Role of Oxidative Stress Markers F2-Isoprostanes and Presenilin-1 in Clinical Diagnosed Alzheimer’s Diseases

ABSTRACT

Introduction:

Alzheimer’s disease (AD), a neurodegenerative disorder closely associated with aging, is characterized by progressive cognitive decline and is a leading cause of dementia worldwide. Oxidative stress plays a pivotal role in AD’s pathophysiology, contributing to amyloid-beta accumulation, neurofibrillary tangles, and neuronal damage.

Aim:

This study investigates the potential of F2-isoprostanes and Presenilin-1 (PSEN1) as biomarkers for oxidative stress and their association with clinically diagnosed Alzheimer’s disease.

Materials and Methods:

A comparative cross-sectional study will be conducted, enrolling 50 AD patients and 50 age-matched healthy controls from the Vidarbha region. Serum levels of F2-isoprostanes and PSEN1 will be measured using advanced analytical techniques, and their correlation with AD progression will be analyzed statistically.

Results and Conclusion:

The findings are expected to provide insights into the diagnostic and prognostic value of these markers, offering potential avenues for early detection and therapeutic intervention in Alzheimer’s disease.

INTRODUCTION

Alzheimer’s disease (AD) is one of the most closely related to aging brain neurodegenerative disease.

Like other neurodegenerative illnesses, AD is characterized by progressive worsening of cognitive capacity and represents the most frequent condition of dementia.[1]

In Alzheimer’s disease, oxidative stress has been shown to contribute to the accumulation of amyloid beta (Aβ) and tau proteins, which are hallmark features of the disease. ROS can also activate inflammatory pathways in the brain, which can contribute to the progression of Alzheimer’s disease. The extracellular accumulation of Aβ and impaired mitochondria function could trigger free radical formation.[2]

Oxidative stress has been implicated in the development of Parkinson’s disease, which is characterized by the loss of dopamine-producing neurons in the brain. ROS can cause damage to these neurons, leading to their dysfunction and death.[3] Additionally, oxidative stress can contribute to the accumulation of alpha-synuclein protein, which is another hallmark feature of Parkinson’s disease.[4]

ISO-PROSTANE F2

F₂-isoprostanes are a group of 64 compounds isomeric in structure to cyclooxygenase-derived PGF_2α. Other products of the isoprostane pathway are also formed in vivo by rearrangement of labile PGH₂-like isoprostane intermediates. These include E₂- and D₂-isoprostanes,[5] cyclopentenone-A₂- and J₂-isoprostanes,[6] and the highly reactive acyclic-ketoaldehydes (isoketals).[7]

PRESENILIN 1

Presenilin 1 (PSEN1) is a protein that plays a critical role in the development and maintenance of the nervous system. It is a transmembrane protein located in the endoplasmic reticulum and plasma membrane of cells and is primarily known for its involvement in the pathogenesis of Alzheimer’s disease.[8] In addition to its role in Alzheimer’s disease, PSEN1 has also been implicated in other neurological disorders, such as frontotemporal dementia, Parkinson’s disease, and Huntington’s disease. Research has shown that PSEN1 is involved in the regulation of calcium signaling, synaptic function, and neuronal survival, among other cellular processes.[9]

OTHER COMMON OXIDATIVE STRESS MARKERS

1. Malondialdehyde (MDA)

2. 4-hydroxynonenal (4-HNE)

3. 8-hydroxy-2-deoxyguanosine (8-OHdG)

4. Advanced Glycation End Products (AGEs)

5. Protein carbonyls

6. Glutathione (GSH) and Glutathione Disulfide (GSSG)

Hypothesis

Null Hypothesis: “There is no significant association between oxidative stress and the aging process or the development of age-related diseases such as Alzheimer’s. Any observed correlations are due to random chance or other confounding factors.”

Alternative Hypothesis “There is a significant association between oxidative stress and the aging process or the development of age-related diseases such as Alzheimer’s. Any observed correlations are due to random chance or other confounding factors.”

