The varicella-zoster virus ORF16 protein promotes both the nuclear transport and the protein abundance of the viral DNA polymerase subunit ORF28.

Although all herpesviruses utilize a highly conserved replication machinery to amplify their viral genomes, different members may have unique strategies to modulate the assembly of their replication components. Herein, we characterize the subcellular localization of seven essential replication proteins of varicella-zoster virus (VZV) and show that several viral replication enzymes such as the DNA polymerase subunit ORF28, when expressed alone, are localized in the cytoplasm. The nuclear import of ORF28 can be mediated by the viral DNA polymerase processivity factor ORF16. Besides, ORF16 could markedly enhance the protein abundance of ORF28. Noteworthily, an ORF16 mutant that is defective in nuclear transport still retained the ability to enhance ORF28 abundance. The low abundance of ORF28 in transfected cells was due to its rapid degradation mediated by the ubiquitin-proteasome system. We additionally reveal that radicicol, an inhibitor of the chaperone Hsp90, could disrupt the interaction between ORF16 and ORF28, thereby affecting the nuclear entry and protein abundance of ORF28. Collectively, our findings imply that the cytoplasmic retention and rapid degradation of ORF28 may be a key regulatory mechanism for VZV to prevent untimely viral DNA replication, and suggest that Hsp90 is required for the interaction between ORF16 and ORF28.

Assessment of the (Pro)renin Receptor Protein Expression in Organs.

The (pro)renin receptor ((P)RR) is an essential component of the renin-angiotensin system (RAS) as a specific single-pass transmembrane receptor for prorenin and renin and has now emerged as a multifunctional protein implicated in a wide variety of developmental and physio-pathological processes and pathways. The (P)RR may be of pathological significance in metabolic syndrome. The (P)RR has received much consideration; substantial efforts have been made to understand the localization, regulation, and function of the (P)RR at both a molecular and system level. (P)RR regulation of cell function depends on whether it is intact or cleaved into its constituent forms. Therefore, the present chapter describes immunohistochemical approaches to examine the expression of (P)RR in various organs. It was shown that different molecular forms of (P)RR could be present in different tissue compartments in almost all organs. Among them, the liver has high PRR activity. Our findings could elucidate more detailed distribution of different (P)RR molecular forms in different organs, which could provide useful information to further investigate the pathophysiological mechanisms of the development of various diseases in the future.

A comparative phenotypic and genomic analysis of methicillin-resistant Staphylococcus aureus ST45 isolates from cellulitis and from osteomyelitis in Taiwan.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 45 is a globally disseminated MRSA lineage. Herein, we investigated whether MRSA ST45 isolates from cellulitis and from osteomyelitis display distinctive phenotypic and genomic characteristics. METHODS: A total of 15 MRSA ST45 isolates from cellulitis (CL-MRSAs; n = 6) or osteomyelitis (OM-MRSAs; n = 9) were collected in a Taiwan hospital. These MRSA ST45 isolates were characterized for their antimicrobial susceptibility, biofilm-forming ability, cellular infectivity in vitro, and pathogenicity in vivo. Four CL-MRSA and six OM-MRSA ST45 isolates were selected for whole-genome sequencing (WGS). RESULTS: Antibiotic resistance tests showed that all OM-MRSA ST45 strains, but not CL-MRSA ST45 strains, were resistant to ciprofloxacin, levofloxacin, gentamicin and doxycycline. Compared to the CL-MRSA ST45 isolates, the OM-MRSA ST45 isolates had stronger biofilm-forming ability and cellular infectivity, and caused more severe disease in mice. WGS analysis revealed that these OM-MRSA ST45 isolates carry multiple common mutations or polymorphisms in genes associated with antibiotic resistance and virulence. Moreover, the transposable elements IS256 and IS257R2 were found only in the OM-MRSA ST45 isolates. CONCLUSIONS: The emergence and spread of the highly pathogenic and multidrug-resistant ST45 MRSAs identified from osteomyelitis may pose a serious threat on public health.

