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Topic Review
Bell Peppers (Capsicum annum L.)
The bell pepper is highly consumed worldwide due to its exotic colors (green, red, yellow, orange, and purple), flavor, and nutritional value. However, after processing bell pepper products, waste remains (seeds, peel, stem, and leaves), representing desirable raw material to obtain phytochemical compounds. They contain diverse bioactive compounds with interesting biological activities (in vivo and in vitro) and applications.
  • 3.1K
  • 22 Oct 2021
Topic Review
Different Types of Adipocytes
Adipose tissue resides in specific depots scattered in peripheral or deeper locations all over the body and it enwraps most of the organs. This tissue is always in a dynamic evolution as it must adapt to the metabolic demand and constraints. It exhibits also endocrine functions important to regulate energy homeostasis. This complex organ is composed of depots able to produce opposite functions to monitor energy: the so called white adipose tissue acts to store energy as triglycerides preventing ectopic fat deposition while the brown adipose depots dissipate it. It is composed of many cell types. Different types of adipocytes constitute the mature cells specialized to store or burn energy. Immature adipose progenitors (AP) presenting stem cells properties contribute not only to the maintenance but also to the expansion of this tissue as observed in overweight or obese individuals.
  • 3.1K
  • 28 Apr 2021
Topic Review
Vascular Endothelial Growth Factors
Vascular endothelial growth factors (VEGFs) are primary regulators of blood and lymphatic vessels. Hemangiogenic VEGFs (VEGF-A, PlGF, and VEGF-B) target mostly blood vessels, while the lymphangiogenic VEGFs (VEGF-C and VEGF-D) target mostly lymphatic vessels. Blocking VEGF-A is used today to treat several types of cancer (“antiangiogenic therapy”). However, in other diseases, it would be beneficial to do the opposite, namely to increase the activity of VEGFs. For example, VEGF-A could generate new blood vessels to protect from heart disease, and VEGF-C could generate new lymphatics to counteract lymphedema. Clinical trials that tried to stimulate blood vessel growth in ischemic diseases have been disappointing so far, and the first clinical trials targeting the lymphatic vasculature have progressed to phase II. Antiangiogenic drugs targeting VEGF-A such as bevacizumab or aflibercept neutralize the growth factor directly. However, since VEGF-C and VEGF-D are produced as inactive precursors, novel drugs against the lymphangiogenic VEGFs could also target the enzymatic activation of VEGF-C and VEGF-D. Because of the delicate balance between too much and too little vascular growth, a detailed understanding of the activation of the VEGF-C and VEGF-D is needed before such concepts can be converted into safe and efficacious therapies.
  • 2.8K
  • 30 Mar 2021
Topic Review
β-Adrenergic Stimulation
β-adrenergic receptor stimulation (β-ARS) is a physiological mechanism that regulates cardiovascular function under stress conditions or physical exercise, producing a positive inotropic (enhanced contraction), lusitropic (faster relaxation), and chronotropic (increased heart rate) effect. 
  • 2.7K
  • 04 Aug 2021
Topic Review
Aging and Its Molecular Mechanism
Aging is a continuous process over time that is mainly related to natural alterations in mechanical–biological processes. This phenomenon is due to several factors, including the time and energy of biological processes. Aging can be attributed to biological factors such as oxidative stress, cell longevity, and stem cell senescence.
  • 2.7K
  • 22 Apr 2022
Topic Review
Acinar Cells for Pancreatic Cancer
The carcinogenesis of pancreatic ductal adenocarcinoma (PDA) progresses according to multi-step evolution, whereby the disease acquires increasingly aggressive pathological features. Lineage-tracing experiments demonstrated that pancreatic cancerous lesions originate from acinar cells, a highly specialized cell type in the pancreatic epithelium. Acinar cells are polarized, pyramidal-shaped cells containing numerous acidophilic granules near the apical side. Those granules contain inactive proteases, which are activated and released into the tubular network upon activation. Primary acinar cells can survive in vitro as organoid-like 3D spheroids, which can transdifferentiate into cells with a clear ductal morphology in response to different cell- and non-cell-autonomous stimuli.This event, termed acinar-to-ductal metaplasia, recapitulates the histological and molecular features of disease initiation.
  • 2.5K
  • 24 Sep 2020
Topic Review
Cell Cycle
The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase.
  • 2.5K
  • 03 Dec 2021
Topic Review
Transcription
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). Averaged over multiple cell types in a given tissue, the quantity of mRNA is more than 10 times the quantity of ncRNA (though in particular single cell types ncRNAs may exceed mRNAs). The general preponderance of mRNA in cells is valid even though less than 2% of the human genome can be transcribed into mRNA (Human genome), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: If the stretch of DNA is transcribed into an RNA molecule that encodes a protein, the RNA is termed messenger RNA (mRNA); the mRNA, in turn, serves as a template for the protein's synthesis through translation. Other stretches of DNA may be transcribed into small non-coding RNAs such as microRNA, transfer RNA (tRNA), small nucleolar RNA (snoRNA), small nuclear RNA (snRNA), or enzymatic RNA molecules called ribozymes as well as larger non-coding RNAs such as ribosomal RNA (rRNA), and long non-coding RNA (lncRNA). Overall, RNA helps synthesize, regulate, and process proteins; it therefore plays a fundamental role in performing functions within a cell. In virology, the term transcription may also be used when referring to mRNA synthesis from an RNA molecule (i.e., equivalent to RNA replication). For instance, the genome of a negative-sense single-stranded RNA (ssRNA -) virus may be a template for a positive-sense single-stranded RNA (ssRNA +)[clarification needed]. This is because the positive-sense strand contains the sequence information needed to translate the viral proteins needed for viral replication. This process is catalyzed by a viral RNA replicase.[clarification needed]
  • 2.3K
  • 14 Apr 2023
Topic Review
PIP2 Regulation in Cell
Phosphoinositides play a crucial role in regulating many cellular functions, such as actin dynamics, signaling, intracellular trafficking, membrane dynamics, and cell–matrix adhesion. Central to this process is phosphatidylinositol bisphosphate (PIP2). The levels of PIP2 in the membrane are rapidly altered by the activity of phosphoinositide-directed kinases and phosphatases, and it binds to dozens of different intracellular proteins. Despite the vast literature dedicated to understanding the regulation of PIP2 in cells over past 30 years, much remains to be learned about its cellular functions. Here, we focus on past and recent exciting results on different molecular mechanisms that regulate cellular functions by binding of specific proteins to PIP2 or by stabilizing phosphoinositide pools in different cellular compartments. Moreover, this review summarizes recent findings that implicate dysregulation of PIP2 in many diseases.
  • 2.2K
  • 19 Nov 2020
Topic Review
Plant Stinging Hairs
True stinging hairs are highly specialized plant structures that are able to inject a physiologically active liquid into the skin. They can be classified into two basic types: Urtica-type stinging hairs with the classical “hypodermic syringe” mechanism expelling only liquid, and Tragia-type stinging hairs expelling a liquid together with a sharp crystal. Since the middle of the 20th century, neurotransmitters(acetylcholine, histamine, serotonin) have been repeatedly detected in stinging hairs of Urticaceae; these substances can explain some of the physiological effects of stinging hairs, but fail to completely explain neuropathic effects, pointing to some yet unidentified neurotoxins. 
  • 2.1K
  • 22 Sep 2021
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