Roles of Hydrogen Sulfide (H2S) as a Potential Therapeutic Agent in Cardiovascular Diseases: A Narrative Review.

Cardiovascular disease (CVD) stands as one of the leading causes of morbidity and mortality worldwide, and the continued search for novel therapeutics is vital for addressing this global health challenge. Over the past decade, hydrogen sulfide (H2S) has garnered significant attention in the field of medical research, as it has been proven to be a cardioprotective gaseous signaling molecule. It joins nitric oxide and carbon monoxide as endogenously produced gasotransmitters. As for its mechanism, H2S functions through the posttranslational addition of a sulfur group to cysteine residues on target proteins in a process called sulfhydration. As a result, the observed physiological effects of H2S can include vasodilation, anti-apoptosis, anti-inflammation, antioxidant effects, and regulation of ion channels. Various studies have observed the cardioprotective benefits of H2S in diseases such as myocardial infarction, ischemia-reperfusion injury, cardiac remodeling, heart failure, arrhythmia, and atherosclerosis. In this review, we discuss the mechanisms and therapeutic potential of H2S in various CVDs.

Diabetic Neuropathy: A Guide to Pain Management.

PURPOSE OF REVIEW: Diabetic neuropathy is a common complication of diabetes mellitus (DM) and can affect up to 50% of DM patients during their lifetime. Patients typically present with numbness, tingling, pain, and loss of sensation in the extremities. Since there is no treatment targeting the underlying mechanism of neuropathy, strategies focus on preventative care and pain management. RECENT FINDINGS: Up to 69% of patients with diabetic neuropathy receive pharmacological treatment for neuropathic pain. The United States Food and Drug Administration (FDA) confirmed four drugs for painful diabetic neuropathy (PDN): pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch. Nonpharmacological treatments such as spinal cord stimulation (SCS) and transcutaneous electrical nerve stimulation (TENS) both show promise in reducing pain in DM patients. Despite the high burden associated with PDN, effective management remains challenging. This update covers the background and management of diabetic neuropathy, including its epidemiology, pathogenesis, preventative care, and current therapeutic strategies.

Silmitasertib (CX-4945) Disrupts ERα/HSP90 Interaction and Drives Proteolysis through the Disruption of CK2ß Function in Breast Cancer Cells.

Aberrant estrogen receptor (ERα) signaling mediates detrimental effects of tamoxifen including drug resistance and endometrial hyperplasia. ERα36, an alternative isoform of ERα, contributes to these effects. We have demonstrated that CK2 modulates ERα expression and function in breast cancer (BCa). Here, we assess if CX-4945 (CX), a clinical stage CK2 inhibitor, can disrupt ERα66 and ERα36 signaling in BCa. Using live cell imaging, we assessed the antiproliferative effects of CX in tamoxifen-sensitive and tamoxifen-resistant BCa cells in monolayer and/or spheroid cultures. CX-induced alterations in ERα66 and ERα36 mRNA and protein expression were assessed by RT-PCR and immunoblot. Co-immunoprecipitation was performed to determine the differential interaction of ERα isoforms with HSP90 and CK2 upon CX exposure. CX caused concentration-dependent decreases in proliferation in tamoxifen-sensitive MCF-7 and tamoxifen-resistant MCF-7 Tam1 cells and significantly repressed spheroid growth in 3D models. Additionally, CX caused dramatic decreases in endogenous or exogenously expressed ERα66 and ERα36 protein. Silencing of CK2ß, the regulatory subunit of CK2, resulted in destabilization and decreased proliferation, similar to CX. Co-immunoprecipitation demonstrated that ERα66/36 show CK2 dependance for interaction with molecular chaperone HSP90. Our findings show that CK2 functions regulate the protein stability of ERα66 and ERα36 through a mechanism that is dependent on CK2ß subunit and HSP90 chaperone function. CX may be a component of a novel therapeutic strategy that targets both tamoxifen-sensitive and tamoxifen-resistant BCa, providing an additional tool to treat ERα-positive BCa.

Stevens-Johnson Syndrome From Combined Allopurinol and Angiotensin-Converting Enzyme Inhibitors: A Narrative Review.

Stevens-Johnson syndrome (SJS) is a severe and potentially debilitating skin reaction frequently related to medication use. Allopurinol and angiotensin-converting enzyme (ACE) inhibitors are commonly prescribed medications for prevalent health conditions worldwide, and their interaction associated with SJS warrants further investigation. A comprehensive literature search was performed to investigate cases as studies related to SJS occurring in patients with concomitant use of allopurinol and ACE inhibitors. We identified case reports and studies detailing hypersensitivity reactions, including SJS, attributed to a combination of allopurinol and ACE inhibitors. Despite the drug-drug interactions or lack thereof seen in patient populations, there is no definitive evidence of a pharmacokinetic interaction between allopurinol and ACE inhibitors. We were only able to find one case report specifically detailing SJS in a patient on combined ACE inhibitors and allopurinol. While the exact mechanism of the interaction is unclear, those reported cases of severe hypersensitivity reactions suggest a previous history of impaired renal function as a predisposing factor in the development of SJS. The potential risk of SJS with coadministration of ACE inhibitors and allopurinol is a drug-drug interaction that physicians should be aware of. This topic requires additional attention to determine if this drug combination should be avoided entirely in certain patients.

