Renal injury in scleromyxoedema due to monoclonal gammopathy associated C3 glomerulonephritis

Scleromyxoedema is a rare mucinosis that primarily affects the skin. It is associated with monoclonal gammopathy and has many extracutaneous manifestations, however, renal involvement is rare. We report the case of a woman with monoclonal gammopathy and scleromyxoedema presenting with progressive exertional dyspnoea and acute renal failure. Workup of her renal failure revealed monoclonal gammopathy associated C3 glomerulonephritis. She was treated with intravenous steroids and discharged with plans to pursue annual monoclonal gammopathy laboratory monitoring. Given the rarity of renal scleromyxoedema, careful investigation of extracutaneous manifestations and comorbidities is critical to discern the primary pathological process in patients with scleromyxoedema who develop renal insufficiency.

A Survey-Based Comparison of Sun Safety Practices in a Representative Cohort of the General Public Versus Attendees of a Skin Cancer Screening

A large proportion of data on photoprotective practices is yielded from free skin cancer screenings. However, the sun safety practices of populations who seek these skin cancer screenings may differ from the general public. To examine differences in skin cancer prevention practices and risk factors, we surveyed pedestrians at six locations in Washington, DC (public group, n=285) and attendees of a free skin cancer screening (screening group, n=144) using an IRB-approved survey. The screening group was older and included more individuals with fair skin than the public group. Respondents from the screening group were significantly more likely to always wear sunscreen, always seeks shade, and always or sometimes wear sun-protective clothing than the public group (P<0.05). To examine whether younger and non-white participants, who were less likely to attend our free screening, have different practices and risk factors than older and white participants, respectively, we compared survey answers for all participants by age and race. White participants were more likely to always or sometimes wear sunscreen and sun-protective clothing than non-white participants (P<0.05). Patients over 61 years were more likely to always seek shade and wear sun-protective clothing than those younger than 31 years (P<0.05). Therefore, free skin cancer screenings need to be better popularized among non-white and younger populations or more effective educational vehicles are needed. J Drugs Dermatol. 2019;18(7):649-653.

A Survey-Based Comparison of Sun Safety Practices in a Representative Cohort of the General Public Versus Attendees of a Skin Cancer Screening

A large proportion of data on photoprotective practices is yielded from free skin cancer screenings. However, the sun safety practices of populations who seek these skin cancer screenings may differ from the general public. To examine differences in skin cancer prevention practices and risk factors, we surveyed pedestrians at six locations in Washington, DC (public group, n=285) and attendees of a free skin cancer screening (screening group, n=144) using an IRB-approved survey. The screening group was older and included more individuals with fair skin than the public group. Respondents from the screening group were significantly more likely to always wear sunscreen, always seeks shade, and always or sometimes wear sun-protective clothing than the public group (P<0.05). To examine whether younger and non-white participants, who were less likely to attend our free screening, have different practices and risk factors than older and white participants, respectively, we compared survey answers for all participants by age and race. White participants were more likely to always or sometimes wear sunscreen and sun-protective clothing than non-white participants (P<0.05). Patients over 61 years were more likely to always seek shade and wear sun-protective clothing than those younger than 31 years (P<0.05). Therefore, free skin cancer screenings need to be better popularized among non-white and younger populations or more effective educational vehicles are needed. J Drugs Dermatol. 2019;18(7):649-653.

Managing Seborrheic Keratosis: Evolving Strategies and Optimal Therapeutic Outcomes

Seborrheic keratosis (SK) is the most common skin tumor seen by dermatologists in everyday practice. Although the lesions are mostly benign, many patients still elect to have asymptomatic SK removed. The historical standards of treatment are cryosurgery and electrocautery, two surgical options that are effective at lesion removal but have high rates of postoperative adverse events such as treatment-site scarring and pigmentary alterations. The cosmetic outcomes of SK treatment modalities are of keen interest to dermatologists, as the American population becomes increasingly more diverse. In this article, the inclusion of darker Fitzpatrick skin types into clinical studies investigating post-treatment side effects of SK therapy is reviewed. The recent approval of a 40% hydrogen peroxide topical formulation is discussed in light of these issues, and several non-invasive topical treatments that optimize cosmetic outcomes of SK lesion removal are highlighted. Finally, treatment strategies aimed at reducing cost and minimizing the burden of adverse sequelae are provided. J Drugs Dermatol. 2018;17(9):933-940.

