In an experimental model of Alzheimer's disease in mice, oral administration of trehalose disaccharide reduces neuroinflammation assessed by the expression level of microglia activation marker Iba1 and affects the neutrophil degranulation activity. A potential anti-inflammatory effect of 4% trehalose solution associated with a decrease in the activity of leukocyte elastase in plasma was revealed.

Dyslipidemia is a well-known risk factor for the development of cardiovascular diseases and atherosclerosis. The effects of combined pretreatment with atorvastatin and fenofibrate (Tricor) were studied in a mouse model of acute lipemia induced by a general lipase inhibitor, poloxamer 407 (P-407, 250 mg/kg). This lipemia is characterized by significantly increased serum levels of triglycerides (TG), low-density lipoprotein (LDL) cholesterol, together with decreased concentration of high-density lipoprotein (HDL) cholesterol. Atorvastatin pretreatment had a hypolipidemic effect, decreasing concentrations of LDL cholesterol and increasing HDL cholesterol. Pretreatment of mice with fenofibrate decreased TG level, increasing HDL cholesterol. Combined pretreatment with atorvastatin and fenofibrate decreased TG and total cholesterol. Elevation of the serum cystatin C level was found in control and lipemic mice pretreated with atorvastatin, fenofibrate, or both. Liver expression of lysosomal acid lipase increased in atorvastatin- or/and fenofibrate-pretreated groups of lipemic mice. It was concluded that increased expression of lysosomal acid lipase is related to the removal of lipid droplets from hepatocytes, thus preventing acute lipemia. Lastly, cystatin C may be a “theranostic” biomarker for hypolipidemic drugs.

The search for biological markers of neurodegenerative diseases, namely, Alzheimer’s (AD) and Parkinson’s (PD) diseases, is actual problem for fundamental biology and modern medicine. The aim of this review was to present some new results on biomarkers of these neurodegenerative disorders, mainly in biological fluids, like plasma and cerebrospinal fluid. Novel biomarkers in AD include plasma assays for amyloid-β and phosphorylated tau and PET (positron emission tomography) scans, which show great promise for clinical and research use. In PD research, serum cystatin C (Cst3) and homocystein in PD patients were higher than in serum of the normal control group and they were considered as new inflammatory biomarkers. Cst3 in biological fluids was suggested as a promising biomarker for diagnosing PD. Recently, extracellular vesicles (exosomes) have been reported as a new concept in the biomarker field. Serving as transfer vehicles between cells, they represent a promising source of biomarkers for a number of diseases, including neurodegenerative disorders. To date, developmental mechanisms and approaches to the treatment of neurodegenerative diseases (AD, PD) seemingly are extremely relevant, requiring common solutions and the development of new approaches.

The search for effective treatment for neurodegeneration implies attacking the multiple mechanisms of this pathology. Such properties were found in disaccharide trehalose, which shows therapeutic effects in models of many diseases and has been approved by the FDA for use in humans. Trehalose consists of two glucose residues bonded together by a flexible α-1-1'-glycosidic bond, giving it chaperone-like activity. Due to this, it prevents abnormal folding of aberrant proteins and has the properties of a cryo- and bioprotector. However, the main therapeutic effect is determined by the induction of mTOR-independent autophagy mediated by AMPK kinase as the main target. The result is a weakening of the accumulation of cytotoxic proteins and factors and an increase in cell viability. Autophagy activation depends on trehalose-induced lysosome and autophagosome biogenesis through activation of transcription factors TFEB and FOXO1. Trehalose has an anti-inflammatory effect closely related to the inhibition of oxidative stress. Trehalose-induced enhancement of endogenous antioxidant defense involves the regulator Nrf2. The review considers the neuroprotective effects of trehalose in models of major neurodegenerative diseases such as Parkinson’s, Alzheimer’s, Huntington’s and others. Overall, trehalose shows high therapeutic potential in the treatment of experimental neurodegeneration and thus stimulating the study of its clinical application.

