The expression of nicotinic acetylcholine receptors by neurons, microglia, and astrocytes suggests possibly diverse mechanisms by which natural nicotinic cholinergic signaling and exposure to nicotine could modulate immune responses within the CNS. In this study, we show that nicotine exposure significantly delays and attenuates inflammatory and autoimmune responses to myelin Ags in the mouse experimental autoimmune encephalomyelitis model. In the periphery, nicotine exposure inhibits the proliferation of autoreactive T cells and alters the cytokine profile of helper T cells. In the CNS, nicotine exposure selectively reduces numbers of CD11c+ dendritic and CD11b+ infiltrating monocytes and resident microglial cells and down-regulates the expression of MHC class II, CD80, and CD86 molecules on these cells. The results underscore roles of nicotinic acetylcholine receptors and nicotinic cholinergic signaling in inflammatory and immune responses and suggest novel therapeutic options for the treatment of inflammatory and autoimmune disorders, including those that affect the CNS.

Amyloid-␤ (A␤) accumulation and aggregation are thought to contribute to the pathogenesis of Alzheimer's disease (AD). In AD, there is a selective decrease in the numbers of radioligand binding sites corresponding to the most abundant nicotinic acetylcholine receptor (nAChR) subtype, which contains human ␣4 and ␤2 subunits (h␣4␤2-nAChR). However, the relationships between these phenomena are uncertain, and effects of A␤ on h␣4␤2-nAChR function have not been investigated in detail. We first confirmed expression of h␣4 and h␤2 subunits as messenger RNA in transfected, human SH-EP1 cells by reverse transcription-polymerase chain reaction and mRNA fluorescence in situ hybridization analyses. Immunoprecipitation Western analyses confirmed ␣4 and ␤2 subunit protein expression and coassembly. Whole cell current recording demonstrated heterologous expression in SH-EP1-h␣4␤2 cells of functional h␣4␤2-nAChRs with characteristic responses to nicotinic agonists or antagonists. Nicotine-induced whole cell currents were suppressed by A␤ 1-42 in a dosedependent manner. Functional inhibition was selective for A␤ 1-42 compared with the functionally inactive, control peptide A␤ 40 -1 . A␤ 1-42 -mediated inhibition of h␣4␤2-nAChR function was non-competitive, voltage-independent, and use-independent. Pre-loading of cells with guanyl-5-yl thiophosphate failed to prevent A␤ 1-42 -induced inhibition, suggesting that down-regulation of h␣4␤2-nAChR function by A␤ 1-42 is not mediated by nAChR internalization. Sensitivity to A␤ 1-42 antagonism at 1 nM was evident for h␣4␤2-nAChRs, but not for heterologously expressed human ␣7-nAChRs, although both nAChR subtypes were functionally inhibited by 100 nM A␤ 1-42 , with the magnitude of functional block being higher for 100 nM A␤ 1-42 acting on h␣7-nAChRs. These findings suggest that h␣4␤2-nAChRs are sensitive and perhaps pathophysiologically relevant targets for A␤ neurotoxicity in AD.Alzheimer's disease (AD) 1 is a progressive, neurodegenerative disorder manifest as a severe impairment of learning and memory. Pathophysiological hallmarks of AD include extracellular deposits of ␤-amyloid peptide (A␤) in senile plaques, formation of intraneuronal neurofibrillary tangles, and cholinergic neuron death (1). Although the precise mechanisms of AD pathogenesis are only partially understood, it is now widely accepted that the accumulation and aggregation of A␤ 1-42 plays a key role in the disease (2). Evidence has indicated an interaction between A␤ and the cholinergic system (3). For example, very low concentrations (pico to nanomolar) of A␤ can directly induce cholinergic hypofunction (4 -6). It has been reported that solubilized A␤ inhibits several steps of acetylcholine synthesis and release (4, 7), inhibits cholinergic enzyme activity (6), impairs cholinergic metabolism and neurotransmission (8 -10), and depresses hippocampal synaptic function (11).Recent evidence suggests possible roles for nicotinic acetylcholine receptors (nAChRs) as central targets for A␤-induced neurotoxicity manifest as...

