Inhibition of Immunoproteasome Attenuates NLRP3 Inflammasome Response by Regulating E3 Ubiquitin Ligase TRIM31

Excessive secretion of pro-inflammatory cytokines leads to the disruption of intestinal barrier in inflammatory bowel disease (IBD). The inflammatory cytokine tumor necrosis factor alpha (TNFα) induces the assembly of the NLRP3 inflammasome, resulting in the augmented secretion of inflammatory cytokines implicated in the pathogenesis of inflammatory bowel disease (IBD). TNFα has also been known to induce the formation of immunoproteasome (IP), which incorporates immunosubunits LMP2, LMP7, and MECL-1. Inhibition of IP activity using the IP subunit LMP2-specific inhibitor YU102, a peptide epoxyketone, decreased the protein levels of NLRP3 and increased the K48-linked polyubiquitination levels of NLRP3 in TNFα-stimulated intestinal epithelial cells. We observed that inhibition of IP activity caused an increase in the protein level of the ubiquitin E3 ligase, tripartite motif-containing protein 31 (TRIM31). TRIM31 facilitated K48-linked polyubiquitination and proteasomal degradation of NLRP3 with an enhanced interaction between NLRP3 and TRIM31 in intestinal epithelial cells. In addition, IP inhibition using YU102 ameliorated the symptoms of colitis in the model mice inflicted with dextran sodium sulfate (DSS). Administration of YU102 in the DSS-treated colitis model mice caused suppression of the NLRP3 protein levels and accompanied inflammatory cytokine release in the intestinal epithelium. Taken together, we demonstrated that inhibiting IP under inflammatory conditions induces E3 ligase TRIM31-mediated NLRP3 degradation, leading to attenuation of the NLRP3 inflammatory response that triggers disruption of intestinal barrier.

Novel S2 subunit-specific antibody with broad neutralizing activity against SARS-CoV-2 variants of concern

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), had a major impact on both the global health and economy. Numerous virus-neutralizing antibodies were developed against the S1 subunit of SARS-CoV-2 spike (S) protein to block viral binding to host cells and were authorized for control of the COVID-19 pandemic. However, frequent mutations in the S1 subunit of SARS-CoV-2 enabled the emergence of immune evasive variants. To address these challenges, broadly neutralizing antibodies targeting the relatively conserved S2 subunit and its epitopes have been investigated as antibody therapeutics and universal vaccines.

Methods

We initiated this study by immunizing BALB/c mice with β-propiolactone-inactivated SARS-CoV-2 (IAV) to generate B-cell hybridomas. These hybridomas were subsequently screened using HEK293T cells expressing the S2-ECD domain. Hybridomas that produced anti-S2 antibodies were selected, and we conducted a comprehensive evaluation of the potential of these anti-S2 antibodies as antiviral agents and versatile tools for research and diagnostics.

Results

In this study, we present a novel S2-specific antibody, 4A5, isolated from BALB/c mice immunized with inactivated SARS-CoV-2. 4A5 exhibited specific affinity to SARS-CoV-2 S2 subunits compared with those of other β-CoVs. 4A5 bound to epitope segment F1109-V1133 between the heptad-repeat1 (HR1) and the stem-helix (SH) region. The 4A5 epitope is highly conserved in SARS-CoV-2 variants, with a significant conformational feature in both pre- and postfusion S proteins. Notably, 4A5 exhibited broad neutralizing activity against variants and triggered Fc-enhanced antibody-dependent cellular phagocytosis.

Discussion

These findings offer a promising avenue for novel antibody therapeutics and insights for next-generation vaccine design. The identification of 4A5, with its unique binding properties and broad neutralizing capacity, offers a potential solution to the challenge posed by SARS-CoV-2 variants and highlights the importance of targeting the conserved S2 subunit in combating the COVID-19.

Chronic rhinosinusitis is not associated with increased incidence of acute myocardial infarction: A national population-based study

BACKGROUND & AIMS

Chronic rhinosinusitis (CRS) is one of the most prevalent upper respiratory tract diseases. However, little is known the effect of CRS on the cardiovascular aspects of patients. This study aimed to investigate the incidence of acute myocardial infarction (AMI) in patients with CRS compared with that in the general population.

