Human Treatment Research Articles

Humanin’s impact on pain markers and neuronal viability in diabetic neuropathy model

Objective This study investigates the impact of chronic humanin (HN) treatment on pain-related markers (NMDA, substance P, TRPV1, and IL-1β) in diabetic mice’s dorsal root ganglia (DRG). Additionally, we assess the effects of HN on cellular viability in DRG neurons. Methods In vivo experiments involved 15 days of HN administration (4 mg/kg) to diabetic mice (n = 10). Protein levels of NMDA, IL-1β, TRPV1, and substance P were measured in diabetic DRG. In vitro experiments explored HN’s impact on apoptosis and cellular viability, focusing on the JAK2/STAT3 pathway. Results Humanin significantly reduced the elevated expression of NMDA, IL-1β, TRPV1, and substance P induced by diabetes (p < .05). Furthermore, HN treatment increased cellular viability in DRG neurons through JAK2/STAT3 pathway activation (p < .05). Conclusion These findings highlight the significance of understanding mitochondrial function and pain markers, as well as apoptosis in diabetes. The study provides insights for managing the condition and its complications.

Humanin Treatment Protects Against Venetoclax-Induced Bone Growth Retardation in Ex Vivo Cultured Rat Bones.

Recent preclinical studies reported that the BCL-2 inhibitor venetoclax can impair bone growth. A strategy to prevent such a side effect of this promising anticancer drug is highly desired. Earlier in vitro and in vivo studies suggested that the mitochondrial peptide humanin has the potential to prevent drug-induced growth impairment. We hypothesized that co-treatment with the humanin analog HNG may prevent venetoclax-induced bone growth impairment. Ex vivo studies were performed in fetal rat metatarsal bones and human growth plate samples cultured for 12 and 2 days, respectively, while in vivo studies were performed in young neuroblastoma mice being treated daily for 14 days. The treatment groups included venetoclax, HNG, venetoclax plus HNG, or vehicle. Bone growth was continuously monitored and at the end point, histomorphometric and immunohistochemical analyses were performed in fixed tissues. Venetoclax suppressed metatarsal bone growth and when combined with HNG, bone growth was rescued and all histological parameters affected by venetoclax monotherapy were normalized. Mechanistic studies showed that HNG downregulated the pro-apoptotic proteins Bax and p53 in cultured metatarsals and human growth plate tissues, respectively. The study in a neuroblastoma mouse model confirmed a growth-suppressive effect of venetoclax treatment. In this short-term in vivo study, no significant bone growth-rescuing effect could be verified when testing HNG at a single dose. We conclude that humanin dose-dependently protects ex vivo cultured metatarsal bones from venetoclax-induced bone growth impairment by restoring the growth plate microstructure.

A Review of the Most Important Antiparasitic Compounds Effective on Human Fascioliasis from the Past Until Now

Background: Fascioliasis is a worldwide parasitic infection caused by a food-borne trematode called Fasciola, and Fasciola infection has been reported in more than 80 countries. Recently, the WHO has presented a roadmap for overlooked diseases from 2021 to 2030, which aims to increase the prevention and control of overlooked different diseases such as Fascioliasis. Methods: Our main objective was to conduct a systematic review aiming to summarize recent knowledge on the antiparasitic compounds against human fascioliasis. A keyword search was performed in PubMed, Web of Science, to gather relevant literature published between the 17th of April 1992 and the 23rd October 2022. A total of 329 records were initially retrieved, with 28 full-text articles retained for the qualitative synthesis. Results: Up to now, various antiparasitic drugs have been used to treat human fascioliasis, the most important of which are: Triclabendazole, Albendazole and Bithionol, Praziquantel, Emetine and Dehydroemetine, Mebendazole in combination with Metronidazole and Nitazoxanide, Chloroquine, Hexylresorcinol. From the past to the present, natural herbal medicines have traditionally been used in most countries to treat various parasitic diseases in humans and animals so that these are known as active anthelmintic phytochemicals such as Artemisinin, Mirazid, Plumbagin, Lycium chinense. Conclusion: Although Triclabendazole is an effective and useful drug of choice for the treatment of human fascioliasis, but due to the gradual resistance of fasciolas to Triclabendazole, further research is needed to find new drugs. Despite many advances in antiparasitic compounds used against human fascioliasis, a number of integrated control measures should be implemented as strong management strategies for fascioliasis.