The expression of two heat-responsive cct (chaperonin-containing Tcp-1) genes from the archaeon Haloferax volcanii was investigated at the transcription level. The cct1 and cct2 genes, which encode proteins of 560 and 557 amino acids, respectively, were identified on cosmid clones of an H. volcanii genomic library and subsequently sequenced. The deduced amino acid sequences of these genes exhibited a high degree of similarity to other archaeal and eucaryal cct family members. Expression of the cct genes was characterized in detail for the purpose of developing a model for studying transcription regulation in the domain Archaea. Northern (RNA) analysis demonstrated that the cct mRNAs were maximally induced after heat shock from 37 to 55°C and showed significant heat inducibility after 30 min at 60°C. Transcription of cct mRNAs was also stimulated in response to dilute salt concentrations. Transcriptional analysis of cct promoter regions coupled to a yeast tRNA reporter gene demonstrated that 5 flanking sequences up to position ؊233 (cct1) and position ؊170 (cct2) were sufficient for promoting heat-induced transcription. Transcript analysis indicated that both basal transcription and stress-induced transcription of the H. volcanii cct genes were directed by a conserved archaeal consensus TATA motif (5-TTTATA-3) centered at ؊25 relative to the mapped initiation site. Comparison of the cct promoter regions also revealed a striking degree of sequence conservation immediately 5 and 3 of the TATA element.All living organisms adapt to adverse environmental conditions by evolving specific molecular responses. In particular, the universally conserved heat shock response occurs when cells are exposed to elevated temperatures, resulting in the rapid and transient overproduction of a limited class of proteins called the heat shock proteins (HSPs). The HSPs produced in the domains Bacteria and Eucarya are highly conserved both in structure and function, and their induction is generally regulated at the transcription initiation level (recently reviewed in reference 31).Among the HSPs, the Cct family is a recently identified group of molecular chaperonins that are distinct from members of the well-studied Hsp60/GroEL family. So far, members of the Cct family have been identified only in the domains Archaea and Eucarya, where they are known variously as Tcomplex polypeptide, or TCP (15); chaperonin-containing Tcp-1, or Cct (25, 62); TCP-1 ring complex, or TriC (13); thermosome complex (59); and thermophilic factor-55, or TF55 (54). Protein members of the Cct and Hsp60/GroEL families display similar double-ringed toroidal structures as their active forms. Differences between the two families include the absence of an HSP10/GroES-like accessory protein necessary for Cct function (25) and the hetero-oligomeric structure of Cct complexes, which contain either 2 (58) or 8 to 10 different subunits (61). Among the members of the Archaea, members of the Cct protein family have been documented in many hyperthermophiles, including Sulfolo...

To evaluate possible physiological roles of the large cytoplasmic loops (C2) and neighboring transmembrane domains of nicotinic acetylcholine receptor (nAChR) subunits, we generated novel fusion constructs in which human nAChR ␣4, ␤2, or ␤4 subunit C2 or C2 and neighboring sequences were replaced by corresponding sequences from the mouse serotonin type 3A (5-HT 3A ) receptor subunit. Following stable expression in human SH-EP1 cells, we found that extensive sequence substitutions involving third and fourth transmembrane domains and neighboring "proximal" C2 sequences (e.g., ␤2 H322-V335 and V449-R460) did not allow functional expression of nAChR containing chimeric subunits. However, expression of functional nAChR was achieved containing wild-type ␣4 subunits and chimeric ␤2 (␤2) subunits whose "nested" C2 domain sequences K336-S448 were replaced with the corresponding 5-HT 3A subunit sequences. Whereas these findings suggested indispensable roles for M3/M4 transmembrane and/or proximal C2 sequences in ␣4␤2-nAChR function, nested C2 sequences in the ␤2 subunit are not essential for functional receptor expression. Ligand-binding analyses also revealed only subtle differences in pharmacological profiles of ␣4␤2-nAChR compared with ␣4␤2-nAChR. Nevertheless, there was heightened emergence of agonist-mediated self-inhibition of ␣4␤2 function, greater sensitivity to functional blockade by a number of antagonists, and faster and more complete acute desensitization of ␣4␤2-nAChR than for ␣4␤2-nAChR. These studies are consistent with unexpected roles of nested C2 sequences in nAChR function.Nicotinic acetylcholine receptors (nAChR) are members of a ligand-gated ion channel superfamily, each comprised of a homo-or heteropentameric assembly of distinct subunits (Lindstrom, 1996;Lukas, 1998;Karlin, 2002). All nAChR subtypes mediate transmembrane ion flux upon activation by interaction with the endogenous neurotransmitter acetylcholine (ACh) or the tobacco alkaloid nicotine. However, each nAChR subtype possesses unique channel properties dictated in part by the subtle diversity of its constituent subunits.Each of the 17, genetically distinct, vertebrate nAChR subunits identified to date share a common topology containing a large extracellular N-terminal domain, four transmembrane domains, a short cytoplasmic domain between the first and second transmembrane segments, a short extracellular domain between second and third transmembrane segments, a large second cytoplasmic loop (C2) situated between the third (M3) and fourth (M4) transmembrane domains, and a short C-terminal extracellular tail. The N-terminal domain contains key elements for ligand-binding/recognition (Sine, 2002), and the transmembrane domains anchor the proteins in the plasma membrane and contribute to channel kinetics and ion selectivity (Corringer et al., 2000). These structural domains are well conserved among different subunits and have been studied extensively. On the other hand, the less studied C2 domain of each subunit contains unique sequence...

