Human hemokinin-1 and human hemokinin-1(4-11), mammalian tachykinin peptides, suppress proliferation and induce differentiation in HL-60 cells

The immunomodulatory effects of tachykinins and their receptors

Tachykinins (TKs) are a family of neuropeptides mainly expressed by neuronal and non-neuronal cell types, especially immune cells. Expression of TKs receptors on immune cell surfaces, their involvement in immune-related disorders, and therefore, understanding their immunomodulatory roles have become of particular interest to researchers. In fact, the precise understanding of TKs intervention in the immune system would help to design novel therapeutic approaches for patients suffering from immune disorders. The present review summarizes studies on TKs function as modulators of the immune system by reviewing their roles in generation, activation, development, and migration of immune cells. Also, it discusses TKs involvement in three main cellular mechanisms including inflammation, apoptosis, and proliferation.

Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review

Background

Radiation therapy induces acute and chronic radiological toxicity, in particular hematological toxicity (HT). This study aimed to explore the mechanistic clue and potential predictors at the messenger RNA (mRNA) level.

Materials and Methods

Peripheral blood was collected from 3 patients with cervical cancer (CC), nasopharynx cancer (NC), and tongue cancer (TC) after the first 2 Gy fraction of radiotherapy (RT). High-throughput sequencing was used to assess mRNA profiles.

Results

Eleven genes, such as ALAS2(5-aminolevulinate synthase), SLC4A1(solute carrier family 4 member 1), HBG2(hemoglobin subunit gamma 2), TNFAIP3 (TNF α-induced protein 3), PER1 (period circadian clock 1), CCDC136 (coiled-coil domain containing 136), C9orf84 (chromosome 9 open reading frame 84), IL1B (interleukin 1β), FOSB (FosB protooncogene), NR4A2 (nuclear receptor subfamily 4), PARP15 (polymerase family member 15), had overlapping expression changes in all 3 cancers of which 3 (ALAS2, FOSB, and HBG2) are suggested as potential predictors for the early diagnosis of HT after RT.

Conclusions

ALAS2, FOSB, and HBG2 may be useful predictors of HT in patients after RT. Eleven overlapping expression mRNAs among 3 cancers might be potential predictors for early diagnosis of radiation toxicity in patients.

Role of hemokinin-1 in health and disease

Hemokinin-1 (HK-1), the newest tachykinin encoded by the Tac4 gene was discovered in 2000. Its name differs from that of the other members of this peptide family due to its first demonstration in B lymphocytes. Since tachykinins are classically found in the nervous system, the significant expression of HK-1 in blood cells is a unique feature of this peptide. Due to its widespread distribution in the whole body, HK-1 is involved in different physiological and pathophysiological functions involving pain inflammation modulation, immune regulation, respiratory and endocrine functions, as well as tumor genesis. Furthermore, despite the great structural and immunological similarities to substance P (SP), the functions of HK-1 are often different or the opposite. They both have the highest affinity to the tachykinin NK1 receptor, but HK-1 is likely to have a distinct binding site and signalling pathways. Moreover, several actions of HK-1 different from SP have been suggested to be mediated via a presently not identified own receptor/target molecule. Therefore, it is very important to explore its effects at different levels and compare its characteristics with SP to get a deeper insight in the different cellular mechanisms. Since HK-1 has recently been in the focus of intensive research, in the present review we summarize the few clinical data and experimental results regarding HK-1 expression and function in different model systems obtained throughout the 16years of its history. Synthesizing these findings help to understand the complexity of HK-1 actions and determine its biomarker values and/or drug development potentials.

Expression and proliferative effect of hemokinin-1 in human B-cells

Tachykinins are a family of structurally related peptides, including substance P (SP), hemokinin-1 (HK-1), neurokinin A (NKA), and neurokinin B. SP and NKA have been shown to modulate hematopoiesis and rat/mouse HK-1 has been found to be involved in the survival and differentiation of mouse B-cells. This study was designed to assess the expression of tachykinins with a focus on human HK-1 (hHK-1) in human B lymphocytes and the role of these peptides in cell differentiation, apoptosis and proliferation. Expression of tachykinin and tachykinin receptor mRNA was determined quantitatively in human B lymphoproliferative malignancies and compared to normal B-cells. Expression of hHK-1 and NK(1) receptor, but not SP, was detected in human B-lymphocytes, and was up-regulated in B-lymphocytes from chronic lymphocytic leukemia and non-Hodgkin's lymphoma, while it was down-regulated in acute lymphoblastic leukemia. Moreover, hHK-1, in contrast to SP, was able to induce proliferation of human pre-B lymphocytes through a NK(1) receptor-independent mechanism. These data suggest a role for hHK-1 in normal and pathological B lymphopoiesis, and open the door to a better understanding of the physiopathological mechanisms leading to lymphoproliferative malignancies.

Targeted deletion of the tachykinin 4 gene (TAC4-/-) influences the early stages of B lymphocyte development

Hemokinin-1 (HK-1), encoded by the TAC4 gene, is a tachykinin peptide that is predominantly expressed in non-neuronal cells, such as immune cells. We have disrupted the mouse TAC4 gene to obtain a better understanding of the actions of HK-1 during hematopoiesis. We demonstrate here that TAC4(-/-) mice exhibit an increase of CD19(+)CD117(+)HSA(+)BP.1(-) "fraction B" pro-B cells in the bone marrow, whereas pre-B, immature, and mature B cells are within the normal range. We show that in vitro cultures derived from TAC4(-/-) bone marrow, sorted "fraction B" pro-B cells or purified long-term reconstituting stem cells, contain significantly higher numbers of pro-B cells compared with controls, suggesting an inhibitory role for HK-1 on developing B cells. Supporting this idea, we show that addition of HK-1 to cultures established from long-term reconstituting stem cells and the newly described intermediate-term reconstituting stem cells leads to a significant decrease of de novo generated pro-B cells. Based on our studies, we postulate that HK-1 plays an inhibitory role in hematopoiesis, and we hypothesize that it may be part of the bone marrow microenvironment that supports and regulates the proliferation and differentiation of hematopoietic cells.