METHODS

This retrospective cohort study was performed using the Korean National Health Insurance Service (NHIS) database. To minimize confounding, age, sex, and cardiovascular risk profiles were adjusted. The primary endpoint was newly diagnosed AMI in patients between January 2005 and December 2018. The relative risk of AMI in patients with CRS was compared with that in controls. Kaplan-Meier survival curves and Cox proportional regression tests were used for statistical analyses.

RESULTS

Among 5,179,981 patients from the NHIS database, 996,679 patients with CRS were selected. The control group was 10 times (n = 9,966,790) the number of individuals in the CRS group. The CRS group had better cardiovascular profiles than those of the control group and had an adjusted hazard ratio of 0.99 (95% confidence interval, 0.97-1.02) for AMI.

CONCLUSION

There was no significant association between the two groups regardless of the presence of nasal polyps. This is the first study adjusting cardiovascular risk profiles and analyzing the relationship between CRS and AMI. CRS was not associated with a high incidence of AMI after adjusting for cardiovascular risk factors.

c-Src inhibitor PP2 inhibits head and neck cancer progression through regulation of the epithelial-mesenchymal transition

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancer, causing considerable mortality and morbidity worldwide. Although HNSCC management has been extensively studied, the treatment outcomes have not improved - the 5-year survival rate of patients with HNSCC is 40%. Recent studies on the development of a novel HNSCC treatment have highlighted proto-oncogene tyrosine-protein kinase Src (c-Src) as one of the major therapeutic targets. However, the clinical efficacy of c-Src inhibitors against HNSCC was not comparable to that obtained in vitro. Furthermore, the molecular mechanisms underlying the efficacy of c-Src inhibitors remain elusive. In this study, we assessed the efficacy of 4-amino-5-(4-chlorophenyl)-7-(dimethylethyl)pyrazolo[3,4-d] pyrimidine (PP2), a selective c-Src inhibitor on HSNCC. Nine HNSCC cell lines (SNU1041, Fraud, SNU46, SNU1076, SNU899, SCC1483, YD15, YD9, and YD10-) were screened, and the effects of PP2 were evaluated using wound healing, apoptosis, and invasion assays. Western blot analysis of downstream markers was conducted to assess the specific mechanism of action of PP2 in HNSCC. The therapeutic efficacy of PP2 was further evaluated in xenograft mice. PP2 reduced tumor cell growth both in vitro and in vivo. Furthermore, it enhanced tumor cell apoptosis in cell lines and prevented metastasis in mice. PP2 also regulated the epithelial-mesenchymal transition pathway downstream of c-Src. More specifically, in SCC1483 and YD15PP2 HNSCC cell lines, PP2 exposure downregulated Erk, Akt/Slug, and Snail but upregulated E-cadherin. These results suggest that PP2 inhibits cell growth and progression in HNSCC by regulating the epithelial-mesenchymal transition pathway.

Identification of broad-spectrum neutralizing antibodies against influenza A virus and evaluation of their prophylactic efficacy in mice

Influenza A virus continuously infects humans, and the antigenic shifts of this respiratory virus enable it to cross the species barrier, threatening public health with the risk of pandemics. Broadly neutralizing antibodies (bnAbs) that target the antigenic surface glycoprotein, hemagglutinin (HA), of influenza A virus protect against various subtypes of the virus. Here, we screened a human scFv library, through phage display and panning against recombinant HA proteins, to discover human monoclonal antibodies (mAbs) that are broadly active. Consequently, two human mAbs, named G1 and G2, were identified, which target the HA proteins of the H1N1 and H3N2 subtypes, respectively. G1, was shown to have broad binding ability to different HA subtypes of group 1. By contrast, G2 had higher binding affinity but sensed exclusively H3 subtype-derived HAs. In a cell culture-based virus-neutralizing assay, both G1 and G2 efficiently suppressed infection of the parental influenza A viruses of H1N1 and H3N2 subtypes. Mode-of-action studies showed that the G1 antibody blocked HA2-mediated membrane fusion. Meanwhile, G2 inhibited HA1-mediated viral attachment to host cells. It is noteworthy that both antibodies elicited antibody-dependent cellular cytotoxicity (ADCC) activities by recruiting FcγRIIIA-expressing effector cells. In mouse challenge models, single-shot, intraperitoneal administration of chimeric G1 and G2 antibodies with the mouse IgG constant region completely protected mice from viral infections at doses above 10 and 1 mg/kg, respectively. The newly identified bnAbs, G1 and G2, could provide insight into the development of broad-spectrum antivirals against future pandemic influenza A virus involving group 1- or H3-subtyped strains.

