Search

Growing evidence has shown that anti-COVID-19 nonpharmaceutical interventions (NPIs) can support prevention and control of various infectious diseases, including intestinal diseases. However, most studies focused on the short-term mitigating impact and neglected the dynamic impact over time. This study is aimed to investigate the dynamic impact of anti-COVID-19 NPIs on hand, foot, and mouth disease (HFMD) over time in Xi'an City, northwestern China. Based on the surveillance data of HFMD, meteorological and web search data, Bayesian Structural Time Series model and interrupted time series analysis were performed to quantitatively measure the impact of NPIs in sequent phases with different intensities and to predict the counterfactual number of HFMD cases. From 2013 to 2021, a total number of 172,898 HFMD cases were reported in Xi'an. In 2020, there appeared a significant decrease in HFMD incidence (-94.52%, 95% CI: -97.54% to -81.95%) in the first half of the year and the peak period shifted from June to October by a small margin of 6.74% compared to the previous years of 2013 to 2019. In 2021, the seasonality of HFMD incidence gradually returned to the bimodal temporal variation pattern with a significant average decline of 61.09%. In particular, the impact of NPIs on HFMD was more evident among young children (0-3 years), and the HFMD incidence reported in industrial areas had an unexpected increase of 51.71% in 2020 autumn and winter. Results suggested that both direct and indirect NPIs should be implemented as effective public health measures to reduce infectious disease and improve surveillance strategies, and HFMD incidence in Xi'an experienced a significant rebound to the previous seasonality after a prominent decline influenced by the anti-COVID-19 NPIs.

BackgroundNon-pharmaceutical interventions (NPIs) against COVID-19 may prevent the spread of other infectious diseases. Our purpose was to assess the effects of NPIs against COVID-19 on infectious diarrhea in Xi'an, China.MethodsBased on the surveillance data of infectious diarrhea, and the different periods of emergence responses for COVID-19 in Xi'an from 2011 to 2021, we applied Bayesian structural time series model and interrupted time series model to evaluate the effects of NPIs against COVID-19 on the epidemiological characteristics and the causative pathogens of infectious diarrhea.FindingsA total of 102,051 cases of infectious diarrhea were reported in Xi'an from 2011 to 2021. The Bayesian structural time series model results demonstrated that the cases of infectious diarrhea during the emergency response period was 40.38% lower than predicted, corresponding to 3,211 fewer cases, during the COVID-19 epidemic period of 2020–2021. The reduction exhibited significant variations in the demography, temporal and geographical distribution. The decline in incidence was especially evident in children under 5-years-old, with decreases of 34.09% in 2020 and 33.99% in 2021, relative to the 2017–2019 average. Meanwhile, the incidence decreased more significantly in industrial areas.InterpretationNPIs against COVID-19 were associated with short- and long-term reductions in the incidence of infectious diarrhea, and this effect exhibited significant variations in epidemiological characteristics.

Influenza shares the same putative transmission pathway with coronavirus disease 2019 (COVID-19), and causes tremendous morbidity and mortality annually globally. Since the transmission of COVID-19 in China, a series of non-pharmaceutical interventions (NPIs) against to the disease have been implemented to contain its transmission. Based on the surveillance data of influenza, Search Engine Index, and meteorological factors from 2011 to 2021 in Xi'an, and the different level of emergence responses for COVID-19 from 2020 to 2021, Bayesian Structural Time Series model and interrupted time series analysis were applied to quantitatively assess the impact of NPIs in sequent phases with different intensities, and to estimate the reduction of influenza infections. From 2011 to 2021, a total of 197,528 confirmed cases of influenza were reported in Xi'an, and the incidence of influenza continuously increased from 2011 to 2019, especially, in 2019–2020, when the incidence was up to 975.90 per 100,000 persons; however, it showed a sharp reduction of 97.68% in 2020–2021, and of 87.22% in 2021, comparing with 2019–2020. The highest impact on reduction of influenza was observed in the phase of strict implementation of NPIs with an inclusion probability of 0.54. The weekly influenza incidence was reduced by 95.45%, and an approximate reduction of 210,100 (95% CI: 125,100–329,500) influenza infections was found during the post-COVID-19 period. The reduction exhibited significant variations in the geographical, population, and temporal distribution. Our findings demonstrated that NPIs against COVID-19 had a long-term impact on the reduction of influenza transmission.

