Brown Adipose Crosstalk in Tissue Plasticity and Human Metabolism.
Endocrine reviews. 2020;41(1)
Plain language summary
Brown adipose tissue (BAT) is an important contributor to the regulation of metabolism via cellular communication with organs such as liver, muscle, gut and central nervous system. BAT is important for heat generation and is at high levels in human infants. Levels of activation of BAT decline as we age and it has been shown that the amount of BAT is smaller and its activity reduced in those with obesity and type 2 diabetes. To date, there is no answer to efficiently restore functional BAT in aging and obese subjects. This review looks at experiments done on the factors secreted from active BAT (batokines). The review aims to provide a structure for the processes and cell types involved in BAT and the recent findings of BAT whole-body communication are discussed. Altogether, these findings demonstrate that BAT has an adaptive capacity. Studying batokines, offers an alternative approach to identify novel drug targets for metabolic regulation.
Infants rely on brown adipose tissue (BAT) as a primary source of thermogenesis. In some adult humans, residuals of brown adipose tissue are adjacent to the central nervous system and acute activation increases metabolic rate. Brown adipose tissue (BAT) recruitment occurs during cold acclimation and includes secretion of factors, known as batokines, which target several different cell types within BAT, and promote adipogenesis, angiogenesis, immune cell interactions, and neurite outgrowth. All these processes seem to act in concert to promote an adapted BAT. Recent studies have also provided exciting data on whole body metabolic regulation with a broad spectrum of mechanisms involving BAT crosstalk with liver, skeletal muscle, and gut as well as the central nervous system. These widespread interactions might reflect the property of BAT of switching between an active thermogenic state where energy is highly consumed and drained from the circulation, and the passive thermoneutral state, where energy consumption is turned off. (Endocrine Reviews 41: XXX - XXX, 2020).
Recent Advances in Psoriasis Research; the Clue to Mysterious Relation to Gut Microbiome.
International journal of molecular sciences. 2020;21(7)
Plain language summary
Psoriasis is a chronic inflammatory disease where the skin forms bumpy red patches covered with white scales. There is no cure, but medications have focused on supressing the immune response. There is a link between the gut microbiome and psoriasis but it is poorly understood. This review includes the current understanding of how psoriasis develops and discusses the recent findings to support further research in this area. The composition of the gut microbiome affects inflammation in the whole body. This inflammation is associated with cardiovascular disease, diabetes mellitus and other inflammatory disorders. Recent studies have linked cardiovascular disease, insulin resistance, and metabolic syndrome to an imbalance in the gut microbiome. Psoriasis is often found alongside these conditions with similar abnormalities in gut bacteria. An imbalance in gut microbiome could cause certain people to develop psoriasis. The role of the gut microbiome needs to be further clarified but mounting evidence for this gut/skin link means that other therapeutic options may be available for treatment in the future.
Psoriasis is a chronic inflammatory cutaneous disease, characterized by activated plasmacytoid dendritic cells, myeloid dendritic cells, Th17 cells, and hyperproliferating keratinocytes. Recent studies revealed skin-resident cells have pivotal roles in developing psoriatic skin lesions. The balance in effector T cells and regulatory T cells is disturbed, leading Foxp3-positive regulatory T cells to produce proinflammatory IL-17. Not only acquired but also innate immunity is important in psoriasis pathogenesis, especially in triggering the disease. Group 3 innate lymphoid cell are considered one of IL-17-producing cells in psoriasis. Short chain fatty acids produced by gut microbiota stabilize expression of Foxp3 in regulatory T cells, thereby stabilizing their function. The composition of gut microbiota influences the systemic inflammatory status, and associations been shown with diabetes mellitus, cardiovascular diseases, psychomotor diseases, and other systemic inflammatory disorders. Psoriasis has been shown to frequently comorbid with diabetes mellitus, cardiovascular diseases, psychomotor disease and obesity, and recent report suggested the similar abnormality in gut microbiota as the above comorbid diseases. However, the precise mechanism and relation between psoriasis pathogenesis and gut microbiota needs further investigation. This review introduces the recent advances in psoriasis research and tries to provide clues to solve the mysterious relation of psoriasis and gut microbiota.
Individual risk management strategy and potential therapeutic options for the COVID-19 pandemic.
