A significant outbreak of respiratory human adenovirus infections among children aged 3-6 years in Hokkaido, Japan, in 2023.

Human adenovirus (HAdV) infections present diverse clinical manifestations upon infecting individuals, with respiratory infections predominating in children. We surveyed pediatric hospitalizations due to respiratory HAdV infections across 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to March 2024, recording 473 admissions. While hospitalizations remained below five cases per week from July 2019 to September 2023, a notable surge occurred in late October 2023, with weekly admissions peaking at 15-20 cases from November to December. There were dramatic shifts in the age distribution of hospitalized patients: during 2019-2021, 1-year-old infants and children aged 3-6 years represented 51.4%-54.8% and 4.1%-13.3%, respectively; however, in 2023-2024, while 1-year-old infants represented 19.0%-20.1%, the proportion of children aged 3-6 years increased to 46.2%-50.0%. Understanding the emergence of significant outbreaks of respiratory HAdV infections and the substantial changes in the age distribution of hospitalized cases necessitates further investigation into the circulating types of HAdV in Hokkaido Prefecture and changes in children's neutralizing antibody titers against HAdV.

Resurgence of human metapneumovirus infection and influenza after three seasons of inactivity in the post-COVID-19 era in Hokkaido, Japan, 2022-2023.

Following the coronavirus disease 2019 (COVID-19) outbreak in February 2020, incidences of various infectious diseases decreased notably in Hokkaido Prefecture, Japan. However, Japan began gradually easing COVID-19 infection control measures in 2022. Here, we conducted a survey of children hospitalized with human metapneumovirus (hMPV), influenza A and B, and respiratory syncytial virus infections in 18 hospitals across Hokkaido Prefecture, Japan, spanning from July 2019 to June 2023. From March 2020 to June 2022 (28 months), only 13 patients were hospitalized with hMPV, and two patients had influenza A. However, in October to November 2022, there was a re-emergence of hMPV infections, with a maximum of 27 hospitalizations per week. From July 2022 to June 2023 (12 months), the number of hMPV-related hospitalizations dramatically increased to 317 patients, with the majority aged 3-6 years (38.2%, [121/317]). Influenza A also showed an increase from December 2022, with a peak of 13 hospitalizations per week in March 2023, considerably fewer than the pre-COVID-19 outbreak in December 2019, when rates reached 45 hospitalizations per week. These findings suggest the possibility of observing more resurgences in infectious diseases in Japan after 2023 if infection control measures continue to be relaxed. Caution is needed in managing potential outbreaks.

Sequence analysis of a feline- and porcine-origin G3P[9] rotavirus A strain in a child with acute gastroenteritis in Japan.

We isolated the rare G3P[9] rotavirus strain RVA/Human-wt/JPN/R11-035/2015/G3P[9] from a 2-year-old girl presenting with vomiting and diarrhea who had daily contact with cats in Japan, 2015. Full-genome analysis revealed that the R11-035 strain had an AU-1-like genetic constellation, except for the NSP3 (T) gene: G3-P[9]-I3-R3-C3-M3-A3-N3-T1-E3-H6. Phylogenetic analysis showed that strain R11-035 is closely related to human/feline-like human strains, and only the NSP3 (T1) gene was clustered together with Taiwanese porcine strains. We postulate that the R11-035 strain was directly transmitted from a cat to the patient and acquired its NSP3 gene through intergenotype reassortment with porcine strains before being transmitted to humans.

Topical non-steroidal agents for the prevention of radiation dermatitis: a systematic review and meta-analysis.