When antibiotic-resistant pathogenic bacteria pose a high threat to human health, bacterial multidrug efflux pumps become major contributors to the high-level antibiotic resistance in most microorganisms. Since traditional antibiotics are still indispensable currently, we report a dual drug delivery system to maximize the antibacterial efficacy of antibiotics by inhibiting efflux pumps in bacteria before their exposure to antibiotics. In this research, a microsphere/hydrogel composite was constructed from ciprofloxacin (Cip)-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres and ginsenoside Rh2 (G-Rh2) dispersed thermo-sensitive hydrogel to treat skin infections. In vitro drug release studies indicated that while G-Rh2 in hydrogel presented a faster and short-term release manner to rapidly inhibit the NorA efflux pumps, Cip showed a sustained and long-term release behavior to provide a local high concentration gradient for facilitating drug percutaneous penetration. The combination of Cip and G-Rh2 demonstrated a high degree of synergism against both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), hence significantly improving their in vitro antibacterial activity and efficiency. Moreover, the antibacterial performance of the microsphere/hydrogel composite with a sequential release profile is superior to that of other formulations in mouse model of MRSA skin infections, indicating its great potential to treat antibiotic-resistant skin infections.

Hemorrhagic fever with renal syndrome (HFRS) is a zoonosis characterized by clinical features of high fever, hemorrhage, and renal damage. China has the largest number of HFRS cases worldwide, accounting for over 90% of the total reported cases. In this paper, we used surveyed HFRS data and satellite imagery to conduct geostatistical analysis for investigating the associations of rapid urbanization, water bodies, and other factors on the spatiotemporal dynamics of HFRS from year 2005 to 2018 in Xi’an City, Northwest China. The results revealed an evident epidemic aggregation in the incidence of HFRS within Xi’an City with a phenomenal fluctuation in periodic time series. Rapid urbanization was found to greatly affect the HFRS incidence in two different time phases. HFRS caused by urbanization influences farmers to a lesser extent than it does to non-farmers. The association of water bodies with the HFRS incidence rate was found to be higher within the radii of 696.15 m and 1575.39 m, which represented significant thresholds. The results also showed that geomatics approaches can be used for spatiotemporally investigating the HFRS dynamic characteristics and supporting effective allocations of resources to formulate strategies for preventing epidemics., Author summary Hemorrhagic fever with renal syndrome (HFRS) is an infectious disease transmitted by the infected reservoir hosts, which chiefly include rodents, shrews, and moles. The mechanism of HFRS infection is determined by a complex interplay of various natural and socioeconomic factors. Previous studies have identified a close relationship between urbanization processes and HFRS transmission dynamics. However, the relationship involves a dual response and has not yet been quantitatively identified. This research aimed to spatiotemporally characterize how rapid urbanization affects the dynamics of HFRS. In addition, the role of water bodies, vegetation, rainfall, and occupation types in epidemic transmissions has also not been adequately investigated at the interurban scale over a long time period. Therefore, we analyzed the spatiotemporal association between the distributions of water bodies and HFRS infections and also investigated the interactions between urbanization, water body, vegetation, rainfall, and different occupation types by using multi-source data through both traditional statistical and geospatial techniques. Our work revealed biphasic associations among HFRS infection with both rapid urbanization and distribution of water bodies. Hence, it can provide useful information to formulate effective strategies for the prevention and control of HFRS.