RESEARCH GAP:

Despite evidence suggesting a link between oxidative stress in clinically diagnosed Alzheimer’s diseases, the precise mechanisms by which oxidative stress contributes to disease progression remain not completely understood. Further research is needed to elucidate these mechanisms at the molecular, cellular, and systemic levels.

Research question

How do oxidative stress markers F2-isoprostanes and presenilin-1 correlate with the progression in clinically diagnosed Alzheimer’s diseases?

Aim and objective

Aim:

1. Study of F2-isoprostanes and presenilin-1 as a biomarker of clinically diagnosed Alzheimer’s diseases.

2. To compare levels of F2-isoprostanes and presenilin-1 as a biomarker of clinically diagnosed Alzheimer’s diseases.

Objective

1. To Estimate F2 Isoprostanes and Presenilin 1 in clinically diagnosed Alzheimer’s diseases.

2. To compare between F2 Isoprostanes and Presenilin 1 in clinically diagnosed Alzheimer’s diseases.

REVIEW OF LITERATURE

Alzheimer’s disease is a neuropsychiatric disorder affecting elderly people first characterized by Alois Alzheimer’s in 1906. It is a progressive mental deterioration manifested by memory loss, inability to calculate, visual-spatial disturbances, confusion, and disorientation.AD causes 50% of dementia seen in clinics and hospitals[10]

Despite extensive studies, the etiology of AD is not yet clearly understood. However studies have shown that oxidative reactions play a significant role in the pathogenesis of AD and oxidative stress is primarily responsible for producing neurofibrillary tangles, the histopathological hallmark of the disease.[11] Which is also generally accompanied by the formation of senile plaques precipitated in the brain.[12] Neuronal loss and impaired synaptic function are the other manifestations. The oxidative stress may be caused by some trace elements.

There is evidence showing that Aβ precipitation and toxicity leading to AD are caused by abnormal interactions with neocortical metal ions, such as Cu, Fe, and Zn.[13,14] The fact that the homeostasis of these metals is perturbed in AD and that they concentrate in senile plaques, neurofibrillary tangles, and cerebrospinal fluid is well supported.[15] Hence it is hypothesized that the accumulation of these metals might be the key to the damage caused in AD and perhaps to its treatment.[16]

Like in the case of PD, the diagnosis of AD is also entirely clinical based on symptoms. As of today, there is no specific “blood test” or imaging test that is used for the diagnosis of Alzheimer’s disease. Alzheimer’s disease is diagnosed when:

1. A person has sufficient cognitive decline to meet the criteria for dementia;

2. The clinical course is consistent with that of Alzheimer’s disease;

3. No other brain diseases or other processes are better explanations for dementia.

Role of oxidative stress in Alzheimer’s

Oxidative stress is believed to play a significant role in the development and progression of Alzheimer’s disease. Oxidative stress is a condition that arises when the production of reactive oxygen species (ROS) exceeds the body’s natural antioxidant defenses, leading to cellular damage and dysfunction.[17]

Overall, the role of oxidative stress in Alzheimer’s disease highlights the importance of maintaining a healthy oxidative balance in the body through a diet rich in antioxidants and other protective nutrients. Additionally, research is ongoing into the development of therapeutic strategies aimed at reducing oxidative stress in Alzheimer’s patients as a way to slow the progression of the disease.[18]

Oxidative stress and aging

Aging is a complex process that involves the accumulation of various cellular and molecular damages over time. One of the mechanisms that contribute to this process is oxidative stress, which is caused by an imbalance between the production of reactive oxygen species (ROS) and the ability of the body’s antioxidant defense mechanisms to neutralize them.[19]

ROS can cause damage to cellular macromolecules such as DNA, proteins, and lipids, leading to cellular dysfunction and ultimately contributing to the aging process. Several studies have demonstrated that the levels of oxidative damage increase with age in various organisms, including humans.[20]

Oxidative stress and Alzheimer’s disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disease that is characterized by the accumulation of beta-amyloid plaques and neurofibrillary tangles in the brain. The role of oxidative stress in AD has been extensively studied, and several lines of evidence suggest that oxidative stress plays a crucial role in the development and progression of the disease.[21]

MATERIAL AND METHODS

This study will be conducted in the biochemistry department, Department of Psychiatry and Medicine at Jawaharlal Nehru Medical College Sawangi (Meghe) Wardha and Datta Meghe Institute of Higher Education and Research (DU) Sawangi (Meghe), Wardha in Maharashtra, India.

