Despite current pharmacological intervention strategies, patients with HIV still suffer from chronic inflammation. The nicotinic acetylcholine receptors (nAChRs) are widely distributed throughout the nervous and immune systems. In macrophages, activation of alpha7-nAChR (α7-nAChR) controls inflammatory processes through the cholinergic anti-inflammatory response (CAR). Given that this innate immune response controls inflammation and α7-nAChR plays a critical role in the regulation of systemic inflammation, we investigated the effects of an R5-tropic HIV soluble component, gp120JRFL, on the CAR functioning. We previously demonstrated that X4-tropic HIV-1 gp120IIIB disrupts the CAR as well as inducing upregulation of the α7-nAChR in vitro in monocyte-derived macrophages (MDMs) which correlates with the upregulation observed in monocytes, T-lymphocytes, and MDMs recovered from HIV-infected people. We demonstrate here using imaging and molecular assays that the R5-tropic HIV-1 glycoprotein gp120JRFL upregulates the α7-nAChR in MDMs dependent on CD4 and/or CCR5 activation. This upregulation was also dependent on MEK1 since its inhibition attenuates the upregulation of α7-nAChR induced by gp120JRFL and was concomitant with an increase in basal calcium levels which did not result in apoptosis. Moreover, the CAR was determined to be disrupted, since α7-nAChR activation in MDMs did not reduce the production of the proinflammatory cytokines IL-6, GRO-α, or I-309. Furthermore, a partial antagonist of α7-nAChR, bupropion, rescued IL-6 but not GRO-α or I-309 production. Together, these results demonstrate that gp120JRFL disrupts the CAR in MDMs. Other medications targeting the α7-nAChR need to be tested to reactivate the CAR to ameliorate inflammation in HIV-infected subjects.

Background: Case Western Reserve University (CWRU)/University Hospitals Cleveland Medical Center in Cleveland, OH, and the University of Pittsburgh (Pitt) in Pittsburgh, PA, forged a strategic alliance to form the Rustbelt Center for AIDS Research. The Rustbelt Center for AIDS Research developed a National Institutes of Health–supported diversity, equity, and inclusion pathway initiative termed the “Rustbelt Investigators for the Next Generation (RING) Program” that provides research training experiences for Puerto Rican students that will help them pursue a biomedical research career in HIV. Setting: The RING Program provides 10-week research training experiences in different disciplines of HIV/AIDS for under-represented minority undergraduate and masters students from 4 campuses (Río Piedras, Mayagüez, Humacao, and Cayey) at the University of Puerto Rico. Mentors are drawn from both CWRU and Pitt. Results: The RING Program recently completed our first wave of recruitment. Recruitment sessions were either virtual or on site at the University of Puerto Rico campuses and included an overview presentation, a Q&A session, and in-person interviews. We interviewed 32 eligible applicants and accepted 10 into the program, of which 9 were female. Five students were matched with faculty at CWRU and 5 with faculty at Pitt. Conclusions: The RING Program is a comprehensive program in laboratory and implementation science that aims to enhance under-represented Hispanic undergraduate and masters students' passion for pursuing a biomedical research career in HIV.