Blastomycosis-like Pyoderma Arising in Lichen Planus

Blastomycosis-like pyoderma (BLP) is a rare reactive skin disease that is most commonly caused by bacterial infection. Herein we present a case of BLP arising in lichen planus, a chronic inflammatory disease. We propose Wolf's isotopic response, or the appearance of a new skin disease at the site of an existing and unrelated disease, as the underlying molecular mechanism responsible for this unusual physical presentation. It is important that clinicians recognize atypical morphologies such as BLP, which mimics squamous cell carcinoma both clinically and pathologically. These similarities highlight the need for a tissue diagnosis to identify infectious etiologies and rule out malignancy when BLP is suspected. J Drugs Dermatol. 2018;17(2):233-235.

G2A Attenuates Propionibacterium acnes Induction of Inflammatory Cytokines in Human Monocytes

Background

Acne vulgaris is a disease of the pilosebaceous unit characterized by increased sebum production, hyperkeratinization, and immune responses to Propionibacterium acnes (PA). Here, we explore a possible mechanism by which a lipid receptor, G2A, regulates immune responses to a commensal bacterium.

Objective

To elucidate the inflammatory properties of G2A in monocytes in response to PA stimulation. Furthermore, our study sought to investigate pathways by which lipids modulate immune responses in response to PA.

Methods

Our studies focused on monocytes collected from human peripheral blood mononuclear cells, the monocytic cell line THP-1, and a lab strain of PA. Our studies involved the use of enzyme-linked immunosorbent, Western blot, reverse transcription polymerase chain reaction, small interfering RNA (siRNA), and microarray analysis of human acne lesions in the measurements of inflammatory markers.

Results

G2A gene expression is higher in acne lesions compared to normal skin and is inducible by the acne therapeutic, 13-cis-retinoic acid. In vitro, PA induces both the Toll-like receptor 2-dependent expression of G2A as well as the production of the G2A ligand, 9-hydroxyoctadecadienoic acid, from human monocytes. G2A gene knockdown through siRNA enhances PA stimulation of interleukin (IL)-6, IL-8, and IL-1β possibly through increased activation of the ERK1/2 MAP kinase and nuclear factor kappa B p65 pathways.

Conclusion

G2A may play a role in quelling inflammatory cytokine response to PA, revealing G2A as a potential attenuator of inflammatory response in a disease associated with a commensal bacterium.

Phenotype and Antimicrobial Activity of Th17 Cells Induced by Propionibacterium acnes Strains Associated with Healthy and Acne Skin

Studies of the human skin microbiome suggest that Propionibacterium acnes strains may contribute differently to skin health and disease. However, the immune phenotype and functions of T helper type 17 (Th17) cells induced by healthy (P_H) versus acne (P_A) skin-associated P. acnes strains are currently unknown. We stimulated peripheral blood mononuclear cells from healthy donors and observed that P_A strains induce higher IL-17 levels than P_H strains. We next generated P_H and P_A strain-specific Th17 clones and show that P. acnes strains induce Th17 cells of varied phenotype and function that are stable in the presence of IL-2 and IL-23. Although P_H- and P_A-specific clones expressed similar levels of LL-37 and DEFB4, only P_H-specific clones secreted molecules sufficient to kill P. acnes. Furthermore, electron microscopic studies showed that supernatants derived from activated P_H and not P_A-specific clones exhibited robust bactericidal activity against P. acnes, and complete breaches in the bacterial cell envelope were observed. This antimicrobial activity was independent of IL-26, because both natural IL-26 released by Th17 clones and rhIL-26 lacked antimicrobial potency against P. acnes. Overall, our data suggest that P. acnes strains may differentially modulate the CD4⁺ T-cell responses, leading to the generation of Th17 cells that may contribute to either homeostasis or acne pathogenesis.