PURPOSE: Radiation dermatitis (RD) is a common side effect of radiation therapy, affecting a majority of breast and head and neck cancer patients with a negative impact on quality of life. Currently, no consensus exists regarding the prevention of RD. METHODS: PubMed, Embase and Cochrane databases (1946 to December 2022) were searched using PRISMA guidelines to identify randomized controlled trials (RCTs) that investigated the use of topical non-steroidal agents in the prevention of RD in patients undergoing radiotherapy. RESULTS: A total of six RCTs were included, comprising 627 patients. Among the topical non-steroidal agents analyzed, only the use of Biafine® in breast cancer patients was significant in preventing grade 4 and 3 + RD as classified by the Radiation Therapy Oncology group (RTOG) scale (OR = 0.07, 95% CI 0.01-0.63, p = 0.02, and OR 0.11, 95% CI 0.03-0.41, p < 0.01, respectively). The remaining agents (trolamine alone and hyaluronic acid/hyaluronan) did not significantly prevent the occurrence of RD. CONCLUSION: The results of this systematic review and meta-analysis indicate that Biafine® can prevent grade 3 + RD in breast cancer patients. The use of trolamine and hyaluronic acid does not significantly affect the incidence of RD.

Neonatal suppurative parotitis: Case reports and literature review.

BACKGROUND: Neonatal suppurative parotitis is a rare disease, characterized mainly by unilateral parotid swelling with erythema and tenderness, and often purulent discharge from the Stensen's duct into the oral cavity. Only 44 cases were reported in the English literature between 1970 and 2013. METHODS: A MEDLINE search was conducted using the terms acute, neonatal, newborn, suppurative, bacterial, purulent, parotitis, parotid swelling, and parotid abscess, limited to the English-language literature starting from 2011. We reviewed all reported cases, together with two more managed cases in our hospital. We also describe the magnetic resonance imaging findings of the early stage of this disease. RESULTS: We identified 26 new cases since 2011. The total number of patients reviewed was 72, including our patients. The infection was unilateral in 83% of patients, and 67% of the affected patients were males. The serum amylase levels were generally not elevated despite marked parotid swelling. Of the causative agents of this disease, 65% were Staphylococcus aureus, of which 19% were methicillin-resistant S. aureus. As the rate of cesarean section was high in patients with this disease, it was considered a risk factor. The diffusion-weighted magnetic resonance images showed multiple punctate hyperintensity regions with reduced apparent diffusion coefficient, suggesting microabscess formation in the affected gland. CONCLUSIONS: Acute suppurative parotitis should be considered in cases of swelling and tenderness in the parotid gland during the neonatal period. Multiple punctate hyperintensities in the parotid gland on the diffusion-weighted images may indicate a retrograde bacterial infection from the Stensen's duct.

Surveillance in hospitalized children with infectious diseases in Japan: Pre- and post-coronavirus disease 2019.

INTRODUCTION: The epidemic of coronavirus disease 2019 (COVID-19) rapidly spread worldwide, and the various infection control measures have a significant influence on the spread of many infectious diseases. However, there have been no multicenter studies on how the number of hospitalized children with various infectious diseases changed before and after the outbreak of COVID-19 in Japan. METHODS: We conducted a multicenter, prospective survey for hospitalized pediatric patients in 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to February 2021. We defined July 2019 to February 2020 as pre-COVID-19, and July 2020 to February 2021 as post-COVID-19. We surveyed various infectious diseases by sex and age. RESULTS: In total, 5300 patients were hospitalized during the study period. The number of patients decreased from 4266 in the pre-COVID-19 period to 701 (16.4%) post-COVID-19. Patients with influenza and RSV decreased from 308 to 795 pre-COVID-19 to zero and three (0.4%) post-COVID-19. However, patients with adenovirus (respiratory infection) only decreased to 60.9% (46-28) of pre-COVID levels. Patients with rotavirus, norovirus, and adenovirus gastroenteritis decreased markedly post-COVID-19 to 2.6% (38-1), 27.8% (97-27) and 13.5% (37-5). The number of patients with UTIs was similar across the two periods (109 and 90). KD patients decreased to 31.7% (161-51) post-COVID-19. CONCLUSIONS: We suggest that current infection control measures for COVID-19 such as wearing masks, washing hands, and disinfecting hands with alcohol are effective against various infectious diseases. However, these effects vary by disease.