Interaction and assembly of the DNA replication core proteins of Kaposi's sarcoma-associated herpesvirus.

IMPORTANCE: Eukaryotic DNA replication is a highly regulated process that requires multiple replication enzymes assembled onto DNA replication origins. Due to the complexity of the cell's DNA replication machinery, most of what we know about cellular DNA replication has come from the study of viral systems. Herein, we focus our study on the assembly of the Kaposi's sarcoma-associated herpesvirus core replication complex and propose a pairwise protein-protein interaction network of six highly conserved viral core replication proteins. A detailed understanding of the interaction and assembly of the viral core replication proteins may provide opportunities to develop new strategies against viral propagation.

Dickkopf-1 Acts as a Profibrotic Mediator in Progressive Chronic Kidney Disease.

Chronic kidney disease (CKD) is a serious public health problem. Due to a high variability in the speed of CKD progression to end-stage renal disease (ESRD) and the critical involvement of Wnt/ß-catenin signaling in CKD, we investigated the role of the Wnt antagonist Dickkopf-1 (DKK1) in CKD progression. Our data revealed that patients with CKD stages 4-5 had higher DKK1 levels in their serum and renal tissues than the control subjects. In an 8-year follow-up, the serum DKK1-high group in the enrolled CKD patients showed a faster progression to ESRD than the serum DKK1-low group. Using a rat model of 5/6 nephrectomy (Nx)-induced CKD, we consistently detected elevated serum levels and renal production of DKK1 in 5/6 Nx rats compared to sham-operated rats. Importantly, the knockdown of the DKK1 levels in the 5/6 Nx rats markedly attenuated the CKD-associated phenotypes. Mechanistically, we demonstrated that the treatment of mouse mesangial cells with recombinant DKK1 protein induced not only the production of multiple fibrogenic proteins, but also the expression of endogenous DKK1. Collectively, our findings suggest that DKK1 acts as a profibrotic mediator in CKD, and elevated levels of serum DKK1 may be an independent predictor of faster disease progression to ESRD in patients with advanced CKD.

Characterization of Human Norovirus Nonstructural Protein NS1.2 Involved in the Induction of the Filamentous Endoplasmic Reticulum, Enlarged Lipid Droplets, LC3 Recruitment, and Interaction with NTPase and NS4.

Human noroviruses (HuNVs) are the leading cause of gastroenteritis worldwide. NS1.2 is critical for HuNV pathogenesis, but the function is still unclear. The GII NS1.2 of HuNVs, unlike GI NS1.2, was localized to the endoplasmic reticulum (ER) and lipid droplets (LDs) and is accompanied by a distorted-filamentous ER morphology and aggregated-enlarged LDs. LC3 was recruited to the NS1.2-localized membrane through an autophagy-independent pathway. NS1.2, expressed from a cDNA clone of GII.4 norovirus, formed complexes with NTPase and NS4, which exhibited aggregated vesicle-like structures that were also colocalized with LC3 and LDs. NS1.2 is structurally divided into three domains from the N terminus: an inherently disordered region (IDR), a region that contains a putative hydrolase with the H-box/NC catalytic center (H-box/NC), and a C-terminal 251-330 a.a. region containing membrane-targeting domain. All three functional domains of NS1.2 were required for the induction of the filamentous ER. The IDR was essential for LC3 recruitment by NS1.2. Both the H-Box/NC and membrane-targeting domains are required for the induction of aggregated-enlarged LDs, NS1.2 self-assembly, and interaction with NTPase. The membrane-targeting domain was sufficient to interact with NS4. The study characterized the NS1.2 domain required for membrane targeting and protein-protein interactions, which are crucial for forming a viral replication complex.

Effects of Supine and Prone Positions on Nasal Patency in Healthy Individuals.