Clinical immunology (Orlando, Fla.). 2020;215:108409
Plain language summary
With the continuing spread of COVID-19 and lack of any approved treatments, this paper examines possible strategies for prevention. The data emerging so far highlights that individual health status plays a critical role in determining clinical severity of COVID-19 symptoms ranging from asymptomatic, mild, moderate, to death. Metabolic status, as determined by a patient’s diet, nutrition, age, sex, medical conditions, lifestyle, and environmental factors can therefore be considered preventative strategies to improve the severity of COVID-19 outcomes. Social distancing and personal hygiene are stated as the most effective strategies to prevent or slow spread of the disease. However individual health status, age and the presence of pre-existing comorbidities influences outcomes, as shown by global data highlighting a prevalence in older, males with metabolic conditions; hypertension in 23.7% patients and diabetes in 16.2% of patients. Older males appear more prone to infectious diseases with high pro-inflammatory immune responses and low adaptive immune responses than an older woman. Diet and healthy intestinal and respiratory tract microbiota may also influence immune system competence. Numerous micronutrients are essential for immunocompetence, particularly vitamin A, C, D, E, Bs, iron, selenium, and zinc. A balanced diet, high in colourful fruits and vegetables with a variation of prebiotic fibres, probiotics, and plant polyphenols and phytonutrients, help promote a healthy, diverse microbiota. Oral probiotics may also be beneficial to vulnerable individuals. Vitamin D supplementation is also proving helpful in prevention of acute respiratory tract infections. Other lifestyle factors such as smoking and exposure to environmental toxins should also be considered. Together these preventative measures may reduce personal risk of getting the disease.
It is an ugly fact that a significant amount of the world's population will contract SARS-CoV-II infection with the current spreading. While a specific treatment is not yet coming soon, individual risk assessment and management strategies are crucial. The individual preventive and protective measures drive the personal risk of getting the disease. Among the virus-contracted hosts, their different metabolic status, as determined by their diet, nutrition, age, sex, medical conditions, lifestyle, and environmental factors, govern the personal fate toward different clinical severity of COVID-19, from asymptomatic, mild, moderate, to death. The careful individual assessment for the possible dietary, nutritional, medical, lifestyle, and environmental risks, together with the proper relevant risk management strategies, is the sensible way to deal with the pandemic of SARS-CoV-II.
COVID-19 infection: the perspectives on immune responses.
Cell death and differentiation. 2020;27(5):1451-1454
Nutrition amid the COVID-19 pandemic: a multi-level framework for action.
Plain language summary
The SARS-CoV-2 infection triggers an immune response which varies greatly from one person to another. It can be roughly divided into three stages: stage I, an asymptomatic incubation period with or without detectable virus; stage II, non-severe symptomatic period with the presence of virus; stage III, severe respiratory symptomatic stage with high viral load. Currently around 15% of people infected end up in severe stage III. There appears to be a two-phase immune response; an early protective phase and a second inﬂammation-driven damaging phase. In phase one the adaptive immune system responds to the virus. Being in good general health is important in this phase to limiting the progression of the disease to a more severe stage. In phase two the innate immune system response to tissue damage caused by the virus could lead to widespread inflammation of the lungs and acute respiratory distress syndrome or respiratory failure. Therapeutically this raises the question of whether the immune response should be boosted in phase one and suppressed in phase two. There also appears to be an element of viral relapse in some patients discharged from hospital indicating that a virus-eliminating immune response may be difficult to achieve naturally. These same patients may also not respond to vaccines. Overall, it is still unclear why some people develop severe disease, whilst others do not. Overall immunity alone does not explain the differences in disease presentation.
European journal of clinical nutrition. 2020;74(8):1117-1121
Unusual Early Recovery of a Critical COVID-19 Patient After Administration of Intravenous Vitamin C.
Plain language summary
This Lebanese articled provides a commentary on the evolving COVID-19 pandemic and aims to give a framework for Nutritional action to help the physical and mental health of individuals, communities, and nations. At an individual level the focus is on the link between diet and immunity and the profound effect diet has on people’s immune system and disease susceptibility. An adequate intake of iron, zinc, and vitamins A, E, B6, and B12 is predominantly vital for the maintenance of immune function. Individuals should aim to eat as healthily as possible, including a wide range of fruits and vegetables, limit snacking, take regular exercise and get an adequate amount of sleep to support their health. Single foods promising cures or prevention of infection are unfounded claims which can give a false sense of security. The focus for communities is on food availability, for nations its food security and on a global level it is about food trade agreements. Its important to protect against hoarding and panic buying to ensure enough food for everyone. National economic instability during COVID-19 can lead to a risk of food security so governments are advised to support local agricultural produce and reduce their reliance on imported goods. Global supply chains and agreements need to be respected to lessen the impact further down the supply chain. The health of each individual has a direct impact on the community and nation and is a direct consequence of their dietary awareness and choices.
