Quantitative proteomics analysis reveals unique but overlapping protein signatures in HIV infections

Prohibitins in infection: potential therapeutic targets

Prohibitins (PHBs) are members of a highly conserved family of proteins, including prohibitin1 and prohibitin2. These proteins are predominantly localized in mitochondria, the nucleus, and cell membranes, where they play critical roles in mitochondrial biogenesis, apoptosis, immune regulation, and other biological processes. Recent studies have demonstrated that both PHB1 and PHB2 can act as a complex or independently to participate in the pathogen infection process. This review focuses on the regulatory roles of PHB1 and PHB2 in viral, bacterial, parasitic and fungal infections, providing a theoretical basis and innovative perspectives for a comprehensive understanding of the roles and mechanisms of PHB1 and PHB2 in the regulation of microbial infections. Due to exerting multiple functions, PHB proteins have been recognized as a potential target for therapeutic interventions, with the expectation that targeting PHB proteins will provide new strategies for the treatment of infection-related diseases.

The proteasome activator subunit PSME1 promotes HBV replication by inhibiting the degradation of HBV core protein

Chronic hepatitis B virus (HBV) infection is a leading cause of liver cirrhosis and hepatocellular carcinoma, representing a global health problem for which a functional cure is difficult to achieve. The HBV core protein (HBc) is essential for multiple steps in the viral life cycle. It is the building block of the nucleocapsid in which viral DNA reverse transcription occurs, and its mediation role in viral-host cell interactions is critical to HBV infection persistence. However, systematic studies targeting HBc-interacting proteins remain lacking. Here, we combined HBc with the APEX2 to systematically identify HBc-related host proteins in living cells. Using functional screening, we confirmed that proteasome activator subunit 1 (PSME1) is a potent HBV-associated host factor. PSME1 expression was up-regulated upon HBV infection, and the protein level of HBc decreased after PSME1 knockdown. Mechanistically, the interaction between PSME1 and HBc inhibited the degradation of HBc by the 26S proteasome, thereby improving the stability of the HBc protein. Furthermore, PSME1 silencing inhibits HBV transcription in the HBV infection system. Our findings reveal an important mechanism by which PSME1 regulates HBc proteins and may facilitate the development of new antiviral therapies targeting PSME1 function.

Prohibitin 2: A key regulator of cell function

The PHB2 gene is located on chromosome 12p13 and encodes prohibitin 2, a highly conserved protein of 37 kDa. PHB2 is a dimer with antiparallel coils, possessing a unique negatively charged region crucial for its mitochondrial molecular chaperone functions. Thus, PHB2 plays a significant role in cell life activities such as mitosis, mitochondrial autophagy, signal transduction, and cell death. This review discusses how PHB2 inhibits transcription factors or nuclear receptors to maintain normal cell functions; how PHB2 in the cytoplasm or membrane ensures normal cell mitosis and regulates cell differentiation; how PHB2 affects mitochondrial structure, function, and cell apoptosis through mitochondrial intimal integrity and mitochondrial autophagy; how PHB2 affects mitochondrial stress and inhibits cell apoptosis by regulating cytochrome c migration and other pathways; how PHB2 affects cell growth, proliferation, and metastasis through a mitochondrial independent mechanism; and how PHB2 could be applied in disease treatment. We provide a theoretical basis and an innovative perspective for a comprehensive understanding of the role and mechanism of PHB2 in cell function regulation.

Human immunodeficiency virus in Saudi Arabia: Current and future challenges

INTRODUCTION

Understanding the pathophysiology of HIV infection has been crucial to the design of effective anti-viral strategies. HIV infection is declining worldwide due to early diagnosis and the effective long-term use of anti-retroviral therapy. New infections decreased from 3.3 million in 2002-2.3 million in 2012. However, in the Middle East and North Africa (MENA), an estimated 83,000 individuals still acquired the virus, with 37,000 morbidities reported. The first incidence of acquired immunodeficiency syndrome (AIDS) from the Kingdom of Saudi Arabia (KSA) was reported in 1984. By the end of 2013, around 1509 patients had been diagnosed with HIV infection. HIV surveillance has improved in KSA with advances in medical care, counseling, family planning, diagnostic evaluation, and anti-retroviral therapy, but challenges remain. Patients receiving anti-retroviral therapy still show significant morbidity and mortality. Further targeted treatment regimens and preventive strategies are required to control HIV infection in KSA. Progress towards meeting the 90-90-90 goals for HIV in the MENA has also not been systematically monitored.

METHOD

In this review, we examine current screening programs, therapeutic modalities, the emergence of drug resistance, and future perspectives for HIV-associated health care in KSA.

CONCLUSION

The aim is to offer insight for healthcare policymakers to comply with the UNAIDS 2020 vision program and help establish the prevailing paradigms in the HIV community for an AIDS-free generation and the 90-90-90 goals for diagnosis.

Plasma proteome perturbation for CMV DNAemia in kidney transplantation

BACKGROUND

Cytomegalovirus (CMV) infection, either de novo or as reactivation after allotransplantation and chronic immunosuppression, is recognized to cause detrimental alloimmune effects, inclusive of higher susceptibility to graft rejection and substantive impact on chronic graft injury and reduced transplant survival. To obtain further insights into the evolution and pathogenesis of CMV infection in an immunocompromised host we evaluated changes in the circulating host proteome serially, before and after transplantation, and during and after CMV DNA replication (DNAemia), as measured by quantitative polymerase chain reaction (QPCR).

METHODS

LC-MS-based proteomics was conducted on 168 serially banked plasma samples, from 62 propensity score-matched kidney transplant recipients. Patients were stratified by CMV replication status into 31 with CMV DNAemia and 31 without CMV DNAemia. Patients had blood samples drawn at protocol times of 3- and 12-months post-transplant. Additionally, blood samples were also drawn before and 1 week and 1 month after detection of CMV DNAemia. Plasma proteins were analyzed using an LCMS 8060 triple quadrupole mass spectrometer. Further, public transcriptomic data on time matched PBMCs samples from the same patients was utilized to evaluate integrative pathways. Data analysis was conducted using R and Limma.

RESULTS

Samples were segregated based on their proteomic profiles with respect to their CMV Dnaemia status. A subset of 17 plasma proteins was observed to predict the onset of CMV at 3 months post-transplant enriching platelet degranulation (FDR, 4.83E-06), acute inflammatory response (FDR, 0.0018), blood coagulation (FDR, 0.0018) pathways. An increase in many immune complex proteins were observed at CMV infection. Prior to DNAemia the plasma proteome showed changes in the anti-inflammatory adipokine vaspin (SERPINA12), copper binding protein ceruloplasmin (CP), complement activation (FDR = 0.03), and proteins enriched in the humoral (FDR = 0.01) and innate immune responses (FDR = 0.01).

CONCLUSION

Plasma proteomic and transcriptional perturbations impacting humoral and innate immune pathways are observed during CMV infection and provide biomarkers for CMV disease prediction and resolution. Further studies to understand the clinical impact of these pathways can help in the formulation of different types and duration of anti-viral therapies for the management of CMV infection in the immunocompromised host.