OBJECTIVES: Supine position reduces nasal patency compared with that in the sitting position; however, data on the effects of prone position on nasal patency is lacking. METHODS: We assessed the nasal patency of 30 healthy individuals without upper respiratory tract disorders by using visual analog scale (VAS) score and acoustic rhinometry in 7 positions: sitting; frontal, right, and left supine; and frontal, right, and left prone. RESULTS: According to the VAS scores, compared with that in the sitting position, both the supine and prone positions significantly increased subjective nasal obstruction (P < .001). The prone position had a more significant effect than did the supine position (P = .017). The results of minimal cross-sectional area measured through acoustic rhinometry demonstrated that both the supine and prone positions reduced the nasal patency significantly, but without significant differences between the effects of prone and supine positions (P = .794). CONCLUSION: This is the first study to elucidate that the prone position can significantly reduce the nasal patency in healthy individuals through subjective and objective assessments. LEVEL OF EVIDENCE: IV.

Innovative Continuous Wound Irrigation Approach for Postoperative Treatment of Masticator Space Abscess.

This is a case of an innovative method of continuous irrigation approach for wound care following surgical drainage. Compared with the traditional labor-intensive irrigation, this novel handy method is not only reducing the workload but is also less time-consuming and inexpensive. This continuous irrigation approach is an efficient alternative approach for wound care in deep infection of the head and neck.

Nasal irrigation with licorice extract (Glycyrrhiza glabra) in treating nasal polyps by reducing fibroblast differentiation and extracellular matrix production in TGF-ß1-stimulated nasal polyp-derived fibroblasts by inhibiting the MAPK/ERK-1/2 pathway - an in vitro and in clinic study.

BACKGROUND: To date, treating nasal polyps (NPs) is still a medical challenge. However, we have developed an innovative therapy using licorice extract (LE: Glycyrrhiza glabra) to treat rhinitis and sinusitis via nasal irrigation and have discovered that it significantly affects treatment of NPs. HYPOTHESIS/PURPOSE: This study investigated the mechanism of LE on NPs. STUDY DESIGN: NPs were collected from three patients using tissue biopsies before and 2 weeks after nasal irrigation with licorice for histopathological analysis. Additionally, NPs from two patients were collected, and nasal polyp-derived fibroblasts (NPDF) were isolated and cultured. METHODS: The TGF-ß1-stimulated NPDF model was used to examine the effect of LE on fibroblast differentiation (biomarker: α-SMA), the consequent production of extracellular matrix (ECM; biomarkers: fibronectin, FBN), and the functional signaling pathway. RESULTS: Immunohistochemistry (IHC) revealed that the number of eosinophils and the expression of α-SMA and interstitial collagen of polyps after licorice treatment significantly decreased. Additionally, RT-PCR, western blotting, and immunofluorescence (IF) showed that α-SMA and FBN expressions were significantly increased in the NPDF, which was stimulated by TGF-ß1, and LE dose-dependently could effectively reduce this effect. Furthermore, western blotting showed that LE could attenuate α-SMA and FBN expressions by preventing the signaling pathway of MAPK/ERK-1/2, which IHC and IF further confirmed. In addition, LE effectively suppressed the cell migration of NPDF, which is related to polyp expansion. CONCLUSION: LE is clinically used to treat sinusitis with NPs through nasal irrigation, which significantly reduces the size of NPs. This effect could attenuate fibroblast differentiation, ECM production and cell migration, and one of the functional mechanisms may be through inhibition of the MAPK/ERK-1/2 signaling pathway. TRIAL REGISTRATION: ISRCTN (No. 51425529) registered on 17/04/2020 (retrospectively registered) - http://www.isrctn.com/ISRCTN51425529.

Kaposi's Sarcoma-Associated Herpesvirus ORF50 Protein Represses Cellular MDM2 Expression via Suppressing the Sp1- and p53-Mediated Transactivation.

