Ubiquitin-Proteasome System: Promising Therapeutic Targets in Autoimmune and Neurodegenerative Diseases

The multifaceted role of proteases and modern analytical methods for investigation of their catalytic activity

We discuss the diverse functions of proteases in the context of their biotechnological and medical significance, as well as analytical approaches used to determine the functional activity of these enzymes. An insight into modern approaches to studying the kinetics and specificity of proteases, based on spectral (absorption, fluorescence), mass spectrometric, immunological, calorimetric, and electrochemical methods of analysis is given. We also examine in detail electrochemical systems for determining the activity and specificity of proteases. Particular attention is given to exploring innovative electrochemical systems based on the detection of the electrochemical oxidation signal of amino acid residues, thereby eliminating the need for extra redox labels in the process of peptide synthesis. In the review, we highlight the main prospects for the further development of electrochemical systems for the study of biotechnologically and medically significant proteases, which will enable the miniaturization of the analytical process for determining the catalytic activity of these enzymes.

Different Trajectories for Diabetes Mellitus Onset and Recovery According to the Centralized Aerobic-Anaerobic Energy Balance Compensation Theory

We recently reported that the restoration of cervical vertebral arterial blood flow access (measured as systolic peak (PS)) to the rhomboid fossa leads to the recovery of the HbA1c level in the case of patients with a pre-Diabetes Mellitus (pre-DM) condition. The theory of centralized aerobic-anaerobic energy balance compensation (TCAAEBC) provides a successful theoretical explanation for this observation. It considers the human body as a dissipative structure. Reported connections between arterial hypertension (AHT) and the level of HbA1c are linked through OABFRH. According to the TCAAEBC, this delivers incorrect information about blood oxygen availability to the cerebellum. The restoration of PS normalizes AHT in 5-6 weeks and HbA1c in 12-13 weeks. In the current study, we demonstrate the model which fits the obtained experimental data. According to the model, pathways of onset and recovery from pre-DM are different. The consequence of these differences is discussed. The great significance of the TCAAEBC for medical practice forces the creation of an appropriate mathematical model, but the required adjustment of the model needs experimental data which can only be obtained from an animal model(s). The essential part of this study is devoted to the analysis of the advantages and disadvantages of widely available common mammalian models for TCAAEBC cases.

Immunological Pathways in Sarcoidosis and Autoimmune Rheumatic Disorders-Similarities and Differences in an Italian Prospective Real-Life Preliminary Study

BACKGROUND

The pathogenesis of sarcoidosis involves T cells and B lymphocytes that produce autoantibodies. We compared the expression of different T and B cell subsets in sarcoidosis and three B-mediated rheumatic diseases that can affect the lungs in an attempt to identify similarities and differences that distinguish these diseases.

METHODS

The study included patients referred to Siena University Hospital's respiratory disease and rheumatology units. Patients were enrolled prospectively and consecutively. Healthy volunteers were also included. Multicolor flow cytometry was performed on phenotype T and B cell subsets. Multivariate analysis was carried out to reduce the dimensionality of the data.

RESULTS

Fifteen patients had a diagnosis of sarcoidosis, fourteen idiopathic inflammatory myopathies (IIM), five granulomatosis with polyangiitis (GPA), ten microscopic polyangiitis (MPA), and seven were controls. Thirty-five T and B cell subsets were phenotyped, 15 of which were significantly different in sarcoidosis, B-mediated rheumatic disorders, and controls. Principal components analysis distinguished the four groups of patients with a total explained variance of 54.7%. A decision tree was constructed to determine which clustering variables would be most useful for distinguishing sarcoidosis, IIM, MPA, and GPA. The model showed regulatory T helper cells (Th-reg) > 5.70% in 91% of sarcoidosis patients as well as Th-reg ≤ 5.70 and Th17 > 43.27 in 100% of MPA. It also showed Th-reg ≤ 5.70, Th17 ≤ 43.27 and Tfh-reg ≥ 7.81 in 100% of GPA patients, and Th-reg ≤ 5.70, Th17 ≤ 43.27 and Tfh-reg ≤ 7.81 in 100% of IIM patients.

