Research Hub
The living record of
peptide science.
PubMed studies synced daily. Active clinical trials. Evidence updates when the science materially changes. Monthly synthesis for practitioners.
Layer 1
Study feed
Transcription factor networks in aged naïve CD4 T cells bias lineage differentiation.
Aging Cell
Bin Hu, Guangjin Li, Zhongde Ye +4 more
With reduced thymic activity, the population of naïve T cells in humans is maintained by homeostatic proliferation throughout adult life. In young adults, naïve CD4 T cells have enormous proliferative potential and plasticity to differentiate into different lineages. Here, we explored whether naïve CD4 T-cell aging is associated with a partial loss of this unbiased multipotency. We find that naïve CD4 T cells from older individuals have developed a propensity to develop into TH9 cells. Two major mechanisms contribute to this predisposition. First, responsiveness to transforming growth factor β (TGFβ) stimulation is enhanced with age due to an upregulation of the TGFβR3 receptor that results in increased expression of the transcription factor PU.1. Secondly, aged naïve CD4 T cells display altered transcription factor profiles in response to T-cell receptor stimulation, including enhanced expression of BATF and IRF4 and reduced expression of ID3 and BCL6. These transcription factors are involved in TH9 differentiation as well as IL9 transcription suggesting that the aging-associated changes in the transcription factor profile favor TH9 commitment.
In-depth serum proteomics reveals biomarkers of psoriasis severity and response to traditional Chinese medicine.
Theranostics
Meng Xu, Jingwen Deng, Kaikun Xu +24 more
Serum and plasma contain abundant biological information that reflect the body's physiological and pathological conditions and are therefore a valuable sample type for disease biomarkers. However, comprehensive profiling of the serological proteome is challenging due to the wide range of protein concentrations in serum. Methods: To address this challenge, we developed a novel in-depth serum proteomics platform capable of analyzing the serum proteome across ~10 orders or magnitude by combining data obtained from Data Independent Acquisition Mass Spectrometry (DIA-MS) and customizable antibody microarrays. Results: Using psoriasis as a proof-of-concept disease model, we screened 50 serum proteomes from healthy controls and psoriasis patients before and after treatment with traditional Chinese medicine (YinXieLing) on our in-depth serum proteomics platform. We identified 106 differentially-expressed proteins in psoriasis patients involved in psoriasis-relevant biological processes, such as blood coagulation, inflammation, apoptosis and angiogenesis signaling pathways. In addition, unbiased clustering and principle component analysis revealed 58 proteins discriminating healthy volunteers from psoriasis patients and 12 proteins distinguishing responders from non-responders to YinXieLing. To further demonstrate the clinical utility of our platform, we performed correlation analyses between serum proteomes and psoriasis activity and found a positive association between the psoriasis area and severity index (PASI) score with three serum proteins (PI3, CCL22, IL-12B). Conclusion: Taken together, these results demonstrate the clinical utility of our in-depth serum proteomics platform to identify specific diagnostic and predictive biomarkers of psoriasis and other immune-mediated diseases.
Serum Myostatin and IGF-1 as Gender-Specific Biomarkers of Frailty and Low Muscle Mass in Community-Dwelling Older Adults.
J Nutr Health Aging
J Chew, L Tay, J P Lim +5 more
(i) To investigate serum myostatin (absolute and normalized for total body lean mass (TBLM)) and IGF-1 as biomarkers of frailty and low relative appendicular skeletal muscle mass (RASM) in older adults, and; (ii) to examine gender differences in the association of serum myostatin and IGF-1 levels with frailty and low RASM.
Switching on the furnace: Regulation of heat production in brown adipose tissue.