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded ORF50 protein is a potent transcriptional activator essential for triggering KSHV lytic reactivation. Despite extensive studies, little is known about whether ORF50 possesses the ability to repress gene expression or has an antagonistic action to cellular transcription factors. Previously, we demonstrated that human oncoprotein MDM2 can promote the degradation of ORF50 protein. Herein, we show that abundant ORF50 expression in cells can conversely downregulate MDM2 expression via repressing both the upstream (P1) and internal (P2) promoters of the MDM2 gene. Deletion analysis of the MDM2 P1 promoter revealed that there were two ORF50-dependent negative response elements located from -102 to -63 and from -39 to +1, which contain Sp1-binding sites. For the MDM2 P2 promoter, the ORF50-dependent negative response element was identified in the region from -110 to -25, which is coincident with the location of two known p53-binding sites. Importantly, we further demonstrated that overexpression of Sp1 or p53 in cells indeed upregulated MDM2 expression; however, coexpression with ORF50 protein remarkably reduced the Sp1- or p53-mediated MDM2 upregulation. Collectively, our findings propose a reciprocal negative regulation between ORF50 and MDM2 and uncover that ORF50 decreases MDM2 expression through repressing Sp1- and p53-mediated transactivation.

The difference in pathogenic bacteria between chronic rhinosinusitis in patients with and without Sjogren's syndrome: a retrospective case-control study.

BACKGROUND: Chronic rhinosinusitis (CRS) affects the quality of life of many people worldwide and can cause comorbidities. Our previous research proved that Sjogren's syndrome (SS) is a predisposing factor for CRS, with a 2.5-fold associated risk. Antibiotics are important in CRS treatment; however, there is a paucity of research on the pathogenic bacteria of SS-CRS in the past. We conducted this study to investigate the pathogenic difference of SS-CRS and non-SS-CRS and aimed to give clinicians references when selecting antibiotics to treat SS-CRS. MATERIALS AND METHODS: A total of 14,678 patients hospitalized for CRS operation from 2004 to 2018 were identified from the Chang Gung Research Database. These CRS cases were classified as either SS-CRS or non-SS-CRS. We analyzed their bacterial distribution by studying the results of the pus cultures performed alongside surgery. RESULTS: The top three facultative anaerobic or aerobic isolated bacteria in the SS-CRS group were coagulase-negative Staphylococcus (CoNS: 34.3%), Pseudomonas aeruginosa (28.6%), methicillin-sensitive Staphylococcus aureus (MSSA: 20%), and Staphylococcus epidermidis (20%). In the non-SS-CRS group, S. epidermidis (29.3%), CoNS (25.7%), and MSSA (14.2%) were identified. The top three anaerobic bacterial genera were Cutibacterium (54.3%), Peptostreptococcus (11.4%), and Fusobacterium (11.4%) in the SS-CRS group and Cutibacterium (53.8%), Peptostreptococcus (25%), and Prevotella (12.9%) in the non-SS-CRS group. CONCLUSIONS: P. aeruginosa is a major pathogen in SS-CRS patients. In addition, physicians should be aware of potential Fusobacterium and antibiotic-resistant bacterial infection in patients with SS-CRS.

Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Periprosthetic Joint Infections.