Context: Uninsured patients living in rural areas of North Carolina have been inordinately affected by the increasing prevalence of sexually transmitted diseases (STDs) in the midst of severe budget cuts to treatment programs and a shortage of rural primary care physicians. The Campbell University Community Care Clinic, a self-funded, student-run clinic, provides free health care to uninsured residents of rural Harnett County. As a relatively new clinic serving a unique population, epidemiologic research is paramount to the clinic's continued efficacy. Objective: To determine which STDs are present in this patient population and to identify demographic groups at higher risk of contracting STDs. Methods: This study was a retrospective analysis of patient medical records from March 1, 2015, to March 6, 2018. Records were evaluated to identify STD cases based on diagnostic information, such as primary diagnoses, positive laboratory results, and clinical indicators. Results: A total of 449 patient records were analyzed, revealing an STD incidence rate of 5.3%, which represents a higher STD frequency than the national average of 2%. Our results identified human papillomavirus infection and gonorrhea as the most frequent STDs (n=7 [29.2%] and n=6 [25%], respectively), followed by chlamydia (n=4 [16.7%]), herpes simplex virus (n=4 [16.7%]), syphilis (n=2 [8.3%]), hepatitis C virus (n=2 [4.2%]), trichomoniasis (n=1 [4.2%]), and HIV (n=1 [4.2%]) infections. Among racial/ethnic groups, Hispanics had a slightly higher relative risk (RR) for STDs by a factor of 1.3 when normalized to the average frequency. Patients aged 26 to 29 and 30 to 39 years had a significantly higher RR for STDs: 2.1 and 2.0, respectively. Furthermore, female patients had an STD frequency 3 times that of male patients. Conclusion: This study reveals noteworthy health risks in a rural uninsured population, including a higher rate of gonorrhea compared with national rates and a higher RR for STDs in certain demographic groups. These findings form a foundation for improvements in care through earlier STD diagnoses, effective treatment, and enhanced patient education.

To evaluate physiological roles of the large, second cytoplasmic loops (C2) situated between the M3 and M4 transmembrane domains of nicotinic acetylcholine receptor (nAChR) subunits. We have constructed chimeric β2 (β2χ) and β4 (β4χ) subunits in which the “nested” C2 domains (but not the “proximal” sequences of ~14 residues immediately adjacent to the M3 or M4 domains) of these β subunits were replaced by the corresponding sequence from the serotonin 5-HT3A receptor subunit. We previously reported that heterologously expressed nAChR containing α4 and β2χ subunits displayed a faster whole-cell current decay in its agonist response compared to responses of all-wild-type α4β2-nAChR. This suggests an unexpected, functional role for the C2 domain of the β2 subunit in α4β2-nAChR acute desensitization. Here we report that there also is faster desensitization of α4β4χ-nAChR relative to α4β4-nAChR stably and heterologously expressed in the human SH-EP1 cell-line. In addition, cell-attached, single channel recording shows that both acetylcholine-activated α4β2χ- and α4β4χ-nAChR have a significantly lower mean open probability, shorter mean open-time, and a longer mean closed-time than their fully wild-type counterparts while not having different conductance amplitudes. These findings reveal microscopic bases for the faster desensitization of α4*-nAChR containing chimeric instead of wild-type β subunits. Our findings also remain consistent with novel and unexpected roles of β subunit nested C2 domains in modulation of α4*-nAChR function.

Medical education curricula have been increasingly undergoing changes in recent years to respond to continuous transformations in the professional education landscape. Utilizing and promoting learning approaches that are most effective in helping learners navigate through these ongoing changes, while fostering optimal educational outcomes, are of particular importance. While there are various learning approaches, they can be categorized into three main types: Superficial, Deep, and Strategic. Although Strategic and Deep Learning approaches were often found in the literature to correlate with high performance among medical students, some researchers suggest that promoting the Strategic Learning Approach predominantly may be more effective. The Campbell University Jerry M. Wallace School of Osteopathic Medicine (CUSOM) opened its doors in 2013 with an innovative, hybrid curriculum, combining discipline‐based and organ system‐based courses, fully integrating biomedical and clinical skills‐based learning. With the ultimate goal in facilitating greater academic success among CUSOM students, as well as among all medical students, this Institutional Review Board (IRB)‐approved study aims to determine the predominant type of learning approaches utilized among medical students at CUSOM using a slightly‐modified Study Skills Inventory for Students (ASSIST) instrument. Descriptive statistics were used to describe participants’ demographic variables. Categorical variables were reported as frequencies or proportions/percentages. Univariate, multivariable, and multivariate statistical analyses were performed as relevant and necessary. Preliminary data were analyzed using the Statistical Package for Social Sciences (SPSS, version 24, Chicago, IL). All inferences will be considered statistically significant whenever P‐value ≤0.05 and will be reported with corresponding effect sizes as necessary. A total of 240 osteopathic medical students voluntarily participated in this study, which began at the start of this current academic year. The first‐year students comprised the largest subgroup of respondents, representing 65.8% of all completed instruments. Preliminary findings indicate that Strategic Learning was the principal approach utilized by participants, accounting for 61% among the fourth‐year, 58% among the first‐year, and 52% among the third‐year students. It is interesting to note that the current second‐year student participants utilize the Deep Learning approach predominantly. These preliminary results serve as an important basis for tailored study skills interventions that could facilitate students’ academic success. Further analysis will explore relationship between the predominant learning approaches and metrics of their academic performance.