Mol Aspects Med
Li Li, Baoguo Li, Min Li +1 more
Endothermy requires a source of endogenous heat production. In birds, this is derived primarily from shivering, but in mammals it is mostly non-shivering thermogenesis (NST). Brown adipose tissue (BAT) is a specialized tissue found in Eutherian mammals that is the source of most NST. Heat production in BAT depends primarily on the activity of uncoupling protein 1 (UCP1), which decouples transport of protons across the inner mitochondrial membrane from synthesis of ATP. UCP1 and hence heat production of BAT is regulated by many factors. In this paper we discuss the main factors activating UCP1 and increasing heat production. Probably the most well-known activator is the catecholamine norepinephrine (NE) which is released from sympathetic nerve endings and binds to adrenergic receptors that are abundantly expressed on BAT. NE stimulates release of free-fatty acids. It was previously thought that such FFAs were essential for activation of UCP1. However recent work has suggested intracellular lipolysis is not essential and FFAs can be derived from extracellular sources. Thyroid hormones also exert impacts on metabolic rate via effects on brown adipocytes which express type 2 deiodinase. Knocking out DIO2 makes mice cold intolerant. Parathyroid hormone appears to also be a potent regulator of BAT activity and may be an important mediator of elevated expenditure during cancer cachexia, although this is disputed by observations that cachexia wasting is not blunted in UCP1 KO mice. Cardiac natriuretic peptides have also been implicated in regulating BAT thermogenesis and the interconversion of beige adipocytes from their white to brown form. Activation of BAT thermogenesis may be an important component of the post-ingestion rise in heat production. Recent work suggests the gut derived hormone secretin may play a key role in this effect, directly linking BAT activation to the alimentary tract. Not only gut hormones but also metabolites derived from gut microbiota such as butyrate may be an important activator of BAT during cold exposure. Additional regulatory factors include bone morphogenic proteins, fibroblast growth factor 21, Vascular endothelial growth factors and transient receptor potential vanilloid receptors which are important components of thermal sensing and hence how brown adipose tissue responds to the cold. In the future the main challenge is to understand how these regulatory factors combine with each other and with inhibitory factors to control heat production from BAT, and what their relative importance is in differing circumstances. Knocking out UCP1 has revealed other sources of heat production in BAT including creatine-dependent cycles and a futile cycle of Ca2+ shuttling into and out of the endoplasmic reticulum via the SERCA and ryanodine receptors.
ZNF479 downregulates metallothionein-1 expression by regulating ASH2L and DNMT1 in hepatocellular carcinoma.
Cell Death Dis
Yi-Ju Wu, Bor-Sheng Ko, Shu-Man Liang +6 more
Decreased expression of metallothionein-1 (MT-1) is associated with a poor prognosis in hepatocellular carcinoma (HCC). Here, we found that MT-1 expression was suppressed by 14-3-3ε, and MT-1 overexpression abolished 14-3-3ε-induced cell proliferation and tumor growth. We identified that 14-3-3ε induced expression of ZNF479, a novel potential transcriptional regulator by gene expression profiling and ZNF479 contributed to 14-3-3ε-suppressed MT-1 expression. ZNF479 induced the expression of DNMT1, UHRF1, and mixed-lineage leukemia (MLL) complex proteins (ASH2L and Menin), and increased tri-methylated histone H3 (H3K4me3) levels, but suppressed H3K4 (H3K4me2) di-methylation. ZNF479-suppressed MT-1 expression was restored by silencing of ASH2L and DNMT1. Furthermore, ZNF479 expression was higher in HCC tissues than that in the non-cancerous tissues. Expression analyses revealed a positive correlation between the expression of ZNF479 and DNMT1, UHRF1, ASH2L, and Menin, and an inverse correlation with that of ZNF479, ASH2L, Menin, and MT-1 isoforms. Moreover, correlations between the expression of ZNF479 and its downstream factors were more pronounced in HCC patients with hepatitis B. Here, we found that ZNF479 regulates MT-1 expression by modulating ASH2L in HCC. Approaches that target ZNF479/MLL complex/MT-1 or related epigenetic regulatory factors are potential therapeutic strategies for HCC.
Drug treatment for spinal muscular atrophy types II and III.
Cochrane Database Syst Rev
Renske I Wadman, W Ludo van der Pol, Wendy Mj Bosboom +4 more
Spinal muscular atrophy (SMA) is caused by a homozygous deletion of the survival motor neuron 1 (SMN1) gene on chromosome 5, or a heterozygous deletion in combination with a (point) mutation in the second SMN1 allele. This results in degeneration of anterior horn cells, which leads to progressive muscle weakness. Children with SMA type II do not develop the ability to walk without support and have a shortened life expectancy, whereas children with SMA type III develop the ability to walk and have a normal life expectancy. This is an update of a review first published in 2009 and previously updated in 2011.