Periprosthetic joint infection (PJI) is a troublesome clinical issue in total joint arthroplasty (TJA). Although methicillin-resistant Staphylococcus aureus (MRSA) is considered to be the most serious pathogen in PJIs, little is known about the genotypic and phenotypic characteristics of MRSA clones isolated from PJI patients. A total of 36 MRSA isolates from PJI patients were collected at the Chang-Gung Memorial Hospital in Taiwan from May 2016 to October 2019. All MRSA isolates were subjected to genome typing. The prevalence of Panton-Valentine leucocidin (PVL), the antibiotic susceptibility profile, and the biofilm formation ability were compared among different MRSA genogroups. Additionally, demographics and clinical manifestations of patients infected with different MRSA genogroups were investigated. Eight sequence types (STs) were identified among 36 isolated from PJIs. According to the incidence of MRSA genotypes in PJIs, in this study, we divided them into four groups, including ST8 (n = 10), ST59 (n = 8), ST239 (n = 11), and other STs (n = 7). For the antibiotic susceptibility testing, we found that all MRSA isolates in the ST239 group were highly resistant to ciprofloxacin, gentamicin trimethoprim-sulfamethoxazole, and levofloxacin. Additionally, ST239 MRSA also had a higher ability to form biofilm than other groups. Importantly, patients with ST239 infection typically had a fever and exhibited higher levels of inflammatory markers, including C-reactive protein (CRP) and white blood cell count (WBC). Epidemiological investigations revealed that knee PJIs were mainly attributed to infection with ST59 MRSA and increasing trends for infection with ST8 and other ST types of MRSAs in PJI patients were observed from 2016 to 2019. The identification of MRSA genotypes in PJIs may be helpful for the management of PJIs.

Caspase-Mediated Cleavage of the Transcription Factor Sp3: Possible Relevance to Cancer and the Lytic Cycle of Kaposi's Sarcoma-Associated Herpesvirus.

The open reading frame 50 (ORF50) protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the master regulator essential for initiating the viral lytic cycle. Previously, we have demonstrated that the ORF50 protein can cooperate with Sp3 to synergistically activate a set of viral and cellular gene promoters through highly conserved ORF50-responsive elements that harbor a Sp3-binding motif. Herein, we show that Sp3 undergoes proteolytic cleavage during the viral lytic cycle, and the cleavage of Sp3 is dependent on caspase activation. Since similar cleavage patterns of Sp3 could be detected in both KSHV-positive and KSHV-negative lymphoma cells undergoing apoptosis, the proteolytic cleavage of Sp3 could be a common event during apoptosis. Mutational analysis identifies 12 caspase cleavage sites in Sp3, which are situated at the aspartate (D) positions D17, D19, D180, D273, D275, D293, D304 (or D307), D326, D344, D530, D543, and D565. Importantly, we noticed that three stable Sp3 C-terminal fragments generated through cleavage at D530, D543, or D565 encompass an intact DNA-binding domain. Like the full-length Sp3, the C-terminal fragments of Sp3 could still retain the ability to cooperate with ORF50 protein to activate specific viral and cellular gene promoters synergistically. Collectively, our findings suggest that despite the proteolytic cleavage of Sp3 under apoptotic conditions, the resultant Sp3 fragments may retain biological activities important for the viral lytic cycle or for cellular apoptosis. IMPORTANCE The ORF50 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the key viral protein that controls the switch from latency to lytic reactivation. It is a potent transactivator that can activate target gene promoters via interacting with other cellular DNA-binding transcription factors, such as Sp3. In this report, we show that Sp3 is proteolytically cleaved during the viral lytic cycle, and up to 12 caspase cleavage sites are identified in Sp3. Despite the proteolytic cleavage of Sp3, several resulting C-terminal fragments that have intact zinc-finger DNA-binding domains still retain substantial influence in the synergy with ORF50 to activate specific gene promoters. Overall, our studies elucidate the caspase-mediated cleavage of Sp3 and uncover how ORF50 utilizes the cleavage fragments of Sp3 to transactivate specific viral and cellular gene promoters.

Pathogens and Prognosis of Deep Neck Infection in End-Stage Renal Disease Patients.