Diabetes T2 with insulin resistance is a serious disease all over the world with a tendency to steady increase the number of cases and a risk factor of neurodegenerative diseases development, among them firstly Alzheimer's disease. The aim of this study was to investigate behavior and general characteristic of genetic model of diabetes T2 mice db/db, trying to reveal beginning of development early symptoms of neurodegeneration development and characteristic of symptoms of diabetes T2 during treatment by liraglutide or autophagy inducer trehalose. Mice age was 3 and 5 months. Db/db mice had an increase in body weight, which progressed with age, a decrease in brain mass. Blood glucose levels were increased in db/db mice. Treatment with trehalose or liraglutide reduces its level. Db/db mice were characterized by decrease of overall orientation-exploratory and locomotor activities, increase in anxiety in the open field test. Liraglutide treatment showed positive change in open field test in db/db mice. Passive avoidance test revealed significant decrease in motivation, locomotor and exploratory activity, decreased learning in db/db mice. Db/db mice of both ages were characterized by an increase in the relative number of PMN and monocytes and a decrease in the number of lymphocytes, indicating an inflammatory response. Treatment with trehalose or liraglutide restored these indicators. Thus, the identified behavioral changes in db/db mice reflected the development of neurodegeneration signs. Some positive effects of liraglutide on behavioral processes have been shown. Trehalose and liraglutide reduced blood glucose levels and the severity of the inflammatory response.

Abstract Pathological aggregation and accumulation of α-synuclein in neurons play a core role in Parkinson’s disease (PD) while its overexpression is a common PD model. Autophagy-lysosomal pathways are general intraneural mechanisms of protein clearance. Earlier a suppressed autophagy in the brain of young transgenic mice overexpressing the А53Т-mutant human α-synuclein (mut(PD)) was revealed. Previous studies have recognized that Cystatin C displays protective activity against neurodegeneration. This cysteine protease inhibitor attracts particular attention as a potential target for PD treatment related to autophagy modulation. Here we evaluated the mRNA levels of Cst3 encoding Cystatin C in different brain structures of 5 m.o. mut(PD) mice at standard conditions and after the chronic treatment with a neuroprotective agent, ceftriaxone (100 mg/kg, 36 days). The inflammatory markers, namely, microglial activation by IBA1 expression and mRNA levels of two chitinases genes (Chit1, Chia1), were also assessed but no significant difference was found between control and transgenic mice. Cst3 mRNA levels were significantly reduced in the striatum and amygdala in the transgenic PD model. Furthermore, this was associated with autophagy decline and might be added to early signs of synucleinopathy development. We first demonstrated the modulation of mRNA levels of Cst3 and autophagy marker Becn1 in the brain by ceftriaxone treatment. Taken together, the results support the potential of autophagy modulation through Cystatin C at early stages of PD-like pathology.

Autophagy is a dynamic cellular process involved in the turnover of proteins, protein complexes, and organelles through lysosomal degradation. It is particularly important in neurons, which do not have a proliferative option for cellular repair. Autophagy has been shown to be suppressed in the striatum of a transgenic mouse model of Parkinson’s disease. Cystatin C is one of the potent regulators of autophagy. Changes in the expression and secretion of cystatin C in the brain have been shown in amyotrophic lateral sclerosis, Alzheimer’s and Parkinson’s diseases, and in some animal models of neurodegeneration, thus proving a protective function of cystatin C. It has been suggested that cystatin C plays the primary role in amyloidogenesis and shows promise as a therapeutic agent for neurodegenerative diseases (Alzheimer’s and Parkinson’s diseases). Cystatin C colocalizes with the amyloid β-protein in the brain during Alzheimer’s disease. Controlled expression of a cystatin C peptide has been proposed as a new approach to therapy for Alzheimer’s disease. In Parkinson’s disease, serum cystatin C levels can predict disease severity and cognitive dysfunction, although the exact involvement of cystatin C remains unclear. The aim: to study the role of cystatin C in neurodegeneration and evaluate the results in relation to the mechanism of autophagy. In our study on humans, a higher concentration of cystatin C was noted in cerebrospinal fluid than in serum; much lower concentrations were observed in other biological fluids (intraocular fluid, bile, and sweat). In elderly persons (61–80 years old compared to practically healthy people at 40–60 years of age), we revealed increased cystatin C levels both in serum and intraocular fluid. In an experiment on C57Bl/6J mice, cystatin C concentration was significantly higher in brain tissue than in the liver and spleen: an indication of an important function of this cysteine protease inhibitor in the brain. Using a transgenic mouse model of Parkinson’s disease (5 months old), we demonstrated a significant increase in osmotic susceptibility of brain lysosomes, depending on autophagy, while in a murine model of Alzheimer’s disease, this parameter did not differ from that in the appropriate control.