Different Propionibacterium acnes Phylotypes Induce Distinct Immune Responses and Express Unique Surface and Secreted Proteomes

Propionibacterium acnes is a skin commensal bacterium that contributes to the development of acne vulgaris and other infections. Recent work revealed that P. acnes clinical isolates can be classified into distinct phylotypes, several of which have associations with healthy skin or acne. We sought to determine if these phylotypes induce different immunological responses and express protein factors that may contribute to their disease associations. We found that acne-associated P. acnes phylotypes induced 2- to 3-fold higher levels of IFN-γ and IL-17 in peripheral blood mononuclear cells compared with healthy phylotypes. On the other hand, P. acnes phylotypes associated with healthy skin induced 2- to 4-fold higher levels of IL-10. Comparative proteomic analysis of P. acnes phylotypes revealed a differential expression of several proteins, including an adhesion protein that was expressed at least 10-fold higher in acne-associated phylotypes and a cell surface hydrolase expressed in all phylotypes except those associated with healthy skin. Taken together, our data provide insight into how specific P. acnes phylotypes influence immune responses and the pathogenesis of acne.

Nitric Oxide-Releasing Nanoparticles Prevent Propionibacterium acnes-Induced Inflammation by Both Clearing the Organism and Inhibiting Microbial Stimulation of the Innate Immune Response

Propionibacterium acnes induction of IL-1 cytokines through the NLRP3 (NLR, nucleotide oligomerization domain-like receptor) inflammasome was recently highlighted as a dominant etiological factor for acne vulgaris. Therefore, therapeutics targeting both the stimulus and the cascade would be ideal. Nitric oxide (NO), a potent biological messenger, has documented broad-spectrum antimicrobial and immunomodulatory properties. To harness these characteristics to target acne, we used an established nanotechnology capable of generating/releasing NO over time (NO-np). P. acnes was found to be highly sensitive to all concentrations of NO-np tested, although human keratinocyte, monocyte, and embryonic zebra fish assays revealed no cytotoxicity. NO-np significantly suppressed IL-1β, tumor necrosis factor-α (TNF-α), IL-8, and IL-6 from human monocytes, and IL-8 and IL-6 from human keratinocytes, respectively. Importantly, silencing of NLRP3 expression by small interfering RNA did not limit NO-np inhibition of IL-1 β secretion from monocytes, and neither TNF-α nor IL-6 secretion, nor inhibition by NO-np was found to be dependent on this pathway. The observed mechanism by which NO-np impacts IL-1β secretion was through inhibition of caspase-1 and IL-1β gene expression. Together, these data suggest that NO-np can effectively prevent P. acnes-induced inflammation by both clearing the organism and inhibiting microbial stimulation of the innate immune response.

Benign prostatic enlargement is not associated with diabetes: a population-based study

The association between diabetes and benign prostatic hyperplasia remains inconclusive. In this case-control study, we examined the association of diabetes with benign prostatic enlargement (BPE) using the Longitudinal Health Insurance Database 2000 in Taiwan. In total, 20 152 patients with BPE as cases and 20 152 age-matched patients without BPE were included as controls. Conditional logistic regression analyses were performed to calculate the odds ratio (OR) and corresponding 95% CI for having been previously diagnosed with diabetes between cases and controls. We found that of the 40 304 sampled patients, 9492 (23.6%) had a history of diabetes before the index date. This mean age for the sampled patients was 65.9 with a standard deviation of 12.0 years. A Chi-squared test revealed that there was a significant difference in the prevalence of prior diabetes between cases and controls (25.3% vs. 21.8%, p < 0.001). The conditional logistic regression found that the OR of prior diabetes for cases was 1.21 (95% CI = 1.15-1.27) compared with controls. However, after adjusting for geographic region, monthly income, urbanization level, hypertension, coronary heart disease (CHD), hyperlipidemia, tobacco use disorder, and obesity, the association between prior diabetes and BPE did not reach a statistically significant level (OR = 1.03, 95% CI = 0.98-1.08). In addition, it was noteworthy that hypertension (OR = 1.25, 95% CI = 1.20-1.31), CHD (OR = 1.40, 95% CI = 1.32-1.48), and hyperlipidemia (OR = 1.30, 95% CI = 1.24-1.36) were all significantly associated with BPE. We found that men with a diagnosis of diabetes were not significantly associated with BPE after adjusting for patient's sociodemographic characteristics and comorbidities.

