Leonardo Vinícius Monteiro De Assis

Leonardo Vinícius Monteiro De Assis
Universität zu Lübeck · Institut für Neurobiologie

BPharm, PhD.

About

51
Publications
6,142
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531
Citations
Introduction
Leonardo de Assis holds a PhD in Physiology by the University of São Paulo (USP, Brazil) and has postdoctoral experience at the same University from April of 2019 until October of 2020. In his PhD, he explored the functionality of the photosensitive system (opsins) and its relationship with the molecular clock of the skin and in cutaneous melanoma. He currently holds a position of research associate at the University of Lübeck in Dr. Henrik Oster’s group.
Additional affiliations
October 2020 - present
Universität zu Lübeck
Position
  • Research Associate
February 2019 - October 2020
University of São Paulo
Position
  • PostDoc Position
February 2017 - June 2017
University of São Paulo
Position
  • Teacher Assistant
Description
  • Teacher assistant of the course: Fundamentals of molecular biology
Education
March 2014 - February 2019
University of São Paulo
Field of study
  • Physiology
January 2012 - April 2013
University of Montana
Field of study
  • Pharmacy
March 2009 - February 2014
Federal University of Ouro Preto
Field of study
  • Pharmacy

Publications

Publications (51)
Article
The mammalian skin has a photosensitive system comprised by several opsins, including rhodopsin (OPN2) and melanopsin (OPN4). Recently, our group showed that UVA (4.4 kJ/m²) leads to immediate pigment darkening (IPD) in murine normal and malignant melanocytes. We show the role of OPN2 and OPN4 as UVA sensors: UVA-induced IPD was fully abolished whe...
Article
Full-text available
IntroductionMelanoma is the most lethal type of skin cancer, with increasing incidence and mortality rates worldwide. Multiple studies have demonstrated a link between cancer development/progression and circadian disruption; however, the complex role of tumor-autonomous molecular clocks remains poorly understood. With that in mind, we investigated...
Article
Full-text available
The skin is the interface between the organism and the external environment, acting as its first barrier. Thus, this organ is constantly challenged by physical stimuli such as UV and infrared radiation, visible light, and temperature as well as chemicals and pathogens. To counteract the deleterious effects of the above-mentioned stimuli, the skin h...
Article
Full-text available
The circadian clock exerts an important role in systemic homeostasis as it acts a keeper of time for the organism. The syn-chrony between the daily challenges imposed by the environment needs to be aligned with biological processes and with the internal circadian clock. In this review, it is provided an in-depth view of the molecular functioning of...
Article
Cutaneous melanocytes and melanoma cells express several opsins, of which melanopsin (OPN4) detects temperature and UVA radiation. To evaluate the interaction between OPN4 and UVA radiation, normal and malignant Opn4WT and Opn4KO melanocytes were exposed to three daily low doses (total 13.2 kJ/m²) of UVA radiation. UVA radiation led to a reduction...
Article
Full-text available
Diurnal (i.e., 24-hour) physiological rhythms depend on transcriptional programs controlled by a set of circadian clock genes/proteins. Systemic factors like humoral and neuronal signals, oscillations in body temperature, and food intake align physiological circadian rhythms with external time. Thyroid hormones (THs) are major regulators of circadi...
Preprint
Full-text available
Metabolic syndrome (MS) and its related diseases, including obesity and non-alcoholic fatty liver disease (NAFLD), have become a public health issue due to their increasing prevalence. Polyphenols, such as grape seed proanthocyanidin extract (GSPE), are bioactive compounds present in fruits and vegetables that show promise for MS treatment. We have...
Article
Full-text available
To investigate the role of the transient receptor potential channel vanilloid type 1 (TRPV1) in hepatic glucose metabolism, we analyzed genes related to the clock system and glucose/lipid metabolism and performed glycogen measurements at ZT8 and ZT20 in the liver of C57Bl/6J (WT) and Trpv1 KO mice. To identify molecular clues associated with metabo...
Article
Full-text available
Environmental cues synchronize endogenous rhythms of many physiological processes such as hormone synthesis and secretion. Little is known about the diurnal pattern of hormones and gene expression of the Callinectes sapidus molt cycle. We aimed to investigate in the eyestalk and hepatopancreas of premolt and intermolt C. sapidus the following param...
Article
Full-text available
Consumption of grape seed proanthocyanidin extract (GSPE) has beneficial effects on the functionality of white adipose tissue (WAT). However, although WAT metabolism shows a clear diurnal rhythm, whether GSPE consumption could affect WAT rhythmicity in a time-dependent manner has not been studied. Ninety-six male Fischer rats were fed standard (STD...
Article
Full-text available
The search for new therapeutical targets for cutaneous melanoma and other cancers is an ongoing task. We expanded this knowledge by evaluating whether opsins, light-and thermo-sensing proteins, could display tumor-modulatory effects on melanoma cancer. Using different experimental approaches, we show that melanoma cell proliferation is slower in th...