Potential role of transforming growth factor-beta 1/Smad signaling in secondary lymphedema after cancer surgery.

Secondary lymphedema often develops after cancer surgery, and over 250 million patients suffer from this complication. A major symptom of secondary lymphedema is swelling with fibrosis, which lowers the patient's quality of life, even if cancer does not recur. Nonetheless, the pathophysiology of secondary lymphedema remains unclear, with therapeutic approaches limited to physical or surgical therapy. There is no effective pharmacological therapy for secondary lymphedema. Notably, the lack of animal models that accurately mimic human secondary lymphedema has hindered pathophysiological investigations of the disease. Here, we developed a novel rat hindlimb model of secondary lymphedema and showed that our rat model mimics human secondary lymphedema from early to late stages in terms of cell proliferation, lymphatic fluid accumulation, and skin fibrosis. Using our animal model, we investigated the disease progression and found that transforming growth factor-beta 1 (TGFB1) was produced by macrophages in the acute phase and by fibroblasts in the chronic phase of the disease. TGFB1 promoted the transition of fibroblasts into myofibroblasts and accelerated collagen synthesis, resulting in fibrosis, which further indicates that myofibroblasts and TGFB1/Smad signaling play key roles in fibrotic diseases. Furthermore, the presence of myofibroblasts in skin samples from lymphedema patients after cancer surgery emphasizes the role of these cells in promoting fibrosis. Suppression of myofibroblast-dependent TGFB1 production may therefore represent an effective pharmacological treatment for inhibiting skin fibrosis in human secondary lymphedema after cancer surgery.

Japanese clinical practice guidelines for vascular anomalies 2017.

The objective was to prepare guidelines to perform the current optimum treatment by organizing effective and efficient treatments of hemangiomas and vascular malformations, confirming the safety, and systematizing treatment, employing evidence-based medicine (EBM) techniques and aimed at improvement of the outcomes. Clinical questions (CQs) were decided based on the important clinical issues. For document retrieval, key words for literature searches were set for each CQ and literature published from 1980 to the end of September 2014 was searched in Pubmed, Cochrane Library, and Japana Centra Revuo Medicina (JCRM). The strengths of evidence and recommendations acquired by systematic reviews were determined following the Medical Information Network Distribution System (MINDS) technique. A total of 33 CQs were used to compile recommendations and the subjects included efficacy of resection, sclerotherapy/embolization, drug therapy, laser therapy, radiotherapy, and other conservative treatment, differences in appropriate treatment due to the location of lesions and among symptoms, appropriate timing of treatment and tests, and pathological diagnosis deciding the diagnosis. Thus, the Japanese Clinical Practice Guidelines for Vascular Anomalies 2017 have been prepared as the evidence-based guidelines for the management of vascular anomalies.

Potential biomarkers of kaposiform lymphangiomatosis.

BACKGROUND: Kaposiform lymphangiomatosis (KLA) has recently been distinguished as a novel subtype of generalized lymphatic anomaly (GLA), and is characterized by foci of spindle endothelial cells amid a background of malformed lymphatic channels. The etiology of these diseases remains unknown and diagnosis is confounded by their similar clinical findings. This study aimed to clarify differences in the clinical findings and plasma cytokine profiles of GLA and KLA patients. PROCEDURE: Clinical features data of GLA and KLA patients were obtained from a national survey. Differences in clinical findings, plasma levels of cytokines, and survival were analyzed. Plasma was obtained from healthy controls and GLA and KLA patients. Thirty-six angiogenic and lymphangiogenic factors were evaluated for cytokine concentration. RESULTS: Twenty-one patients with GLA and 11 with KLA were recruited. Mediastinal masses, hemorrhagic pericardial and pleural effusion, coagulation disorders, and thrombocytopenia were more frequent in KLA than in GLA. KLA had a significantly poorer outcome than GLA (P = 0.044). Soluble VEGFR3, angiopoietin 2, HGF, soluble HER2, tenascin C, and soluble HGFR levels were higher in KLA. Notably, soluble VEGFR3 and angiopoietin 2 levels were approximately 10-fold higher than those of other molecules measured. However, soluble VEGFR1 and soluble TIE2 were lower in KLA than in GLA and the controls. CONCLUSIONS: Patients with KLA have an unfavorable prognosis and serious symptoms (hemorrhagic pleural effusion and coagulation disorders). Our data indicate that eight angiogenic cytokines might be potential biomarkers of KLA.