Pentobra: A novel antibiotic with potent antimicrobial activity against Propionibacterium acnes (TECH2P.901)

Although antibiotics are a common form of treatment against acne, the difficulties inherent to effective antimicrobial penetration in sebum and selective antimicrobial action in skin are recently compounded by increasing resistance of Propionibacterium acnes clinical isolates. To address these problems, we engineered Pentobra, a peptide-aminoglycoside molecule which has multiple mechanisms of antibacterial action, and investigated whether it can be a potential candidate for the treatment of acne. Pentobra combines the potent ribosomal activity of aminoglycosides with the bacteria-selective membrane-permeabilizing abilities of antimicrobial peptides. Pentobra demonstrated potent and selective killing of P. acnes, but not against human skin cells. In direct comparison, Pentobra demonstrated bactericidal activity and drastically outperformed free tobramycin (by 5-7 logs) against multiple P. acnes strains. Moreover, EM studies showed that Pentobra also had robust membrane activity, as treatment with Pentobra killed P. acnes cells. Pentobra may also have potential anti-inflammatory effects. Importantly, the killing activity was maintained in sebaceous environments as Pentobra was bactericidal against clinical isolates in microcomedone extracts isolated from human donors. Our work demonstrates that equipping aminoglycosides with selective membrane activity is a viable approach for developing new antibiotics against P. acnes that are effective in cutaneous environments.

Fluorescence-based endoscopic imaging of Thomsen-Friedenreich antigen to improve early detection of colorectal cancer

Thomsen-Friedenreich (TF) antigen belongs to the mucin-type tumor-associated carbohydrate antigen. Notably, TF antigen is overexpressed in colorectal cancer (CRC) but is rarely expressed in normal colonic tissue. Increased TF antigen expression is associated with tumor invasion and metastasis. In this study, we sought to validate a novel nanobeacon for imaging TF-associated CRC in a preclinical animal model. We developed and characterized the nanobeacon for use with fluorescence colonoscopy. In vivo imaging was performed on an orthotopic rat model of CRC. Both white light and fluorescence colonoscopy methods were utilized to establish the ratio-imaging index for the probe. The nanobeacon exhibited specificity for TF-associated cancer. Fluorescence colonoscopy using the probe can detect lesions at the stage which is not readily confirmed by conventional visualization methods. Further, the probe can report the dynamic change of TF expression as tumor regresses during chemotherapy. Data from this study suggests that fluorescence colonoscopy can improve early CRC detection. Supplemented by the established ratio-imaging index, the probe can be used not only for early detection, but also for reporting tumor response during chemotherapy. Furthermore, since the data obtained through in vivo imaging confirmed that the probe was not absorbed by the colonic mucosa, no registered toxicity is associated with this nanobeacon. Taken together, these data demonstrate the potential of this novel probe for imaging TF antigen as a biomarker for the early detection and prediction of the progression of CRC at the molecular level.