Introduction To explore the impact of coronavirus disease 2019 (COVID-19) on the stability of patients with neovascular age-related macular degeneration (nAMD) receiving the treat and extend (T&E) or the pro re nata (PRN) treatment regimen and to identify indicators that may predict the disease stability of nAMD. Methods This is a retrospective study of patients with nAMD treated at the Second Affiliated Hospital of Harbin Medical University whose treatment schedule was interrupted at least once between 1 February and 31 May 2020. The demographic and clinical characteristics, including the best corrected visual acuity (BCVA), optical coherence tomography (OCT) features, subfoveal choroidal thickness (SFCT), interval between the last injection and the beginning of the pandemic, and the number of anti-vascular endothelial growth factor (VEGF) injections, were analyzed. Results A total of 209 stable patients with nAMD (122 eyes received the T&E regimen; 87 eyes received the PRN regimen) were identified. Compared to those who received the PRN regimen, the patients who received the T&E regimen were more stable during the first visit after COVID-19 (53.3% vs. 33.3%, P = 0.004), the BCVA was significantly better (58.5 letters vs. 56 letters, P = 0.006), and the CRT fluctuated only slightly (15 μm vs. 35 μm, P = 0.001). Furthermore, a multivariate logistic regression analysis showed that stable patients with nAMD with type 1 choroidal neovascularization (CNV) (OR 2.493 [95% CI 1.179–5.272], compared with type 2 CNV; P = 0.017; OR 2.912 [95% CI 1.133–7.485], compared with retinal angiomatous proliferation; P = 0.026) or with pigment epithelial detachment (PED) were more likely to remain stable when treatment was interrupted (OR 0.392 [95% CI 0.181–0.852], compared with no PED; P = 0.018). Conclusion Compared to patients who received the PRN treatment regimen, stable patients with nAMD who received the T&E treatment regimen could better maintain stability when the treatments were suddenly interrupted by the COVID-19 pandemic. In addition, patients with type 1 CNV or patients with PED were more likely to remain stable. At present, the COVID-19 pandemic is becoming increasingly normalized, and the T&E regimen can become a more advanced treatment option for patients undergoing therapy.

Androgen-inducible genes (AIGs), which can be regulated by androgen level, constitute a group of genes characterized by the presence of the AIG/FAR-17a domain in its protein sequence. Previous studies on AIGs demonstrated that one member of the gene family, AIG1, is involved in many biological processes in cancer cell lines and that ADTRP is associated with cardiovascular diseases. It has been shown that the numbers of AIG paralogs in humans, mice, and zebrafish are 2, 2, and 3, respectively, indicating possible gene duplication events during vertebrate evolution. Therefore, classifying subgroups of AIGs and identifying the homologs of each AIG member are important to characterize this novel gene family further. In this study, vertebrate AIGs were phylogenetically grouped into three major clades, ADTRP, AIG1, and AIG-L, with AIG-L also evident in an outgroup consisting of invertebrsate species. In this case, AIG-L, as the ancestral AIG, gave rise to ADTRP and AIG1 after two rounds of whole-genome duplications during vertebrate evolution. Then, the AIG family, which was exposed to purifying forces during evolution, lost or gained some of its members in some species. For example, in eutherians, Neognathae, and Percomorphaceae, AIG-L was lost; in contrast, Salmonidae and Cyprinidae acquired additional AIG copies. In conclusion, this study provides a comprehensive molecular phylogenetic analysis of vertebrate AIGs, which can be employed for future functional characterization of AIGs.