Autophagy is a dynamic cellular process involved in the turnover of proteins, protein complexes, and organelles through lysosomal degradation. It is particularly important in neurons, which do not have a proliferative option for cellular repair. Autophagy has been shown to be suppressed in the striatum of a transgenic mouse model of Parkinson's disease. Cystatin C is one of the potent regulators of autophagy. Changes in the expression and secretion of cystatin C in the brain have been shown in amyotrophic lateral sclerosis, Alzheimer's and Parkinson's diseases, and in some animal models of neurodegeneration, thus proving a protective function of cystatin C. It has been suggested that cystatin C plays the primary role in amyloidogenesis and shows promise as a therapeutic agent for neurodegenerative diseases (Alzheimer's and Parkinson's diseases). Cystatin C colocalizes with the amyloid beta-protein in the brain during Alzheimer's disease. Controlled expression of a cystatin C peptide has been proposed as a new -approach to therapy for Alzheimer's disease. In Parkinson's disease, serum cystatin C levels can predict disease severity and cognitive dysfunction, although the exact involvement of cystatin C remains unclear. The aim: to study the role of cystatin C in neurodegeneration and evaluate the results in relation to the mechanism of autophagy. In our study on humans, a higher concentration of cystatin C was noted in cerebrospinal fluid than in serum; much lower concentrations were observed in other biological fluids (intraocular fluid, bile, and sweat). In elderly persons (61-80 years old compared to practically healthy people at 40-60 years of age), we revealed increased cystatin C levels both in serum and intraocular fluid. In an experiment on C57Bl/6J mice, cystatin C concentration was significantly higher in brain tissue than in the liver and spleen: an indication of an important function of this cysteine protease inhibitor in the brain. Using a transgenic mouse model of Parkinson's disease (5 months old), we demonstrated a significant increase in osmotic susceptibility of brain lysosomes, depending on autophagy, while in a murine model of Alzheimer's disease, this parameter did not differ from that in the appropriate control.

The development of arterial hypertension in male Wistar rats with fructose-induced metabolic syndrome (12.5% of fructose solution as the only drinking source for 10 weeks) along with impaired glucose tolerance and increased serum concentration of triglycerides and LPO products caused a decrease in the content of serum blood calcitonin gene-related peptide (CGRP). Low-frequency transcutaneous electrical nerve stimulation (1 mA, 2 Hz, 10 min daily for 2 weeks) performed in 8 weeks after the beginning of fructose treatment reduced systolic BP and serum concentration of triglycerides and LPO produces and improved glucose tolerance. After stimulation, CGRP content in rats maintained on fructose diet returned to normal values and the content of nitric oxide metabolites increased. We hypothesize that CGRP and nitric oxide are involved in mechanisms mediating the therapeutic effect of low-frequency transcutaneous electrical nerve stimulation on arterial hypertension developing in metabolic syndrome.

The neuroprotective effect of autophagy activation by rapamycin and trehalose was studied in a mouse model of Parkinson's disease (PD) induced by neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Both rapamycin (10 mg/kg/day, 7 days) and trehalose (2% in drinking water, 7 days) increased the expression of LC3-II (a marker of autophagy activation) in the frontal cortex and striatum of normal C57Bl/6J mice, with signs of an additive effect. Autophagy stimulation in the striatum was confirmed by a lysosomal osmotic test. In the model of MPTP-induced PD, the two drugs were applied starting from the 2nd day after subchronic daily MPTP administration (20 mg/kg/day, 4 days). A marked increase in LC3-II expression in the striatum was detected under the action of trehalose and in the S. nigra after combined treatment with rapamycin and trehalose. The drugs had a positive effect for recovery of dopaminergic neurons and neuroprotection after MPTP-induced PD-like injury. The therapeutic effect was proven by active restoration of tyrosine hydroxylase (TH) content in the striatum and S. nigra and by improved cognition measured by the passive avoidance learning task. The results revealed the additive effect of the combined treatment with rapamycin and trehalose on dopaminergic deficits (according to the levels of TH expression in the nigrostriatal system) but not on the behavioral performance in the mouse PD model. Thus, the autophagy activation through different pathways by the combination of rapamycin and trehalose reverses both neuronal dopaminergic and behavioral deficits in vivo and seems to be a promising therapy for PD-like pathology.

