Autophagic degradation of IRF3 induced by the small-molecule auranofin inhibits its transcriptional and proapoptotic activities

The ubiquitously expressed transcription factor interferon (IFN) regulatory factor 3 (IRF3) is critical for the induction of antiviral genes, e.g., type-I IFN. In addition to its transcriptional function, IRF3 also activates a nontranscriptional, proapoptotic signaling pathway. While the proapoptotic function of IRF3 protects against viral infections, it is also involved in harmful immune responses that trigger hepatocyte cell death and promote liver disease. Thus, we hypothesized that a small-molecule inhibitor of the proapoptotic activity of IRF3 could alleviate fatty-acid-induced hepatocyte cell death. We conducted a high-throughput screen, which identified auranofin as a small-molecule inhibitor of the proapoptotic activity of IRF3. In addition to the nontranscriptional apoptotic pathway, auranofin also inhibited the transcriptional activity of IRF3. Using biochemical and genetic tools in human and mouse cells, we uncovered a novel mechanism of action for auranofin, in which it induces cellular autophagy to degrade IRF3 protein, thereby suppressing IRF3 functions. Autophagy-deficient cells were unable to degrade IRF3 upon auranofin treatment, suggesting that the autophagic degradation of IRF3 is a novel approach to regulate IRF3 activities. Using a physiologically relevant in vitro model, we demonstrated that auranofin inhibited fatty-acid-induced apoptotic cell death of hepatocytes. In summary, auranofin is a novel inhibitor of IRF3 functions and may represent a potential therapeutic option in diseases where IRF3 is deleterious.

A high throughput screen to identify small molecule activators of IRF3-mediated antiviral apoptotic pathway

The transcription factor interferon (IFN) regulatory factor 3 (IRF3) provides cellular antiviral response by expressing IFN and antiviral genes. In addition to the transcriptional activation, IRF3 triggers a direct pro-apoptotic pathway, RIPA, in virus-infected cells. The pathway of IRF3 activation in RIPA is independent of and distinct from the transcriptional activation of IRF3 (Chattopadhyay et al. Immunity, 2016, J Virol, 2013, 2011, EMBO J, 2010). Using knock-in mice expressing transcriptionally-inactive, but RIPA-competent, IRF3 mutant, we demonstrated that RIPA contributes to the antiviral response of the host. Because RIPA is a cellular antiviral pathway, we hypothesized that RIPA-promoting small molecules would act as antiviral agents. To test this, we conducted a high throughput screen of a library of 1,200 FDA-approved compounds to identify RIPA activators. Our screen isolated twenty-four primary candidates with diverse therapeutic activities, e.g. anti-cancer, anti-inflammatory, anti-bacterial, etc. We screened these primary candidates for their antiviral activities against RNA (vesicular stomatitis virus) and DNA (herpes simplex virus-1) viruses. The antiviral screen revealed a small subset of antiviral compounds, which specifically promote RIPA but not the transcriptional pathway of IRF3. We further validated their antiviral activities against additional viruses, e.g. respiratory syncytial virus and vector-borne flaviviruses. Therefore, we report a high throughput screen, which identified novel antiviral compounds that are specific activators of RIPA branch of IRF3. Currently, we are investigating the mechanisms of these RIPA-promoting antiviral compounds.

A high throughput genetic screen to uncover novel antiviral mechanisms of the interferon system

The innate immune responses provide the first line of host defense against virus infection. Type I interferon (IFN) system is a well-known mediator of the host innate antiviral responses. Virus infection is recognized by the cellular sensors, also known as pattern recognition receptors, which via a series of signaling pathways, induce the synthesis of IFNs and the IFN-stimulated genes (ISGs). The ISG-encoded protein products function as viral restriction factors, either by interfering with the stages of viral life cycle or by promoting cell death. We have shown that the IRF3, a key transcription factor responsible for inducing IFNs and ISGs, also provides antiviral responses by triggering apoptosis of the infected cells (Chattopadhyay et al Immunity, 2016). To investigate how the IRF3-inducible genes provide antiviral protection, we performed a high throughput genetic screen of human ISGs. Using an shRNA library of the human ISGs, we have identified a novel antiviral ISG, tudor domain containing 7 (TDRD7). TDRD7 inhibits virus replication by interfering with the cellular autophagy pathway, which is required for the replication a number of viruses. Mechanistically, TDRD7 inhibits the autophagy-initiating kinase, AMPK to suppress virus-induced autophagy pathway. We reported that multiple paramyxoviruses, including the clinically relevant human pathogens, respiratory syncytial virus (RSV) and human parainfluenza virus (HPIV3), are inhibited by the new antiviral mechanism of TDRD7 (Subramanian et al PLOS Pathogens, 2018). Using additional RNA and DNA viruses, which activate autophagy during infection, we are investigating whether the new antiviral mechanism similarly inhibits them.

