of DRG neurons. Moreover, blockage of the Ang1 receptor, Tie2, with a neutralized antibody against Tie2 abolished the beneficial effect of sildenafil on tube formation and neurite outgrowth. Collectively, our data indicate that sildenafil has a therapeutic effect on long term peripheral neuropathy of middle aged diabetic mice and that improvement of neurovascular dysfunction by sildenafil likely contributes to the amelioration of nerve function. The Ang1/Tie2 signaling pathway may play an important role in these restorative processes.

A dominant loss-of-function GJA1 (Cx43) mutant impairs parturition in the mouse.

Expression of GJA1 (commonly known as connexin43 or Cx43), a major myometrial gap junction protein, is upregulated before the onset of delivery, suggesting an essential role for Cx43-mediated gap junctional intercellular communication (GJIC) in normal uterine contraction during parturition. To determine how a disease-linked Cx43 mutation affects myometrial function, we studied a mutant mouse model carrying an autosomal dominant mutation (Gja1(Jrt)) in the gene encoding Cx43 that displays features of the human genetic disease oculodentodigital dysplasia. We found that Cx43 level, specifically the phosphorylated species of the protein, is significantly reduced in the myometrium of the mutant mice (Gja1(Jrt)/+), as revealed by Western blotting and immunostaining. Patch-clamp electrophysiological measurements demonstrated that coupling between myometrial smooth muscle cells is reduced to <15% of wild-type, indicating that the mutant protein acts dominantly on its wild-type counterpart. The phosphorylated species of Cx43 in the mutant myometrium failed to increase prior to parturition as well as in response to exogenous estrogen. Correspondingly, in vitro experiments with uterine strips revealed weaker contraction of the mutant myometrium and reduced responsiveness to oxytocin, providing an explanation for the prolonged gestation and presence of suffocated fetuses in the uteri that were observed in some of the mutant mice. We conclude that the Gja1(Jrt) mutation has a dominant-negative effect on Cx43 function in the myometrium, severely reducing GJIC, leading to impaired parturition.