Post-weaning social isolation exacerbates aggression in both sexes and affects the vasopressin and oxytocin system in a sex-specific manner.
Neuropharmacology
Vinícius Elias de Moura Oliveira, Inga D Neumann, Trynke R de Jong
Post-weaning social isolation (PWSI) is known to induce exaggerated and abnormal aggression in male rats. Here we aimed to assess the effects of PWSI on aggressiveness and social behavior in both male and female rats. Furthermore, we evaluated how PWSI affects the central oxytocin (OXT) and vasopressin (AVP) systems in both sexes. Wistar rats were isolated (IS) or group housed (GH) in same-sex groups immediately after weaning. After seven weeks, rats underwent an intruder test to assess aggression. In one group, brains were immediately dissected afterwards for in situ hybridization and receptor autoradiography. The other group underwent additional anxiety-like and social behavior tests. PWSI induced increased (abnormal) aggression and impaired social memory in both sexes. Especially IS females exhibited abnormal aggression towards juveniles. Furthermore, PWSI increased OXT mRNA expression in the paraventricular nucleus of the hypothalamus (PVN) and decreased OXTR binding in the anterior portion of the nucleus accumbens (NAcc), independent of the sex. V1a receptor binding was decreased in the lateral hypothalamus (LH) and dentate gyrus (DG) in IS rats, regardless of sex. However, V1a receptor binding in the anterior portion of the bed nucleus of stria terminalis (BNSTa) was decreased in IS females but increased in IS males. Taken together, our data support PWSI as a reliable model to exacerbate aggression not only in male but also in female rats. In addition, OXT receptors in the NAcca and V1a receptors in the LH, DG, and BNSTa may play a role in the link between PWSI and aggression. This article is part of the Special Issue entitled 'Current status of the neurobiology of aggression and impulsivity'.
Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial.
Lancet HIV
Takara L Stanley, Lindsay T Fourman, Meghan N Feldpausch +16 more
Non-alcoholic fatty liver disease (NAFLD) is a substantial cause of comorbidity in people with HIV and there are no proven pharmacological treatments for the disease in this population. We assessed the effects of tesamorelin on liver fat and histology in people with HIV and NAFLD.
Immunomodulatory effect of thymopentin on lymphocytes from supramammary lymph nodes of dairy cows.
Immunol Lett
Ran Guan, Wei Xu, Lijia Yuan +3 more
Previous study showed that injection of thymopentin (TP 5) in the area of supramammary lymph nodes (SMLN) had therapeutic effect on the intramammary infection (IMI) in cows. This study was to explore the underlying mechanisms by investigating the immunomodulatory effect of TP 5 on SMLN lymphocytes. Lymphocyte proliferation, cell cycle distribution and cytokine mRNA expression were determined by MTT, FCM and RT-qPCR, respectively. Laser scanning confocal microscope (LSCM) was used to observe the binding between TP 5 and SMLN lymphocytes. Moreover, RNA-sequencing (RNA-seq) was performed to observe the difference between the lymphocytes with and without TP 5 treatment. The results showed that TP 5 significantly promoted lymphocyte proliferation, accelerated cell cycle progression, and enhanced mRNA expression of IL-17A and IL-17F. Laser scanning confocal microscopic analysis revealed the binding of TP 5 to the surface of SMLN lymphocytes. A total of 1094 genes were identified as differentially expressed genes (DEGs) using RNA-seq with 692 up- and 402 down-regulated genes. 48 significantly enriched GO terms were identified by RNA-seq. In KEGG analysis, 1/3 of DEGs were enriched in the immune system pathway, including IL-17 signaling pathway, cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, T cell receptor signaling pathway, Th17 cell differentiation. Among them, IL-17 signaling pathway was the most prominent. This study suggested that the therapeutic benefit of TP 5 in the treatment of bovine mastitis might be attributed to its immunomodulatory activity in SMLN lymphocytes.