CONCLUSION

The immune cell profile sheds light on similarities and differences between sarcoidosis and B-mediated rheumatic diseases. Sarcoidosis and autoimmune diseases show similar patterns of cellular immune dysregulation, suggesting a common pathogenic pathway that may provide an opportunity for further understanding autoimmunity and exploring biological therapies to treat sarcoidosis.

The Impact of ACE Gene Variants on Acute-Phase Reactants in Children with Rheumatic Heart Disease

Rheumatic heart disease (RHD) is the most important sequela of upper respiratory group A Streptococcus (GAS) infection. The role of the common angiotensin-converting enzyme (ACE) insertion/deletion (I/D) variant in the disease and its subtypes remains uncertain. The acute-phase reactants (APRs) C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) form part of the Jones criteria for diagnosing RHD, and genetic factors are known to influence baseline CRP and ESR levels. Therefore, here, we investigated the relationship between the ACE I/D polymorphism and APR levels in RHD. A total of 268 individuals were recruited, including 123 RHD patients and 198 healthy controls. There was a trend toward a higher D allele frequency in RHD patients. The ACE I/D polymorphism genotype frequency and DD+ID allelic carriage were significantly associated with a high APR level (p = 0.04 and p = 0.02, respectively). These results highlight the importance of ACE I/D polymorphisms in RHD for disease stratification, but not for disease predisposition. Further studies in larger cohorts and different populations are now required to confirm this association and to explore the mechanism of this effect.

Valproic Acid Inhibits Progressive Hereditary Hearing Loss in a KCNQ4 Variant Model through HDAC1 Suppression

Genetic or congenital hearing loss still has no definitive cure. Among genes related to genetic hearing loss, the potassium voltage-gated channel subfamily Q member 4 (KCNQ4) is known to play an essential role in maintaining ion homeostasis and regulating hair cell membrane potential. Variants of the KCNQ4 show reductions in the potassium channel activity and were responsible for non-syndromic progressive hearing loss. KCNQ4 has been known to possess a diverse variant. Among those variants, the KCNQ4 p.W276S variant produced greater hair cell loss related to an absence of potassium recycling. Valproic acid (VPA) is an important and commonly used histone deacetylase (HDAC) inhibitor for class I (HDAC1, 2, 3, and 8) and class IIa (HDAC4, 5, 7, and 9). In the current study, systemic injections of VPA attenuated hearing loss and protected the cochlear hair cells from cell death in the KCNQ4 p.W276S mouse model. VPA activated its known downstream target, the survival motor neuron gene, and increased acetylation of histone H4 in the cochlea, demonstrating that VPA treatment directly affects the cochlea. In addition, treatment with VPA increased the KCNQ4 binding with HSP90β by inhibiting HDAC1 activation in HEI-OC1 in an in vitro study. VPA is a candidate drug for inhibiting late-onset progressive hereditary hearing loss from the KCNQ4 p.W276S variant.

The Association between Blood Lipids and Systemic Lupus Erythematosus: A Two-Sample Mendelian Randomization Research