Protective effects of chronic humanin treatment in mice with diabetic encephalopathy: A focus on oxidative stress, inflammation, and apoptosis

Diabetes is known to cause cognitive impairments through various mechanisms, including oxidative stress, inflammation, and apoptosis. Humanin (HN) has been shown to have protective effects on cognitive impairments induced by factors such as Aβ, muscarinic receptor antagonists, and aging in rodents. However, the mechanisms underlying the protective effects of HN in the prefrontal cortex and hippocampus in the context of diabetes are not well understood. In this study, we aimed to investigate the potential protective role of HN on oxidative stress, inflammation, and apoptosis in mice with diabetes.We divided the mice into four groups, including a control group (treated with saline), a humanin group (treated with 4 mg/kg of HN), a streptozotocin (STZ) group (diabetic control), and an STZ+Humanin group. The mice were administered HN daily for 15 days. Our results showed that in the prefrontal cortex and hippocampus of the diabetes group, oxidative stress parameters, pro-inflammatory cytokines, apoptosis and, blood glucose levels were increased, while antioxidant and anti-inflammatory cytokines were diminished compared to the control group. However, HN treatment was able to modulate these markers, including blood glucose and the markers of oxidative stress, inflammation, and apoptosis.In conclusion, our findings suggest that hyperglycemia, oxidative stress, inflammation, and apoptosis may contribute to the development of diabetes-induced cognitive impairments. By regulating these changes with HN treatment, we may be able to positively contribute to the treatment of cognitive impairments induced by diabetes.

Effectiveness of analog of Humanin in ameliorating streptozotocin-induced diabetic nephropathy in Sprague Dawley rats

Diabetes mellitus (DM) is associated with numerous complications, including nephropathy, which principally occur due to hyperglycemia-induced oxidative stress and inflammation. Humanin (HN), a novel peptide generated from mitochondria, has anti-oxidant and anti-inflammatory potential as observed in different disease models. However, role of HN in diabetic nephropathy (DN) has not yet been explored. This study aimed to evaluate biochemical and molecular aspects of the effects of HN analog, Humanin-glycine ([S14G]-humanin) on streptozotocin (STZ)-induced rat model of DN. Ninety Sprague Dawley (SD) rats were randomly segregated into three groups – A (control), B (disease control) and C (treatment). DM type-I was induced in group B and C via single intra-peritoneal dose of STZ (45 mg/Kg). Seven days following STZ injection, rats were deemed diabetic if their blood glucose level was > 250 mg/dL. Subsequently, diabetic rats in group C were injected with [S14G]-humanin intra-peritoneally (0.4 mg/Kg/day) for sixteen weeks. Biochemical analysis revealed that diabetic rats had markedly elevated levels of serum glucose, creatinine, BUN, TNF-α, and kidney tissue SOD. Whereas, significant decline was detected in serum insulin and albumin levels. All these parameters were significantly reversed in group C after administering [S14G]-humanin. Moreover, qRT-PCR analysis displayed up-regulation of pro-inflammatory (IL-18, IL-6, IL-1α, IL-1β, TNF-α) and down-regulation of anti-inflammatory cytokines (IL-10, IL-1RN, IL-4) in diabetic rats (group B). [S14G]-humanin treatment significantly reversed the expression of IL-18 and IL-1α, however, change in relative expression of IL-6, IL-1β, TNF-α and anti-inflammatory cytokines was insignificant (group C). Conclusively, the findings of this study depicted potential therapeutic role of [S14G]-humanin in pre-clinical rodent model of DN.

Intranasal delivery of mitochondrial protein humanin rescues cell death and promotes mitochondrial function in Parkinson's disease.