OBJECTIVES/HYPOTHESIS: To examine the pathogenic bacterial spectra and prognosis of deep neck infection (DNI) in end-stage renal disease (ESRD) patients. STUDY DESIGN: Retrospective study. METHODS: Patients diagnosed with DNI between 2004 and 2015 in Chang Gung Memorial Hospital were enrolled and divided into three groups, namely ESRD-DNI, chronic kidney disease (CKD)-DNI, and non-CKD-DNI. Differences in pathogenic bacteria, treatment, and prognosis were compared across the three groups. RESULTS: The bacterial spectra differed among the three groups. The main three facultative anaerobic or aerobic bacteria causing ESRD-DNIs were methicillin-resistant Staphylococcus aureus (MRSA; 25.4%), methicillin-susceptible S. aureus (MSSA; 14.1%), and Klebsiella pneumoniae (KP; 12.7%). For CKD-DNIs, they were KP (23.5%), Viridans streptococci (VS; 23.5%), and MSSA (14.7%). For non-CKD-DNIs, they were VS (31.7%), KP (17.2%), and coagulase-negative staphylococci (8.0%). Compared with the other groups, the ESRD-DNI group had higher white blood cell and C-reactive protein levels, longer hospital stays, more frequent admissions to the intensive care unit, more mediastinal complications, and a significantly higher mortality rate. CONCLUSIONS: The ESRD-DNI group exhibited more severe disease activity and higher mortality compared with those of the CKD-DNI and non-CKD-DNI groups. MRSA was the leading pathogen for patients with ESRD-DNI. Physicians must implement strategies for the early detection of MRSA to accurately prescribe antibiotics and prevent nosocomial transmission. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1403-1409, 2022.

The Pathogenic Bacteria of Deep Neck Infection in Patients with Type 1 Diabetes, Type 2 Diabetes, and Without Diabetes from Chang Gung Research Database.

Deep neck infection (DNI) is a lethal emergent condition. Patients with types 1 and 2 diabetes mellitus (T1DM and T2DM, respectively) are predisposed to DNI and have poorer prognoses. The mainstay of the treatment is surgical drainage and antibiotics; however, the pathogenic bacteria of T1DM-DNI have not been studied before. We obtained the data of 8237 patients with DNI who were hospitalized from 2004 to 2015 from the Chang Gung Research Database, which contains multi-institutional medical records in Taiwan. Using diagnostic codes, we classified them into T1DM-DNI, T2DM-DNI, and non-DM-DNI and analyzed their pathogenic bacteria, disease severity, treatment, and prognosis. The top three facultative anaerobic or aerobic bacteria of T1DM-DNI were Klebsiella pneumoniae (KP, 40.0%), Viridans Streptococci (VS, 22.2%), and methicillin-sensitive Staphylococcus aureus (MSSA, 8.9%), similar for T2DM (KP, 32.2%; VS, 23.3%; MSSA, 9.5%). For non-DM-DNI, it was VS (34.6%), KP (9.8%), and coagulase-negative Staphylococci (8.7%). The order of anaerobes for the three groups was Peptostreptococcus micros, Prevotella intermedia, and Peptostreptococcus anaerobius. Patients with T1DM-DNI and T2DM-DNI had higher white blood cell (WBC) counts and C-reactive protein (CRP) levels, more cases of surgery, more cases of tracheostomy, longer hospital stays, more mediastinal complications, and higher mortality rates than those without DM-DNI. Patients in the death subgroup in T1DM-DNI had higher WBC counts, band forms, and CRP levels than those in the survival subgroup. Patients with DM-DNI had more severe disease and higher mortality rate than those without DM-DNI. KP and Peptostreptococcus micros are the leading pathogens for both patients with T1DM-DNI and those with T2DM-DNI. Clinicians should beware of high serum levels of infection markers, which indicate potential mortality.

Identification and Characterization of Human Norovirus NTPase Regions Required for Lipid Droplet Localization, Cellular Apoptosis, and Interaction with the Viral P22 Protein.