AMPK-induced mitochondrial biogenesis decelerates retinal pigment epithelial cell degeneration under nutrient starvation

The implications of nutrient starvation due to aging on the degeneration of the retinal pigment epithelium (RPE) is yet to be fully explored. We examined the involvement of AMPK activation in mitochondrial homeostasis and its relationship with the maintenance of a healthy mitochondrial population and epithelial characteristics of RPE cells under nutrient starvation. Nutrient starvation induced mitochondrial senescence, which led to the accumulation of reactive oxygen species (ROS) in RPE cells. As nutrient starvation persisted, RPE cells underwent pathological epithelial-mesenchymal transition (EMT) via the upregulation of TWIST1, a transcription regulator which is activated by ROS-induced NF-κB signaling. Enhanced activation of AMPK with metformin decelerated mitochondrial senescence and EMT progression through mitochondrial biogenesis, primed by activation of PGC1-α. Thus, by facilitating mitochondrial biogenesis, AMPK protects RPE cells from the loss of epithelial integrity due to the accumulation of ROS in senescent mitochondria under nutrient starvation. [BMB Reports 2023; 56(2): 84-89].

Relationship between Chronic Rhinosinusitis and the Incidence of Head and Neck Cancer: A National Population-Based Study

We analyzed the relationship between chronic rhinosinusitis (CRS) and the incidence of head and neck cancers (HNCs) in a Korean adult population. This retrospective cohort study included data from the Korean National Health Insurance Service database. Adjustments were made to minimize risk variables for sex, age, diabetes, hypertension, dyslipidemia, and rhinitis between the two groups. The primary endpoint was newly diagnosed HNC between January 2009 and December 2018. Among 1,337,120 subjects in the Korean National Health Insurance Service database, data from 324,774 diagnosed with CRS (CRS group) and 649,548 control subjects (control group) were selected. Patients with CRS exhibited a statistically significant greater risk for nasal cavity/paranasal sinus cancer, hypopharynx/larynx cancer, and thyroid cancer compared with the control group. In the CRS group, the adjusted hazard ratios for nasal cavity/paranasal sinus cancer were 1.809 (95% confidence interval (CI) 1.085–3.016), 1.343 (95% CI 1.031–1.748) for hypopharynx and larynx cancer, and 1.116 (95% CI 1.063–1.173) for thyroid cancer. CRS was associated with a higher incidence of HNCs. Therefore, physicians should carefully consider the possibility of HNC progression and implement therapeutic strategies to minimize the impact of these diseases.

Computational epitope binning reveals functional equivalence of sequence-divergent paratopes

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Epitope binning groups target-specific protein binders recognizing the same binding region.

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The “Epibin” method utilizes docking models to computationally predict competition and identify bins.

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Epibin recapitulated binding competition of repebody variants as determined by immunoassays.

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In addition, Epibin enabled identification of ‘paratope-equivalent’ residues in sequence-dissimilar variants.

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Computational epitope binning can scale to allow characterization of entire antigen-specific antibody repertoires.