Diabetic cardiac autonomic neuropathy (DCAN) is a complication that affects more than 60% of diabetic patients. There is evidence for the involvement of P2X4 receptor in DCAN. This study showed that the expression of the long noncoding RNA (lncRNA) UC.360+ was increased in the stellate ganglion (SG) of type 2 diabetes mellitus (DM) rats, and in situ hybridization revealed a clear presence of UC.360+ in SG neurons. The potential roles of UC.360+ in DCAN and its relationship with P2X4 receptor in SG were further explored via application of the short hairpin RNA (shRNA) against lncRNA UC.360+ in DM rats. The abnormal cardiac sympathetic changes in diabetic rats were improved after treatment with lncRNA UC.360+ shRNA. In the SG of these shRNA-treated DM rats, the upregulation of P2X4, tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and phosphorylated ERK1/2 was inhibited. Thus, lncRNA UC.360+ shRNA treatment may improve DCAN mediated by the P2X4 receptor in SG.

The mortality of colorectal cancer ranked fifth in China according to cancer statistics in 2015. Cancer screening had been repeatedly proved to play a vital role in decreasing the incidence and mortality of colorectal cancer, but the existing screening methods could not meet the requirements. So it is of urgent need to develop a non-invasive, convenient and accurate screening method. In this study, stool samples were collected from 102 colorectal cancer, 20 colorectal adenoma, 6 hyperplastic polyps patients and 105 normal controls, and stool DNA was extracted for detection of methylation (BMP3, NDRG4, SDC2 and SFRP2) and KRAS mutations. Meanwhile, hemoglobin in stool samples was detected by immunoassays. Then, the logistic regression model used for classification was built with these biomarkers, and a ROC curve was drawn to evaluate the performance of each biomarker and the panel of them. Meanwhile, conventional serum biomarkers were detected for the comparison of positive rate in colorectal cancer between serum biomarkers and stool DNA biomarkers. As a result, a classification model built with methylation of SDC2 and SFRP2, KRAS mutations and hemoglobin showed a sensitivity of 91.4% for colorectal cancer and 60% for adenoma with the specificity of 86.1%. Compared with it, most of the conventional serum biomarkers showed a sensitivity of less than 20% for colorectal cancer which was significantly lower than stool DNA biomarkers. A novel panel comprised of stool DNA biomarkers was of much higher sensitivity and specificity in early screening of colorectal neoplasms than conventional serum biomarkers.

‘precision medicine’ is characterized by the selection of targeted drugs based on genetic characteristics of tumor from patients, and no longer selected basis on the type of cancer tissue. Among them, clinical trials on neurotrophin receptor tyrosine kinase genes (NTRK) have proven that great anti-cancer effects can be achieved in different cancer patients. In this paper, a novel total of twenty compounds in two categories have been designed and synthesized. Results of Kinase activity tests showed that I-9 (TRKA IC50 = 1.3 nM, TRKAG595R IC50 = 6.1 nM), and I-10 (TRKA IC50 = 1.1 nM, TRKAG595R IC50 = 5.3 nM) have significant inhibitory activity, and results of cell viability tests showed that I-9 and I-10 can maintain a great inhibitory effect in the Ba/F3-LMNA-NTRK1 cell line(IC50 = 81.1 nM and 41.7 nM, respectively), and in Ba/F3-LMNA-NTRK1-G595R cell line, I-9 and I-10 have better cell activity (IC50 was 495.3 nM, 336.6 nM, respectively) compared with the positive control drug LOXO-101. These results indicate that I-9 and I-10 are potential TRK inhibitors that can overcome drug resistance for further investigation.

Neuronal amyloid-β (Aβ) accumulation plays an important role in the pathogenesis of Alzheimer's disease (AD). The conformation and toxicity of Aβ are regulated by lipids on the plasma membrane. Previously, we found downregulation of Rolling Blackout (RBO) or phosphatidylinositol-4-kinase type IIIα (PI4KIIIα) reduces neuronal Aβ accumulation and associated neural deficits in a Drosophila model expressing Aβ42. In mammals, the homologs of RBO and PI4KIIIα were reported to form a plasma membrane-localized complex with a scaffold protein TTC7 and cytosolic protein Hyccin/FAM126A to tightly control the plasmalemmal level of phosphatidylinositol-4-phosphate. Here, we show genetic downregulation of Drosophila TTC7 and Hyccin also reduces neuronal Aβ accumulation and associated synaptic and motor defects as well as premature death in Aβ42-expressing flies, while overexpression of TTC7 and Hyccin produced the opposite effect. These results, together with our previous study, demonstrate that RBO/TTC7/PI4KIIIα/Hyccin regulate neuronal Aβ accumulation and associated neural deficits in the Drosophila model, further supporting the RBO/Efr3-PI4KIIIα complex as a potential therapeutic target for AD.