Metabolomic profile of diet-induced obesity mice in response to humanin and small humanin-like peptide 2 treatment.
Metabolomics
Hemal H Mehta, Jialin Xiao, Ricardo Ramirez +4 more
The mitochondrial-derived peptides (MDPs) are a novel group of natural occurring peptides that have important signaling functions and biological activity. Both humanin and small-humanin-like peptide 2 (SHLP2) have been reported to act as insulin sensitizers and modulate metabolism.
Tesamorelin, liver fat, and NAFLD in the setting of HIV.
Lancet HIV
Jennifer Audsley, Joe Sasadeusz, Sharon R Lewin
Synthesis and Pharmacological Evaluation of Hybrids Targeting Opioid and Neurokinin Receptors.
Molecules
Karol Wtorek, Anna Adamska-Bartłomiejczyk, Justyna Piekielna-Ciesielska +6 more
Morphine, which acts through opioid receptors, is one of the most efficient analgesics for the alleviation of severe pain. However, its usefulness is limited by serious side effects, including analgesic tolerance, constipation, and dependence liability. The growing awareness that multifunctional ligands which simultaneously activate two or more targets may produce a more desirable drug profile than selectively targeted compounds has created an opportunity for a new approach to developing more effective medications. Here, in order to better understand the role of the neurokinin system in opioid-induced antinociception, we report the synthesis, structure-activity relationship, and pharmacological characterization of a series of hybrids combining opioid pharmacophores with either substance P (SP) fragments or neurokinin receptor (NK1) antagonist fragments. On the bases of the in vitro biological activities of the hybrids, two analogs, opioid agonist/NK1 antagonist Tyr-[d-Lys-Phe-Phe-Asp]-Asn-d-Trp-Phe-d-Trp-Leu-Nle-NH2 (2) and opioid agonist/NK1 agonist Tyr-[d-Lys-Phe-Phe-Asp]-Gln-Phe-Phe-Gly-Leu-Met-NH2 (4), were selected for in vivo tests. In the writhing test, both hybrids showed significant an antinociceptive effect in mice, while neither of them triggered the development of tolerance, nor did they produce constipation. No statistically significant differences in in vivo activity profiles were observed between opioid/NK1 agonist and opioid/NK1 antagonist hybrids.
[ACE-inhibition and bradykinin-mediated angioedema].
Rev Med Liege
D Ndjekembo Shango, O Simonet, F Vallot +2 more
Angiotensin converting enzyme inhibitors (ACE-i) are the most common cause of bradykininin angioedema. These bradykinin-mediated angioedemas are sometimes confused with histamine-induced angioedema, which may cause a late diagnosis and hence poor initial management, deleterious to the patient. This report describes a patient with a bradykinin-mediated angioedema soon after the initiation of perindopril, with laryngeal involvement requiring orotracheal intubation in emergency. The diagnosis was confirmed later and the assay of the activity of the enzymes involved in the catabolism of kinins - aminopeptidase P (APP), carboxypeptidase N (CPN) and Angiotensin-Converting Enzyme (ACE) - demonstrated a decrease of activity of both APP and ACE. As the diagnosis was not made initially, the specific treatments - concentrate of C1 inhibitor or antagonist of the B2 receptor of bradykinin (Icatibant) - were not administered. Any angioedema occurring during a treatment with ACE-i should be considered as a bradykinin-mediated angioedema.
SOX2 protein biochemistry in stemness, reprogramming, and cancer: the PI3K/AKT/SOX2 axis and beyond.
Oncogene
Thorsten Schaefer, Claudia Lengerke
Research of the past view years expanded our understanding of the various physiological functions the cell-fate determining transcription factor SOX2 exerts in ontogenesis, reprogramming, and cancer. However, while scientific reports featuring novel and exciting aspects of SOX2-driven biology are published in near weekly routine, investigations in the underlying protein-biochemical processes that transiently tailor SOX2 activity to situational demand are underrepresented and have not yet been comprehensively summarized. Largely unrecognizable to modern array or sequencing-based technology, various protein secondary modifications and concomitant function modulations have been reported for SOX2. The chemical modifications imposed onto SOX2 are inherently heterogeneous, comprising singular or clustered events of phosphorylation, methylation, acetylation, ubiquitination, SUMOylation, PARPylation, and O-glycosylation that reciprocally affect each other and critically impact SOX2 functionality, often in a tissue and species-specific manner. One recurring regulatory principle though is the canonical PI3K/AKT signaling axis to which SOX2 relates in various entangled, albeit not exclusive ways. Here we provide a comprehensive review of the current knowledge on SOX2 protein modifications, their proposed relationship to the PI3K/AKT pathway, and regulatory influence on SOX2 with regards to stemness, reprogramming, and cancer.