Rationale: Mitochondrial dysfunction is a key factor in the pathogenesis of Parkinson's disease (PD). Accordingly, many aspects of mitochondrial function have been studied as a putative therapeutic target. Here we present a novel strategy to promote mitochondrial function and protect against Parkinson's disease by the peptide encoded within mitochondrial genome, mitochondria-derived peptide (MDP) humanin (HN). Methods: To test humanin as a potential biomarker in PD, we measured protein levels of circulating humanin from the plasma of PD patients and transgenic or neurotoxic mouse models of PD. Next, we aimed to identify whether HN peptide treatment can regulate its activity or expression. Using mouse models of PD, we assessed HN delivery to the brain via the nasal route of administration. We further revealed a possible mechanism underlying the therapeutic effectiveness of HN peptide for PD using in vitro and ex vivo model of PD. Results: Although the expression of intracellular HN was not correlated with PD, HN treatment itself could induce intracellular HN expression and enhance mitochondrial biogenesis inducing mitochondrial gene expression. After intranasal administration, HN peptide resulted in neuroprotection and behavioral recovery in an animal model of PD. Interestingly, HN peptide following intranasal delivery was found within the brain, mainly via the trigeminal pathways. Mechanistically, HN treatment induced activation of phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway which led to enhanced mitochondrial biogenesis resulting in upregulation of mitochondrial gene including humanin. Conclusion: These data support a novel role of mitochondrial protein humanin in mitochondrial function and neuronal survival against Parkinson's disease, in which humanin treatment is sufficient for stimulating mitochondrial gene expression.

Humanin Ameliorates Late-onset Hypogonadism in Aged Male Rats.

The potential to reproduce declines with age. Late-onset hypogonadism is characterized by reduced serum testosterone. Humanin is a mitochondrial-derived signaling peptide encoded by short open reading frames within the mitochondrial genome. It may protect against some age-related diseases such as atherosclerosis by its cytoprotective effects. The study aimed to investigate the potential anti-aging effects of humanin on the testicular architecture, oxidative stress, some apoptotic and inflammatory markers in the hypogonadal aged male rats. Forty male albino rats were divided into 4 groups: normal adult controls, aged vehicle- treated group, aged testosterone-treated group, and aged humanin-treated group. Twenty-month- old male rats with declined serum testosterone were selected to be the animal models of lateonset hypogonadism. Testicular weights, serum testosterone, and some sperm parameters were measured. Testicular tissue IL-6 and TNF-α, superoxide dismutase activity, glutathione peroxidase, and malondialdehyde were assessed. The activity of caspase-3, BCL2, PCNA, and the nuclear factor erythroid 2-related factor 2-antioxidant response element pathway were evaluated. Testes were subjected to histopathological and immunohistochemical examination. Statistical analysis was executed using. One Way Analysis of variance (ANOVA) followed by Post hoc (LSD) test to compare means among all studied groups. Humanin treatment significantly improved serum testosterone, sperm characteristics, and antioxidant defenses. It decreased active caspase-3, pro-apoptotic BAX expression, and increased antiapoptotic BCL2 and proliferating cell nuclear antigen (PCNA) possibly via activating the (Nrf2- ARE) pathway. Humanin might be a promising therapeutic modality in late-onset hypogonadism as it ameliorated some age-related testicular and hormonal adverse effects.

Dextran Sulfate Inhibits Cell Proliferation and Induces Apoptosis by Regulating EZH2 in Gastric Carcinoma.

Gastric cancer (GC) is one of the most common gastrointestinal malignancies. According to reports, the enhancer of zeste homolog 2 (EZH2) exhibits carcinogenic function in a variety of cancers. Therefore, EZH2 may be a potential therapeutic target for the treatment of human cancer. Macromolecular Dextran Sulfate (DS) has been displayed to play a critical role in tumor inhibition. However, the molecular mechanism by which DS mediates this effect is unclear. In this study, we explored the effects of DS on the proliferation and apoptosis of gastric cancer and the related mechanisms. Cell proliferation and counting assays, as well as cell colony formation assays, revealed that DS inhibited the proliferation and tumorigenesis of GC cells. Additionally, flow cytometry analysis displayed that DS blocked the cell cycle of GC cells in the G1/S phase and promoted their apoptosis. Bioinformatics analyses, enzyme-linked immunosorbent assays, immunohistochemistry, and other methods were applied to measure the expression of EZH2 in human GC cells and tissues. Further studies have shown that DS treatment can reduce the expression of proliferating cell nuclear antigen (PCNA) and increase the level of the ratio of Bax: Bcl-2 protein in GC cells. In addition, DS reduced EZH2 levels and increased CXXC finger protein 4 levels both in vitro and in vivo. In addition, down-regulation of EZH2 with EZH2 inhibitors reversed the inhibitory effect of DS on gastric cancer cells. Collectively, our work demonstrates that DS suppresses proliferation and promotes apoptosis of GC cells by regulating EZH2. Our study suggests that DS is a promising therapeutic compound for the treatment of GC.