In a fluorescence polarization screen for the MYC-MAX interaction, we have identified a novel small-molecule inhibitor of MYC, KJ-Pyr-9, from a Kröhnke pyridine library. The Kd of KJ-Pyr-9 for MYC in vitro is 6.5 ± 1.0 nM, as determined by backscattering interferometry; KJ-Pyr-9 also interferes with MYC-MAX complex formation in the cell, as shown in a protein fragment complementation assay. KJ-Pyr-9 specifically inhibits MYC-induced oncogenic transformation in cell culture; it has no or only weak effects on the oncogenic activity of several unrelated oncoproteins. KJ-Pyr-9 preferentially interferes with the proliferation of MYC-overexpressing human and avian cells and specifically reduces the MYC-driven transcriptional signature. In vivo, KJ-Pyr-9 effectively blocks the growth of a xenotransplant of MYC-amplified human cancer cells.

Deregulation of the phosphoinositide 3-kinase (PI3K) signaling pathway such as by PTEN loss or PIK3CA mutation occurs frequently in human cancer and contributes to resistance to antitumor therapies. Inhibition of key signaling proteins in the pathway therefore represents a valuable targeting strategy for diverse cancers. PF-04691502 is an ATP-competitive PI3K/mTOR dual inhibitor, which potently inhibited recombinant class I PI3K and mTOR in biochemical assays and suppressed transformation of avian fibroblasts mediated by wild-type PI3K γ, δ, or mutant PI3Kα. In PIK3CA-mutant and PTEN-deleted cancer cell lines, PF-04691502 reduced phosphorylation of AKT T308 and AKT S473 (IC50 of 7.5–47 nmol/L and 3.8–20 nmol/L, respectively) and inhibited cell proliferation (IC50 of 179–313 nmol/L). PF-04691502 inhibited mTORC1 activity in cells as measured by PI3K-independent nutrient stimulated assay, with an IC50 of 32 nmol/L and inhibited the activation of PI3K and mTOR downstream effectors including AKT, FKHRL1, PRAS40, p70S6K, 4EBP1, and S6RP. Short-term exposure to PF-04691502 predominantly inhibited PI3K, whereas mTOR inhibition persisted for 24 to 48 hours. PF-04691502 induced cell cycle G1 arrest, concomitant with upregulation of p27 Kip1 and reduction of Rb. Antitumor activity was observed in U87 (PTEN null), SKOV3 (PIK3CA mutation), and gefitinib- and erlotinib-resistant non–small cell lung carcinoma xenografts. In summary, PF-04691502 is a potent dual PI3K/mTOR inhibitor with broad antitumor activity. PF-04691502 has entered phase I clinical trials. Mol Cancer Ther; 10(11); 2189–99. ©2011 AACR.