A comparative test of the theory of reasoned action and the theory of planned behavior in the prediction of condom use intentions in a national sample of English young people

Based on the theories of reasoned action (TRA) and planned behavior (TPB), predictors of condom use intentions were investigated in 949 young people (16-24 years of age) from a national survey conducted in England. Contrary to expectations, the TPB did not perform significantly better than the TRA, even among women. Measures of past behavior were the best predictors of intentions and attenuated the effects of attitude and subjective norm. There was only weak evidence for the multiplicative assumption underlying the TRA and TPB. Although the TRA components were not the strongest predictors, the beliefs on which they are based are potentially amenable to change through information-based intervention programs. A number of practical suggestions for developing intervention strategies are offered.

A comparative test of the theory of reasoned action and the theory of planned behavior in the prediction of condom use intentions in a national sample of English young people

Based on the theories of reasoned action (TRA) and planned behavior (TPB), predictors of condom use intentions were investigated in 949 young people (16-24 years of age) from a national survey conducted in England. Contrary to expectations, the TPB did not perform significantly better than the TRA, even among women. Measures of past behavior were the best predictors of intentions and attenuated the effects of attitude and subjective norm. There was only weak evidence for the multiplicative assumption underlying the TRA and TPB. Although the TRA components were not the strongest predictors, the beliefs on which they are based are potentially amenable to change through information-based intervention programs. A number of practical suggestions for developing intervention strategies are offered.

Role of community pharmacies in relation to HIV prevention and drug misuse: findings from the 1995 national survey in England and Wales

OBJECTIVES

To establish activity levels of community (high street) pharmacies in the provision of HIV prevention services to drug misusers and to compare these findings with the levels identified in 1988.

DESIGN

Self completion questionnaire (four mailings) to a random 1 in 4 sample of all community pharmacies, stratified by family health services authority.

SETTING

England and Wales.

SUBJECTS

Data provided by pharmacist in charge of the dispensary, on service provision at the pharmacy.

MAIN OUTCOME MEASURES

Quantitative reports of current activity levels for (a) dispensing of controlled drugs to drug misusers, (b) sale of needles and syringes, (c) needle and syringe exchange.

RESULTS

74.8% response rate (1984/2654). In 1995, 50.1% (992/1980) of pharmacies were dispensing controlled drugs (mostly methadone), compared with 23.0% (562/2457) in 1988; 34.5% (677/1962) of pharmacies were selling injecting equipment, compared with 28.0% (676/2434) in 1988; 18.9% (366/1937) were providing a needle exchange service, compared with 3.0% (65/2415) in 1988.

CONCLUSION

Activity levels increased substantially across all three service areas. Increased activity included greater individual activity as well as higher proportions of pharmacies participating. The network of community pharmacies represents an underused point of contact for this Health of the Nation target population.

Role of community pharmacies in prevention of AIDS among injecting drug misusers: findings of a survey in England and Wales

OBJECTIVE

To determine the current and potential roles of community pharmacists in the prevention of AIDS among misusers of injected drugs.

DESIGN

Cross sectional postal survey of a one in four random sample of registered pharmacies in England and Wales.

SETTING

Project conducted in the addiction research unit of the Institute of Psychiatry, London.

SUBJECTS

2469 Community pharmacies in the 15 regional health authorities in England and Wales.

MAIN OUTCOME MEASURES

Willingness of pharmacists to sell injecting equipment to known or suspected misusers of drugs; pharmacists' attitudes to syringe exchange schemes, keeping a "sharps" box for use by misusers of drugs, and offering face to face advice and leaflets; and opinions of community pharmacists on their role in AIDS prevention and drug misuse.

RESULTS

1946 Questionnaires were returned, representing a response rate of 79%. This fell short of the target of one in four pharmacies in each family practitioner committee area in England and Wales, and total numbers of respondents were therefore weighted in inverse proportion to the response rate in each area. The findings disclosed a substantial demand for injecting equipment by drug misusers. After weighting of numbers of respondents an estimated 676 of 2434 pharmacies were currently selling injecting equipment and 65 of 2415 (3%) were participating in local syringe exchange schemes; only 94 of 2410 pharmacies (4%) had a sharps box for used equipment. There was a high degree of concern among pharmacists about particular consequences of drug misusers visiting their premises, along with a widespread acceptance that the community pharmacist had an important part to play.