The therapeutic efficacy of a protein binder largely depends on two factors: its binding site and its binding affinity. Advances in in vitro library display screening and next-generation sequencing have enabled accelerated development of strong binders, yet identifying their binding sites still remains a major challenge. The differentiation, or “binning”, of binders into different groups that recognize distinct binding sites on their target is a promising approach that facilitates high-throughput screening of binders that may show different biological activity. Here we study the extent to which the information contained in the amino acid sequences comprising a set of target-specific binders can be leveraged to bin them, inferring functional equivalence of their binding regions, or paratopes, based directly on comparison of the sequences, their modeled structures, or their modeled interactions. Using a leucine-rich repeat binding scaffold known as a “repebody” as the source of diversity in recognition against interleukin-6 (IL-6), we show that the “Epibin” approach introduced here effectively utilized structural modelling and docking to extract specificity information encoded in the repebody amino acid sequences and thereby successfully recapitulate IL-6 binding competition observed in immunoassays. Furthermore, our computational binning provided a basis for designing in vitro mutagenesis experiments to pinpoint specificity-determining residues. Finally, we demonstrate that the Epibin approach can extend to antibodies, retrospectively comparing its predictions to results from antigen-specific antibody competition studies. The study thus demonstrates the utility of modeling structure and binding from the amino acid sequences of different binders against the same target, and paves the way for larger-scale binning and analysis of entire repertoires.

Delta neutrophil index levels can be a good indicator to predict patients with chronic rhinosinusitis who need surgery

OBJECTIVES

Predicting the need for surgical treatment among patients with chronic rhinosinusitis (CRS) is challenging. The delta neutrophil index (DNI) has been proposed as a useful laboratory marker of immature granulocytes, which indicates infection or severe inflammation in several diseases. This study evaluated DNI as an early predictor of the need for surgery in patients with CRS.

METHODS

A total of 117 patients diagnosed with CRS were enrolled in this retrospective and observational study. Medical records, including symptoms data, WBC count, ESR level, LUC count, Lund-Mackay scores, and DNI, were reviewed. The receiver operating characteristic (ROC) curves were analyzed to determine the optimal cut-off values for predicting surgery.

RESULTS

Among 117 patients, 49 patients (41.9%) needed surgical intervention. The areas under the WBC, ESR, LUC, and DNI ROC curves were .571, .600, .592, and .782, respectively. The optimal cut-off value of DNI to predict surgery was .9%. The prognostic precision of DNI showed that the sensitivity was 59.2% and the specificity was 98.5%. In the analysis of risk factors, DNI levels were significantly associated with surgical intervention (odds ratio, 2.22; 95% confidence interval, 1.48-3.34; P < .01).

CONCLUSIONS

The level of DNI, which reflects the severity of the disease, may be a useful predictor for determining the need for surgical intervention in patients with CRS. This is the first literature to verify the role of DNI in upper airway disease.

KRT8 (keratin 8) attenuates necrotic cell death by facilitating mitochondrial fission-mediated mitophagy through interaction with PLEC (plectin)

Dysregulation of mitochondrial homeostasis and accumulation of damaged mitochondria cause degenerative diseases such as age-related macular degeneration (AMD). We studied the effects of the intermediate cytofilament KRT8 (keratin 8) on mitochondrial homeostasis in relation to the morphology and function of mitochondria in retinal pigment epithelial cells under oxidative stress. When the mitochondria were damaged owing to oxidative stress, the damaged mitochondria were readily disposed of via mitophagy following mitochondrial fission. During this process, KRT8 was found to physically interact with the mitochondria through PLEC (plectin) and facilitate the mitochondrial fission-mediated mitophagy. However, the association between PLEC-anchoring mitochondria and KRT8 was dwindled by KRT8 phosphorylation under oxidative stress. The efficient KRT8-facilitated mitophagy flux suppressed the accumulation of damaged mitochondria and consequently diminished necrotic cell death under oxidative stress. Thus, by facilitating mitophagy, KRT8 protects RPE cells against necrotic cell death due to oxidative stress.