We evaluated the causal effects of blood lipid levels on systemic lupus erythematosus with a two-sample Mendelian randomization analysis. Independent single-nucleotide polymorphisms related to blood lipids levels (p < 5 × 10−8) were selected as instrumental variables (IVs) from a published genome-wide association study (GWAS). SLE GWAS analysis that included 4036 cases and 6959 controls of European ancestry provided the related roles between instrumental variables and result (SLE). The causal effects were evaluated with two-sample Mendelian randomization (MR) analyses. According to the inverse-variance weighted approaches, genes predictive of increased LDL cholesterol (OR: 1.131; 95% CI: 0.838, 1.528; p = 0.420), HDL cholesterol (OR: 1.093; 95% CI: 0.884, 1.352; p = 0.412), triglycerides (OR: 0.903; 95% CI: 0.716, 1.137; p = 0.384), Apolipoprotein A-I (OR: 0.854; 95% CI: 0.680, 1.074; p = 0.177), and Apolipoprotein B (OR: 0.933; 95% CI: 0.719, 1.211; p = 0.605) were not causally related to the risk of SLE, consistent with multivariate Mendelian randomization analysis. The reverse-MR analyses showed no massive causal roles between SLE and LDL cholesterol (OR: 0.998; 95% CI: 0.994, 1.001; p = 0.166) as well as Apolipoprotein B (OR: 0.998; 95% CI: 0.994, 1.001; p = 0.229). Nevertheless, a causal role of SLE in decreasing HDL cholesterol (OR: 0.993; 95% CI: 0.988, 0.997; p = 0.002), triglycerides (OR: 0.996; 95% CI: 0.993, 0.999; p = 0.010), and Apolipoprotein A-I (OR: 0.995; 95% CI: 0.990, 0.999; p = 0.026) was validated to some extent. Our study found no causal association between abnormal blood lipids and SLE nor a causal effect between SLE and LDL cholesterol as well as Apolipoprotein B. Nevertheless, some evidence showed that SLE exerted a causal effect on lowering HDL cholesterol, Apolipoprotein A-I, and triglyceride levels.

Bacterial Compositional Shifts of Gut Microbiomes in Patients with Rheumatoid Arthritis in Association with Disease Activity

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disabling autoimmune disorder. Little is known regarding the association between the gut microbiome and etiopathogenesis of RA. We aimed to dissect the differences in gut microbiomes associated with RA in comparison to healthy individuals and, in addition, to identify the shifts in the bacterial community in association with disease activity; Methods: In order to identify compositional shifts in gut microbiomes of RA patients, V3-V4 hypervariable regions of 16S rRNA were sequenced using Illumina MiSeq. In total, sixty stool samples were collected from 45 patients with RA besides 15 matched healthy subjects; Results: Notably, RA microbiomes were significantly associated with diverse bacterial communities compared with healthy individuals. Likewise, a direct association between bacterial diversity and disease activity was detected in RA patients (Kruskal Wallis; p = 0.00047). In general, genus-level analysis revealed a positive coexistence between RA and Megasphaera, Adlercreutzia, Ruminococcus, Bacteroides, Collinsella, and Acidaminococcus. Furthermore, Spearman correlation analysis significantly stratified the most dominant genera into distinct clusters that were mainly based on disease activity (r ≥ 0.6; p ≤ 0.05). The predictive metabolic profile of bacterial communities associated with RA could support the potential impact of gut microbiomes in either the development or recovery of RA; Conclusions: The overall shifts in bacterial composition at different disease statuses could confirm the cross-linking of certain genera either to causation or progression of RA.

Interplay of Environmental, Individual and Genetic Factors in Rheumatoid Arthritis Provocation

In this review, we explore systemization of knowledge about the triggering effects of non-genetic factors in pathogenic mechanisms that contribute to the development of rheumatoid arthritis (RA). Possible mechanisms involving environmental and individual factors in RA pathogenesis were analyzed, namely, infections, mental stress, sleep deprivation ecology, age, perinatal and gender factors, eating habits, obesity and smoking. The non-genetic factors modulate basic processes in the body with the impact of these factors being non-specific, but these common challenges may be decisive for advancement of the disease in the predisposed body at risk for RA. The provocation of this particular disease is associated with the presence of congenital loci minoris resistentia. The more frequent non-genetic factors form tangles of interdependent relationships and, thereby, several interdependent external factors hit one vulnerable basic process at once, either provoking or reinforcing each other. Understanding the specific mechanisms by which environmental and individual factors impact an individual under RA risk in the preclinical stages can contribute to early disease diagnosis and, if the factor is modifiable, might be useful for the prevention or delay of its development.