Preprint
Diurnal (i.e., 24-hour) physiological rhythms depend on transcriptional programs controlled by a set of circadian clock genes/proteins. Systemic factors like humoral and neuronal signals, oscillations in body temperature, and food intake align physiological circadian rhythms with external time. Thyroid hormones (THs) are major regulators of circadi...
Article
Full-text available
Intratumoral heterogeneity (ITH) is an intrinsic feature of malignant tumors that eventually allows a subfraction of resistant cancer cells to clonally evolve and cause therapy failure or relapse. ITH, cellular plasticity and tumor progression are driven by epithelial–mesenchymal transition (EMT) and the reverse process, MET. During these developme...
Article
Introduction: Mineralocorticoid receptor antagonists (MRAs) are effective in reducing left ventricle remodeling and sudden death after acute myocardial infarction (AMI). Objectives: MRAs in vitro display cardioprotective effects, independent of MR; however, it is unknown whether the rapid effects of MRAs are cardioprotective in vivo. This study eva...
Article
Full-text available
The control of the biological rhythms begins with the activation of photo-and thermosensitive cells located in various organs of the fish such as brain, eye, and skin, but a central clock is still to be identified in teleosts. Thermal changes are stressors which increase cortisol and affect the rhythm of other hormones such as melatonin and growth...
Article
Full-text available
Skin melanocytes harbor a complex photosensitive system comprised of opsins, which were shown, in recent years, to display light- and thermo-independent functions. Based on this premise, we investigated whether melanopsin, OPN4, displays such a role in normal melanocytes. In this study, we found that murine Opn4KO melanocytes displayed a faster pro...
Article
Full-text available
Since the discovery of melanopsin as a retinal non-visual photopigment, opsins have been described in several organs and cells. This distribution is strikingly different from the classical localization of photopigments in light-exposed tissues such as the eyes and the skin. More than 10 years ago, a new paradigm in the field was created as opsins w...
Article
In mammals, 24-h rhythms of physiology and behavior are organized by a body-wide network of clock genes and proteins. Despite the well-known function of the adult circadian system, the roles of maternal, fetal and placental clocks during pregnancy are poorly defined. In the mature mouse placenta, the labyrinth zone (LZ) is of fetal origin and key f...
Article
Full-text available
Melanoma skin cancer is extremely aggressive with increasing incidence and mortality. Among the emerging therapeutic targets in the treatment of cancer, the family of transient receptor potential channels (TRPs) has been reported as a possible pharmacological target. Specifically, the ankyrin subfamily, representing TRPA1 channels, can act as a pro...
Article
Linked Article: Lan et al. Br J Dermatol 2021; https://doi.org/ 10.1111/bjd.19797 The opsins are light-detecting molecules that classically participate in image-and non-image-forming processes in the eyes. However, they are also expressed in the skin. 1-3 More than 20 years ago, the pioneering study by Miyashita et al. 4 opened a new and exciting r...
Article
The consensus on the negative effects of excessive sun exposure on human health has long emphasized the negative effects of solar UV radiation. Nevertheless, although UV radiation has been demonized, less is known about the consequences of sun exposure while using sunscreen, which can lead to high visible light exposure. UV and visible light play a...
Article
Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and ph...
Article
Activation of mineralocorticoid receptor antagonists (MRAs) is cardioprotective; however, this property is lost upon blockade or inactivation of adenosine (ADO) receptor A 2b. In this study, we investigated whether the effects of MRAs are mediated by an interaction between cardioprotective ADO receptors A 1 and A 3. Spironolactone (SPI) or eplereno...
Article
Full-text available
The biological clock has received increasing interest due to its key role in regulating body homeostasis in a time-dependent manner. Cancer development and progression has been linked to a disrupted molecular clock; however, in melanoma, the role of the biological clock is largely unknown. We investigated the effects of the tumor on its micro- (TME...
Article
Full-text available
Melanopsin (OPN4) is a photo-pigment found in a small subset of intrinsically photosensitive ganglion cells (ipRGCs) of the mammalian retina. These cells play a role in synchronizing the central circadian pacemaker to the astronomical day by conveying information about ambient light to the hypothalamic suprachiasmatic nucleus, the site of the maste...
Article
Transient receptor potential (TRP) channels are known to regulate energy metabolism, and TRPM8 has become an interesting player in this context. Here we demonstrate the role of the cold sensor TRPM8 in the regulation of clock gene and clock controlled genes in brown adipose tissue (BAT). We investigated TrpM8 temporal profile in the eyes, suprachia...