Study period: The study period will be more than 3 years.

Study area: The study will be carried out in at rural area in Vidarbha region.

Study design: Comparative Cross-Sectional Study.

Inclusion criteria

1. Participants aged 60 years and above.

2. Individuals with documented measures of oxidative stress markers.

3. Individuals with Clinically Diagnosed Alzheimer’s disease.

Exclusion criteria

1. Participants below the age of 60 years.

2. Individuals without a diagnosis of Alzheimer’s disease.

3. Individuals with other causes of dementia will be excluded.

4. Studies lacking quantifiable measures of oxidative stress markers.

5. Studies lacking essential clinical data or outcome measures relevant to oxidative stress markers.

Sample size

This Comparative Cross-Sectional Study experimental study on Clinically Diagnosed Alzheimer’s disease patients is proposed to be conducted at JNMC and DMMC. As per available statistical data from National and state estimates from a nationwide study 1^st January 2023 incidence rate of Alzheimer’s disease in the age group of 60 years and above is 7.4%.[22]

The sample size was computed using Epi Info software (version 7.0) with a precision of 7% and a confidence level of 95%, with a design effect of 1%. Exclusion criteria included 10% Alzheimer’s disease linked with concurrent pathologies such as diabetes, hypertension, renal failure, and seriously unwell patients, as well as 10% non-responsive patients. As a result, the ultimate sample size is 50 for study group and 50 for the control group, using the following formula.

$$n=\frac{z^{2}p(1-p)}{e^2}$$

n is the sample size

z is the selected critical value of the desired confidence level (CL95% = 1.96).

p is the estimated proportion of an attribute that is present in the population (7.4% = 0.074).

e is the desired level of precision (7% = 0.07).

So, the final Calculated Sample size is 50 for the study group.

And 50 sample sizes for the control group.

Blood sample collection

Serum samples will be collected in plain tubes and allow samples to clot for 2 hours at room temperature or overnight at 2-8°C. Centrifuge at approximately 1000 × g (or 3000 rpm) for 15 minutes. Collect serum and assay immediately or aliquot and store samples at −20°C or −80°C for estimation F2 Isoprostanes and Presenilin 1.

Statistical analysis

All estimated results will be expressed as mean ± SD. Mean values will be assessed for significance by unpaired student t-test. A statistical analysis will be performed using the Statistical Package for the Social Science program (SPSS, 24.0). Frequencies and percentages will be used for the categorical measures. Probability values P < 0.05 will be considered statistically significant.

SCOPE IMPLICATION (PROBABLE)

Exploring the role of oxidative stress markers F2 isoprostanes and presenilin 1 in clinically diagnosed Alzheimer’s diseases holds promise for advancing our understanding of disease mechanisms, identifying therapeutic targets, developing biomarkers, promoting healthy aging, and ultimately improving clinical outcomes for individuals affected by these conditions.

Expected outcome

Measuring F2 isoprostanes and presenilin 1 levels can provide useful information about the early diagnosis, severity, and progression of Alzheimer’s disease. Elevated levels of F2 isoprostanes may indicate increased oxidative stress and inflammation, which can contribute to the progression and early detection of the diseases. Similarly, and also measuring presenilin 1 levels may help to identify individuals who are at risk for developing Alzheimer’s disease or who may be experiencing early onset of the disease.

However, it’s important to note that the use of biomarkers like F2 isoprostanes and presenilin 1 in diagnosing Alzheimer’s disease is still being studied, and additional research is needed to fully understand their diagnostic and prognostic value.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.