Modulating the Ubiquitin–Proteasome System: A Therapeutic Strategy for Autoimmune Diseases

Multiple sclerosis (MS) is an autoimmune, neurodegenerative disease associated with the central nervous system (CNS). Autoimmunity is caused by an abnormal immune response to self-antigens, which results in chronic inflammation and tissue death. Ubiquitination is a post-translational modification in which ubiquitin molecules are attached to proteins by ubiquitinating enzymes, and then the modified proteins are degraded by the proteasome system. In addition to regulating proteasomal degradation of proteins, ubiquitination also regulates other cellular functions that are independent of proteasomal degradation. It plays a vital role in intracellular protein turnover and immune signaling and responses. The ubiquitin–proteasome system (UPS) is primarily responsible for the nonlysosomal proteolysis of intracellular proteins. The 26S proteasome is a multicatalytic adenosine-triphosphate-dependent protease that recognizes ubiquitin covalently attached to particular proteins and targets them for degradation. Damaged, oxidized, or misfolded proteins, as well as regulatory proteins that govern many essential cellular functions, are removed by this degradation pathway. When this system is affected, cellular homeostasis is altered, resulting in the induction of a range of diseases. This review discusses the biochemistry and molecular biology of the UPS, including its role in the development of MS and proteinopathies. Potential therapies and targets involving the UPS are also addressed.

Genome Editing Using CRISPR-Cas9 and Autoimmune Diseases: A Comprehensive Review

Autoimmune diseases are disorders that destruct or disrupt the body's own tissues by its own immune system. Several studies have revealed that polymorphisms of multiple genes are involved in autoimmune diseases. Meanwhile, gene therapy has become a promising approach in autoimmune diseases, and clustered regularly interspaced palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) has become one of the most prominent methods. It has been shown that CRISPR-Cas9 can be applied to knock out proprotein convertase subtilisin/kexin type 9 (PCSK9) or block PCSK9, resulting in lowering low-density lipoprotein cholesterol. In other studies, it can be used to treat rare diseases such as ornithine transcarbamylase (OTC) deficiency and hereditary tyrosinemia. However, few studies on the treatment of autoimmune disease using CRISPR-Cas9 have been reported so far. In this review, we highlight the current and potential use of CRISPR-Cas9 in the management of autoimmune diseases. We summarize the potential target genes for immunomodulation using CRISPR-Cas9 in autoimmune diseases including rheumatoid arthritis (RA), inflammatory bowel diseases (IBD), systemic lupus erythematosus (SLE), multiple sclerosis (MS), type 1 diabetes mellitus (DM), psoriasis, and type 1 coeliac disease. This article will give a new perspective on understanding the use of CRISPR-Cas9 in autoimmune diseases not only through animal models but also in human models. Emerging approaches to investigate the potential target genes for CRISPR-Cas9 treatment may be promising for the tailored immunomodulation of some autoimmune diseases in the near future.

Nano/Microrobots Line Up for Gastrointestinal Tract Diseases: Targeted Delivery, Therapy, and Prevention

Nano/microrobots (NMRs) are tiny devices that can convert energy into motion and operate at nano/microscales.54 Especially in biomedical research, NMRs have received much attention over the past twenty years because of their excellent capabilities and great potential in various applications, including on-demand drug delivery, gene and cell transport, and precise microsurgery. Reports published in recent years show that synthetic nano/microrobots have promising potential to function in the gastrointestinal (GI) region, particularly in terms of drug delivery. These tiny robots were able to be designed in such a way that they propel in their surroundings (biological media) with high speed, load cargo (drug) efficiently, transport it safely, and release upon request successfully. Their propulsion, retention, distribution, and toxicity in the GI tract of mice has been evaluated. The results envisage that such nano/microrobots can be further modified and developed as a new-generation treatment of GI tract diseases. In this minireview, we focus on the functionality of micro/nanorobots as a biomedical treatment system for stomach/intestinal diseases. We review the research progress from the first in vivo report in December 2014 to the latest in August 2021. Then, we discuss the treatment difficulties and challenges in vivo application (in general) and possible future development routes.