Article
Background: The accumulation of soluble factors in the tumor microenvironment and their release into the bloodstream lead to systemic effects, resulting in cancer-associated syndromes such as cachexia. Another association observed in the latter scenario is chrono-disruption, which has been related with tumor onset and development. In fact,a positiv...
Article
Full-text available
O ensino de fisiologia endócrina faz parte do currículo dos estudantes da área de Ciências Biomédicas. Contudo, em função da necessidade de um conjunto de conhecimentos bem fundamentados de Biologia Celular, Molecular e Bioquímica, há dificuldade na assimilação desse tópico, principalmente por alunos dos primeiros dois anos de graduação, o que cria...
Article
The skin is under the influence of oscillatory factors such as light and temperature. This organ possesses a local system that controls several aspects in a time-dependent manner; moreover, the skin has a well-known set of opsins whose function is still unknown. We demonstrate that heat shock reduces Opn2 expression in normal Melan-a melanocytes, w...
Article
It is believed that the biological systems perceiving temperature and light daily cycles were subjected to the simultaneous selective pressures, which resulted in their co-evolutionary association. We investigated the influence of 1 h 33 °C heat shock on the expression of clock and heat shock protein genes, as well as the role of the thermo-TRP cha...
Article
Full-text available
Aldosterone is the most known mineralocorticoid hormone synthesized by the adrenal cortex. The genomic pathway displayed by aldosterone is attributed to the mineralocorticoid receptor (MR) signaling. Even though the rapid effects displayed by aldosterone are long known, our knowledge regarding the receptor responsible for such event is still poor....
Article
Transient receptor potential (TRPs) channels are involved in thermogenesis, and temperature and energy balance control. Mice lacking TrpV1 become more obese and develop insulin resistance when fed with high fat diet; however, a relationship between metabolic disorders, TRP channels, and clock genes is still unknown. Based on this, we hypothesized t...
Article
Full-text available
Melanin production within melanocytes is regulated, among others, by estradiol, whose effects on melanogenesis are still not completely elucidated. Here we show that although 10⁻⁷ M 17β-estradiol (E2) increased tyrosinase mRNA levels in B16-F10 malignant melanocytes, there was a transient decrease and abolishment of the temporal variation of melani...
Article
The skin possesses a photosensitive system comprised of opsins whose function is not fully understood, and clock genes which exert an important regulatory role in skin biology. Here, we evaluated the presence of opsins in normal (Melan-a cells) and malignant (B16-F10 cells) murine melanocytes. Both cell lines express Opn2, Opn4 – for the first time...
Article
Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the level...
Article
Mineralocorticoid receptor (MR) antagonists of aldosterone (spironolactone and eplerenone) display beneficial effects in the treatment of cardiopathies; however, many of these responses are independent of this antagonism. The mechanisms of action of these drugs are not well known; few studies have comparatively evaluated whether eplerenone as well...
Article
The aim of this study was to identify the effects of swimming training on the mRNA expression and protein levels of the calcium handling proteins in the hearts of renovascular hypertensive rats submitted to swimming protocol during 6 weeks. Fischer rats with renovascular hypertension 2-kidney 1-clip (2K1C) and SHAM groups were divided among sedenta...
Article
Full-text available
Malignant mesothelioma (MM) is a highly aggressive form of cancer, has a long latency period, and is resistant to chemotherapy. It is extremely fatal, with a mean survival of less than one year. The development of MM is strongly correlated with exposure to asbestos and erionite, as well as to simian virus 40. Although various countries have banned...
Article
Malignant Mesothelioma (MM) is a very aggressive cancer with low survival rates and often diagnosed at an advanced stage. Several players have been implicated in the development of this cancer, such as asbestos, erionite and the simian virus 40 (SV40). Here, we have reviewed the involvement of erionite, SV40, as well as, the role of several genes (...
Article
Heart failure is a serious public health issue with a growing prevalence, and it is related with the aging of the population. Hypertension is identified as the main precursor of left ventricular hypertrophy and therefore can lead to diastolic dysfunction and heart failure. Scientific studies have confirmed the beneficial effects of the physical exe...
Article
The malignant mesothelioma is an aggressive form of cancer with a mean survival rate of less than a year. Moreover, environmental exposure to minerals is an important factor in the development of malignant mesothelioma (MM), especially the mineral asbestos, which has a well-documented role in MM, and more recently, the mineral erionite has been pro...

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