Mechanisms and Treatment Options for Hyperthyroid-Induced Osteoporosis: A Narrative Review.

Normal thyroid hormone levels are crucial for the homeostasis of many metabolic cycles and processes throughout the human body. Thyroid dysfunction, such as thyrotoxicosis, can result from many different etiologies, including Graves' disease (GD), toxic multinodular goiter (MNG), and toxic adenoma. These hyperthyroid disease states can cause devastating complications and disease, including the disruption of the bone remodeling cycle and skeletal development, which can result in osteoporosis. Osteoporosis is characterized by a decrease in bone mineral density and a propensity for fragility fractures. In addition to patients with overt hyperthyroidism, studies have provided evidence of other high-risk patient demographics, such as individuals with subclinical hyperthyroidism and postmenopausal women, who may be at an increased risk for the development of secondary osteoporosis. The treatment of patients with hyperthyroid-induced osteoporosis often requires a multifaceted management plan that may be unique to each patient's situation. Antithyroid therapy is often the first step in treating this disease and may include thioamide medications. Radioactive iodine-131 therapy (RAI) and the surgical removal of the thyroid gland may also be reasonable approaches for restoring normal thyroid function. Following thyrotoxicosis mitigation, antiresorptive drugs such as bisphosphonates, calcitonin, and selective estrogen receptor modulators (SERMs) may be used to counteract decreased bone mineral density (BMD). Additionally, the implementation of vitamin D, calcium supplements, and weight-bearing exercise may also reduce bone loss. While the effects of thyroid stimulating hormone (TSH) and triiodothyronine (T3) on bone remodeling have been studied in the past, more research is needed to identify unknown mechanisms and develop future improved treatments for this condition.

H2S Prodrug, SG-1002, Protects against Myocardial Oxidative Damage and Hypertrophy In Vitro via Induction of Cystathionine ß-Synthase and Antioxidant Proteins.

Endogenously produced hydrogen sulfide (H2S) is critical for cardiovascular homeostasis. Therapeutic strategies aimed at increasing H2S levels have proven cardioprotective in models of acute myocardial infarction (MI) and heart failure (HF). The present study was undertaken to investigate the effects of a novel H2S prodrug, SG-1002, on stress induced hypertrophic signaling in murine HL-1 cardiac muscle cells. Treatment of HL-1 cells with SG-1002 under serum starvation without or with H2O2 increased the levels of H2S, H2S producing enzyme, and cystathionine ß-synthase (CBS), as well as antioxidant protein levels, such as super oxide dismutase1 (SOD1) and catalase, and additionally decreased oxidative stress. SG-1002 also decreased the expression of hypertrophic/HF protein markers such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), galectin-3, TIMP1, collagen type III, and TGF-ß1 in stressed HL-1 cells. Treatment with SG-1002 caused a significant induction of cell viability and a marked reduction of cellular cytotoxicity in HL-1 cells under serum starvation incubated without or with H2O2. Experimental results of this study suggest that SG-1002 attenuates myocardial cellular oxidative damage and/or hypertrophic signaling via increasing H2S levels or H2S producing enzymes, CBS, and antioxidant proteins.

Multifunctional patch for use during laser procedures: Optimization and feasibility testing.