CONCLUSIONS

Promoting the participation of community pharmacists in the prevention of AIDS among misusers of injected drugs is a viable policy, but several problems would need to be overcome before it was implemented.

Findings of a national survey of the role of general practitioners in the treatment of opiate misuse: views on treatment

An important component of government policy on services for drug misusers is to encourage general practitioners to take a more active role. There are, however, some indications that general practitioners regard drug misusers as undesirable patients, although no evidence is available. As part of a wider investigation of the role of general practitioners in the treatment of opiate misuse, a questionnaire, which was sent in mid-1985 to a 5% random sample of general practitioners in England and Wales, included a section designed to elicit their views on policy and treatment connected with opiate misuse. The results showed that although most general practitioners consider opiate misuse to be a priority concern for the Health Service, they also generally regard opiate misusers as especially difficult to manage, beyond their competence to treat, and less acceptable as patients than others in need of care. General practitioners who have qualified recently were somewhat less unfavourable in their views. These findings suggest that the effective implementation of government policy will require trying to modify general practitioners' attitudes and providing support for them.

Findings of a national survey of the role of general practitioners in the treatment of opiate misuse: dealing with the opiate misuser

Because there has been a substantial increase in the scale of drug misuse general practitioners have become increasingly concerned in responding to this problem. Little is known, however, about how general practitioners manage drug misusers. The findings from a national survey carried out in mid-1985 of a 5% random sample of general practitioners in England and Wales show the extent to which various actions were undertaken by general practitioners who reported on the consultation with the opiate misuser whom they last attended. In more than half of the cases the opiate misuser had been under the care of the general practitioners for this problem for at least six months. The findings indicate that most general practitioners refer these patients to specialist drug dependence clinics or to general psychiatric services but rarely to other agencies. Opiate drugs had been prescribed in nearly a third of cases. The rate of notification to the Home Office conforms with that in other studies and indicates a high degree of undernotification. More detailed study of general practitioners' activities in managing drug misusers is needed.

Findings of a national survey of the role of general practitioners in the treatment of opiate misuse: extent of contact with opiate misusers

With the recent unprecedented growth in the spread of drug misuse in the United Kingdom the role of the general practitioner has become more and more prominent, both in response to demands for treatment and as the focus of national policy on drug misuse. Although general practitioners may be the first contact, few data are available on the extent of their contact with drug misusers. A postal survey was carried out in mid-1985 of a 5% national sample of general practitioners in England and Wales concerning their role in and views on the treatment of opiate misusers, including the extent of their contact with such patients during a four week period. Of the 1166 general practitioners surveyed, 845 replied, a response rate of 72%. The results show that roughly one in five general practitioners in England and Wales attended an opiate misuser during this four week period, seeing an estimated 6000 to 9000 patients, one third of whom were "new" to the general practitioner. A cautious estimate of between 30,000 and 44,000 new cases of opiate misuse presenting to general practitioners in a year is suggested, with some adjustment necessary because of double counting. A wide variation in the prevalence of consultations among regional health authorities was found, and several of the regions with a high prevalence are outside the London area. The scale of contact thus confirms the importance of the general practitioner in the national response to drug misuse.

Lenz microphthalmia: a malformation syndrome with variable expression of multiple congenital anomalies

Lenz microphthalmia is a syndrome of microphthalmia accompanied by multiple congenital anomalies, none of which is unique to the syndrome. The patient described in this paper had, in addition to the microphthalmia, dysmorphic facies and dental anomalies, several features not previously described in this syndrome: synophrys, an isolated cleft of the soft palate, a webbed neck and sacral pits. Other congenital syndromes associated with microphthalmia (oculodentodigital dysplasia, cryptophthalmos and the 10q+ syndrome) were excluded. The frequency of the anomalies described in 22 case reports is presented as a guide to diagnosis in isolated cases.

Spectrum of anomalies in Fanconi anaemia

The frequency of various anomalies was compared in probands with Fanconi anaemia and their affected sibs. As probands are usually ascertained because of a 'characteristic' array of physical anomalies, the frequencies of these specific anomalies may be overestimated in probands, whereas their affected sibs may provide a more accurate estimate. The frequencies of growth retardation, skin hyperpigmentation, radial ray deformities, radial ray reduction deformities, hypogenitalia, and supernumerary thumbs were significantly lower in the affected sibs of probands than in probands. Since 25% of the affected sibs had no dysmorphic features, absence of dysmorphism is not sufficient to rule out the diagnosis.