Proteostasis and neurodegeneration: a closer look at autophagy in Alzheimer's disease

Alzheimer's disease (AD) is characterized by the accumulation of misfolded amyloid-beta and tau proteins. Autophagy acts as a proteostasis process to remove protein clumps, although it progressively weakens with aging and AD, thus facilitating the accumulation of toxic proteins and causing neurodegeneration. This review examines the impact of impaired autophagy on the progression of AD disease pathology. Under normal circumstances, autophagy removes abnormal proteins and damaged organelles, but any dysfunction in this process can lead to the exacerbation of amyloid and tau pathology, particularly in AD. There is increasing attention to therapeutic tactics to revitalize autophagy, including reduced caloric intake, autophagy-stimulating drugs, and genetic therapy. However, the translation of these strategies into clinical practice faces several hurdles. In summary, this review integrates the understanding of the intricate role of autophagy dysfunction in Alzheimer's disease progression and reinforces the promising prospects of autophagy as a beneficial target for treatments to modify the course of Alzheimer's disease.

The Association between Serum Oxidative Stress Indexes and Pathogenesis of Parkinson's Disease in the Northwest of Iran

Background:

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder. Oxidative stress is a main modulator in the advancement of PD. This investigation aimed to evaluate the relations between serum trace elements, vitamin C, ferritin, transferrin, Nitrite Oxide (NOx) and Peroxynitrite (PrN) concentrations and clinical parameters in patients with PD.

Methods:

Serum concentrations of variables were measured in 75 PD patients and 75 healthy subjects from Imam Reza Hospital, Tabriz University of Medical Sciences, Tabriz, Iran between Feb 2016 and Sep 2018. Receiver Operating Characteristic (ROC) analysis was performed to examine incremental diagnostic value of vitamin C, NOx, and PrN in the study groups.

Results:

Mean serum NOx (35.81±5.16 vs. 11.27±3.59 mol/L, P<0.001) and PrN (15.78±4.23 vs. 9.62±4.57 mol/L, P= 0.004) were markedly higher in patient group versus healthy individuals. Significant differences were also observed in the serum levels of vitamin C (P<0.001), copper (Cu) (P<0.001), Iron (Fe) (P=0.003), and Zinc (Zn) (P<0.001) between patients with PD and healthy subjects. Nevertheless, the serum levels of Se (P=0.515), ferritin (P=0.103), and transferrin (P=0.372) were not statistically significant between the study groups. ROC analysis has revealed a diagnostic ability of serum vitamin C levels for PD with an area under ROC curve of ≥0.7 (P<0.05) and relatively high sensitivity and specificity.

Conclusion:

Serum levels of NOx and PrN are significantly higher in patients with PD. In additions, serum vitamin C levels have a diagnostic value as a biomarker. Further studies are required with larger sample size to provide more detailed information about the cognitive profile of participants and the outcome measures.

Serum lipid profile of Parkinson's disease patients: A study from the Northwest of Iran

BACKGROUND

Parkinson's disease (PD) is defined as a long-lasting, neurological illness. Low levels of serum lipid fractions are related with a high risk of PD. Current investigation was designed to evaluate the concentration blood lipid fractions in patients suffering from PD and compared with healthy subjects.

METHODS

This case-control study was conducted from February 2016 to September 2018 in Tabriz University of Medical Sciences, Tabriz, Iran. The present investigation consisted of 75 persons who had PD and 75 normal people. The blood levels of lipid fractions were measured by concentrations of total cholesterol (TC), serum triglycerides (TG), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and total cholesterol. The results were analyzed with SPSS software using Kolmogorov-Smirnov, chi-square, and student's t-test.

RESULTS

Serum level of TG was remarkably lower in patients with PD (111.92±8.75 mg/dL) compared with healthy subjects (123.64±9.97 mg/dL, P=0.008). Furthermore, we saw an important difference in the level of LDL-C (P=0.001) and TC (P=0.004) between the two groups. However, there was not any observed meaningful difference in the serum concentrations of HDL-C between the studied groups (P=0.135).

CONCLUSION

Our results showed that the serum concentration of TG, LDL-C, and TC are noticeably lower in the PD suffering patients. Further investigations are needed to provide comprehensive information on the participants' cognitive layout and subsequent actions.