Voluntary Exercise Rescues the Spatial Memory Deficit Associated With Early Life Isoflurane Exposure in Male Rats.
Anesth Analg
Gregory A Chinn, Jennifer M Sasaki Russell, Esther T Banh +2 more
Early life anesthesia exposure results in long-term cognitive deficits in rats. Environmental enrichment consisting of social housing, a stimulating environment, and voluntary exercise can rescue this deficit. We hypothesized that exercise alone is sufficient to rescue the cognitive deficit associated with perinatal anesthesia.
Effects of prolonged type 2 diabetes on mitochondrial function in cerebral blood vessels.
Am J Physiol Heart Circ Physiol
Ivan Merdzo, Ibolya Rutkai, Venkata N L R Sure +2 more
One of the major characteristics of hyperglycemic states such as type 2 diabetes is increased reactive oxygen species (ROS) generation. Since mitochondria are a major source of ROS, it is vital to understand the involvement of these organelles in the pathogenesis of ROS-mediated conditions. Therefore, we investigated mitochondrial function and ROS production in cerebral blood vessels of 21-wk-old Zucker diabetic fatty obese rats and their lean controls. We have previously shown that in the early stages of insulin resistance, and short periods of type 2 diabetes mellitus, only mild differences exist in mitochondrial function. In the present study, we examined mitochondrial respiration, mitochondrial protein expression, and ROS production in large-surface cerebral arteries. We used 21-wk-old animals exposed to peak glucose levels for 7 wk and compared them with our previous studies on younger diabetic animals. We found that the same segments of mitochondrial respiration (basal respiration and proton leak) were diminished in diabetic groups as they were in younger diabetic animals. Levels of rattin, a rat humanin analog, tended to decrease in the diabetic group but did not reach statistical significance (P = 0.08). Other mitochondrial proteins were unaffected, which might indicate the existence of compensatory mechanisms with extension of this relatively mild form of diabetes. Superoxide levels were significantly higher in large cerebral vessels of diabetic animals compared with the control group. In conclusion, prolonged dietary diabetes leads to stabilization, rather than deterioration, of metabolic status in the cerebral circulation, despite continued overproduction of ROS.NEW & NOTEWORTHY We have characterized for the first time the dynamics of mitochondrial function during the progression of type 2 diabetes mellitus with regard to mitochondrial respiration, protein expression, and reactive oxygen species production. In addition, this is the first measurement of rattin levels in the cerebral vasculature, which could potentially lead to novel treatment options.
Hemokinin-1 is an important mediator of pain in mouse models of neuropathic and inflammatory mechanisms.