OBJECTIVE: The objective of this study was to develop a patch that can be placed on the skin during laser hair removal and similar procedures, that serves to reduce the laser-induced plume, provides a ready indicator to the laser surgeon of where pulses have been applied, and cools the skin. METHODS: A two-layer patch composed of a cooling hydrogel layer and an indicator layer was optimized and tested ex vivo. The hydrogel was composed of gelatin and glycerin. The concentration of each hydrogel component was optimized to determine the minimum gelatin concentration at which the gel can be handled without breakage and the minimum glycerin concentration that allows for storage at -20°C without crystallization. This is the temperature of a conventional freezer; application of the cooling layer to the skin would help prevent epidermal injury. The indicator layer was composed of a plastic transparency sheet with small dots of black ink particles printed onto its surface. Transparency sheets were printed from templates created in Adobe Photoshop in which dots are at a specified density; additionally, Photoshop's opacity function was used to vary the opacity of the dots themselves. Performance was tested using a 755 nm alexandrite laser used clinically for hair removal by measuring light transmission through the patch and observing the sheet's ability to indicate the location of laser exposures. The transmittance of patch components across a broad spectrum was also measured using a microplate reader. Several adhesives, including a two-part epoxy, silicone rubber, and cyanoacrylate, were tested for their ability to adhere to the hydrogel and indicator layers. Assembled patches composed of the hydrogel layer, indicator layer, and adhesive were tested ex vivo for their ability to mitigate the laser hair removal plume by measuring airborne particulate matter during simulated laser hair removal. RESULTS: A minimum gelatin concentration of 5% was found to enable easy handling of the hydrogel. A mixture composed of 60% water and 40% glycerin by volume consistently allowed storage at -20°C without crystallization. For the indicator layer, ink particle density of 50% and opacity of 5% provided a readily apparent indicator function following laser exposure. Transmission through the sheet measured during alexandrite laser exposures was 90% and was not different than transmission through the sheet alone without ink particles. A cyanoacrylate glue was found to adhere to the hydrogel and indicator layers, while the other adhesives proved inadequate. Measurements using a microplate reader confirmed that the reflection from the transparency sheet itself was the primary contributor to energy loss. In experiments exposing hair clippings to the laser with and without the patch, the patch allowed an increase of 5000 particles/cc relative to baseline particles in the environmental air, while the absence of the patch allowed an increase of 150,000 particles/cc relative to baseline, indicating that the patch decreased particle debris in the plume by 97%. CONCLUSIONS: A two-layer patch composed of hydrogel and plastic indicator layer with cyanoacrylate adhesive can be stored in a conventional freezer without crystallization, then placed over an area of skin to be treated for laser hair removal. The patch clearly indicates the pattern and sites of laser exposure, while blocking almost all (97%) of particles in the laser-induced plume. Future work will include safety validation and in vivo testing of efficacy, as these were not undertaken in this study.

HolistIC: leveraging Hi-C and whole genome shotgun sequencing for double minute chromosome discovery.

MOTIVATION: Double minute (DM) chromosomes are acentric extrachromosomal DNA artifacts that are frequently observed in the cells of numerous cancers. They are highly amplified and contain oncogenes and drug-resistance genes, making their presence a challenge for effective cancer treatment. Algorithmic discovery of DM can potentially improve bench-derived therapies for cancer treatment. A hindrance to this task is that DMs evolve, yielding circular chromatin that shares segments from progenitor DMs. This creates DMs with overlapping amplicon coordinates. Existing DM discovery algorithms use whole genome shotgun sequencing (WGS) in isolation, which can potentially incorrectly classify DMs that share overlapping coordinates. RESULTS: In this study, we describe an algorithm called 'HolistIC' that can predict DMs in tumor genomes by integrating WGS and Hi-C sequencing data. The consolidation of these sources of information resolves ambiguity in DM amplicon prediction that exists in DM prediction with WGS data used in isolation. We implemented and tested our algorithm on the tandem Hi-C and WGS datasets of three cancer datasets and a simulated dataset. Results on the cancer datasets demonstrated HolistIC's ability to predict DMs from Hi-C and WGS data in tandem. The results on the simulated data showed the HolistIC can accurately distinguish DMs that have overlapping amplicon coordinates, an advance over methods that predict extrachromosomal amplification using WGS data in isolation. AVAILABILITY AND IMPLEMENTATION: Our software, named 'HolistIC', is available at http://www.github.com/mhayes20/HolistIC. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Circulating Hydrogen Sulfide (H2S) and Nitric Oxide (NO) Levels Are Significantly Reduced in HIV Patients Concomitant with Increased Oxidative Stress Biomarkers.

Human immunodeficiency virus (HIV) attacks the immune system and weakens the ability to fight infections/disease. Furthermore, HIV infection confers approximately two-fold higher risk of cardiac events compared with the general population. The pathological mechanisms responsible for the increased incidence of cardiovascular disease in HIV patients are largely unknown. We hypothesized that increased oxidative stress and attenuated circulating levels of the cardioprotective gaseous signaling molecules, nitric oxide (NO), and hydrogen sulfide (H2S) were involved in the cardiovascular pathobiology observed in HIV patients. Plasma samples from both HIV patients and age-matched normal subjects were used for all assays. Oxidative stress was determined by analyzing the levels of advanced oxidation protein products (AOPP) and H2O2. Antioxidant levels were determined by measuring the levels of trolox equivalent capacity. ADMA, hs-CRP, and IL-6 were determined by using ELISA. The levels of H2S (free H2S and sulfane sulfur) and NO2 (nitrite) were determined in the plasma samples by using gas chromatography and HPLC, respectively. In the present study we observed a marked induction in the levels of oxidative stress and decreased antioxidant status in the plasma of HIV patients as compared with the controls. Circulating levels of the cardiovascular disease biomarkers: ADMA, hs-CRP (high-sensitivity C-reactive protein), and IL-6 were significantly increased in the circulatory system of HIV patients. The levels of both nitrite and H2S/sulfane sulfur were significantly reduced in the plasma of HIV patients as compared with normal subjects. Our data demonstrate significant increases in circulating biomarkers of oxidative stress and cardiovascular (CV) in conjunction with decreased bioavailability of H2S and NO in HIV patients. Diminished levels of these two cardioprotective gaseous signaling molecules may be involved in the pathogenesis of CV disease in the setting of HIV.