A new magnetic resonance imaging (MRI) contrast agent based on the trimetallic nitride templated (TNT) metallofullerene Gd(3)N@C(80) was synthesized by a facile method in high yield. The observed longitudinal and transverse relaxivities r(1) and r(2) for water hydrogens in the presence of the water-soluble gadofullerene 2 Gd(3)N@C(80)(OH)(approximately 26)(CH(2)CH(2)COOM)(approximately 16) (M = Na or H) are 207 and 282 mM(-1) s(-1) (per C(80) cage) at 2.4 T, respectively; these values are 50 times larger than those of Gd(3+) poly(aminocarboxylate) complexes, such as commercial Omniscan and Magnevist. This high (1)H relaxivity for this new hydroxylated and carboxylated gadofullerene derivative provides high signal enhancement at significantly lower Gd concentration as demonstrated by in vitro and in vivo MRI studies. Dynamic light scattering data reveal a unimodal size distribution with an average hydrodynamic radius of ca. 78 nm in pure water (pH = 7), which is significantly different from other hydroxylated or carboxylated fullerene and metallofullerene derivatives reported to date. Agarose gel infusion results indicate that the gadofullerene 2 displayed diffusion properties different from those of commercial Omniscan and those of PEG5000 modified Gd(3)N@C(80). The reactive carboxyl functionality present on this highly efficient contrast agent may also serve as a precursor for biomarker tissue-targeting purposes.

The order Mononegavirales (comprised of nonsegmented negative-stranded RNA viruses or NNSVs) contains many important pathogens. Parainfluenza virus 5 (PIV5), formerly known as simian virus 5, is a prototypical paramyxovirus and encodes a V protein, which has a cysteine-rich C terminus that is conserved among all paramyxoviruses. The V protein of PIV5, like that of many other paramyxoviruses, plays an important role in regulating viral RNA synthesis. In this work, we show that V interacts with Akt, a serine/threonine kinase, also known as protein kinase B. Both pharmacological inhibitors and small interfering RNA against Akt1 reduced PIV5 replication, indicating that Akt plays a critical role in PIV5 replication. Furthermore, treatment with Akt inhibitors also reduced the replication of several other paramyxoviruses, as well as vesicular stomatitis virus, the prototypical rhabdovirus, indicating that Akt may play a more universal role in NNSV replication. The phosphoproteins (P proteins) of NNSVs are essential cofactors for the viral RNA polymerase complex and require heavy phosphorylation for their activity. Inhibition of Akt activity reduced the level of P phosphorylation, suggesting that Akt is involved in regulating viral RNA synthesis. In addition, Akt1 phosphorylated a recombinant P protein of PIV5 purified from bacteria. The finding that Akt plays a critical role in replication of NNSV will lead to a better understanding of how these viruses replicate, as well as novel strategies to treat infectious diseases caused by NNSVs.

Paramyxoviruses include many important animal and human pathogens. The genome of parainfluenza virus 5 (PIV5), a prototypical paramyxovirus, encodes a V protein that inhibits viral RNA synthesis. In this work, the mechanism of inhibition was investigated. Using mutational analysis and a minigenome system, we identified regions in the N and C termini of the V protein that inhibit viral RNA synthesis: one at the very N terminus of V and the second at the C terminus of V. Furthermore, we determined that residues L16 and I17 are critical for the inhibitory function of the N-terminal region of the V protein. Both regions interact with the nucleocapsid protein (NP), an essential component of the viral RNA genome complex (RNP). Mutations at L16 and I17 abolished the interaction between NP and the N-terminal domain of V. This suggests that the interaction between NP and the N-terminal domain plays a critical role in V inhibition of viral RNA synthesis by the N-terminal domain. Both the N- and C-terminal regions inhibited viral RNA replication. The C terminus inhibited viral RNA transcription, while the N-terminal domain enhanced viral RNA transcription, suggesting that the two domains affect viral RNA through different mechanisms. Interestingly, V also inhibited the synthesis of the RNA of other paramyxoviruses, such as Nipah virus (NiV), human parainfluenza virus 3 (HPIV3), measles virus (MeV), mumps virus (MuV), and respiratory syncytial virus (RSV). This suggests that a common host factor may be involved in the replication of these paramyxoviruses. IMPORTANCE We identified two regions of the V protein that interact with NP and determined that one of these regions enhances viral RNA transcription via its interaction with NP. Our data suggest that a common host factor may be involved in the regulation of paramyxovirus replication and could be a target for broad antiviral drug development. Understanding the regulation of paramyxovirus replication will enable the rational design of vaccines and potential antiviral drugs.