Brain Res Bull
Ágnes Hunyady, Zsófia Hajna, Tímea Gubányi +5 more
The Tac4 gene-derived hemokinin-1 (HK-1) is present in pain-related regions and activates the tachykinin NK1 receptor, but with binding site and signaling pathways different from Substance P (SP). NK1 receptor is involved in nociception, but our earlier data showed that it has no role in chronic neuropathic hyperalgesia, similarly to SP. Furthermore, NK1 antagonists failed in clinical trials as analgesics due to still unknown reasons. Therefore, we investigated the role of HK-1 in pain conditions of distinct mechanisms using genetically modified mice. Chronic neuropathic mechanical and cold hyperalgesia after partial sciatic nerve ligation (PSL) were determined by dynamic plantar aesthesiometry and withdrawal latency from icy water, motor coordination on the accelerating Rotarod. Peripheral nerve growth factor (NGF) production was measured by ELISA, neuronal and glia cell activation by immunohistochemistry in pain-related regions. Acute somatic and visceral chemonocifensive behaviors were assessed after intraplantar formalin or intraperitoneal acetic-acid injection, respectively. Resiniferatoxin-induced inflammatory mechanical and thermal hyperalgesia by aesthesiometry and increasing temperature hot plate. Chronic neuropathic mechanical and cold hypersensitivity were significantly decreased in HK-1 deficient mice. NGF level in the paw homogenates of intact mice were significantly lower in case of HK-1 deletion. However, it significantly increased under neuropathic condition in contrast to wildtype mice, where the higher basal concentration did not show any changes. Microglia, but not astrocyte activation was observed 14 days after PSL in the ipsilateral spinal dorsal horn of wildtype, but not HK-1-deficient mice. However, under neuropathic conditions, the number of GFAP-positive astrocytes was significantly smaller in case of HK-1 deletion. Acute visceral, but not somatic nocifensive behavior, as well as neurogenic inflammatory mechanical and thermal hypersensitivity were significantly reduced by HK-1 deficiency similarly to NK1, but not to SP deletion. We provide evidence for pro-nociceptive role of HK-1, via NK1 receptor activation in acute inflammation models, but differently from SP-mediated actions. Identification of its targets and signaling can open new directions in pain research.
Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in Rats.
Bull Exp Biol Med
L G Kolik, A V Nadorova, T A Antipova +3 more
The effects of a peptide anxiolytic Selank synthesized on the basis of the endogenous peptide tuftsin on memory impairment and content of brain-derived neurotrophic factor (BDNF) in brain structures were analyzed in outbred rats receiving 10% ethanol as the only source of fluid for 30 weeks. In the object recognition test, Selank (0.3 mg/kg a day, 7 days, intraperitoneally) produced a cognitive-stimulating effect in 9 months rats not exposed to ethanol (p<0.05) and prevented the formation of ethanol-induced memory and attention disturbances (p<0.01) developing during alcohol withdrawal. In ex vivo experiments, Selank prevented ethanol-induced increase in BDNF content in the hippocampus and frontal cortex (p<0.05). These results indicate positive effects of the tuftsin analogue on age-related memory disturbances associated with chronic alcohol intoxication and confirm the involvement of the neurotrophin mechanism related to BDNF production into the effect of Selank.
[Biology and signaling pathways involved in the oncogenesis of desmoid tumors].
Bull Cancer
Sébastien Salas, Frédéric Chibon
Desmoid tumors (TDs) are derived from mesenchymal stem cells and their pathogenesis is strongly linked to the Wingless/Wnt cascade where the deregulation of β-catenin plays a major role. A mutation of the CTNNB1 encoding β-catenin is found in the majority of sporadic TD cases and constitutional mutations of APC have been described in heritable forms in patients with familial adenomatous polyposis (FAP). Estrogens could also play a role in pathogenesis and this is the basis for the use of hormone therapy. Other signaling pathways have been involved in the development of TDs such as Notch, Hedgehog, JAK/STAT, PI3 Kinase/AKT and mTOR. Metalloproteases are expressed in TDs and play a role in invasiveness. TGF-ß, as a growth factor, stimulates the transcriptional activity of β-catenin. Future studies will need to focus on better describing and understanding the immune environment of TDs. One of the major difficulties for the experimental study of TDs is the virtual absence of a preclinical model, either in vitro or in vivo. This is partly why the interactions between the different signaling pathways presented here and their consequences for the development of TDs are still poorly understood.
Clinical efficacy and safety of synthetic thymic peptides with chemotherapy for non-small cell lung cancer in China: A systematic review and meta-analysis of 27 randomized controlled trials following the PRISMA guidelines.
Int Immunopharmacol
Fen-Lian Zeng, Zheng Xiao, Cheng-Qiong Wang +10 more
Synthetic thymic peptides (sTPs) are used with chemotherapy to treat non-small cell lung cancer (NSCLC). In this study, we have performed a systematic review and meta-analysis of published trials to confirm the clinical efficacy and safety of sTPs, and determine the optimal types, usages, and sTP/chemotherapy combinations to produce the desired responses.