Linking genes of unknown function with abiotic stress responses by high-throughput phenotype screening

Over 13% of all genes in the Arabidopsis thaliana genome encode for proteins classified as having a completely unknown function, with the function of >30% of the Arabidopsis proteome poorly characterized. Although empirical data in the form of mRNA and proteome profiling experiments suggest that many of these proteins play an important role in different biological processes, their functional characterization remains one of the major challenges in modern biology. To expand the annotation of genes with unknown function involved in the response of Arabidopsis to different environmental stress conditions, we selected 1007 such genes and tested the response of their corresponding homozygous T-DNA insertional mutants to salinity, oxidative, osmotic, heat, cold and hypoxia stresses. Depending on the specific abiotic stresses tested, 12-31% of mutants had an altered stress-response phenotype. Interestingly, 832 out of 1007 mutants showed tolerance or sensitivity to more than one abiotic stress treatment, suggesting that genes of unknown function could play an important role in abiotic stress-response signaling, or general acclimation mechanisms. Further analysis of multiple stress-response phenotypes within different populations of mutants revealed interesting links between acclimation to heat, cold and oxidative stresses, as well as between sensitivity to ABA, osmotic, salinity, oxidative and hypoxia stresses. Our findings provide a significant contribution to the biological characterization of genes with unknown function in Arabidopsis and demonstrate that many of these genes play a key role in the response of plants to abiotic stresses.

A novel flow cytometric analysis for platelet activation on immobilized von Willebrand factor or fibrillar collagen

Under flow conditions, platelets adhere singly or in small aggregates on von Willebrand factor (VWF)-coated surfaces, but form large aggregates on immobilized fibrillar collagen. We developed a novel flow cytometric analysis to study the mechanisms underlying these distinct platelet deposition patterns. Flow cytometry was used to measure platelet activation after platelet adherence onto microspheres coated with either VWF or collagen fibrils. Two representative indices were calculated to quantify activated GpIIb-IIIa and P-selectin expression on adherent platelets. The signaling pathways responsible for platelet activation after interacting with fibrillar collagen were elucidated using various inhibitors. An in vitro endothelial cell wound model was also used to study the roles of VWF and fibrillar collagen in platelet deposition onto subendothelial matrixes. The adherent platelets on fibrillar collagen express more activated GpIIb-IIIa and P-selectin than those on VWF. Activation of GpIIb-IIIa and expression of P-selectin after platelet interaction with collagen occur via different intracellular signaling pathways; however, Ca2+ released from intracellular pools is common to both phenomena. Platelets were deposited singly or formed small aggregates on the endothelial cell wounded area, and this deposition pattern was dependent on VWF molecules secreted by endothelial cells and the absence of subendothelial collagen fibrils. As less activated GpIIb-IIIa and P-selectin are expressed after platelets interact with immobilized VWF alone, subsequent flowing platelet recruitment is minimal. Collagen fibrils, however, can activate adherent platelets sufficiently to promote the formation of large platelet aggregates.

The human immunodeficiency virus type 1 accessory protein Vpu induces apoptosis by suppressing the nuclear factor kappaB-dependent expression of antiapoptotic factors

Human immunodeficiency virus (HIV) type 1 Vpu is an integral membrane protein with a unique affinity for betaTrCP (TrCP), a key member of the SkpI-Cullin-F-box E3 ubiquitin ligase complex that is involved in the regulated degradation of cellular proteins, including IkappaB. Remarkably, Vpu is resistant to TrCP-mediated degradation and competitively inhibits TrCP-dependent degradation of IkappaB, resulting in the suppression of nuclear factor (NF)-kappaB activity in Vpu-expressing cells. We now report that Vpu, through its interaction with TrCP, potently contributes to the induction of apoptosis in HIV-infected T cells. Vpu-induced apoptosis is specific and independent of other viral proteins. Mutation of a TrCP-binding motif in Vpu abolishes its apoptogenic property, demonstrating a close correlation between this property of Vpu and its ability to inhibit NF-kappaB activity. The involvement of NF-kappaB in Vpu-induced apoptosis is further supported by the finding that the levels of antiapoptotic factors Bcl-xL, A1/Bfl-1, and TNF receptor-associated factor (TRAF)1, all of which are expressed in an NF-kappaB-dependent manner, are reduced and, at the same time, levels of active caspase-3 are elevated. Thus, Vpu induces apoptosis through activation of the caspase pathway by way of inhibiting the NF-kappaB-dependent expression of antiapoptotic genes.