Polarization measurements are sensitive to the microstructure of tissues and can be used to detect pathological changes. Many tissues contain anisotropic fibrous structures. We obtain the local orientation of aligned fibrous scatterers using different groups of the backscattering Mueller matrix elements. Experiments on concentrically well-aligned silk fibers and unstained human papillary thyroid carcinoma tissues show that the m 22 , m 33 , m 23 , and m 32 elements have better contrast but higher degeneracy for the extraction of orientation angles. The m 12 and m 13 elements show lower contrast, but allow us to determine the orientation angle for the fibrous scatterers along all directions. Moreover, Monte Carlo simulations based on the sphere-cylinder scattering model indicate that the oblique incidence of the illumination beam introduces some errors in the orientation angles obtained by both methods. Mapping the local orientation of anisotropic tissues may not only provide information on pathological changes, but can also give new leads to reduce the orientation dependence of polarization measurements.

Polarization measurements allow one to enhance the imaging contrast of superficial tissues and obtain new polarization sensitive parameters for better descriptions of the micro- and macro- structural and optical properties of complex tissues. Since the majority of cancers originate in the epithelial layer, probing the morphological and pathological changes in the superficial tissues using an expended parameter set with improved contrast will assist in early clinical detection of cancers. We carry out Mueller matrix imaging on different cancerous tissues to look for cancer specific features. Using proper scattering models and Monte Carlo simulations, we examine the relationship between the microstructures of the samples, which are represented by the parameters of the scattering model and the characteristic features of the Mueller matrix. This study gives new clues on the contrast mechanisms of polarization sensitive measurements for different cancers and may provide new diagnostic techniques for clinical applications.

Addition of short (6 to 16 amino acids) peptide sequences to the N-terminus of p110α induces a gain of function. Such sequences include the common Flag, His and VSV tags as well as random sequences. An N-terminal myristylation signal generally believed to activate p110α by providing a constitutive membrane address is also activating, even if myristylation is mutationally abolished. The gain of function seen with N-terminally tagged (NTT) p110α constructs extends to signaling, oncogenic transformation and stimulation of cell growth. The activating effect of N-terminal tags requires a functional Rasbinding domain in p110α. Mutations in the RBD domain (T208D and K227A) abolish the gains of function in oncogenicity and signaling. The dominant negative mutant of Ras, RasN17, interferes with transformation induced by NTT p110α. In contrast, binding to p85 activity is not required for cellular transformation and enhanced signaling by NTT p110α.

Cancer-specific mutations in the iSH2 (inter-SH2) and nSH2 (N-terminal SH2) domains of p85alpha, the regulatory subunit of phosphatidylinositide 3-kinase (PI3K), show gain of function. They induce oncogenic cellular transformation, stimulate cellular proliferation, and enhance PI3K signaling. Quantitative determinations of oncogenic activity reveal large differences between individual mutants of p85alpha. The mutant proteins are still able to bind to the catalytic subunits p110alpha and p110beta. Studies with isoform-specific inhibitors of p110 suggest that expression of p85 mutants in fibroblasts leads exclusively to an activation of p110alpha, and p110alpha is the sole mediator of p85 mutant-induced oncogenic transformation. The characteristics of the p85 mutants are in agreement with the hypothesis that the mutations weaken an inhibitory interaction between p85alpha and p110alpha while preserving the stabilizing interaction between p85alpha iSH2 and the adapter-binding domain of p110alpha.