The American journal of case reports. 2020;21:e925521
Plain language summary
Coronavirus disease (Covid-19) continues to spread globally and to date there are no proven treatments. Current treatment focuses on the management of the associated acute respiratory distress syndrome (ARDS). There are many studies demonstrating that in severe sepsis and ARDS; Vitamin C reduces systemic inflammation, prevents lung damage, reduces the duration of mechanical ventilation (MV) and the length of intensive care unit (ICU) stay in patients. This is a case report where a critically ill patient received high-dose Vitamin C intravenous (IV) infusions and recovered. A 74 year-old woman with Covid-19, developed ARDS and septic shock. Usual medications were given. She needed MV and deteriorated rapidly. On Day 7 she was administered Vitamin C (11g per 24 hours as a continuous IV infusion). Her clinical condition improved slowly after this. In this case, high dose IV Vitamin C was associated with fewer days on mechanical intervention, a shorter ICU stay and earlier recovery. These results show the importance of further investigation of IV Vitamin C to assess its efficacy in critically ill Covid-19 patients requiring mechanical ventilation and ICU care.
BACKGROUND Coronavirus disease 2019 (COVID-19) continues to spread, with confirmed cases now in more than 200 countries. Thus far there are no proven therapeutic options to treat COVID-19. We report a case of COVID-19 with acute respiratory distress syndrome who was treated with high-dose vitamin C infusion and was the first case to have early recovery from the disease at our institute. CASE REPORT A 74-year-old woman with no recent sick contacts or travel history presented with fever, cough, and shortness of breath. Her vital signs were normal except for oxygen saturation of 87% and bilateral rhonchi on lung auscultation. Chest radiography revealed air space opacity in the right upper lobe, suspicious for pneumonia. A nasopharyngeal swab for severe acute respiratory syndrome coronavirus-2 came back positive while the patient was in the airborne-isolation unit. Laboratory data showed lymphopenia and elevated lactate dehydrogenase, ferritin, and interleukin-6. The patient was initially started on oral hydroxychloroquine and azithromycin. On day 6, she developed ARDS and septic shock, for which mechanical ventilation and pressor support were started, along with infusion of high-dose intravenous vitamin C. The patient improved clinically and was able to be taken off mechanical ventilation within 5 days. CONCLUSIONS This report highlights the potential benefits of high-dose intravenous vitamin C in critically ill COVID-19 patients in terms of rapid recovery and shortened length of mechanical ventilation and ICU stay. Further studies will elaborate on the efficacy of intravenous vitamin C in critically ill COVID-19.
Vitamin C levels in patients with SARS-CoV-2-associated acute respiratory distress syndrome.
Critical care (London, England). 2020;24(1):522
Vitamin C: an essential "stress hormone" during sepsis.
Plain language summary
Sepsis related acute respiratory disease (ARDS) is associated with Covid-19. ARDS patients can present with decreased levels of vitamin C and so by association Covid-19 patients may also have low vitamin C levels. In this cohort study, 18 Covid-19 ARDS patients of which all survived were assessed for vitamin C levels. 17 patients had undetectable levels of vitamin C and one had low levels. It was concluded that more than 90% of the patients in this study had undetectable levels of vitamin C, which may be due to several reasons, such as reduced absorption of vitamin C in the gut and decreased production. Clinicians could use this study to understand the importance of monitoring vitamin C levels in patients with Covid-19.
Journal of thoracic disease. 2020;12(Suppl 1):S84-S88
Plain language summary
Most mammals can synthesise vitamin C, except humans, other primates and guinea pigs, who lost this ability through a mutation. It is estimated that goats produce 2-4g of vitamin C per day, but significantly more when stressed. Vitamin C is thought to play an important role in our stress response. This short review articles discusses the importance of vitamin C during stress, in particular the stress of sepsis. The adrenal glands, our “stress organs”, contain very high levels of vitamin C which is released when the hypothalamus-pituitary-adrenal (HPA) axis (which deals with our response to stressors) is stimulated. In animals, there is an inverse relationship between vitamin C internal manufacture and cortisol release under stress: the less vitamin C an animal can produce, the more cortisol they release. A number of vitamin C’s biological actions including antioxidant, anti-inflammatory, immune function, synthesis of the stress hormones adrenaline and noradrenaline and wound healing, may play an important role during a stress response. During sepsis vitamin C gets used up at alarming rate. Sepsis is a complex disease and vitamin C’s biological actions can affect many of the underlying pathophysiological processes. Preclinical and clinical studies have shown a beneficial effect of vitamin C in patients with sepsis and synergistic effects are seen with thiamine (vitamin B1), corticosteroids and antibiotics.