Effective inhibition of C3a-mediated pro-inflammatory response by a human C3a-specific protein binder

Complement component 3a (C3a) plays a crucial role in the immune response and host defense, but it is also involved in pro-inflammatory responses, causing many inflammatory disorders. Blockade of C3a has been regarded as a potent therapeutic strategy for inflammatory diseases. Here, we present the development of a human C3a (hC3a)-specific protein binder, which effectively inhibits pro-inflammatory responses. The protein binder, which is composed of leucine-rich repeat modules, was selected against hC3a through phage display, and its binding affinity was matured up to 600 pM by further expanding the binding interface in a module-by-module manner. The developed protein binder was shown to have more than 10-fold higher specificity to hC3a compared with human C5a, exhibiting a remarkable suppression effect on pro-inflammatory response in monocyte, by blocking the interaction between hC3a and its receptor. The hC3a-specific protein binder is likely to have a therapeutic potential for C3a-mediated inflammatory diseases.

A small-sized protein binder specific for human PD-1 effectively suppresses the tumour growth in tumour mouse model

Immune checkpoint inhibitors have drawn a consider attention as an effective cancer immunotherapy, and several monoclonal antibodies targeting the immune checkpoint receptors, such as human programmed cell death-1 (hPD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), are clinically used for treatment of various cancers. Here we present the development of a small-sized protein binder which specifically binds to hPD-1. The protein binder, which is composed of leucine-rich repeat (LRR) modules, was selected against hPD-1 through phage display, and its binding affinity was maturated up to 17 nM by modular evolution approach. The protein binder was shown to be highly specific for hPD-1, effectively inhibiting the interaction between hPD-1 and its ligand, hPD-L1. The protein binder restored T-cell function in vitro, and exhibited a strong anti-tumour activity in tumour mouse model, indicating that it acts as an effective checkpoint blockade. Based on the results, the developed protein binder specific for hPD-1 is likely to find a potential use in cancer immunotherapy.

The roughening kinetics of hydrogenated graphene

The roughness is a common property of all growing surfaces – however, the way the roughness of a growing surface changes with time and space is uniquely related to the underlying growth process, i.e. to how the atoms stick to the surface during the first stage of nucleation. This concept allows getting insights on the nucleation process of a growing surface by measuring two scaling exponents, α and β, known as roughness and growth exponents, respectively. In this work, we studied hydrogenation of graphene using the roughening kinetics. The coverage of graphene will depend on how the H ions stick on the surface, giving rise to a unique roughness evolution in time and space. We measured a roughness exponent of ~0.5 (derived from a Fourier index of ~3), and a growth exponent of ~0.3. The values of the growth and roughness exponents are close to those reported for clustered carbon, suggesting a roughening mechanism by clustering, in good agreement with the theory. We also compared our coverage data with a different model, used to describe the dynamics of graphene coverage, during chemical vapour deposition. Our data are in agreement with a nucleation-dominated growth, further confirming that hydrogenation is happening by clustering.

Prospective multinational serosurveillance study of Bordetella pertussis infection among 10- to 18-year-old Asian children and adolescents

OBJECTIVES

Bordetella pertussis continues to cause outbreaks worldwide. To assess the role of children and adolescent in transmission of pertussis in Asia, we performed a multinational serosurveillance study.

METHODS

From July 2013 to June 2016, individuals aged 10 to 18 years who had not received any pertussis-containing vaccine within the prior year were recruited in 10 centres in Asia. Serum anti-pertussis toxin (PT) IgG was measured by ELISA. Demographic data and medical histories were obtained. In the absence of pertussis immunization, anti-PT IgG ≥62.5 IU/mL was interpreted as B. pertussis infection within 12 months prior, among them levels ≥125 IU/mL were further identified as infection within 6 months.

RESULTS

A total of 1802 individuals were enrolled. Anti-PT IgG geometric mean concentration was 4.5, and 87 (4.8%) individuals had levels ≥62.5 IU/mL; among them, 73 (83.9%) had received three or more doses of pertussis vaccine before age 6 years. Of 30 participants with persistent cough during the past 6 months, one (3.3%) had level ≥125 IU/mL. There was no significant difference in proportions with anti-PT IgG ≥62.5 IU/mL among age groups (13-15 vs. 10-12 years, 16-18 vs. 10-12 years), between types of diphtheria, pertussis and tetanus (DTP; whole cell vs. acellular), number of doses before age 6 years within the DTP whole-cell pertussis vaccine (five vs. four doses) or acellular pertussis vaccine (five vs. four doses) and history of persistent cough during the past 6 months (yes vs. no).