The main objective of the present study was to find detergents that can maintain the functionality and stability of the Torpedo californica nicotinic acetylcholine receptor (Tc-nAChR). We examined the functionality, stability, and purity analysis of affinity-purified Tc-nAChR solubilized in detergents from the Cyclofos (CF) family [cyclofoscholine 4 (CF-4), cyclofoscholine 6 (CF-6), and cyclofloscholine 7 (CF-7)]. The functionality of the CF-Tc-nAChR-detergent complex (DC) was evaluated using the Two Electrode Voltage Clamp (TEVC) method. To assess stability, we used the florescence recovery after photobleaching (FRAP) in Lipidic Cubic Phase (LCP) methodology. We also performed a lipidomic analysis using Ultra-Performance Liquid Chromatography (UPLC) coupled to electrospray ionization mass spectrometry (ESI–MS/MS) to evaluate the lipid composition of the CF-Tc-nAChR-DCs. The CF-4-Tc-nAChR-DC displayed a robust macroscopic current (− 200 ± 60 nA); however, the CF-6-Tc-nAChR-DC and CF-7-Tc-nAChR-DC displayed significant reductions in the macroscopic currents. The CF-6-Tc-nAChR and CF-4-Tc-nAChR displayed higher fractional florescence recovery. Addition of cholesterol produced a mild enhancement of the mobile fraction on the CF-6-Tc-nAChR. The lipidomic analysis revealed that the CF-7-Tc-nAChR-DC displayed substantial delipidation, consistent with the lack of stability and functional response of this complex. Although the CF-6-nAChR-DC complex retained the largest amount of lipids, it showed a loss of six lipid species [SM(d16:1/18:0); PC(18:2/14:1); PC(14:0/18:1); PC(16:0/18:1); PC(20:5/20:4), and PC(20:4/20:5)] that are present in the CF-4-nAChR-DC. Overall, the CF-4-nAChR displayed robust functionality, significant stability, and the best purity among the three CF detergents; therefore, CF-4 is a suitable candidate to prepare Tc-nAChR crystals for structural studies. Graphical abstract

Obtaining high-resolution 3D structures of membrane proteins through X-ray crystallography remains a longstanding bottleneck in the field of structural biology. This challenge has led to the optimization of purification methods to acquire high-yielding, pure proteins suitable for crystallization. In this study, we performed crystallization screenings of purified human α4β2 nAChR using a polarized in meso method. After reconstituting the detergent-solubilized α4β2 nAChR into the LCP matrix, the samples were incubated in a polarized lipid matrix using the RMP@LMx device developed in our laboratory. The results showed that under these conditions, the α4β2-nAChR-LFC 16 complex gave a mobile fraction >0.8, suggesting that its diffusion in the polarized lipid matrix is favorable for crystal nucleation. Voltages above 70 mV restricted crystal formation due to sample dehydration. Furthermore, a lipid analysis using UPLC-ESI MS/MS revealed a profile necessary for preserving protein integrity and promoting diffusion across the LCP. We harvested a single crystal and subjected it to X-ray diffraction, resulting in reflections comparable to previous studies of the muscle-type nAChR from Torpedo californica. X-ray diffraction of a single crystal gave distinct low-resolution diffractions of protein nature. These findings lay the groundwork for further optimization of membrane protein crystallization in polarized in meso phases.

Background/Objectives: Andrographolide (ADG) is a plant-derived compound with promising anticancer properties, but its medical use is limited due to poor water solubility and low bioavailability. This study proposes developing a gold-based nanocomposite drug delivery system, using a simplified synthesis method, to improve ADG’s hydrophilicity and enhance its delivery efficiency. Methods: A one-step method was used to synthesize gold nanocomposites with carbon quantum dots (CBQDs) and doped CBQDs acting as reducing and stabilizing agents. These nanocomposites were then conjugated with ADG and thoroughly characterized using multiple structural and spectroscopic techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM), Raman spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Hydrophilicity enhancement was evaluated using NMR-based log P measurements. Biological assessment involved cell viability assays and confocal microscopy studies in PC3 prostate cancer cells, along with the morphological evaluation of human red blood cells. Results: XRD confirmed the formation of crystalline, face-centered cubic gold nanoparticles, while spectroscopic analyses verified successful nanocomposite formation and ADG conjugation. NMR results showed enhanced hydrophilicity of ADG. Biological tests demonstrated that the nanocomposites were compatible with cells. Conclusions: This study presents a straightforward strategy for synthesizing gold-based nanocomposites that enhance the hydrophilicity and delivery potential of andrographolide, supporting their applicability as nanocarrier platforms for anticancer drug delivery.