Ectodomain Shedding of Lymphatic Vessel Endothelial Hyaluronan Receptor 1 (LYVE-1) Is Induced by Vascular Endothelial Growth Factor A (VEGF-A).

Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), a type I transmembrane glycoprotein, is known as one of the most specific lymphatic vessel markers in the skin. In this study, we found that the ectodomain of LYVE-1 undergoes proteolytic cleavage, and this process produces soluble LYVE-1. We further identified the cleavage site for ectodomain shedding and generated an uncleavable mutant of LYVE-1. In lymphatic endothelial cells, ectodomain shedding of LYVE-1 was induced by vascular endothelial growth factor (VEGF)-A, an important factor for angiogenesis and lymphangiogenesis under pathological conditions. VEGF-A-induced LYVE-1 ectodomain shedding was mediated via the extracellular signal-regulated kinase (ERK) and a disintegrin and metalloproteinase (ADAM) 17. Wild-type LYVE-1, but not uncleavable LYVE-1, promoted migration of lymphatic endothelial cells in response to VEGF-A. Immunostaining analyses in human psoriasis skin lesions and VEGF-A transgenic mouse skin suggested that the ectodomain shedding of LYVE-1 occurred in lymphatic vessels undergoing chronic inflammation. These results indicate that the ectodomain shedding of LYVE-1 might be involved in promoting pathological lymphangiogenesis.

Platelets Regulate the Migration of Keratinocytes via Podoplanin/CLEC-2 Signaling during Cutaneous Wound Healing in Mice.

Podoplanin is an endogenous ligand for C-type lectin-like receptor 2 (CLEC-2), which is expressed on platelets. Recent evidence indicates that this specific marker of lymphatic endothelial cells is also expressed by keratinocytes at the edge of wounds. However, whether podoplanin or platelets play a role in keratinocyte activity during wound healing remains unknown. We evaluated the effect of podoplanin expression levels on keratinocyte motility using cultured primary normal human epidermal keratinocytes (NHEKs). Down-regulation of podoplanin in NHEKs via transfection with podoplanin siRNA inhibited their migration, indicating that podoplanin plays a mandatory role in this process. In addition, down-regulation of podoplanin was correlated with up-regulation of E-cadherin, suggesting that podoplanin-mediated stimulation of keratinocyte migration is associated with a loss of E-cadherin. Both the addition of platelets and treatment with CLEC-2 inhibited the migration of NHEKs. The down-regulation of RhoA activity and the up-regulation of E-cadherin in keratinocytes were also induced by CLEC-2. In conclusion, these results suggest that podoplanin/CLEC-2 signaling regulates keratinocyte migration via modulating E-cadherin expression through RhoA signaling. Altering the regulation of keratinocyte migration by podoplanin might be a novel therapeutic approach to improve wound healing.

On What Day of Illness Does the Dilatation of Coronary Arteries in Patients With Kawasaki Disease Begin?