The Role Of The Medan Police In Law Enforcement Of Criminal Acts Of Narcotics

Narcotics are needed by humans for treatment so that to meet the needs in the field of medicine and scientific studies, a continuous production of narcotics is needed for these sufferers. On the basis of considering Law Number 35 of 2009 concerning Narcotics, it is stated that narcotics on the one hand are drugs or materials that are useful in the field of treatment or health services and the development of science and on the other hand can also cause dependence which is very detrimental if misused or used without strict control and supervision. The problem in this research is how to tackle and eradicate narcotics crime? What are the efforts of the Medan Police in overcoming and eradicating narcotics crimes? What are the Obstacles in the Countermeasures and Eradication of Narcotics Crimes at the Medan Police? This research is descriptive in nature, which aims to describe exactly what the characteristics of an individual, condition, symptom, or group are, or to determine the spread of a symptom, or to determine whether there is a relationship between a symptom and other symptoms in society. Efforts to overcome and eradicate narcotics crimes within the jurisdiction of the Medan City Police are carried out through non-penal policies and penal policies. Non-penal policies are carried out through preventive and preemptive measures which are implemented through counseling, narcotics safaris, distribution of pamphlets and billboards as well as approaches to traditional and religious leaders as well as community development. This approach was carried out by the Medan City Police Resort in collaboration with BNN and experts through the perspectives of cultural anthropology, sociology, communication, psychology, healthy life education (public health science). The non-penal policy is aimed at children (including school-age youth) and the general public. Penal policies through law enforcement are also applied to police officers who make mistakes in disclosing narcotics cases. Obstacles in overcoming and eradicating narcotics crime in the jurisdiction of the Medan City Police Resort can be viewed from legal factors, law enforcement factors, facilities and facilities in law enforcement, community factors and cultural factors. In general, Law Number 35 of 2009 concerning Narcotics is more comprehensive in regulating the actions that can be taken to uncover narcotics networks. factors of facilities and facilities in law enforcement, community factors and cultural factors. In general, Law Number 35 of 2009 concerning Narcotics is more comprehensive in regulating the actions that can be taken to uncover narcotics networks. factors of facilities and facilities in law enforcement, community factors and cultural factors. In general, Law Number 35 of 2009 concerning Narcotics is more comprehensive in regulating the actions that can be taken to uncover narcotics networks.

The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan.

Humanin is a member of a new family of peptides that are encoded by short open reading frames within the mitochondrial genome. It is conserved in animals and is both neuroprotective and cytoprotective. Here we report that in C. elegans the overexpression of humanin is sufficient to increase lifespan, dependent on daf-16/Foxo. Humanin transgenic mice have many phenotypes that overlap with the worm phenotypes and, similar to exogenous humanin treatment, have increased protection against toxic insults. Treating middle-aged mice twice weekly with the potent humanin analogue HNG, humanin improves metabolic healthspan parameters and reduces inflammatory markers. In multiple species, humanin levels generally decline with age, but here we show that levels are surprisingly stable in the naked mole-rat, a model of negligible senescence. Furthermore, in children of centenarians, who are more likely to become centenarians themselves, circulating humanin levels are much greater than age-matched control subjects. Further linking humanin to healthspan, we observe that humanin levels are decreased in human diseases such as Alzheimer’s disease and MELAS (Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes). Together, these studies are the first to demonstrate that humanin is linked to improved healthspan and increased lifespan.

Differential survival requirements for Lck- and CD3e-dependent signaling defines two populations of ATMKO thymic T cell lymphomas