The human norovirus (HuNV)-encoded nucleoside-triphosphatase (NTPase) is a multifunctional protein critically involved in viral replication and pathogenesis. Previously, we have shown that the viral NTPase is capable of forming vesicle clusters in cells, interacting with other viral proteins such as P22, and promoting cellular apoptosis. Herein, we demonstrate that NTPase-associated vesicle clusters correspond to lipid droplets (LDs) wrapped by the viral protein and show that NTPase-induced apoptosis is mediated through both caspase-8- and caspase-9-dependent pathways. Deletion analysis revealed that the N-terminal 179-amino-acid (aa) region of NTPase encompasses two LD-targeting motifs (designated LTM-1 and LTM-2), two apoptosis-inducing motifs, and multiple regulatory regions. Interestingly, the identified LTM-1 and LTM-2, which are located from aa 1 to 50 and from aa 51 to 90, respectively, overlap with the two apoptosis-inducing motifs. Although there was no positive correlation between the extent of LD localization and the degree of cellular apoptosis for NTPase mutants, we noticed that mutant proteins defective in LD-targeting ability could not induce cellular apoptosis. In addition to LD targeting, the amphipathic LTM-1 and LTM-2 motifs could have the potential to direct fusion proteins to the endoplasmic reticulum (ER). Furthermore, we found that the LTM-1 motif is a P22-interacting motif. However, P22 functionally augmented the proapoptotic activity of the LTM-2 fusion protein but not the LTM-1 fusion protein. Overall, our findings propose that NTPase may participate in multiple cellular processes through binding to LDs or to the ER via its N-terminal amphipathic helix motifs. IMPORTANCE Human noroviruses (HuNVs) are the major agent of global gastroenteritis outbreaks. However, due to the lack of an efficient cell culture system for HuNV propagation, functions of the viral-encoded proteins in host cells are still poorly understood. In the current study, we present that the viral NTPase is a lipid droplet (LD)-associated protein, and we identify two LD-targeting motifs, LTM-1 and LTM-2, in its N-terminal domain. In particular, the identified LTM-1 and LTM-2 motifs, which contain a hydrophobic region and an amphipathic helix, are also capable of delivering the fusion protein to the endoplasmic reticulum (ER), promoting cellular apoptosis, and physically or functionally associating with another viral protein P22. Since LDs and the ER have been linked to several biological functions in cells, our study therefore proposes that the norovirus NTPase may utilize LDs or the ER as replication platforms to benefit viral replication and pathogenesis.

GMI, an Immunomodulatory Peptide from Ganoderma microsporum, Restrains Periprosthetic Joint Infections via Modulating the Functions of Myeloid-Derived Suppressor Cells and Effector T Cells.

Periprosthetic joint infections (PJIs) caused by Staphylococcus aureus infection are difficult to treat due to antibiotic resistance. It is known that the biofilms from methicillin-resistant S. aureus (MRSA) promote expansion of myeloid-derived suppressor cells (MDSCs) to suppress T-cell proliferation and benefit bacterial infections. This study finds that GMI, a fungal immunomodulatory peptide isolated from Ganoderma microsporum, suppresses MDSC expansion to promote the proliferation of cytotoxic T cells. The enhancement is likely attributed to increased expression of IL-6 and TNF-α and reduction in ROS expression. Similar beneficial effects of GMI on the suppression of MDSC expansion and IL-6 expression are also observed in the whole blood and reduces the accumulation of MDSCs in the infected bone region in a mouse PJI infection model. This study shows that GMI is potentially useful for treating S. aureus-induced PJIs.

High Risk of Peritonsillar Abscess in End-Stage Renal Disease Patients: A Nationwide Real-World Cohort Study.