An Unusual Presentation of Crohn's Disease Diagnosed Following Accidental Ingestion of Fruit Pits: Report of Two Cases and Review of the Literature

The clinical course of Crohn's disease (CD) is often complicated by intestinal strictures, which can be fibrotic, inflammatory, or mixed, therefore leading to stenosis and eventually symptomatic obstruction. We report two cases of subclinical CD diagnosed after fruit pit ingestion, causing bowel obstruction; additionally, we conducted a narrative review of the scientific literature on cases of intestinal obstruction secondary to impacted bezoars due to fruit pits. Symptoms of gastrointestinal bezoars in CD patients are not diagnostic; and the diagnosis should be based on a combined assessment of history, clinical presentation, imaging examination and endoscopy findings. This report corroborates the concept that CD patients are at a greater risk of bowel obstruction with bezoars generally and shows that accidental ingestion of fruit pits may lead to an unusual presentation of the disease. Therapeutic options in this group of patients differ from the usual approaches implemented in other patients with strictures secondary to CD.

Key Players in the Mutant p53 Team: Small Molecules, Gene Editing, Immunotherapy

The transcription factor p53 is a key tumor suppressor that is inactivated in almost all cancers due to either point mutations in the TP53 gene or overexpression of its negative regulators. The p53 protein is known as the “cellular gatekeeper” for its roles in facilitating DNA repair, cell cycle arrest or apoptosis upon DNA damage. Most p53 mutations are missense and result in either structural destabilization of the protein, causing its partial unfolding and deactivation under physiological conditions, or impairment of its DNA-binding properties. Tumor cells with p53 mutations are generally more immunogenic due to “hot spot” neoantigens that instigate the immune system response. In this review, we discuss the key therapeutic strategies targeting mutant p53 tumors, including classical approaches based on small molecule intervention and emerging technologies such as gene editing and T cell immunotherapy.

Stabilization of ADAM9 by N-α-acetyltransferase 10 protein contributes to promoting progression of androgen-independent prostate cancer

N-α-Acetyltransferase 10 protein (Naa10p) was reported to be an oncoprotein in androgen-dependent prostate cancer (PCa; ADPC) through binding and increasing transcriptional activity of the androgen receptor (AR). PCa usually progresses from an androgen-dependent to an androgen-independent stage, leading to an increase in the metastatic potential and an incurable malignancy. At present, the role of Naa10p in androgen-independent prostate cancer (AIPC) remains unclear. In this study, in silico and immunohistochemistry analyses showed that Naa10 transcripts or the Naa10p protein were more highly expressed in primary and metastatic PCa cancer tissues compared to adjacent normal tissues and non-metastatic cancer tissues, respectively. Knockdown and overexpression of Naa10p in AIPC cells (DU145 and PC-3M), respectively, led to decreased and increased cell clonogenic and invasive abilities in vitro as well as tumor growth and metastasis in AIPC xenografts. From the protease array screening, we identified a disintegrin and metalloprotease 9 (ADAM9) as a potential target of Naa10p, which was responsible for the Naa10p-induced invasion of AIPC cells. Naa10p can form a complex with ADAM9 to maintain ADAM9 protein stability and promote AIPC's invasive ability which were independent of its acetyltransferase activity. In contrast to the Naa10p-ADAM9 axis, ADAM9 exerted positive feedback regulation on Naa10p to modulate progression of AIPC in vitro and in vivo. Taken together, for the first time, our results reveal a novel cross-talk between Naa10p and ADAM9 in regulating the progression of AIPC. Disruption of Naa10p-ADAM9 interactions may be a potential intervention for AIPC therapy.

Alzheimer's Disease: A Contextual Link with Nitric Oxide Synthase

Nitric oxide (NO) is a gasotransmitter with pleiotropic effects which has made a great impact on biology and medicine. A multidimensional neuromodulatory role of NO has been shown in the brain with specific reference to neurodegenerative disorders like Alzheimer's disease (AD) and cognitive dysfunction. It has been found that NO/cGMP signalling pathway has an important role in learning and memory. Initially, it was considered that indirectly NO exerted neurotoxicity in AD via glutamatergic excitotoxicity. However, considering the early development of cognitive functions involved in the learning memory process including long term potentiation and synaptic plasticity, NO has a crucial role. Increasing evidence uncovered the above facts that isoforms of NOS viz endothelial NO synthase (eNOS), neuronal NO synthase (nNOS) and inducible NO synthase (iNOS) having a variable expression in AD are mainly responsible for learning and memory activities. In this review, we focus on the role of NOS isoforms in AD parallel to NO. Further, this review provides convergent evidence that NO could provide a therapeutic avenue in AD via modulation of the relevant NOS expression.