CONCLUSIONS

There is significant circulation of B. pertussis amongst Asian children and adolescents, with one in 20 having serologic evidence of recent infection regardless of vaccination background.

Impact of Early Hospital Readmissions After Kidney Transplantation on Graft Function

Early hospital readmissions are common after kidney transplantation. This single-center retrospective study investigated the relationship between early hospital readmissions and clinical outcomes. All adult patients receiving a kidney transplant at this center between March 2009 and June 2015 were included. The early hospital readmissions within the first 30 days were numbered, and the diagnosis was ascertained. The patients were divided into None and Readmission groups. Clinical outcomes and patient- and death-censored graft survival were compared. Among the 103 patients included in the study, 32 (31.1%) had 1 or more readmissions within 30 days. Surgical complications, electrolyte imbalance, and acute rejection were common causes of readmission. No differences were observed in baseline characteristics between the two groups. Patients with early readmissions exhibited low renal function at 3, 6, and 12 months postoperatively (P = .002, .020, and .013, respectively). No difference in graft function was found 12 months after transplantation between the None and Readmission groups. Five-year graft and patient survival also showed no difference between the two groups (P = .424 and .442, respectively). In conclusion, early readmission after kidney transplantation affected lower graft function until 1 year after kidney transplantation. However, the long-term effect on graft function is limited in this study.

Prognostic value of preoperative systemic inflammation markers in localized upper tract urothelial cell carcinoma: a large, multicenter cohort analysis

BACKGROUND

The aim of this study was to investigate the prognostic value of preoperative systemic inflammation markers in upper tract urothelial carcinoma (UTUC).

METHODS

A total of 1137 patients who underwent radical nephroureterectomy with bladder cuff excision at 9 institutions from 2004 to 2015, were retrospectively reviewed. The Glasgow Prognostic Score (GPS), modified GPS (mGPS), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) for each patient were calculated. Univariable and multivariable analysis was performed using the Cox proportional hazards regression model. Cut-off values for NLR and PLR were calculated using a receiver operating characteristic curve.

RESULTS

The median follow-up period was 39.1 (interquartile range: 18.3-63.8) months. Univariable analysis revealed that GPS, mGPS, PLR, and NLR (all, P=0.001) were significantly associated with both recurrence-free survival (RFS) and cancer-specific survival (CSS). Multivariable analysis revealed that GPS (P=0.001), PLR (hazards ratio [HR] =1.32; 95% CI: 1.08-1.62, P=0.007 and HR =1.87; 95% CI: 1.21-2.92, P=0.005), NLR (HR =1.38; 95% CI: 1.12-1.69, P=0.003 and HR =1.70; 95% CI: 1.10-2.62, P=0.017) were significantly associated with RFS and CSS.

CONCLUSIONS

Our results suggest that preoperative systemic inflammation markers such as GPS, PLR, and NLR are independent prognostic factors in patients with UTUC after surgery.

Early Weight Gain After Transplantation Can Cause Adverse Effect on Transplant Kidney Function

BACKGROUND

The outcomes of kidney transplant recipients with increased body mass index (BMI) remain controversial. We studied the relationship between changes in BMI and kidney transplant function, especially during the first year after transplantation.

METHODS

We performed an observational cohort study of all kidney transplant recipients at our center from March 2009 to June 2014 to determine whether changes in BMI were associated with kidney transplant function, as measured by estimated glomerular filtration rate (eGFR). Recipient BMI and eGFR were calculated pre-transplant and at 1, 3, 6, 9, and 12 postoperative months (POM) after transplantation. The correlation between changes in BMI and eGFR was then evaluated.

RESULTS

Eighty-one patients were studied. There was a strong negative correlation between changes in BMI and eGFR from pre-transplant to POM 1 (correlation coefficient, -0.406; P < .0001) and from POM 1 to POM 3 (r = -0.324, P = .004).