Abstract The product of theataxia-telangiectasia mutated gene (ATM) is a serine-threonine kinase thatcommunicates between molecules that detect dangerous DNA double strand breaksand effector mechanisms that maintain genomic integrity. ATM deficiency in bothhumans and mice is associated with genomic instability and increased malignancies. ATMKO mice exclusively develop thymic T cell lymphomas that resemble thymically-derivedT-ALL that occur in human ATM-deficient ataxia telangiectasia patients. Flowcytometry identified two subsets of ATMKO T cell lymphomas based on surfaceexpression of CD3ɛ, TCRβ and pre-Tα:Cells that express surface CD3ɛ, TCRβ and pre-Tα(surface receptor high; sRhi) and cells that do not express detectable surface CD3ɛ, TCRβ orpre-Tα(sRlo). When assayed for CD25 and CD44 expression sRhi lymphomas resemble DN3or DN4 cells while sRlo lymphomas resemble more immature DN1 or DN2 cells. Pre-TCRsignaling in normal DN3 and DN4 thymocytes provides an essential survivalsignal that is proposed to be constitutive and ligand-independent. Therefore, weasked if surface sRhi and sRlo cells are dependent on pre-TCR signaling byincubating cells with either Lck inhibitor, CAS 213743-31-8, or CD3ɛshRNA to inhibit pre-TCR signaling. Both treatments significantly inhibitedsurvival of sRhi lymphomas, while survival of sRlo cells was largely unaffected. These results suggest that ATMKO T celllymphomas arise from cells transformed at different stages of DN development andthat sRhigh cells, like normal DN3 and DN4 thymocytes, retain apre-TCR-dependent survival requirement. These results also suggest that pre-TCRsignaling may be a useful target for clinical intervention in treatment ofhuman T-ALL that express a pre-TCR.

Humanin prevents high glucose-induced monocyte adhesion to endothelial cells by targeting KLF2

Endothelial dysfunction and vascular complications induced by hyperglycemia play an important role in the pathological development of atherosclerosis in diabetes. Humanin, a 24-amino acid mitochondria-derived polypeptide, has displayed its cytoprotective effects in diverse cell types and tissues. In the current study, we aimed to characterize the effects of humanin on high glucose-induced endothelial dysfunction. Firstly, we found that humanin treatment induced the expression of Krüppel-like factor 2 (KLF2), an essential transcriptional regulator of endothelial function, at the transcriptional level in human umbilical vein endothelial cells (HUVECs). Additionally, our results indicate that humanin treatment regulated the expression of KLF2 target genes such as endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1). Evidence demonstrated that the effects of humanin on KLF2 expression was mediated by the phosphorylation of extracellular signal regulated kinase 5 (ERK5). Furthermore, humanin restored high glucose-induced reduction of KLF2 expression. We also showed that humanin significantly reduced the expression of vascular cell adhesion molecule 1 (VCAM-1) and E-selectin. Notably, humanin treatment markedly prevented high glucose-induced attachment of the monocyte THP-1 cells to HUVECs. However, knockdown of KLF2 abolished these effects. Lastly, we report that humanin treatment inhibited high glucose-induced secretion of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). These findings suggest that humanin may have therapeutic potential for the treatment of hyperglycemia-associated endothelial dysfunction.

Chronic treatment with the mitochondrial peptide humanin prevents age-related myocardial fibrosis in mice.

Cardiac fibrosis is a biological process that increases with age and contributes to myocardial dysfunction. Humanin (HN) is an endogenous mitochondria-derived peptide that has cytoprotective effects and reduces oxidative stress. The present study aimed to test the hypothesis that chronic supplementation of exogenous HN in middle-aged mice could prevent and reverse cardiac fibrosis and apoptosis in the aging heart. Female C57BL/6N mice at 18 mo of age received 14-mo intraperitoneal injections of vehicle (old group; n = 6) or HN analog (HNG; 4 mg/kg 2 times/wk, old + HNG group, n = 8) and were euthanized at 32 mo of age. C57BL/6N female mice (young group, n = 5) at 5 mo of age were used as young controls. HNG treatment significantly increased the ratio of cardiomyocytes to fibroblasts in aging hearts, as shown by the percentage of each cell type in randomly chosen fields after immunofluorescence staining. Furthermore, the increased collagen deposition in aged hearts was significantly reduced after HNG treatment, as indicated by picrosirius red staining. HNG treatment also reduced in aging mice cardiac fibroblast proliferation (5'-bromo-2-deoxyuridine staining) and attenuated transforming growth factor-β1, fibroblast growth factor-2, and matrix metalloproteinase-2 expression (immunohistochemistry or real-time PCR). Myocardial apoptosis was inhibited in HNG-treated aged mice (TUNEL staining). To decipher the pathway involved in the attenuation of the myocardial fibrosis by HNG, Western blot analysis was done and showed that HNG upregulated the Akt/glycogen synthase kinase -3β pathway in aged mice. Exogenous HNG treatment attenuated myocardial fibrosis and apoptosis in aged mice. The results of the present study suggest a role for the mitochondria-derived peptide HN in the cardioprotection associated with aging. NEW & NOTEWORTHY Cardiac fibrosis is a biological process that increases with age and contributes to myocardial dysfunction. Humanin is an endogenous mitochondria-derived peptide that has cytoprotective effects and reduces oxidative stress. Here, we demonstrate, for the first time, that exogenous humanin treatment attenuated myocardial fibrosis and apoptosis in aging mice. We also detected upregulated Akt/glycogen synthase kinase-3β pathway in humanin analog-treated mice, which might be the mechanism involved in the cardioprotective effect of humanin analog in aging mice.

