The production of heterologous proteins for medical use is an important area of interest. The optimization of the bioprocesses includes the improvement of time, costs, and unit operations. Our study shows that a lectin fraction from Tepary bean (Phaseolus acutifolius) (TBLF) has cytotoxic effects on colon cancer cells and in vivo antitumorigenic activity. However, the low-yield, time-consuming, and expensive process made us focus on the development of a strategy to obtain a recombinant lectin using engineered Pichia pastoris yeast. Pure glycerol is one of the most expensive supplies; therefore, we worked on process optimization using crude glycerol from biodiesel production. Recombinant lectin (rTBL-1) production and purification were evaluated for the first time by an experimental design where crude glycerol (G65) was used and compared against pure glycerol (G99) in a controlled stirred-tank bioreactor with a fed-batch system. The recombinant lectin was detected and identified by SDS-PAGE, Western blot, and UHPLC–ESI–QTOF/MS analysis. The results show that the recombinant lectin can be produced from G65 with no significant differences with respect to G99: the reaction rates were 2.04 and 1.43 mg L⁻¹ h⁻¹, and the yields were 264.95 and 274.67 mgL⁻¹, respectively. The current low cost of crude glycerol and our results show the possibility of producing heterologous proteins using this substrate with high productivity.

Maternal milk supports offspring development by providing microbiota, macronutrients, micronutrients, immune factors, and hormones. The hormone prolactin (PRL) is an important milk component with protective effects against metabolic diseases. Because maternal milk regulates microbiota composition and adequate microbiota protect against the development of metabolic diseases, we aimed to investigate whether PRL/PRL receptor signaling regulates gut microbiota composition in newborn mice at weaning. 16SrRNA sequencing of feces and bioinformatics analysis was performed to evaluate gut microbiota in PRL receptor-null mice (Prlr-KO) at weaning (postnatal day 21). The normalized colon and cecal weights were higher and lower, respectively, in the Prlr-KO mice relative to the wild-type mice (Prlr-WT). Relative abundances (Simpson Evenness Index), phylogenetic diversity, and bacterial concentrations were lower in the Prlr-KO mice. Eleven bacteria species out of 470 differed between the Prlr-KO and Prlr-WT mice, with two genera (Anaerotruncus and Lachnospiraceae) related to metabolic disease development being the most common in the Prlr-KO mice. A higher metabolism of terpenoids and polyketides was predicted in the Prlr-KO mice compared to the Prlr-WT mice, and these metabolites had antimicrobial properties and were present in microbe-associated pathogenicity. We concluded that the absence of the PRL receptor altered gut microbiota, resulting in lower abundance and richness, which could contribute to metabolic disease development.

Lectins are bioactive proteins with the ability to recognize cell membrane carbohydrates in a specific way. Diverse plant lectins have shown diagnostic and therapeutic potential against cancer, and their cytotoxicity against transformed cells is mediated through the induction of apoptosis. Previous works have determined the cytotoxic activity of a Tepary bean (Phaseolus acutifolius) lectin fraction (TBLF) and its anti-tumorigenic effect on colon cancer. In this work, lectins from the TBLF were additionally purified by ionic-exchange chromatography. Two peaks with agglutination activity were obtained: one of them was named TBL-IE2 and showed a single protein band in two-dimensional electrophoresis; this one was thus selected for coupling to quantum dot (QD) nanoparticles by microfluidics (TBL-IE2-QD). The microfluidic method led to low sample usage, and resulted in homogeneous complexes, whose visualization was achieved using multiphoton and transmission electron microscopy. The average particle size (380 nm) and the average zeta potential (−18.51 mV) were determined. The cytotoxicity of the TBL-IE2 and TBL-IE2-QD was assayed on HT-29 colon cancer cells, showing no differences between them (p ≤ 0.05), where the LC₅₀ values were 1.0 × 10⁻³ and 1.7 × 10⁻³ mg/mL, respectively. The microfluidic technique allowed control of the coupling between the QD and the protein, substantially improving the labelling process, providing a rapid and efficient method that enabled the traceability of lectins. Future studies will focus on the potential use of the QD-labelled lectin to recognize tumor tissues.

Previous works showed that a Tepary bean lectin fraction (TBLF) induced apoptosis on colon cancer cells and inhibited early colonic tumorigenesis. One Tepary bean (TB) lectin was expressed in Pichia pastoris (rTBL-1), exhibiting similarities to one native lectin, where its molecular structure and in silico recognition of cancer-type N-glycoconjugates were confirmed. This work aimed to determine whether rTBL-1 retained its bioactive properties and if its apoptotic effect was related to EGFR pathways by studying its cytotoxic effect on colon cancer cells. Similar apoptotic effects of rTBL-1 with respect to TBLF were observed for cleaved PARP-1 and caspase 3, and cell cycle G0/G1 arrest and decreased S phase were observed for both treatments. Apoptosis induction on SW-480 cells was confirmed by testing HA2X, p53 phosphorylation, nuclear fragmentation, and apoptotic bodies. rTBL-1 increased EGFR phosphorylation but also its degradation by the lysosomal route. Phospho-p38 increased in a concentration- and time-dependent manner, matching apoptotic markers, and STAT1 showed activation after rTBL-1 treatment. The results show that part of the rTBL-1 mechanism of action is related to p38 MAPK signaling. Future work will focus further on the target molecules of this recombinant lectin against colon cancer.

Prolactin promotes lactation in the mother and is present in maternal milk; however, its effects on lactating pups have been overlooked. Our study shows that milk-derived prolactin acts on the intestine of mouse pups, maintaining the neonatal phenotype of the intestinal epithelium, preventing an accelerated transition to an adult-type epithelium. This process allows optimal utilization of nutrients and signals from maternal milk. These findings highlight the relevance of milk-borne maternal signals in regulating neonatal physiology.

Maternal milk supports offspring development by providing microbiota, macronutrients, micronutrients, immune factors, and hormones. The hormone prolactin (PRL) is an important component of milk with protective effects against chronic non-communicable diseases (NCDs). Because maternal milk regulates microbiota composition and microbiota protect against NCDs, we aimed to investigate whether PRL regulates gut microbiota in newborn mice. 16SrRNA sequencing of feces and bioinformatics analysis were performed to evaluate gut microbiota in mice null for the PRL receptor (Prlr-KO) at the onset of weaning (postnatal day 21). The normalized colon and cecal weights were higher and lower, respectively, in Prlr-KO mice relative to wild-type mice (Prlr-WT). Relative abundance (Simpson Evenness Index), phylogenetic diversity, and bacterial concentration in gut contents were lower in the absence of the PRL receptor. Eleven bacteria species, out of 470, differed between Prlr-KO and Prlr-WT mice with two bacterial genera (Anaerotruncus and Lachnospiraceae) related to NCD development being the most common in Prlr-KO. Furthermore, a higher metabolism of terpenoids and polyketides was predicted in Prlr-KO mice compared to Prlr-WT mice; these metabolites have antimicrobial properties and are present in microbe-associated pathogenicity. In summary, the absence of the PRL receptor changes intestinal microbiota composition, resulting in lower microbiota abundance and richness, which could contribute to NCD development.