Therapeutic Editing of the TP53 Gene: Is CRISPR/Cas9 an Option?

The TP53 gene encodes the transcription factor and oncosuppressor p53 protein that regulates a multitude of intracellular metabolic pathways involved in DNA damage repair, cell cycle arrest, apoptosis, and senescence. In many cases, alterations (e.g., mutations of the TP53 gene) negatively affect these pathways resulting in tumor development. Recent advances in genome manipulation technologies, CRISPR/Cas9, in particular, brought us closer to therapeutic gene editing for the treatment of cancer and hereditary diseases. Genome-editing therapies for blood disorders, blindness, and cancer are currently being evaluated in clinical trials. Eventually CRISPR/Cas9 technology is expected to target TP53 as the most mutated gene in all types of cancers. A majority of TP53 mutations are missense which brings immense opportunities for the CRISPR/Cas9 system that has been successfully used for correcting single nucleotides in various models, both in vitro and in vivo. In this review, we highlight the recent clinical applications of CRISPR/Cas9 technology for therapeutic genome editing and discuss its perspectives for editing TP53 and regulating transcription of p53 pathway genes.

Targeting Dendritic Cells with Antigen-Delivering Antibodies for Amelioration of Autoimmunity in Animal Models of Multiple Sclerosis and Other Autoimmune Diseases

The specific targeting of dendritic cells (DCs) using antigen-delivering antibodies has been established to be a highly efficient protocol for the induction of tolerance and protection from autoimmune processes in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS), as well as in some other animal disease models. As the specific mechanisms of such induced tolerance are being investigated, the newly gained insights may also possibly help to design effective treatments for patients. Here we review approaches applied for the amelioration of autoimmunity in animal models based on antibody-mediated targeting of self-antigens to DCs. Further, we discuss relevant mechanisms of immunological tolerance that underlie such approaches, and we also offer some future perspectives for the application of similar methods in certain related disease settings such as transplantation.

Serological Testing for Mycobacterial Heat Shock Protein Hsp65 Antibody in Health and Diseases

Mycobacterial heat shock protein 65 gene (Hsp65) has been widely used for classification of Mycobacterial species, and detection of Mycobacterial genes by molecular methods and has proven useful in identification of Mycobacterial infection in various clinical conditions. Circulating antibody against Mycobacterial hsp65 has been found in many clinical diseases including autoimmune diseases (Crohn's disease, lupus erythematosus, multiple sclerosis, diabetes, etc.), atherosclerosis and cancers. The prevalence of anti-Hsp65 antibody in the normal healthy population is unknown. We determined the blood levels of antibody against Mycobacterial hsp65 in the normal population represented by 288 blood donors of the American Red Cross and tested the blood of 109 patients with Crohn's disease and 28 patients with Sjogren's syndrome for comparison. The seroprevalence of anti-Hsp65 IgG in the normal population of Red Cross donors was 2.8% (8 of 288 positive). The Hsp65 antibody levels were significantly elevated in patients with Crohn's disease and Sjogren's syndrome. The prevalence of Hsp65 antibody in Crohn's disease patients was 67.9% (74 of 109 patients), and 85.7% for Sjogren's patients (24 of 28 patients). Our data indicate that anti-Hsp65 antibody is rare in the normal population, but frequent in chronic diseases. The presence of circulating Hsp65 antibody reflects an abnormal immune (adaptive) response to Mycobacterial exposure in patients with chronic diseases, thus differentiating the patients with chronic diseases from those clinical mimics.