CONCLUSIONS

We found that increased BMI caused a significant decline in renal function as measured by eGFR, especially in the initial 3 months after kidney transplantation.

Adjustment Experience of Kidney Transplantation Recipients in Korea

BACKGROUND

The purpose of this study was to understand the adjustment process after kidney transplantation.

METHODS

The research method followed grounded theory methodology of Strauss and Corbin. Twelve recipients after kidney transplantation were selected. The data were collected through in-depth, face-to-face interviews or e-mailing or phone-interviews and analyzed by means of a constant comparative method.

RESULTS

Through the category analysis, "struggling for independence" was verified as the central phenomenon of recipients, and the causal conditions that influence this phenomenon were "unpredictable physical status," "the difficulty of self-care," "apathy of families and friends," and "emotional instability." The contextual conditions were "social prejudice" and "difficulty in returning to society," and the intervening conditions were "significant others support" and "religious support." The action/interaction strategies were "inner reviewing strategies," "interactive strategies," and "active self-maintaining strategies." From this observation, "establishing guidelines for living" was derived as the result.

CONCLUSIONS

The results of this study provided deep understanding on the adjustment process after kidney transplantation, and this would help to provide a frame for individualized medical and nursing intervention strategies in assisting the psychosocial adaptation of the kidney transplantation recipient.

Indole derivatives inhibit hepatitis C virus replication through induction of pro-inflammatory cytokines

Previously, we discovered a series of indole derivatives as a new class of hepatitis C virus (HCV) replication inhibitors by using a target-free chemical genetic strategy. Through a structure-activity relationship study, the compound 12e was identified as the most potent inhibitor of this class (EC50 = 1.1 μmol/l) with minimal cytotoxicity (CC50 = 61.8 μmol/l). In order to gain insight into its detailed antiviral mechanism of action, we performed PCR array analyses and found that 12e was able to activate transcription of a number of pro-inflammatory as well as antiviral cytokine genes including CXCL-8, IL-1α, TNF-α, IL-3, IRAK-1, and DDX58. Their induction by 12e was verified by individual RT-PCR analyses. In addition, 12e was found to stimulate secretion of soluble factors with anti-HCV replication activity. Among the 12e-induced pro-inflammatory cytokines, CXCL-8 showed a strong positive correlation between its transcriptional activation and antiviral potency. Interestingly, a recombinant CXCL-8 protein also reduced HCV replication, though only moderately. In conclusion, we found a novel mode of action of indole derivatives in inhibiting HCV replication, particularly the induction of pro-inflammatory cytokines.

Carbon monoxide and nitric oxide interactions in magnocellular neurosecretory neurones during water deprivation

Nitric oxide (NO) and carbon monoxide (CO) are diffusible gas messengers in the brain. Previously, we have shown their independent involvement in central fluid/electrolyte homeostasis control. In the present study, we investigated a possible functional interaction between NO/CO in the regulation of vasopressin (VP) and oxytocin (OT) magnocellular neurosecretory cells (MNCs) activity in euhydrated (EU) and dehydrated [48-h water-deprived (48WD)] rats. Using brain slices from EU and 48WD rats, we measured, by immunohistochemistry, the expression of neuronal NO synthase (nNOS, which synthesises NO) and haeme-oxygenase (HO-1, which synthesises CO) in the hypothalamic supraoptic nucleus (SON). In addition, we used patch-clamp electrophysiology to investigate whether regulation of SON MNC firing activity by endogenous CO was dependent on NO bioavailability and GABAergic inhibitory synaptic function. We found a proportion of OT and VP SON MNCs in EU rats to co-express both of HO-1 and nNOS (33.2 ± 2.9% and 15.3 ± 1.4%, respectively), which was increased in 48WD rats (55.5 ± 0.9% and 21.0 ± 1.7%, respectively, P < 0.05 for both). Inhibition of endogenous HO activity [chromium mesoporphyrin IX chloride (CrMP) 20 μm] induced MNC membrane hyperpolarisation and decreased firing activity, and these effects were blunted by previous blockade of endogenous NOS activity (l-NAME, 2 mm) or blockade of inhibitory GABA function [Picrotoxin (Sigma-Aldrich, St Louis, MO, USA), 50 μm]. No significant changes in SON NO bioavailability (4,5 diaminofluorescein diacetate fluorescence) were observed after CrMP treatment. Taken together, our results support a state-dependent functional inter-relationship between NO and CO in MNCs, in which CO acts as an excitatory gas molecule, whose effects are largely dependent on interactions with the inhibitory SON signals NO and GABA.

