Effect of oxamic analogues on functional mice sperm parameters

Qiangjing tablets ameliorate asthenozoospermia via mitochondrial ubiquitination and mitophagy mediated by LKB1/AMPK/ULK1 signaling

CONTEXT

Therapeutic effects of Qiangjing tablets (QJT) on sperm vitality and asthenozoospermia (AZS) have been confirmed. However, the mechanism of action remains unclear.

OBJECTIVE

This study investigates the effects of QJT on AZS and the underlying mechanism of action.

MATERIALS AND METHODS

Sixty Sprague-Dawley rats were randomly divided into six groups: Control, ORN (ornidazole; 200 mg/kg), ORN + QJT-low (0.17 g/mL), ORN + QJT-middle (0.33 g/mL), ORN + QJT-high (0.67 g/mL), and ORN + QJT + Radicicol (0.67 g/mL QJT and 20 mg/kg radicicol) groups. Pathological evaluation and analysis of mitophagy were conducted by H&E staining and transmission electron microscopy, respectively. Reactive oxygen species were detected by flow cytometry. Protein expression was determined by Western blotting.

RESULTS

QJT significantly improved ORN-treated sperm motility and kinematic parameters, as well as the pathological symptoms of testicular and epididymal tissues. In particular, QJT mitigated impaired mitochondrial morphology, and increased the PHB, Beclin-1, LC3-II protein, and ROS levels (p < 0.05), and reduced the protein expression levels of LC3-I and p62 (p < 0.05). Mechanistically, QJT antagonized the downregulation of SCF and Parkin protein levels (p < 0.05). Furthermore, QJT significantly increased the protein expressions levels of LKB1, AMPKα, p-AMPKα, ULK1 and p-ULK1 (p < 0.05). The ameliorative effect of QJT on pathological manifestations, mitochondrial morphology, and the expressions of mitophagy and mitochondrial ubiquitination-related proteins was counteracted by radicicol.

DISCUSSION AND CONCLUSIONS

QJT improved AZS via mitochondrial ubiquitination and mitophagy mediated by the LKB1/AMPK/ULK1 signaling pathway. Our study provides a theoretical basis for the treatment of AZS and male infertility.

Cancer-testis antigen lactate dehydrogenase C4 as a novel biomarker of male infertility and cancer

A unique lactate dehydrogenase (LDH) isoenzyme designated as lactate dehydrogenase C4 (LDH-C4) is found in mammalian mature testis and spermatozoa. Thus far, LDH-C4 has been well studied with regard to its gene and amino acid sequences, structure, biological properties, and peptide synthesis. Accumulating evidence has shown that LDH-C4 is closely related to spermatic energy metabolism and plays a critical role in sperm motility, capacitation, and fertilization. Defects in the catalytic activity of LDH-C4 are key to pathophysiological abnormalities underlying infertility. LDH-C4 was originally thought to be present only in mature testis and spermatozoa; however, recent studies have implicated LDH-C4 as a cancer-testis antigen (CTA), owing to its aberrant transcription in a broad spectrum of human neoplasms. This review highlights the recent findings on LDH-C4 with particular emphasis on its role in male infertility and tumors.

Patent highlights October-November 2018

A snapshot of noteworthy recent developments in the patent literature of relevance to pharmaceutical and medical research and development.

Expression of lactate dehydrogenase C correlates with poor prognosis in renal cell carcinoma

Lactate dehydrogenase C is an isoenzyme of lactate dehydrogenase and a member of the cancer-testis antigens family. In this study, we aimed to investigate the expression and functional role of lactate dehydrogenase C and its basic mechanisms in renal cell carcinoma. First, a total of 133 cases of renal cell carcinoma samples were analysed in a tissue microarray, and Kaplan-Meier survival curve analyses were performed to investigate the correlation between lactate dehydrogenase C expression and renal cell carcinoma progression. Lactate dehydrogenase C protein levels and messenger RNA levels were significantly upregulated in renal cell carcinoma tissues, and the patients with positive lactate dehydrogenase C expression had a shorter progression-free survival, indicating the oncogenic role of lactate dehydrogenase C in renal cell carcinoma. In addition, further cytological experiments demonstrated that lactate dehydrogenase C could prompt renal cell carcinoma cells to produce lactate, and increase metastatic and invasive potential of renal cell carcinoma cells. Furthermore, lactate dehydrogenase C could induce the epithelial-mesenchymal transition process and matrix metalloproteinase-9 expression. In summary, these findings showed lactate dehydrogenase C was associated with poor prognosis in renal cell carcinoma and played a pivotal role in the migration and invasion of renal cell carcinoma cells. Lactate dehydrogenase C may act as a novel biomarker for renal cell carcinoma progression and a potential therapeutic target for the treatment of renal cell carcinoma.

Expression of lactate dehydrogenase C in MDA‑MB‑231 cells and its role in tumor invasion and migration

The cancer/testis antigen (CTA) lactate dehydrogenase C (LDHC) is a unique LDH isoenzyme associated with glucose and adenosine triphosphate production in mammalian germ cells. However, the role of LDHC in cancer has thus far largely remained elusive. The present study described the expression status of LDHC in human MDA‑MB‑231 breast cancer cells as well as its role in tumor invasion and migration. Immunohistochemical analysis revealed endogenous LDHC expression in the cytoplasm and nuclei of MDA‑MB‑231 cells yielded. In addition, in vitro cell invasion and migration assays revealed that when LDHC expression was blocked by its specific inhibitor, cell invasion and migration were compromised in MDA‑MB‑231 cells. Of note, inhibition of LDHC was unable to induce apoptosis in MDA‑MB‑231 cells. The present study provided evidence that the LDHC enzyme acts as a CTA in breast carcinoma and exerts an essential role in tumor invasion and migration.

Quick histochemical staining method for measuring lactate dehydrogenase C4 activity in human spermatozoa

The enzyme activity of lactate dehydrogenase C4 (LDH-C4, due to tetrameric nature of C-subunit) has been proposed as an important parameter in evaluating sperm motility and semen quality. A novel histochemical staining method for detecting LDH-C4 activity in human spermatozoa is described in this report. The staining working solution comprises sodium 2-hydroxybutyrate (an affinity substrate of LDH-C4), nitrotetrazolium blue chloride (NBT), nicotinamide adenine dinucleotide (NAD) and naphthol blue. The positive products were purple black lumps concentrated in the neck segment of the spermatozoa and weakly in the middle piece. A normal reference range for the integral enzyme activity was constructed from 120 healthy males based upon the scoring criteria. The study further compared the staining method with the routine spectrophotometry technique in terms of the results of 96 cases with infertile status. Moreover, we found the down-regulated LDH-C4 expression was significantly correlated with the lowered enzyme activity (r=0.865, P=0.000). Our data suggest that the histochemical staining method hallmarks a relatively high accuracy and may be a better alternative for measuring LDH-C4 activity in human spermatozoa.