Rapamycin is a strong inducer of autophagy which binds with its target protein mTOR and causes inhibition of biosynthetic and mitotic cell activities. The review considers neuroprotective properties of autophagy induction by rapamycin. The most important feature of the neurodegenerative diseases is the accumulation of specific proteins, such as amyloid-β, α-synuclein, huntingtin, etc. Their accumulation is associated with the weakening of the cellular function of the protein quality control provided by the ubiquitin-proteasomal system and autophagy, including chaperone-mediated autophagy. In many cases, activation of autophagy by rapamycin is able to restore the quality control of proteins and organelles, to attenuate the accumulation of pathogenic proteins. Mechanisms of rapamycin therapeutic effects include activation of the clearance of neurons from pathogenic material and induction of both autophagosomal segregation of cellular material and the lysosomal flux by activating TFEB factor, which is the inductor of the lysosomal biogenesis. Short-term treatment with rapamycin has a positive therapeutic effect in models of acute brain injury (trauma, ischemia, hypoxia). Inhibition of neurodegeneration requires long-term therapy. Neuroprotective effect of rapamycin is higher if started at young age. Good results are achieved by prolonged treatment with rapamycin in intermittent mode.

Cysteine proteases are regulated by the rate of the conversion of their inactive proforms into active forms and by specific endogenous inhibitors (cystatins), playing the important role in their regulation, especially in tumor growth and metastasis process. The content of procatepsin B, endogenous inhibitors of cysteine proteases cystatin B and cystatin C in biological fluids (blood serum, ascites fluid) in women with malignant neoplasms of the genital organs was studied. The comparative study of the concentration of procotepsin B, cystatin B and C in blood serum in practically healthy women and women with tumors of the reproductive system was carried out with the use of the enzyme immunoassay nethod. A high content of procatepsin B was shown to be found in all the study groups. The concentration of cystatin B was within the limits of significance and concentration of cystatin C was not changed in same patients in the study groups as compared with the control. The level of cystatin C in the serum was found to be correlated with the progression of the disease. In ascitic fluid (in comparison with blood serum), a sharp increase in the concentration of procatepsin B was revealed, reflecting its elevated extracellular secretion by tumor cells.

Mannans, which are biological macromolecules of polysaccharide origin and function as immunomodulators, have been shown to stimulate macrophages in vivo by interaction with the mannose receptor. Thus, they can be used to stimulate macrophages in order to effectively remove circulating atherogenic lipoproteins. Our primary aim was to evaluate the hypolipidemic potential of mannans from C. albicans serotype A (mannan A) and serotype B (mannan B) in a murine model of hyperlipidemia. Mannan A and mannan B were shown to significantly (p<0.05) stimulate both the proliferation (p <0.05) and nitric oxide production of murine peritoneal macrophages in vitro. Pre-treatment of CBA/Lac mice with mannan A prior to induction of hyperlipidemia significantly (p<0.001) reduced serum atherogenic LDL-cholesterol, total cholesterol, and triglycerides. Mannan B exhibited a similar, but more potent, hypolipidemic effect. Electron microscopic analysis of liver revealed a significant (p<0.001) decrease in the volume of lipid droplets when hyperlipidemic mice were pretreated by both mannans. In conclusion, our findings would suggest that both polysaccharide-based biological macromolecules evaluated in the present study, specifically, the natural immunomodulators (mannans A and B), appeared to function as effective lipid-lowering macromolecules, which could potentially serve as adjunct therapy to more conventional hypolipidemic medications such as a statin drug.

The role of autophagy in supporting cellular survival and inhibiting neurodegeneration in Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, which are accompanied by the accumulation of the proteins β-amyloid, α-synuclein, and huntingtin, is discussed. Autophagy undergoes various degrees of weakening in these diseases, and also decreases in aging. Removal of accumulated toxic proteins and structures is mediated by the mechanisms of autophagy (chaperone-mediated autophagy, macroautophagy, mitophagy) in interactions with the ubiquitin-proteasome system. In many cases, activation of mTOR-dependent autophagy and mTOR-independent pathways for its regulation leads to the therapeutic effect of inhibiting neurodegeneration in cell cultures and animal models of diseases. A number of autophagy activators (resveratrol, metformin, rilmenidine, lithium, cucurmin, etc.) are in the stage of clinical trials.