The stress response is a preserved evolutionary response that functions to enhance the survival of the species. In mammals, the stress response is characterized by activation of the HPA axis and sympathoadrenal system (SAS) as well as the increased synthesis and secretion of vitamin C. Cortisol, catecholamines, and vitamin C act synergistically to increase hemodynamic reserve, maintain immune function and protect the host against excessive oxidant injury. Humans (and anthropoid apes) have lost the ability to synthesize vitamin C and therefore have an impaired stress response. The inability to produce vitamin C has serious implications in septic humans. Treatment with vitamin C appears to restore the stress response and improve the survival of stressed humans.
Short- and potential long-term adverse health outcomes of COVID-19: a rapid review.
Emerging microbes & infections. 2020;9(1):2190-2199
Plain language summary
The Coronavirus pandemic (Covid-19) has infected millions of people worldwide and there is evidence that it affects many systems in the human body. This rapid review summarises the current evidence on short-term negative health outcomes of Covid-19. It also assesses the risk of potential long-term negative effects by looking at data from the other coronaviruses; Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). The burden for caring for Covid-19 survivors is likely to be huge and so policy makers need suitable data to put the appropriate care strategies in place. The review is divided into sections as per body system affected: Immune, respiratory, cardiovascular, gastrointestinal, hepatic and renal, neurological, dermatological, mental health, pregnancy and prenatal exposure. The evidence (short-term and long-term) is then reviewed by experts in those fields. Further large-scale studies are needed to monitor the adverse effects and to measure the long-term health consequences.
The coronavirus disease 2019 (COVID-19) pandemic has resulted in millions of patients infected worldwide and indirectly affecting even more individuals through disruption of daily living. Long-term adverse outcomes have been reported with similar diseases from other coronaviruses, namely Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). Emerging evidence suggests that COVID-19 adversely affects different systems in the human body. This review summarizes the current evidence on the short-term adverse health outcomes and assesses the risk of potential long-term adverse outcomes of COVID-19. Major adverse outcomes were found to affect different body systems: immune system (including but not limited to Guillain-Barré syndrome and paediatric inflammatory multisystem syndrome), respiratory system (lung fibrosis and pulmonary thromboembolism), cardiovascular system (cardiomyopathy and coagulopathy), neurological system (sensory dysfunction and stroke), as well as cutaneous and gastrointestinal manifestations, impaired hepatic and renal function. Mental health in patients with COVID-19 was also found to be adversely affected. The burden of caring for COVID-19 survivors is likely to be huge. Therefore, it is important for policy makers to develop comprehensive strategies in providing resources and capacity in the healthcare system. Future epidemiological studies are needed to further investigate the long-term impact on COVID-19 survivors.
Immediate and long-term consequences of COVID-19 infections for the development of neurological disease.
Alzheimer's research & therapy. 2020;12(1):69
Plain language summary
Covid-19 may cause brain dysfunction evidenced by symptoms individuals experience once they have contracted the disease. Loss of smell, taste and confusion have all been reported by patients and a number of severe cases have reported incidences of stroke. These are all of concern, as Covid-19 can severely affect the elderly who ordinarily are the most likely to suffer from brain disorders. This small review paper of 27 studies stated that there are four possible ways in which Covid-19 may affect the brain, which put Covid-19 sufferers at an increased risk of long-term brain disorders. This was supported by findings, which showed one third of Covid-19 patients leave hospital with evidence of brain dysfunction. Inflammation was heavily reviewed by the authors as a possible causal factor. It was concluded that patients who survive Covid-19 infection are at an increased risk for developing brain disorders such as Alzheimer's disease, however it was acknowledged that further studies are required. Clinicians could use this study to understand the possible need for both short-term and long-term monitoring of brain function in individuals who have survived Covid-19, especially if they are elderly.
Increasing evidence suggests that infection with Sars-CoV-2 causes neurological deficits in a substantial proportion of affected patients. While these symptoms arise acutely during the course of infection, less is known about the possible long-term consequences for the brain. Severely affected COVID-19 cases experience high levels of proinflammatory cytokines and acute respiratory dysfunction and often require assisted ventilation. All these factors have been suggested to cause cognitive decline. Pathogenetically, this may result from direct negative effects of the immune reaction, acceleration or aggravation of pre-existing cognitive deficits, or de novo induction of a neurodegenerative disease. This article summarizes the current understanding of neurological symptoms of COVID-19 and hypothesizes that affected patients may be at higher risk of developing cognitive decline after overcoming the primary COVID-19 infection. A structured prospective evaluation should analyze the likelihood, time course, and severity of cognitive impairment following the COVID-19 pandemic.