Non-invasive assessment of cutaneous wound healing using fluorescent imaging

BACKGROUND/PURPOSE

Optical imaging is a very important technique in the biomedical sciences. The purpose of this study was to develop an in vivo optical system for fluorescent imaging and molecular imaging applications using quantum dots (QDs).

METHODS

The in vivo optical system was composed of modular parts, including a light source, light guide, excitation filter wheel, excitation filters, emission filter wheel, emission filters, liquid crystal tunable filter (LCTF), macro lens, dark chamber, and a cooled charged-coupled device (CCD) camera for recording images. Filters were selected based on the excitation and absorption spectra of QDs to allow spectral separation and optimization of the acquired image. In contrast with conventional systems, our system allows selection of the emission bandwidth.

RESULTS

The system was tested in an in vivo study using a wound-healing model in nude mice. The healing process was examined after injection of fibroblasts and keratinocytes labeled with two different sets of QDs. The different QD probes were readily detected and distinguished using our system.

CONCLUSION

An in vivo optical system is a very useful tool for the detection of genes, proteins, and small-molecule drugs inside living animals, and this imaging modality can also be adopted for real-time visualization of cancer cell metastasis in live animals.

Frequency downshift of Nd:YAG lasers and terahertz radiation

The interaction between an intense laser and a cotraveling relativistic dense electron beam could result in the downshifting of the laser frequency. It is theoretically analyzed that this process can generate a coherent terahertz radiation. The radiation energy could reach the order of 1 mJ per shot in the duration of 100 ps, or a temporal radiation power of 10 MW, with a set of practically relevant parameters.

Enhanced expression of heme oxygenase-1 and carbon monoxide excitatory effects in oxytocin and vasopressin neurones during water deprivation

A growing body of evidence indiates that carbon monoxide (CO) acts as a gas neurotransmitter within the central nervous system. Although CO has been shown to affect neurohypophyseal hormone release in response to osmotic stimuli, the precise sources, targets and mechanisms underlying the actions of CO within the magnocellular neurosecretory system remain largely unknown. In the present study, we combined immunohistochemistry and patch-clamp electrophysiology to study the cellular distribution of the CO-synthase enzyme heme oxygenase type 1 (HO-1), as well as the actions of CO on oxytocin (OT) and vasopressin (VP) magnocellular neurosecretory cells (MNCs), in euhydrated (EU) and 48-h water-deprived rats (48WD). Our results show the expression of HO-1 immunoreactivity both in OT and VP neurones, as well as in a small proportion of astrocytes, both in supraoptic (SON) and paraventricular (PVN) nuclei. HO-1 expression, and its colocalisation with OT and VP neurones within the SON and PVN, was significantly enhanced in 48WD rats. Inhibition of HO activity with chromium mesoporphyrin IX chloride (CrMP; 20 μm) resulted in a slight membrane hyperpolarisation in SON neurones from EU rats, without significantly affecting their firing activity. In 48WD rats, on the other hand, CrMP resulted in a more robust membrane hyperpolarisation, significantly decreasing neuronal firing discharge. Taken together, our results indicate that magnocellular SON and PVN neurones express HO-1, and that CO acts as an excitatory gas neurotransmitter in this system. Moreover, we found that the expression and actions of CO were enhanced in water-deprived rats, suggesting that the state-dependent up-regulation of the HO-1/CO signalling pathway contributes to enhance MNCs firing activity during an osmotic challenge.