Current Protein and Peptide Science - Volume 26, Issue 2, 2025

Hypogalactia and agalactia in lactating mothers are the major causes of child malnutrition, mortality, morbidity, and overall ill health. The development of such treatments requires a well-designed preclinical study with suitable laboratory animals, which needs to be improved. Thus, a suitably designed study with a laboratory animal to analyse galactagogue activity, along with an assessment of the quality and quantity of milk, is required.

This study aimed to evaluate the potential of rabbit as an animal model for studying lactogenic activity.

The structural homology of prolactin, gene prolactin receptor, and prolactin hormone in humans, rabbit, and rat was studied using BLAST and PyMol to assess similarity in the lactogenic system. Daily and cumulative milk production and pre-treatment (control) and post-treatment (three drugs) in rabbits were recorded and evaluated by analysing protein, fat, lactose, solid non-fat, and ash values. All parameters were recorded on the 0th day and at the end of weeks 1, 2, and 3. Mammary gland histopathology was performed to evaluate the effects on mammary glands.

Homology studies revealed that the sequences of the human and rabbit prolactin genes, receptors, and hormones had a high similarity index. Treatment with Domperidone, Metoclopramide, and Shatavari significantly enhanced milk production by enhancing prolactin secretion; only Shatavari increased milk nutrition. Enlargement of the tubuloalveolar ducts of the mammary glands was observed.

Our findings suggest that rabbits are robust, reproducible, ethically superior, and preclinically relevant animals for assessing lactogenic activity.

Caleosins are recognized as the key proteins found in Lipid Droplets (LDs) and are crucial for the creation, maintenance, and breakdown of LDs. Nevertheless, our understanding of caleosins remains limited within Theaceae, a prominent botanical family encompassing economically significant tea and oil tea species.

In this research, we conducted a comprehensive genome-wide exploration and examination of the caleosin family in Theaceae species with sequenced genomes. The gene number of caleosin was similar among Theaceae species. Segmental duplication was the main form of caleosin expansion in Shuchazao (SCZ), Huangdan (HD), Biyun (BY), Tieguanyin (TGY), Longjing (LJ), C. lanceoleosa (Cla) and C. chekiangoleosa (CCH). Synteny analysis revealed one-to-more and more-to-one collinear relationships of caleosin genes among Theaceae species.

Caleosins in Theaceae are categorized into either the H-family or the L-family, each exhibiting distinct motif structures and physicochemical properties. Expression analysis revealed an apparent flower-predominant expression pattern of  caleosin  genes in Theaceae species. In addition, most paralogous pairs displayed expression divergence.

This research enhanced our understanding of the lineage-specific evolution of caleosin genes in Theaceae, and is valuable for future functional analysis of this gene family in tea and oil-tea species.

Preeclampsia (PE) is an immensely prevalent condition that poses a significant risk to both maternal and fetal health. It is recognized as a primary cause of perinatal morbidity and mortality. Despite extensive research efforts, the precise impact of JDP2 on trophoblast invasion and migration in the context of preeclampsia remains unclear.

The present study aimed to investigate the differential expression of JDP2 between normal control and preeclampsia placentas through the use of quantitative polymerase chain reaction (qPCR), western blotting, and immunostaining techniques. Furthermore, the effects of JDP2 overexpression and silencing on the migration, invasion, and wound healing capabilities of HTR-8/SVneo cells were evaluated. In addition, this study also examined the impact of JDP2 on epithelial-mesenchymal transition (EMT)-associated biomarkers and the Wnt/β-catenin pathway.

In the present investigation, it was ascertained that Jun dimerization protein 2 (JDP2) exhibited a substantial decrease in expression levels in placentae afflicted with preeclampsia in comparison to those of normal placentae. Impairment in migration and invasion was noted upon JDP2 down-regulation, whereas augmentation of migration and invasion was observed upon JDP2 overexpression in HTR-8/SVneo cells. Subsequently, western blot and immunofluorescence assays were conducted, revealing marked alterations in EMT-associated biomarkers, such as E-cadherin, N-cadherin, and β-catenin, thereby indicating that JDP2 can facilitate cell invasion by modulating the EMT process in HTR-8/SVneo cells. Finally, activation of Wnt/β-catenin signaling was observed as a result of JDP2. After that, IWR-1, a Wnt inhibitor, was used in the recovery study. IWR-1 could inhibit the role of JDP2 in promoting migration and invasion in HTR-8/SVneo cells.

Our findings elucidated the impact of JDP2 on trophoblast invasion and migration in preeclampsia by suppressing the EMT through the Wnt/β-catenin signaling pathway, thereby offering a potential prognostic and therapeutic biomarker for this condition.