Association between Lipoprotein Levels and Humoral Reactivity to Mycobacterium avium subsp. paratuberculosis in Multiple Sclerosis, Type 1 Diabetes Mellitus and Rheumatoid Arthritis

Environmental factors such as bacterial infections may play an important role in the development of autoimmune diseases. Mycobacterium avium subsp. paratuberculosis (MAP) is an obligate pathogen of ruminants able to use the host's cholesterol for survival into macrophages and has been associated with multiple sclerosis (MS), type 1 diabetes (T1DM) and rheumatoid arthritis (RA) through a molecular mimicry mechanism. Here, we aimed at investigating the correlation between humoral reactivity against MAP and serum lipoprotein levels in subjects at T1DM risk (rT1DM) grouped by geographical background and in patients affected by MS or RA. Our results showed significant differences in HDL, LDL/VLDL and Total Cholesterol (TC) levels between patients and healthy controls (p < 0.0001). Patients positive to anti-MAP Abs (MAP+) had lower HDL levels in comparison with Abs negative (MAP-) subjects, while opposite trends were found for LDL/VLDL concentrations (p < 0.05). TC levels varied between MAP+ and MAP- patients in all three assessed diseases. These findings suggest the implication of anti-MAP Abs in fluctuations of lipoprotein levels highlighting a possible link with cardiovascular disease. Further studies will be needed to confirm these results in larger groups.

Isatin-Schiff base-copper (II) complex induces cell death in p53-positive tumors

Medicinal bioinorganic chemistry is a thriving field of drug research for cancer treatment. Transition metal complexes coordinated to essential biological scaffolds represent a highly promising class of compounds for design of novel target-specific therapeutics. We report here the biological evaluation of a novel Isatin-Schiff base derivative and its Cu(II) complex in several tumor cell lines by assessing their effects on cellular metabolism, real-time cell proliferation and induction of apoptosis. Further, the impact of compounds on the p53 protein and expression of its target genes, including MDM2, p21/CDKN1A, and PUMA was evaluated. Results obtained in this study provide further evidence in support of our prior data suggesting the p53-mediated mechanism of action for Isatin-Schiff base derivatives and their complexes and also shed light on potential use of these compounds for stimulation of apoptosis in breast cancer cells via activation of the pro-apoptotic PUMA gene.

Promising new therapeutic targets for regulation of inflammation and immunity: RING-type E3 ubiquitin ligases

Ubiquitin-proteasome system (UPS) is a primary signaling pathway for regulation of protein turnover and removal of misfolded proteins in eukaryotic cells. Enzymes of the UPS pathway - E1 activating, E2 conjugating, E3 ligating - act together to covalently tag substrate proteins with a chain of ubiquitins, small regulatory proteins. The poly-ubiquitin chain then serves as a recognition motif for 26S proteasome to recognize and degrade the substrate. In recent years UPS has emerged as attractive enzymatic cascade for development of novel therapeutics against various human diseases. Building on the previous success of targeting this pathway in cancer - the broader scientific community is currently looking for ways to elucidate functions of E3 ligases, substrate-specific members of the UPS. RING-type E3 ubiquitin ligases, the largest class of E3s, represent prospective targets for small molecule modulation and their importance is reinforced by ever growing evidence of playing role in non-cancer diseases, primarily associated with inflammatory and immune disorders. In this review, we aim to briefly cover the current knowledge of biological functions of RING-type E3 ligases in inflammation and immunity.

Efficacy of Synthetic Peptide Corresponding to the ACTH-Like Sequence of Human Immunoglobulin G1 in Experimental Autoimmune Encephalomyelitis

Peptide immunocortin sequence corresponds to the amino acid residues 11-20 of the variable part of human immunoglobulin G1 (IgG1) heavy chain. Since immunocortin was shown previously to inhibit phagocytosis in peritoneal macrophages and ConA-induced T-lymphocytes proliferation in culture, we suggested that immunocortin administering may be of use for patients with self-immune syndrome. Immunocortin in concentration 10 μM inhibited proliferation of both antigen (myelin)-induced and ConA-induced LN lymphocytes isolated from the lymph nodes of Dark Agouti (DA) rats immunized with chorda shear. The biological trials of the synthetic immunocortin were carried out on the DA rats with induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. These in vivo experiments have shown that intraperitoneal injections of immunocortin in a daily dosage 100 μg per animal reduced symptoms of EAE in DA rats.