Humanin promotes mitochondrial biogenesis in pancreatic MIN6 β-cells

Mitochondrial dysfunction is associated with β-cell failure and insulin resistance in diabetes. Humanin is an endogenous cytoprotective peptide. In the current study, we aimed to define the effects of Humanin on mitochondrial biogenesis in pancreatic β-cells. Our findings demonstrated that Humanin treatment significantly increased the expression of PGC-1α and its downstream target genes NRF1 and TFAM in MIN6 β-cells. Notably, Humanin treatment significantly promoted mitochondrial biogenesis by increasing mitochondrial mass, elevating mtDNA/nDNA ratio, and stimulating the expression of cytochrome B, which were suppressed by the specific AMPK inhibitor compound C. Indeed, Humanin treatment caused the phosphorylation of AMPK, which was involved in the induction of PGC-1α, NRF1, and TFAM by Humanin. Importantly, our findings indicate that Humanin treatment led to a possible functional gain of the mitochondria by increasing ATP levels and respiratory rate. Our findings provided a new insight into the molecular mechanisms of action by which Humanin improves pancreatic β-cell function via enhanced mitochondrial mass and performance.

Ethnobotanical Study of Medicinal Plants Used for the Treatment of Human and Livestock Ailments in Dawe Kachen District of Bale Zone, Southeast Ethiopia

An ethnobotanical study of medicinal plants was carried out in Dawe Kachen district of Bale zone, southeastEthiopia with the objectives to identify medicinal plants and to document the knowledge associated with themedicinal plants. Four Kebeles were selected for the study based on the vegetation cover and availability ofthe practices. Accordingly,80 informants were systematically selected. Recommendation from local leadersand elders was employed to select the key informants. Semi-structured interview and observation was used tocollect the data from the traditional healers. The collected data was analyzed using Micro-soft Excelspreadsheet 2007 and summarized using descriptive statistical methods. A total of 42 medicinal plants(belonging to 36 genera and 23 families) used to cure different ailments in the area were recorded.Accordingly Euphorbiaceous followed by Asclepiadaceae dominated the families. Almost all medicinal plantswere collected from the wild. Herbs (38.1%) followed by shrubs (30.9%), trees (28.6%) and climbers (2.4%)dominated the plant growth forms. Root (35.71%) is the most commonly harvested plant part in the areafollowed by leaf (19.05%), stem (14.28%), root & leaf (9.52%), latex (7.14%), bark (4.76%) and root & stem,leaf & stem, flower, seed (2.38%) each. Majority of the medicinal plants (76.19%) used for the treatment ofhuman ailments. Most of the medicinal plants (61.9%), in the study area used in fresh form. Crushing(52.38%) followed by powdering (23.8%) was the most commonly used methods of preparation in the area.Oral administration is the dominant rout (45.20%), followed by dermal (38.10%),oral & dermal(9.50%),nasal (4.80%) and anal (2.38%). Of the five medicinal plants of preference ranking, the highest rankwas given first for Cyphiaql and ulifera used for the treatment of abdominal pain. Gamphocarpus integerwas also perceived as the most threaten medicinal plant in the area based on the priority ranking. Aconservation measure for the medicinal plants in the area is recommended

The mitochondrial-derived peptide humanin activates the ERK1/2, AKT, and STAT3 signaling pathways and has age-dependent signaling differences in the hippocampus.