BACKGROUND: In the present study we used echocardiography to investigate coronary artery diameter at the time of diagnosis of Kawasaki disease (KD), before the start of treatment.Methods and Results:Diameters of the right, left main, left anterior descending, and left circumflex coronary arteries were determined in 410 patients before KD treatment commenced. The maximum Z-score was considered to be the pretreatment, maximum coronary artery Z-score (preZmax). The cumulative probability of coronary arterial dilatation was analyzed using the Kaplan-Meier method. In the present study, 31 patients (7.6%) had a preZmax ≥3.0, 56 (13.7%) had a preZmax ≥2.5, and 96 (23.4%) had a preZmax ≥2.0. The cumulative probability of a preZmax ≥2.0 was >20% on Day 5 of illness, 40% on Day 7, and 70% on Day 10. The positive predictive value (PPV) of a preZmax of 2.0 was approximately 0.9 on Day 5 of illness. CONCLUSIONS: The present study demonstrates that the coronary arteries may dilate before Day 5 of illness, and that the rate of dilatation increases gradually until Day 10. Because preZmax 2.0 has high PPV after Day 5 of illness, it is a useful marker of coronary artery dilatation in the early phase of KD.

Kallikrein-related peptidase 5 functions in proteolytic processing of profilaggrin in cultured human keratinocytes.

Filaggrin protein is synthesized in the stratum granulosum of the skin and contributes to the formation of the human skin barrier. Profilaggrin is cleaved by proteolytic enzymes and converted to functional filaggrin, but its processing mechanism remains not fully elucidated. Kallikrein-related peptidase 5 (KLK5) is a major serine protease found in the skin, which is secreted from lamellar granules following its expression in the stratum granulosum and activated in the extracellular space of the stratum corneum. Here, we searched for profilaggrin-processing protease(s) by partial purification of epidermal extracts and found KLK5 as a possible candidate. We used high performance liquid chromatography coupled with electrospray tandem mass spectrometry to show that KLK5 cleaves profilaggrin. Furthermore, based on a proximity ligation assay, immunohistochemistry, and immunoelectron microscopy analysis, we reveal that KLK5 and profilaggrin co-localize in the stratum granulosum in human epidermis. KLK5 knockdown in normal cultured human epidermal keratinocytes resulted in higher levels of profilaggrin, indicating that KLK5 potentially functions in profilaggrin cleavage.

Pseudomonas aeruginosa elastase causes transient disruption of tight junctions and downregulation of PAR-2 in human nasal epithelial cells.

BACKGROUND: Pseudomonas aeruginosa causes chronic respiratory disease, and the elastase enzyme that it produces increases the permeability of airway epithelial cells owing to the disruption of tight junctions. P. aeruginosa is also implicated in prolonged chronic rhinosinusitis. However, the effects of P. aeruginosa elastase (PE) against the barrier formed by human nasal epithelial cells (HNECs) remain unknown. METHODS: To investigate the mechanisms involved in the disruption of tight junctions by PE in HNECs, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were used. The hTERT-HNECs were pretreated with inhibitors of various signal transduction pathways, PKC, MAPK, p38MAPK, PI3K, JNK, NF-κB, EGF receptor, proteasome, COX1 and COX2 before treatment with PE. Some cells were pretreated with siRNA and agonist of protease activated receptor-2 (PAR-2) before treatment with PE. Expression and structures of tight junctions were determined by Western blotting, real-time PCR, immunostaining and freeze-fracture. Transepithelial electrical resistance (TER) was examined as the epithelial barrier function. RESULTS: PE treatment transiently disrupted the epithelial barrier and downregulated the transmembrane proteins claudin-1 and -4, occludin, and tricellulin, but not the scaffold PDZ-expression proteins ZO-1 and -2 and adherens junction proteins E-cadherin and ß-catenin. The transient downregulation of tight junction proteins was controlled via distinct signal transduction pathways such as the PKC, MAPK, PI3K, p38 MAPK, JNK, COX-1 and -2, and NF-κB pathways. Furthermore, treatment with PE transiently decreased PAR-2 expression, which also regulated the expression of the tight junction proteins. Treatment with a PAR-2 agonist prevented the downregulation of the tight junction proteins after PE treatment in HNECs. CONCLUSIONS: PE transiently disrupts tight junctions in HNECs and downregulates PAR-2. The transient disruption of tight junctions by PE might occur repeatedly during chronic rhinosinusitis.