Changes in cell morphology and rearrangements of the actin cytoskeleton are common features accompanying cell transformation induced by various oncogenes. In this study, we show that promyelocytic leukemia zinc finger protein (PLZF) binds to the promoter of smooth muscle α-actin, reducing mRNA and protein levels encoded by this gene and resulting in a reorganization of the actin cytoskeleton. In cultures of chicken embryo fibroblasts (CEF), this effect on α-actin expression is correlated with a change in cellular phenotype from spindle shaped to polygonal and flattened. This morphological change is dependent on Ras function. The polygonal, flattened CEF show a high degree of resistance to the transforming activity of several oncoproteins. Our results support the conclusion that reorganization of the actin cytoskeleton plays an important role in tumor suppression by PLZF.

Parainfluenza virus 5 (PIV5) is a prototypical paramyxovirus. The V/P gene of PIV5 encodes two mRNA species through a process of pseudotemplated insertion of two G residues at a specific site during transcription, resulting in two viral proteins, V and P, whose N termini of 164 amino acid residues are identical. Previously it was reported that mutating six amino acid residues within this identical region results in a recombinant PIV5 (rPIV5-CPI−) that exhibits elevated viral protein expression and induces production of cytokines, such as beta interferon and interleukin 6. Because the six mutations correspond to the shared region of the V protein and the P protein, it is not clear whether the phenotypes associated with rPIV5-CPI− are due to mutations in the P protein and/or mutations in the V protein. To address this question, we used a minigenome system and recombinant viruses to study the effects of mutations on the functions of the P and V proteins. We found that the P protein with six amino acid residue changes (Pcpi−) was more efficient than wild-type P in facilitating replication of viral RNA, while the V protein with six amino acid residue changes (Vcpi−) still inhibits minigenome replication as does the wild-type V protein. These results indicate that elevated viral gene expression in rPIV5-CPI− virus-infected cells can be attributed to a P protein with an increased ability to facilitate viral RNA synthesis. Furthermore, we found that a single amino acid residue change at position 157 of the P protein from Ser (the residue in the wild-type P protein) to Phe (the residue in Pcpi−) is sufficient for elevated viral gene expression. Using mass spectrometry and 33 P labeling, we found that residue S157 of the P protein is phosphorylated. Based on these results, we propose that phosphorylation of the P protein at residue 157 plays an important role in regulating viral RNA replication.

The paramyxovirus family includes many well-known human and animal pathogens as well as emerging viruses such as Hendra virus and Nipah virus. The V protein of simian virus 5 (SV5), a prototype of the paramyxoviruses, contains a cysteine-rich C-terminal domain which is conserved among all paramyxovirus V proteins. The V protein can block both interferon (IFN) signaling by causing degradation of STAT1 and IFN production by blocking IRF-3 nuclear import. Previously, it was reported that recombinant SV5 lacking the C terminus of the V protein (rSV5VΔC) induces a severe cytopathic effect (CPE) in tissue culture whereas wild-type (wt) SV5 infection does not induce CPE. In this study, the nature of the CPE and the mechanism of the induction of CPE were investigated. Through the use of DNA fragmentation, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, and propidium iodide staining assays, it was shown that rSV5VΔC induced apoptosis. Expression of wt V protein prevented apoptosis induced by rSV5VΔC, suggesting that the V protein has an antiapoptotic function. Interestingly, rSV5VΔC induced apoptosis in U3A cells (a STAT1-deficient cell line) and in the presence of neutralizing antibody against IFN, suggesting that the induction of apoptosis by rSV5VΔC was independent of IFN and IFN-signaling pathways. Apoptosis induced by rSV5VΔC was blocked by a general caspase inhibitor, Z-VAD-FMK, but not by specific inhibitors against caspases 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 13, suggesting that rSV5VΔC-induced apoptosis can occur in a caspase 12-dependent manner. Endoplasmic reticulum stress can lead to activation of caspase 12; compared to the results seen with mock and wt SV5 infection, rSV5VΔC infection induced ER stress, as demonstrated by increased expression levels of known ER stress indicators GRP 78, GRP 94, and GADD153. These data suggest that rSV5VΔC can trigger cell death by inducing ER stress.