Humanin is a small secreted peptide that is encoded in the mitochondrial genome. Humanin and its analogues have a protective role in multiple age-related diseases including type 2 diabetes and Alzheimer's disease, through cytoprotective and neuroprotective effects both in vitro and in vivo. However, the humanin-mediated signaling pathways are not well understood. In this paper, we demonstrate that humanin acts through the GP130/IL6ST receptor complex to activate AKT, ERK1/2, and STAT3 signaling pathways. Humanin treatment increases phosphorylation in AKT, ERK 1/2, and STAT3 where PI3K, MEK, and JAK are involved in the activation of those three signaling pathways, respectively. Furthermore, old mice, but not young mice, injected with humanin showed an increase in phosphorylation in AKT and ERK1/2 in the hippocampus. These findings uncover a key signaling pathway of humanin that is important for humanin's function and also demonstrates an age-specific in vivo effect in a region of the brain that is critical for memory formation in an age-dependent manner.

Humanin prevents brain mitochondrial dysfunction in a cardiac ischaemia-reperfusion injury model.

What is the central question of this study? Myocardial ischaemia-reperfusion (I/R) injury causes interference in the systemic circulation and damages not only the heart but also several vital organs, including the brain. Recently, a novel peptide called humanin has been shown to exert potent neuroprotective effects. However, the effect of humanin on the brain during cardiac I/R injury has not yet been investigated. What is the main finding and its importance? The I/R injury caused blood-brain barrier breakdown, increased brain oxidative stress and resulted in mitochondrial dysfunction. Only the humanin treatment before ischaemia attenuated brain mitochondrial dysfunction, but it did not prevent blood-brain barrier breakdown or brain oxidative stress. Humanin treatment during ischaemia and in the reperfusion period provided no neuroprotection. These findings indicate that humanin exerted neuroprotection during cardiac I/R injury via improved brain mitochondrial function. Myocardial ischaemia-reperfusion (I/R) injury causes interference in the systemic circulation and damages not only the heart but also several vital organs, including the brain. Nevertheless, limited information is available regarding the effect of cardiac I/R injury on the brain, including blood-brain barrier (BBB) breakdown, brain oxidative stress and mitochondrial function. Recently, a novel peptide called humanin has been shown to exert potent neuroprotective effects. However, the effect of humanin on the brain during cardiac I/R injury has not yet been investigated. Forty-two male Wistar rats were divided into the following two groups: an I/R group, which was subjected to a 30min left anterior descending coronary artery occlusion followed by 120min reperfusion (I/R group; n=36); and a sham group (n=6). The I/R group was divided into six subgroups. Each subgroup was given either vehicle or humanin analogue (84μgkg(-1) , i.v.) at three different time points, namely before ischaemia, during ischaemia or at the onset of reperfusion. At the end of the experimental protocol, animals were killed and the brains removed for determination of mitochondrial function, oxidative stress and Western blot analyses. The I/R injury caused BBB breakdown, increased brain oxidative stress and resulted in mitochondrial dysfunction. Only the humanin treatment before ischaemia attenuated brain mitochondrial dysfunction, but it did not prevent BBB breakdown or brain oxidative stress. Humanin treatment during ischaemia and in the reperfusion period provided no neuroprotection. These findings indicate that humanin exerted neuroprotection during cardiac I/R injury via improved brain mitochondrial function.

The Mitochondrial-Derived Peptide Humanin Protects RPE Cells From Oxidative Stress, Senescence, and Mitochondrial Dysfunction.

PurposeTo investigate the expression of humanin (HN) in human retinal pigment epithelial (hRPE) cells and its effect on oxidative stress–induced cell death, mitochondrial bioenergetics, and senescence.MethodsHumanin localization in RPE cells and polarized RPE monolayers was assessed by confocal microscopy. Human RPE cells were treated with 150 μM tert-Butyl hydroperoxide (tBH) in the absence/presence of HN (0.5–10 μg/mL) for 24 hours. Mitochondrial respiration was measured by XF96 analyzer. Retinal pigment epithelial cell death and caspase-3 activation, mitochondrial biogenesis and senescence were analyzed by TUNEL, immunoblot analysis, mitochondrial DNA copy number, SA-β-Gal staining, and p16INK4a expression and HN levels by ELISA. Oxidative stress–induced changes in transepithelial resistance were studied in RPE monolayers with and without HN cotreatment.ResultsA prominent localization of HN was found in the cytoplasmic and mitochondrial compartments of hRPE. Humanin cotreatment inhibited tBH-induced reactive oxygen species formation and significantly restored mitochondrial bioenergetics in hRPE cells. Exogenous HN was taken up by RPE and colocalized with mitochondria. The oxidative stress–induced decrease in mitochondrial bioenergetics was prevented by HN cotreatment. Humanin treatment increased mitochondrial DNA copy number and upregulated mitochondrial transcription factor A, a key biogenesis regulator protein. Humanin protected RPE cells from oxidative stress–induced cell death by STAT3 phosphorylation and inhibiting caspase-3 activation. Humanin treatment inhibited oxidant-induced senescence. Polarized RPE demonstrated elevated cellular HN and increased resistance to cell death.ConclusionsHumanin protected RPE cells against oxidative stress–induced cell death and restored mitochondrial function. Our data suggest a potential role for HN therapy in the prevention of retinal degeneration, including AMD.