Sirolimus treatment for intractable lymphatic anomalies: an open-label, single-arm, multicenter, prospective trial.

Introduction: Intractable lymphatic anomalies (LAs) include cystic lymphatic malformation (LM; macrocystic, microcystic, or mixed), generalized lymphatic anomaly, and Gorham-Stout disease. LAs can present with severe symptoms and poor prognosis. Thus, prospective studies for treatments are warranted. We conducted a prospective clinical trial of sirolimus for intractable LAs. Methods: This was an open-label, single-arm, multicenter, prospective trial involving five institutions in Japan. All patients with LAs received oral sirolimus once daily, and the dose was adjusted to ensure that the trough concentration remained within 5-15 ng/mL. We prospectively assessed the drug response (response rate for radiological volumetric change in target lesion), performance state, change in respiratory function, visceral impairment (pleural effusion, ascites, bleeding, pain), laboratory examination data, quality of life (QOL), and safety at 12, 24, and 52 weeks of administration. Results: Eleven patients with LAs (9 generalized lymphatic anomaly, 1 cystic LM, 1 Gorham-Stout disease) were treated with sirolimus, of whom 6 (54.5%; 95% confidence interval: 23.4-83.3%) demonstrated a partial response on radiological examination at 52 weeks of administration. No patients achieved a complete response. At 12 and 24 weeks of administration, 8 patients (72.7%) already showed a partial response. However, patients with stable disease showed minor or no reduction after 12 weeks. Adverse events, such as stomatitis, acneiform dermatitis, diarrhea, and fever, were common with sirolimus. Sirolimus was safe and tolerable. Conclusion: Sirolimus can reduce the lymphatic tissue volume in LAs and may lead to improvements in clinical symptoms and QOL.

Topical simvastatin accelerates wound healing in diabetes by enhancing angiogenesis and lymphangiogenesis.

Impaired wound healing is a major complication of diabetes. Recent studies have reported reduced lymphangiogenesis and angiogenesis during diabetic wound healing, which are thought to be new therapeutic targets. Statins have effects beyond cholesterol reduction and can stimulate angiogenesis when used systemically. However, the effects of topically applied statins on wound healing have not been well investigated. The present study tested the hypothesis that topical application of simvastatin would promote lymphangiogenesis and angiogenesis during wound healing in genetically diabetic mice. A full-thickness skin wound was generated on the back of the diabetic mice and treated with simvastatin or vehicle topically. Simvastatin administration resulted in significant acceleration of wound recovery, which was notable for increases in both angiogenesis and lymphangiogenesis. Furthermore, simvastatin promoted infiltration of macrophages, which produced vascular endothelial growth factor C in granulation tissues. In vitro, simvastatin directly promoted capillary morphogenesis and exerted an antiapoptotic effect on lymphatic endothelial cells. These results suggest that the favorable effects of simvastatin on lymphangiogenesis are due to both a direct influence on lymphatics and indirect effects via macrophages homing to the wound. In conclusion, a simple strategy of topically applied simvastatin may have significant therapeutic potential for enhanced wound healing in patients with impaired microcirculation such as that in diabetes.

Marked induction of matrix metalloproteinase-10 by respiratory syncytial virus infection in human nasal epithelial cells.