BACKGROUND: Peritonsillar abscess (PTA) is an infectious emergency in the head and neck, and patients with end-stage renal disease (ESRD) have an immunocompromised status. However, no relevant research has focused on the ESRD-PTA relationship. This study explored PTA in ESRD patients and their prognosis. METHODS: We identified 157,026 patients diagnosed as having ESRD over January 1997 to December 2013 from Taiwan's National Health Insurance Research Database (NHIRD). Each patient with ESRD (hereafter, patients) was matched with one control without chronic kidney disease (CKD; hereafter, controls) by sex, age, urbanization level, and income. Next, PTA incidence until death or the end of 2013 was compared between the two groups, and the relative risk of PTA was analyzed using a multiple logistic regression model. RESULTS: The patients had a significantly higher PTA incidence than did the controls (incidence rate ratio: 2.02, 95% confidence interval [CI]: 1.40-2.91, p < 0.001). The Kaplan-Meier analysis revealed that the patients had a higher cumulative incidence of PTA than did the controls (p < 0.001). In Cox regression analysis, the patients had nearly twofold higher PTA risk (adjusted hazard ratio [HR]: 1.98, 95% CI: 1.37-2.86, p < 0.001). The between-group differences in the PTA-related hospital stay length (8.1 ± 10.3 days in patients and 5.7 ± 4.6 days in controls, p = 0.09), consequent deep-neck infection complication (4.2% in patients and 6.3% in controls, p = 0.682), and mortality (0.0% in both groups) were nonsignificant. Conclusions: Although ESRD does not predict a poor prognosis of PTA, it is an independent PTA risk factor.

Biodegradable Stent with mTOR Inhibitor-Eluting Reduces Progression of Ureteral Stricture.

In this study, we investigated the effect of mTOR inhibitor (mTORi) drug-eluting biodegradable stent (DE stent), a putative restenosis-inhibiting device for coronary artery, on thermal-injury-related ureteral stricture in rabbits. In vitro evaluation confirmed the dose-dependent effect of mTORi, i.e., rapamycin, on fibrotic markers in ureteral component cell lines. Upper ureteral fibrosis was induced by ureteral thermal injury in open surgery, which was followed by insertion of biodegradable stents, with or without rapamycin drug-eluting. Immunohistochemistry and Western blotting were performed 4 weeks after the operation to determine gross anatomy changes, collagen deposition, expression of epithelial-mesenchymal transition markers, including Smad, α-SMA, and SNAI 1. Ureteral thermal injury resulted in severe ipsilateral hydronephrosis. The levels of type III collagen, Smad, α-SMA, and SNAI 1 were increased 28 days after ureteral thermal injury. Treatment with mTORi-eluting biodegradable stents significantly attenuated thermal injury-induced urinary tract obstruction and reduced the level of fibrosis proteins, i.e., type III collagen. TGF-ß and EMT signaling pathway markers, Smad and SNAI 1, were significantly modified in DE stent-treated thermal-injury-related ureteral stricture rabbits. These results suggested that intra-ureteral administration of rapamycin by DE stent provides modification of fibrosis signaling pathway, and inhibiting mTOR may result in fibrotic process change.

The Epstein-Barr Virus Lytic Protein BMLF1 Induces Upregulation of GRP78 Expression through ATF6 Activation.

The unfolded protein response (UPR) is an intracellular signaling pathway essential for alleviating the endoplasmic reticulum (ER) stress. To support the productive infection, many viruses are known to use different strategies to manipulate the UPR signaling network. However, it remains largely unclear whether the UPR signaling pathways are modulated in the lytic cycle of Epstein-Barr virus (EBV), a widely distributed human pathogen. Herein, we show that the expression of GRP78, a central UPR regulator, is up-regulated during the EBV lytic cycle. Our data further revealed that knockdown of GRP78 in EBV-infected cell lines did not substantially affect lytic gene expression; however, GRP78 knockdown in these cells markedly reduced the production of virus particles. Importantly, we identified that the early lytic protein BMLF1 is the key regulator critically contributing to the activation of the grp78 gene promoter. Mechanistically, we found that BMLF1 can trigger the proteolytic cleavage and activation of the UPR senor ATF6, which then transcriptionally activates the grp78 promoter through the ER stress response elements. Our findings therefore provide evidence for the connection between the EBV lytic cycle and the UPR, and implicate that the BMLF1-mediated ATF6 activation may play critical roles in EBV lytic replication.