Human immunodeficiency virus type 1 Vif protein is packaged into the nucleoprotein complex through an interaction with viral genomic RNA

The human immunodeficiency virus type 1 (HIV-1) Vif protein plays a critical role in the production of infectious virions. Previous studies have demonstrated the presence of small amounts of Vif in virus particles. However, Vif packaging was assumed to be nonspecific, and its functional significance has been questioned. We now report that packaging of Vif is dependent on the packaging of viral genomic RNA in both permissive and restrictive HIV-1 target cells. Mutations in the nucleocapsid zinc finger domains that abrogate packaging of viral genomic RNA abolished packaging of Vif. Additionally, an RNA packaging-defective virus exhibited significantly reduced packaging of Vif. Finally, deletion of a putative RNA-interacting domain in Vif abolished packaging of Vif into virions. Virion-associated Vif was resistant to detergent extraction and copurified with components of the viral nucleoprotein complex and functional reverse transcription complexes. Thus, Vif is specifically packaged into virions as a component of the viral nucleoprotein complex. Our data suggest that the specific association of Vif with the viral nucleoprotein complex might be functionally significant and could be a critical requirement for infectivity of viruses produced from restrictive host cells.

Functional interaction between the cytoplasmic leucine-zipper domain of HIV-1 gp41 and p115-RhoGEF

The long cytoplasmic tail of the human immunodeficiency virus (HIV)-1 transmembrane protein gp41 (gp41C) is implicated in the replication and cytopathicity of HIV-1 [1]. Little is known about the specific functions of gp41C, however. HIV-1 or simian immunodeficiency virus (SIV) mutants with defective gp41C have cell-type- or species-dependent phenotypes [2] [3] [4] [5] [6]. Thus, host factors are implicated in mediating the functions of gp41C. We report here that gp41C interacted with the carboxy-terminal regulatory domain of p115-RhoGEF [7], a specific guanine nucleotide exchange factor (GEF) and activator of the RhoA GTPase, which regulates actin stress fiber formation, activation of serum response factor (SRF) and cell proliferation [8] [9]. We demonstrate that gp41C inhibited p115-mediated actin stress fiber formation and activation of SRF. An amphipathic helix region with a leucine-zipper motif in gp41C is involved in its interaction with p115. Mutations in gp41C leading to loss of interaction with p115 impaired HIV-1 replication in human T cells. These findings suggest that an important function of gp41C is to modulate the activity of p115-RhoGEF and they thus reveal a new potential anti-HIV-1 target.

A single dose of the ovotoxicant 4-vinylcyclohexene diepoxide is protective in rat primary ovarian follicles

Repeated dosing of rats with the ovotoxic chemical, 4-vinylcyclohexene diepoxide (VCD), destroys primordial and primary ovarian follicles via apoptosis (physiological cell death) by accelerating the normal rate of atresia. The present study investigated the effect of a single dose (1x) of VCD. Immature (d28) female Fischer 344 rats were dosed 1x or 15x with VCD (80 mg/kg ip). Ovaries were collected 24 h or 15 days following 1x VCD or after 15x for classification and evaluation. Following 1x VCD the number of healthy primary follicles was greater (p < 0.05) than control 24 h and 15 days later. This effect reflected a slowing of the normal rate of atresia seen in control ovaries. There was no effect of a single dose on primordial or growing follicles at any time. Expression of mRNA encoding the cell death gene bax was reduced (p < 0.05) on d1 after 1x VCD in isolated primordial and primary follicles. These observations were in contrast to a decreased (p < 0. 05) number of healthy primary and primordial follicles in ovaries and increased (p < 0.05) bax mRNA in isolated follicles from rats dosed 15x for 15 days. Immunofluorescence staining revealed that, the distribution of Bax protein was similar between ovaries from controls and 1x or 15x VCD-treated rats. These data provide evidence for a "protective" response against the normal rate of atresia in primary ovarian follicles following exposure to 1x VCD. Additionally, changes in expression of bax mRNA paralleled alterations in the rate of atresia.