Investigation of insulin-like growth factors/insulin-like growth factor binding proteins regulation in metabolic syndrome patients

OBJECTIVE

The insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are thought to play a significant role in metabolic pathways and glucose metabolism. Unregulated levels of IGFs/IGFBPs have been associated with the development of glucose intolerance and metabolic syndrome X (MSx). We hypothesized that change of IGFs/IGFBPs levels could increase the risk of MSx; thus, this study aimed to evaluate the serostatus of IGFs/IGFBPs in individuals with MSx.

RESULTS

After adjustment for metabolic parameters, MSx patients had a lower level of IGF-1, IGFBP-1, and IGFBP-2 compared with subjects in the control group. Further analysis revealed a positive correlation between serum levels of IGF-1 and IGF-2 (p < 0.05), as well as serum IGFBP-3 and IGF-2 (p < 0.05). Also, the statistical analysis showed a negative association of serum IGF-1 with plasma glucose and total cholesterol levels (p < 0.05). Besides, a negative relationship was found between serum concentrations of IGF-1/IGF-2 and the risk of developing MSx. These data indicated that some components of IGFs/IGFBPs are linked with the pathogenesis of MSx. In conclusion, these inverse associations showed a possible linkage between the IGF/IGFBP signaling pathway and the development of MSx. It seems the decreased concentrations of IGFs edmay be regarded as a potential biomarker for early diagnosis or even prognosis of MSx but need more systematic studies to confirmed it.

The effects of high and low doses of folic acid on oxidation of protein levels during pregnancy: a randomized double-blind clinical trial

Objective

Oxidants include important active molecules which are created in the body and attack biological molecules especially lipids, carbohydrates, nucleic acids and proteins, and cause oxidation and various diseases in the body. Antioxidants existing in the body help to avoid the incidence of these injuries. Pregnant women are among those where oxidation of biological molecules may do irreparable damage to them and their embryos. So, the purpose of this study was to review the effect of folic acid with both high (5 mg/day) and low (0.5 mg/day) doses on the changes of oxidative protein in reducing plasma homocystein concentration during pregnancy.

Materials and methods

Forty-five pregnant women participated in this study. They were divided into two groups: group 1 included 23 women who received 5 mg/day folic acid and group 2 included 23 women who took 0.5 mg/day folic acid before pregnancy till the 36th week pregnancy. We measured the biochemical variables in the serum of pregnant women at the beginning and at the end of the study.

Results

Folic acid reduced plasma homocytein in both low and high dose groups (p = 0.035, p = 0.012, respectively). Also, the results showed that folic acid prescription led to reduce plasma level of carbonyl groups in both low and high dose groups (p = 0.01, p = 0.03, respectively). Furthermore, the results showed that there is no significant difference between two groups and folic acid affects both groups equally.

Conclusion

It is possible that folic acid administration can reduce plasma homocysteine and carbonyl levels during pregnancy in dose independent manner

Protective effect of vitamin E against ethanol-induced small intestine damage in rats

The role of oxidative stress and inflammatory reaction has been reported in various ethanol-induced complications. The purpose of this study was to evaluate the effect of ethanol-induced structural alteration, oxidative stress, and inflammatory reaction on the small intestine of rats, and plausible protective effect of vitamin E to determine whether it inhibits the abnormality induced by ethanol in the small intestine. Twenty-four male wistar rats were divided into three groups, namely: Control, ethanol, and vitamin E treated ethanol groups. After six weeks of treatment, the small intestine length, villus height, crypt depth and muscular layer thickness, oxidative stress, and inflammatory parameters showed significant changes in the ethanol treated group compared to the control group. Vitamin E consumption along with ethanol ameliorated structural alteration of the small intestine and reduced the elevated amount of oxidative stress and inflammatory markers such as protein carbonyl, OX-LDL, IL-6, Hcy, and TNF-α. Furthermore, their total antioxidant capacity was increased significantly compared to that of the ethanol group. These findings indicate that ethanol induces the small intestine abnormality by oxidative and inflammatory stress, and that these effects can be alleviated by using vitamin E as an antioxidant and anti-inflammatory molecule.