Abstracts From the 36th Annual Scientific Meeting of the HBPRCA

### CONTRIBUTION OF THE AREA POSTREMA TO THE INCREASED CARDIAC SYMPATHETIC NERVE ACTIVITY IN OVINE HEART FAILURE Abukar Y, Ramchandra R, May CN The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia Background : Heart failure (HF) is associated with an increase in cardiac sympathetic nerve activity (CSNA), which is directly linked to mortality in HF patients. The mechanisms responsible for the elevated CSNA remain unclear. Previous studies indicate that the area postrema (AP), a circumventricular organ in the brainstem, plays a role in the control of sympathetic nerve activity. We hypothesized that the elevated CSNA in HF is mediated by the AP and lesioning this region would reduce the increased CSNA in sheep with HF. Aims : To determine the effect of sham lesion or lesion of the AP on CSNA and hemodynamics in conscious sheep with HF. Methods : Studies were conducted in 2 groups of sheep with pacing-induced HF: sham (n=6) and AP lesion (n=6) sheep. Mean arterial blood pressure (MAP), heart rate (HR) and CSNA were recorded simultaneously in conscious sheep at least 4 days after surgery. Results : Heart failure was associated with a significant decrease in ejection fraction (from 74±2 % to 38±1 %; P<0.001), which was similar in both groups. There was a significant reduction in CSNA burst incidence in the AP lesion group compared with the sham group (45±10 and 89±3 bursts/100 heartbeats, respectively; P<0.01). Conclusions : In sheep with HF, the group with lesion of the AP had a significantly lower CSNA compared with the sham group. These data suggest that the AP plays a role in setting the detrimental high levels of CSNA in HF. ### G PROTEIN-COUPLED ESTROGEN RECEPTOR SIGNALING IMPROVES STROKE OUTCOME IN FEMALE MICE Broughton BRS, Jansen GL, Sobey CG Department of Pharmacology, Monash University, Clayton, Victoria, Australia Background: Estrogen has been assumed to provide neuroprotection following stroke entirely via classical estrogen receptors. Interestingly, there is recent evidence that activation of a novel G …

SH3-binding Protein 5 Mediates the Neuroprotective Effect of the Secreted Bioactive Peptide Humanin by Inhibiting c-Jun NH2-terminal Kinase

Humanin is a secreted bioactive peptide that suppresses cell toxicity caused by a variety of insults. The neuroprotective effect of Humanin against Alzheimer disease (AD)-related death is mediated by the binding of Humanin to its heterotrimeric Humanin receptor composed of ciliary neurotrophic receptor α, WSX-1, and gp130, as well as the activation of intracellular signaling pathways including a JAK2 and STAT3 signaling axis. Despite the elucidation of the signaling pathways by which Humanin mediates its neuroprotection, the transcriptional targets of Humanin that behaves as effectors of Humanin remains undefined. In the present study, Humanin increased the mRNA and protein expression of SH3 domain-binding protein 5 (SH3BP5), which has been known to be a JNK interactor, in neuronal cells. Similar to Humanin treatment, overexpression of SH3BP5 inhibited AD-related neuronal death, while siRNA-mediated knockdown of endogenous SH3BP5 expression attenuated the neuroprotective effect of Humanin. These results indicate that SH3BP5 is a downstream effector of Humanin. Furthermore, biochemical analysis has revealed that SH3BP5 binds to JNK and directly inhibits JNK through its two putative mitogen-activated protein kinase interaction motifs (KIMs).