The Level of ALR is Regulated by the Quantity of Mitochondrial DNA

The Changes of Mitochondria during Aging and Regeneration

Aging and regeneration are opposite cellular processes. Aging refers to progressive dysfunction in most cells and tissues, and regeneration refers to the replacement of damaged or dysfunctional cells or tissues with existing adult or somatic stem cells. Various studies have shown that aging is accompanied by decreased regenerative abilities, indicating a link between them. The performance of any cellular process needs to be supported by the energy that is majorly produced by mitochondria. Thus, mitochondria may be a link between aging and regeneration. It should be interesting to discuss how mitochondria behave during aging and regeneration. The changes of mitochondria in aging and regeneration discussed in this review can provide a timely and necessary study of the causal roles of mitochondrial homeostasis in longevity and health.

Role of augmenter of liver regeneration on testicular ischemia and ischemia/reperfusion injury: An experimental study

Background

Testicular torsion causes ischemic injury, and torsion causes reperfusion injury.

Aim

Evaluating the role of augmenter of liver regeneration (ALR) in testicular ischemia and ischemia/reperfusion injury.

Materials and Method(s)

Seventy-eight (78) healthy Wistar albino male rats were randomly divided into four groups; control (C) (n = 6), sham (S) (n = 24), torsion (T) (n = 24), and torsion/detorsion (T/D) (n = 24). S, T, and T/D groups were divided into four subgroups (n = 6) as 1st, 2nd, 3rd, and 4th hours. Blood, tissue ALR, and histology analyses were performed between groups and subgroups.

Results

The increase in plasma ALR values at the 3rd and 4th hours compared to the 1st hour in the T group were significant (P < 0.01, P < 0.001, respectively). In the T/D group, a significant increase was observed in plasma ALR values at the 3rd and 4th hours compared to the 1st hour (P < 0.05, P < 0.001, respectively). Plasma ALR values at the 1st, 2nd, 3rd, and 4th hours were higher in the T and T/D groups than in the C group (P < 0.001, P < 0.05, respectively). Plasma ALR values were higher in the T group at the 1st, 2nd, 3rd, and 4th hours than in the S group (P < 0.05). A significant increase was observed in tissue ALR at the 3rd and 4th hours than at the 1st hour in the T group (P < 0.05, P < 0.001, respectively). A significant increase was observed in tissue ALR at the 3rd and 4th hours than in the 1st hour in the T/D group (P < 0.05, P < 0.001, respectively).

Discussion

ALR in plasma and testicular tissue has a potential role in the early diagnosis of testicular torsion and in predicting the prognosis of T and T/D.

Comparison of the response of alternative oxidase and uncoupling proteins to bacterial elicitor induced oxidative burst

Plant UCPs are proved to take part in the fine-tuning of mitochondrial ROS generation. It has emerged that mitochondrion can be an important early source of intracellular ROS during plant-pathogen interaction thus plant UCPs must also play key role in this redox fine-tuning during the early phase of plant-pathogen interaction. On the contrary of this well-established assumption, the expression of plant UCPs and their activity has not been investigated in elicitor induced oxidative burst. Thus, the level of plant UCPs both at RNA and protein level and their activity was investigated and compared to AOX as a reference in Arabidopsis thaliana cells due to bacterial harpin treatments. Similar to the expression and activity of AOX, the transcript level of UCP4, UCP5 and the UCP activity increased due to harpin treatment and the consequential oxidative burst. The expression of UCP4 and UCP5 elevated 15-18-fold after 1 h of treatment, then the activity of UCP reached its maximal value at 4h of treatment. The quite rapid activation of UCP due to harpin treatment gives another possibility to fine tune the redox balance of plant cell, furthermore explains the earlier observed rapid decrease of mitochondrial membrane potential and consequent decrease of ATP synthesis after harpin treatment.