Diabetes mellitus type 1 (T1D) is a complex disease resulting from the interplay of genetic, epigenetic, and environmental factors. Recent progress in understanding the genetic basis of T1D has resulted in an increased recognition of childhood diabetes heterogeneity. After the initial success of family-based linkage analyses, which uncovered the strong linkage and association between HLA gene variants and T1D, genome-wide association studies performed with high-density single-nucleotide polymorphism genotyping platforms provided evidence for a number of novel loci, although fine mapping and characterization of these new regions remains to be performed. T1D is one of the most heritable common diseases, and among autoimmune diseases it has the largest range of concordance rates in monozygotic twins. This fact, coupled with evidence of various epigenetic modifications of gene expression, provides convincing proof of the complex interplay between genetic and environmental factors. In T1D, epigenetic phenomena, such as DNA methylation, histone modifications, and microRNA dysregulation, have been associated with altered gene expression. Increasing epidemiologic and experimental evidence supports the role of genetic and epigenetic alterations in the etiopathology of diabetes. We discuss recent results related to the role of genetic and epigenetic factors involved in development of T1D.
Tumor progression is strongly associated with the activity of receptor tyrosine kinases (RTKs) and their intracellular signal transduction pathways, which regulate several cell functions including proliferation, apoptosis, motility, adhesion and angiogenesis. Detailed structural and functional studies of RTKs, including the stem cell factor receptor c-KIT, revealed the complexity of these receptor systems and contributed to development of targeted clinical approaches with relevance in both prognosis and therapy. C-KIT signaling network has been the subject of intense research and pharmaceutical strategies to identify novel target-based approaches for cancer treatment. Evidence that c-KIT signaling promotes cell proliferation and survival, along with the frequency in which this pathway is aberrantly activated in cancer, support the current efforts to identify approaches for its efficient inhibition. C-KIT mutations are associatied with several human malignancies, such as gastrointestinal stromal tumors, acute myeloid leukemia, mast cell leukemia, and melanoma. Novel therapies are developed that target some of the identified genetic defects. It is therefore anticipated that newly-identified genetic markers will acquire a predictive value, that is, the ability to predict differential efficacy of a therapy. This review describes the evolving understanding of c-KIT/SCF axis and their downstream signaling in cancer, and the strategies for c-KIT-directed targeted cancer therapy.
Most cases of juvenile-onset diabetes (JOD) are diagnosed as type 1 diabetes (T1D), for which genetic studies conducted in outbred Caucasian populations support the concept of multifactorial inheritance. However, this view may be partly challenged in particular population settings. In view of the suggestive evidence for a high prevalence of Wolfram syndrome (WFS) in Lebanon, the phenotypic variability associated with WFS1 mutations, and the high consanguinity rate in Lebanon, we aimed to evaluate the contribution of WFS1 mutations as monogenic determinants to JOD in Lebanon. We performed a family-based genetic study, with linkage analysis followed by systematic mutation screening of WFS1 exons in all JOD probands. The study population consisted of an unbiased recruitment of all juvenile-onset insulin-dependent diabetic patients from a specialized diabetes pediatric clinic in Beirut, Lebanon. Homozygous or compound heterozygous WFS1 mutations were found in 22 of the 399 JOD probands (5.5%), resulting in WFS (17 probands) or in non-syndromic non-autoimmune diabetes mellitus (DM, five probands). These accounted for 12.1% (21/174) of probands in consanguineous families, compared with 0.4% (1/225) in non-consanguineous families. Of the 38 patients identified with homozygous or compound heterozygous WFS1 mutations, 11 (29%) had non-syndromic DM, all of whom carried a particular WFS1 mutation, WFS1LIB, encoding a protein with an extended C-terminal domain. This mutation resulted in a delayed onset or absence of extrapancreatic features. These results underscore the major impact of population-specific factors, such as population-specific mutations and founder effects, and family structure in the genetic determinism of JOD.
The gut–brain axis is a bidirectional communication network in which gut microbiota and their metabolites influence central nervous system (CNS) function. Among these metabolites, bile acids have emerged as key signaling molecules that modulate metabolic and neuroendocrine pathways. Microbiota-mediated modifications of bile acid composition affect receptors such as farnesoid X receptor (FXR)and Takeda G protein-coupled receptor 5 (TGR5), thereby influencing neuronal activity, appetite control, glucose metabolism, and energy balance. Emerging evidence indicates that bile acids act both directly on the CNS and indirectly via endocrine and immune mediators, linking microbial metabolism to brain function. By integrating microbiological, metabolic, and neuroendocrine perspectives, bile acids can be viewed as critical messengers in the communication between the gut microbiota and the CNS. The purpose of this review is thus to synthesize current mechanisms underlying these interactions and highlight their therapeutic potential in metabolic and neurodegenerative disorders.
Nano-drug delivery systems provide targeted solutions for addressing various drug delivery challenges, leveraging nanotechnology to enhance drug solubility and permeability. Liposomes, explored for several decades, face hurdles, especially in oral delivery. Bile-acid stabilized vesicles (bilosomes) are flexible lipid vesicles, composed of phospholipids or other surfactants, along with amphiphilic bile salts, and they show superior stability and pharmacokinetic behavior in comparison to conventional vesicular systems (liposomes and niosomes). Bilosomes enhance skin penetration, fluidize the stratum corneum, and improve drug stability. In oral applications, bilosomes overcome drawbacks, offering improved bioavailability, controlled release, and reduced side effects. Vaccines using bilosomes demonstrate efficacy, and bilosomes for intranasal, inhalation, ocular, and buccal applications enhance drug delivery, offering targeted, efficient, and controlled activities. Formulations vary based on active substances and optimization techniques, showcasing the versatility and potential of bilosomes across diverse drug delivery routes. Therefore, the aim of this comprehensive review was to critically explore the state-of-the-art of bilosomes in drug delivery and potential therapeutic applications.
22 April 2021 in Pharmaceutical Development and Technology
Despite a relatively low prevalence of primary brain tumors, they continuously attract scientific interest because of the complexity of their treatment due to their location behind the blood–brain barrier. The main challenge in treatment of brain tumors is not the efficacy of the drugs, per se, but the low efficiency of drug delivery to malignant cells. At the core of the problem is the complex structure of the blood–brain barrier. Nowadays, there is evidence supporting the claim that bile acids have the ability to cross the blood–brain barrier. That ability can be exploited by taking a part in novel drug carrier designs. Bile acids represent a drug carrier system as a part of a mixed micelle composition, bilosomes and conjugates with various drugs. This review discusses the current knowledge related to bile acid molecules as drug penetration modifying agents, with the focus on central nervous system antitumor drug delivery. Graphical Abstract