Respiratory syncytial virus (RSV) is an important pathogen of bronchiolitis, asthma, and severe lower respiratory tract disease in infants and young children. Matrix metalloproteinases (MMPs) play key roles in viral infection, inflammation and remodeling of the airway. However, the roles and regulation of MMPs in human nasal epithelial cells (HNECs) after RSV infection remain unclear. To investigate the regulation of MMP induced after RSV infection in HNECs, an RSV-infected model of HNECs in vitro was used. It was found that mRNA of MMP-10 was markedly increased in HNECs after RSV infection, together with induction of mRNAs of MMP-1, -7, -9, and -19. The amount of MMP-10 released from HNECs was also increased in a time-dependent manner after RSV infection as was that of chemokine RANTES. The upregulation of MMP-10 in HNECs after RSV infection was prevented by inhibitors of NF-κB and pan-PKC with inhibition of RSV replication, whereas it was prevented by inhibitors of JAK/STAT, MAPK, and EGF receptors without inhibition of RSV replication. In lung tissue of an infant with severe RSV infection in which a few RSV antibody-positive macrophages were observed, MMP-10 was expressed at the apical side of the bronchial epithelial cells and alveolar epithelial cells. In conclusion, MMP-10 induced by RSV infection in HNECs is regulated via distinct signal transduction pathways with or without relation to RSV replication. MMP-10 may play an important role in the pathogenesis of RSV diseases and it has the potential to be a novel marker and therapeutic target for RSV infection.

Dual oxidase 1 induced by Th2 cytokines promotes STAT6 phosphorylation via oxidative inactivation of protein tyrosine phosphatase 1B in human epidermal keratinocytes.

Although hydrogen peroxide (H(2)O(2)) is better known for its cytotoxic effects, in recent years it has been shown to play a crucial role in eukaryotic signal transduction. In respiratory tract epithelial cells, the dual oxidase (DUOX) proteins 1 and 2 has been identified as the cellular source of H(2)O(2). However, the expression of DUOX1 or DUOX2 has not yet been examined in keratinocytes. In this study, using a DNA microarray, we demonstrated that, of the seven NOX/DUOX family members in normal human epidermal keratinocytes (NHEK), IL-4/IL-13 treatment augments the expression of only DUOX1 mRNA. We next confirmed the IL-4/IL-13 induction of DUOX1 in NHEK at the mRNA and protein level using quantitative real-time PCR and Western blotting, respectively. In addition, we demonstrated that this augmented DUOX1 expression was accompanied by increased H(2)O(2) production, which was significantly suppressed both by diphenyleneiodonium, an inhibitor of NADPH oxidase, and by small interfering RNA against DUOX1. Finally, we demonstrated that the increased expression of DUOX1 in IL-4/IL-13-treated NHEK augments STAT6 phosphorylation via oxidative inactivation of protein tyrosine phosphatase 1B. These results revealed a novel role of IL-4/IL-13-induced DUOX1 expression in making a positive feedback loop for IL-4/IL-13 signaling in keratinocytes.

Doxycycline-dependent inducible and reversible RNA interference mediated by a single lentivirus vector.

RNA interference has been applied to the development of a method of silencing genes of interest. Short hairpin RNA (shRNA) expression vectors are useful in driving gene-silencing. Standard shRNA vectors produce a knockdown phenotype soon after transduction. An alternative strategy for conditional gene knockdown would be useful to investigate gene functions in a time-dependent manner. In this study, we developed an inducible gene knockdown system based on lentivirus-mediated gene transfer. A single lentivirus vector capable of inducible expression of a designed microRNA-based shRNA was generated using a tetracycline-dependent transactivation system. The lentiviral vector facilitated doxycycline-dependent inducible knockdown specific to the target gene. Withdrawal of doxycycline after transient treatment resulted in complete recovery of target gene expressions to normal levels. Thus the single lentiviral vector developed in this study should be a powerful tool for doxycycline-dependent inducible and reversible RNA interference in molecular genetic studies.

Lymphatic reprogramming of blood vascular endothelium by Kaposi sarcoma-associated herpesvirus.

Kaposi sarcoma is considered a neoplasm of lymphatic endothelium infected with Kaposi sarcoma-associated herpesvirus. It is characterized by the expression of lymphatic lineage-specific genes by Kaposi sarcoma tumor cells. Here we show that infection of differentiated blood vascular endothelial cells with Kaposi sarcoma-associated herpesvirus leads to their lymphatic reprogramming; induction of approximately 70% of the main lymphatic lineage-specific genes, including PROX1, a master regulator of lymphatic development; and downregulation of blood vascular genes.